Draft:Original research/North Sea continental shelves

"Eighteen thousand years ago, the seas around northern Europe were some 400 feet lower than today. Britain was not an island but the uninhabited northwest corner of Europe, and between it and the rest of the continent stretched frozen tundra. As the world warmed and the ice receded, deer, aurochs, and wild boar headed northward and westward. The hunters followed. Coming off the uplands of what is now continental Europe, they found themselves in a vast, low-lying plain."

"Doggerland is now believed to have been settled by Mesolithic people, probably in large numbers, until they were forced out of it thousands of years later by the relentlessly rising sea. A period of climatic and social upheaval ensued until, by the end of the Mesolithic, Europe had lost a substantial portion of its landmass and looked much as it does today."

"Based on seismic survey data gathered mostly by oil companies prospecting under the North Sea, [...] the contours [...] translate into gently rolling hills, wooded valleys, lush marshes, and lagoons."

"In addition to the human jawbone, [there are] accumulated more than a hundred other artifacts —animal bones showing signs of butchery and tools made from bone and antler, among them an ax decorated with a zigzag pattern. Because [there are] coordinates of these finds, and because objects on the seabed tend not to move far from where erosion liberates them, [...] many come from a specific area of the southern North Sea that the Dutch call De Stekels (the Spines), characterized by steep seabed ridges."

"The most rapid rises of sea level were on the order of three to six feet a century, but because of the variable topography of the land, the flooding would not have been even. In areas as flat as modern-day East Anglia, a six-foot rise could have shifted the coast inland by miles; in hillier places, less. Down in low-lying Doggerland, the rising sea turned inland lakes into estuaries."

“There would have been huge population shifts. People who were living out in what is now the North Sea would have been displaced very quickly.”

Northwest Britain
"Local Bathymetry and ocean currents [include in the image on the right] LSW:Labrador Sea Water; NADW:North Atlantic Deep Water; NSOW:Norwegian Sea Overflow Water)."

"Sediments near the top of the Ling Bank Formation at its type locality have been correlated with ‘type’ Holsteinian sections in Denmark and Germany (Knudsen and Sejrup, 1993). However, it is still widely believed that marine Holsteinian deposits, in general, directly overlie the major erosion surface at the top of the Aberdeen Ground Formation (P915281). There was, therefore, a widespread glaciation during the Elsterian stage, which involved ice flowing from Scandinavia into the southern North Sea (Cameron et al., 1992) and extending to the continental shelf edge north-west of Scotland (Stoker et al., 1994)."

"In the northern North Sea and on the West Shetland Shelf a widespread surface of marine erosion has been correlated with the OIS 4/3 boundary. It is overlain by the mainly arctic marine Cape Shore Formation, which is securely placed in the Middle Weichselian on several lines of evidence (Johnson et al., 1993; Skinner et al., 1986; Sejrup et al., 1994; Holmes, 1997). Thus the seas to the north and west of Scotland were also free of glacier ice during this stage and perhaps much of the Scottish mainland."

"At Clava, near Inverness, rafts of highboreal to low-arctic shallow marine mud originally deposited in Loch Ness, then a fjord, are probably early to middle Devensian in age (Merritt, 1992). The deposits correlate with those of the Bø Interstadial in Norway on amino-acid dating evidence (P915290). Rafts of broadly similar age have been located at the Boyne Limestone Quarry, King Edward and Gardenstown sites."

An "ice sheet [may have] extended to the continental shelf break, and beyond, to the north and west of Scotland (Holmes, 1991; Stoker and Holmes, 1991; Stoker et al., 1993; P915288). The resultant sediments are correlated on the basis of regional seismostratigraphy with Late Weichselian (OIS 2) deposits in the northern North Sea (Johnson et al., 1993). A radiocarbon date of about 22.5 ka BP from glaciomarine deposits within the limit of glaciation on the outer shelf to the west of St Kilda (Selby, 1989) appears to be consistent with the Late Devensian glacial maximum predating 18 ka BP (P915288)."

"Warm North Atlantic waters did not reach the north-east Atlantic and western Scotland until about 13 ka BP, when conditions changed from high arctic to boreal possibly in less than 50 years (Kroon et al., 1987; Peacock and Harkness, 1990)."

"The return of warm North Atlantic Drift waters to the Scottish seas occurred within a few decades just prior to 10,100 BP (Peacock and Harkness, 1990). At first sea temperatures were 2 to 3° lower than those of the present day, but a warming occurred at about 9600 BP."

Stratigraphy
Most "of the southern North Sea was low-lying land like the Netherlands until the first major glaciation. Moraines are preserved at the shelf-edge north-west of mainland Scotland, more than 60 km west of the nearest coastline (Holmes et al., 1993; Stoker et al., 1993). Conversely, marine deposits are preserved more than 10 km inland from the modern coastline at the head of the Moray Firth and at least 6 km inland near Elgin."

"At least five major glacial episodes have been recognised in the North Sea basin, within a sequence that is dominanted by deltaic, low salinity cold-water marine and glaciomarine conditions (Sutherland, 1984a). The thickest and most complete sequence (more than 500 m) is preserved in the Central Graben of the North Sea, which has subsided tectonically throughout the Quaternary. At least ten till units are present within the Norwegian Channel with six or seven extending to the distal shelf break (Sejrup et al., 2000)."

Scottish Highlands
"To the north and west of 58°N 01°E, the unconformity is interpreted from 3-D seismic evidence to take the form of fluvial channels. These features merge downslope into furrowed surfaces like those known to have been produced by grounded icebergs or sea-ice keels (Holmes, 1997). This evidence for ice scour within the Aberdeen Ground Formation is reinforced by the occurrence of periodic ice-rafted debris in sequences of equivalent age on the Atlantic margins off north-west Scotland (Stoker et al., 1994). Hence, the Scottish Highlands were probably glaciated to some extent during the colder stages of the Early Quaternary before 1.2 Ma."

"The oldest known glacial deposits laid down offshore by ice flowing from the Scottish Highlands have been found in boreholes in the Forth Approaches and the Moray Firth (Stoker and Bent, 1985; Bent, 1986). There, towards the top of the Aberdeen Ground Formation, glaciomarine sediments laid down by a grounded ice sheet occur in the west, with the facies becoming increasingly more distal to the east. The deposits lie immediately above the Brunhes–Matuyama palaeomagnetic boundary (P915280; P915341) suggesting that the glaciation occurred in OIS 18, within the Cromerian Complex."

Northern North Sea
"In the northern North Sea, the Shackleton Formation (Johnson et al., 1993) [Early Quaternary glaciations (1.2 to 0.78 Ma)] includes an erosion surface that separates sand-rich sediments below from mud-rich sediments above. The incoming of mud-rich sediments is reflected by a change of acoustic facies that is tentatively attributed by Johnson et al. (1993) to the first impact of regional glaciation [Menapian/Bavelian, see image in Stratigraphy] on the depositional environment of the northern North Sea."

On "the basis of seismostratigraphical correlation, it predates the 1.07 to 0.99 Ma Jaramillo Subchron (P915280), which has been reported from the overlying Mariner Formation (Stoker et al., 1983; compare with Skinner et al., 1986)."

Evidence occurs "in the Troll region of the Norwegian Channel for the ‘Fedje Glaciation’, which postdates the 1.19 Ma Cobb Mountain Event within the Matuyama Reversed Polarity Chron (Funnell, 1995; P915341). On the basis of the micropalaeontology, Sr-isotopes, palaeomagnetism and amino-acid geochronology, this glaciation has been assigned an age close to 1.1 Myr (Sejrup et al., 1995)."

"The presence of the diamicton, the geometry of the reflector and other evidence have been put forward as evidence of shelf glaciation extending from Norway across the northern North Sea to areas west of Shetland (Holmes, 1997)."

"The earliest evidence for glaciation of the sea bed offshore from north-east Scotland occurs in the Fladen area of the central North Sea where a 10 m-thick unit of diamicton lies just above the Jaramillo Subchron within the Aberdeen Ground Formation. As the diamicton is overlain by sediment containing microfossils with an interglacial aspect provisionally correlated with the Leerdam Netherlands Pollen Stage, Sejrup et al. (1987) place the glacial event within the Bavelian Complex, between 800 and 900 ka."

"Evidence for Saalian glaciations off north-east Scotland occurs in the Fisher and Coal Pit formations. The predominantly arctic glaciomarine Fisher Formation rests on a major, gently undulating unconformity that cuts across (onlaps) the Ling Bank and Aberdeen Ground formations (P915280, P915281). The unconformity results from a marine transgression and the overlying Fisher Formation is thought to be no older than OIS 7 (Jensen and Knudsen, 1988; Holmes, 1997). A till has been identified within the Fisher Formation (Sejrup et al., 1987) and contemporaneous subglacial erosion is thought to have occurred to the north of 58.6°N in the Moray Firth (Bent, 1986). The top of the Fisher Formation is defined by another regional unconformity, but unlike the one at its base, this one is typically crenulate (P915281) and is believed to be the result of the Saalian glaciation (Gatliff et al., 1994). The channels are mainly infilled with glaciomarine deposits belonging to the overlying Coal Pit Formation (Sejrup et al., 1987), although some fragmentary beds deposited in warmer waters have been identified within the formation in the northern and central North Sea (Gatliff et al., 1994)."

"The glaciomarine basal deposits of the Coal Pit Formation are succeeded by marine sediments containing foraminiferal assemblages typical of the Eemian–Ipswichian Interglacial (Cameron et al., 1987). These in turn underlie a horizon that has been correlated with the palaeomagnetic Blake Event at the OIS 5e/5d boundary (Stoker et al., 1985)."

Ice "flowing from the mainland affected the northern North Sea at least as far south as 56°N (Sutherland and Gordon, 1993) and it reached the shelf break to the north-west of Scotland (Skinner et al., 1986; Stevenson, 1991; Holmes, 1997)."

"The Wee Bankie Formation (Stoker et al., 1985) lies directly off the east coast of Scotland. It has a sheet-like geometry with an uneven, ridged top and comprises up to 40 m of stiff, matrix-dominated diamicton with some interbeds of sand, pebbly sand and silty clay."

"The Wee Bankie Formation is replaced eastwards by the Marr Bank Formation, commonly at a low, eastward-facing scarp interpreted as a former ice-contact slope, but the two formations probably interdigitate locally (Stoker et al., 1985). The Marr Bank Formation consists mostly of sands and muddy sands of Scottish provenance with a sparse microfauna indicative of shallow, high boreal to arctic waters. It forms a sheet-like deposit up to 25 m thick resting on an extensive surface of marine planation dipping north-eastwards (Holmes, 1977). As it is traced eastwards, the basal reflector of the Marr Bank Formation becomes acoustically indistinguishable from the upper part of the adjacent Coal Pit Formation, and the two formations probably pass laterally into one another locally (Gatliff et al., 1994)."

"Much of the northern North Sea north of 58°N had been deglaciated by 16 to 14 ka BP, and was either subaerially exposed or inundated by a very shallow sea (Peacock, 1995). This is compatible with a maximum age of about 14.1 ka BP for the onset of glaciomarine sedimentation following retreat of ice from the Witch Ground area (P915291; Sejrup et al., 1994) and at about 15 ka BP in the Norwegian Channel (Sejrup et al., 1995). The onset of deglaciation on the Hebridean Shelf has been dated to about 15.2 ka BP, predating the onset of warming in the North Atlantic (Peacock et al., 1992; Austin and Kroon, 1996). Shells within glaciomarine sediments occurring onshore near Peterhead have yielded ages of about 14.3 and 14.9 ka BP (St Fergus)."

"Radiocarbon dates from Portlandia arctica Gray, a high arctic marine bivalve, indicate that polar water, and probably seasonal sea-ice, remained in the northern North Sea until at least 13.2 to 13.1 ka BP when warmer waters arrived. Glaciomarine and estuarine silts and clays of the Errol Formation accumulated along the coasts (Peacock, 1999), while the muddy St Abbs Formation was laid down in this polar sea off the eastern coast of Scotland (Stoker et al., 1985; P915281)."

"A record of the Windermere Interstadial is probably contained within the Swatchway Formation, which occurs to the north-east of Buchan (P915281). It comprises shelly muds and sands with a mixed northern temperate to arctic microfauna (Stoker et al., 1985; Harland, 1988). It occurs more certainly in the Largo Bay Member of the Forth Formation, which is more widespread off north-east Scotland (Stoker et al., 1985; P915281). It includes up to 30 m of silty muds that become coarser grained and pebbly upwards with concomitant decreasing faunal diversity. The trends probably reflect lowering sea level and cooling seas towards the onset of the Loch Lomond Stadial. The overlying St Andrews Member was laid down as coastal sand bars in a very shallow sea during the subsequent Loch Lomond Stadial. High arctic marine fauna returned during the stadial, during which nearshore marine summer temperatures were approaching 10° below present levels (Graham et al., 1990; Peacock, 1996)."

Central North Sea
"A record of the Eemian (Ipswichian) is contained within the central part of the Coal Pit Formation, which fills channels that were probably eroded during, or immediately after, the Saalian glaciation in the Moray Firth and central North Sea (Andrews et al., 1990; Gatliff et al., 1994; P915281)."

"In southern Norway, the Eemian is now thought to have been succeeded by a prolonged period of interstadial conditions with restricted mountain glaciation (Sejrup et al., 2000)."

An "ice stream occupied the Norwegian Channel after 80 ka, suggesting that a regional glaciation occurred equivalent to the Karmoy Glaciation established in south-west Fennoscandia (P915290). Micromorphological studies of sediments from several boreholes in the central North Sea also suggest regional glaciation at that time involving coalescing Scottish and Scandinavian ice sheets (Carr, 1998)."

"The Coal Pit Formation in the central North Sea includes a sequence of shelly glaciomarine clays that have been placed tentatively in OIS 3 on palaeomagnetic evidence (Stoker et al., 1985) indicating that this area was free of glacier ice during this stage."

"In the central North Sea, the lower part of the Swatchway Formation, at Borehole 77/2 (P915291), is formed mainly of glaciomarine sediments from which AMS radiocarbon dates of 22.7, 20.9 and 19.7 ka BP have been obtained on in situ mollusc and benthic foraminiferids (Sejrup et al., 1994). This evidence suggests that the area was free of grounded ice during that period. However, a diamicton underlying the glaciomarine deposits in that borehole is interpreted as a till (Sejrup et al., 1994). It contains reworked arctic benthic foraminiferids that have provided a maximum AMS radiocarbon age of 42.3 ka BP. The diamicton rests on cold marine deposits assigned to the Ålesund Interstadial of north-west Fennoscandia and it is concluded by Sejrup et al. (1994) that the till was laid down between 28 ka BP and 22 ka BP during an initial, maximal stage of the Late Devensian glaciation."

The "central North Sea was also glaciated in the previous Skjonghelleren Glaciation of Fennoscandia, between about 50 and 40 ka BP (P915290)."

The "Scottish and Scandinavian ice sheets reached their maximum extent in the Late Devensian prior to about 22 ka BP and that they very probably coalesced (P915288). At least the uppermost part of the Wee Bankie Formation postdates this early phase. Following retreat to an unknown position at about 20 ka BP, during the Hamnsund Interstadial of Norway (Valen et al., 1996), the Scottish ice sheet probably then re-advanced to the eastern boundaries of the ‘Bosies Bank Moraine’ (Bent, 1986; P915291). This event probably equates with the Tampen Glaciation of Norway, when ice re-advanced onto the shelf and an ice stream reoccupied the Norwegian Channel (Sejrup et al., 2000; P915290)."

Southern North Sea
"The top of the Aberdeen Ground Formation is cut by a succession of isolated, anastomosing and locally stacked channels, some of which may have been formed as sub-glacial or ice-marginal ‘tunnel’ valleys. The channels, together with the oldest units of sediment contained within them (Ling Bank Formation), have been correlated on the basis of regional seismostratigraphy with the widespread Elsterian glaciation of the north-west European mainland (Stoker et al., 1985; Cameron et al., 1987)."

"The channelled surfaces at the top of the Aberdeen Ground Formation may well have formed in more than one glacial cycle, including the severe Cromerian glaciation of OIS 16 (Holmes, 1997). It follows that the first major interruption of the growth of deltas across the southern North Sea may have occurred in the Cromerian and not the Elsterian as commonly believed (P915341)."

Heligoland


The recent history period dates from around 1,000 b2k to present.

Heligoland is a small archipelago in the North Sea. A part of the German state of Schleswig-Holstein since 1890, the islands were historically possessions of Denmark, then became the possessions of the United Kingdom from 1807 to 1890, and briefly managed as a war prize from 1945 to 1952.

The islands are located in the Heligoland Bight (part of the German Bight) in the southeastern corner of the North Sea. They are the only German islands not in the vicinity of the mainland. They lie approximately 69 km by sea from Cuxhaven at the mouth of the River Elbe.

The German Bight and the area around the island are known to have been inhabited since prehistoric times. Flint tools have been recovered from the bottom of the sea surrounding Heligoland. On the Oberland, prehistoric burial mounds were visible until the late 19th century, and excavations showed skeletons and artifacts. Moreover, prehistoric copper plates have been found under water near the island; those plates were almost certainly made on the Oberland.

The island of Heligoland is a geological oddity; the presence of the main island's characteristic red sedimentary rock in the middle of the German Bight is unusual. It is the only such formation of cliffs along the continental coast of the North Sea. The formation itself, called the Bunter sandstone or Buntsandstein, is from the early Triassic geologic age. It is older than the white chalk that underlies the island Düne, the same rock that forms the white cliffs of Dover in England and cliffs of Danish and German islands in the Baltic Sea. In fact, a small chalk rock close to Heligoland, called witt Kliff (white cliff), is known to have existed within sight of the island to the west until the early 18th century, when storm floods finally eroded it to below sea level.

Heligoland's rock is significantly harder than the postglacial sediments and sands forming the islands and coastlines to the east of the island. This is why the core of the island, which a thousand years ago was still surrounded by a large, low-lying marshland and sand dunes separated from coast in the east only by narrow channels, has remained to this day, although the onset of the North Sea has long eroded away all of its surroundings. A small piece of Heligoland's sand dunes remains—the sand isle just across the harbour called Düne (Dune). A referendum in June 2011 dismissed a proposal to reconnect the main island to the Düne islet with a landfill.

German Bight
The German Bight, sometimes called the German Bay, is the southeastern bight of the North Sea bounded by the Netherlands and Germany to the south, and Denmark and Germany to the east (the Jutland peninsula). To the north and west is the Dogger Bank.

The Bight contains the Frisian and Danish Wadden Sea Islands. The Wadden Sea is approximately ten to twelve kilometres wide at the location of the German Bight. The Frisian islands and the nearby coastal areas are collectively known as Frisia. The southern portion of the bight is also known as the Heligoland Bight. Between 1949 and 1956 the BBC Sea Area Forecast (Shipping Forecast) used "Heligoland" as the designation for the area now referred to as German Bight.

Roskilde Fjords
The "Blytt-Sernander climatic zones [Boreal (dry), Atlantic (humid), Subboreal (dry and warm) and Subatlantic (humid and cool), with the Atlantic period divided in two zones the Early Atlantic Period and the Full Atlantic Period (Jessen 1937, Jørgensen 1963)] show up clearly in the lithology (chemical analysis) of the marine core (RF6). Furthermore, the lithological changes are synchronous with the shift in pollen zones. [...] the inner part of Roskilde Fjord is configured as an evaporation pan, in the middle of Sjælland, with fluctuating inflows of seawater and freshwater. [...] the Blytt-Sernander climatic zones have been established using the traditional pollen indicators namely the distinct elm-fall at the Full Atlantic/Subboreal transition, and the rise of Beech at the Subboreal/Subatlantic transition. In dating the zones, we follow the investigations in Store Bælt (Christensen et al. 1997). However, 14C datings in RF6 of both the top of Boreal (AAR-3347) and the bottom of Early Atlantic (AAR-3346) confirmed the date of 7000 BC. Similarly, dating the elm-fall in both RF6 (AAR-3345) and Lake Kornerup (AAR- 6263) confirmed the date of 3800 BC."

Little Ice Age
The Little Ice Age (LIA) appears to have lasted from about 1218 (782 b2k) to about 1878 (122 b2k).

"The populated 1.0 km² main island (Hauptinsel) to the west and the Düne to the east, which is somewhat smaller at 0.7 km², as well as lower, and surrounded by sand beaches. They were connected until 1720, when the natural connection was destroyed by a storm flood."

witt Kliff (white cliff) was a small chalk rock east of Helgoland until the early 18th century, when it was eroded to below sea level.

Classical history
The classical history period dates from around 2,000 to 1,000 b2k.

Subatlantic history
The "calibration of radiocarbon dates at approximately 2500-2450 BP [2500-2450 b2k] is problematic due to a "plateau" (known as the "Hallstatt-plateau") in the calibration curve [...] A decrease in solar activity caused an increase in production of 14C, and thus a sharp rise in Δ 14C, beginning at approximately 850 cal (calendar years) BC [...] Between approximately 760 and 420 cal BC (corresponding to 2500-2425 BP [2500-2425 b2k]), the concentration of 14C returned to "normal" values."

Early history
The early history period dates from around 3,000 to 2,000 b2k.

Iron Age
The iron age history period began between 3,200 and 2,100 b2k.

A semi-circular stone wall at left hints at the existence of a large and ancient building and to the right are the ruins of various other stone structures. In the background a low cliff divides a body of water from grassy fields.

Subboreal history
The "period around 850-760 BC [2850-2760 b2k], characterised by a decrease in solar activity and a sharp increase of Δ 14C [...] the local vegetation succession, in relation to the changes in atmospheric radiocarbon content, shows additional evidence for solar forcing of climate change at the Subboreal - Subatlantic transition."

The "Holocene climatic optimum in this interior part of Asia [Lake Baikal] corresponds to the Subboreal period 2.5–4.5 ka".

"The sea only breached the narrow landbridge at the Brig o' Waithe in Stenness, filling the loch was salt water, around 1500BC - 500 to 1,000 years after the ring was built."

The Subboreal is 3800-500 BC, 5800-2500 b2k.

"The boundary between the Atlantic and Subboreal periods is defined by the marked fall in the elm (Ulmus) curve."

"At the same time, a catastrophic fall in the ivy (Hedera) pollen curves is seen in Danish pollen diagrams. This fall is especially striking in coastal areas. It seems that the fjords in Subboreal times (due to lack of tides?) started to freeze in the winters, thereby reversing the climatic effect of the sea (Iversen 1973)."

Subboreal-3
Subboreal-3 is 4200-3600 BP.

"During the subsequent fluctuations in the lake levels the settlements shifted to higher levels. Radiocarbon dates for this stage: 4000-3700 (lake-level rise) and 3700-3600 (lake-level fall) BP. These settlements are considered as belonging to different cultural traditions: Zhizhitsian and North-Byelorussian, the latter being viewed as a local variant of the Corded Ware. The deposits of this stage contain limited amount of bones of domesticates (sheep, goat, cattle, pig), yet their overall rate is less that 14 %. Following the catastrophic transgression the tradition of lake dwellings ceased and was never resumed again. Early Iron Age sites (starting with Uzmenian culture) emerged on higher levels at greater distance from the lakes."

Bronze Age
The bronze age history period began between 5,300 and 2,600 b2k.

Skara Brae on the Bay of Skaill, west coast of Mainland, Orkney, consists of a number of small houses without roofs.

Subboreal-2
Subboreal-2 is 5500-4200 BP.

"During the subsequent rise of the lake level, the settlement was repeatedly relocated onto higher levels and nearer to the shore and eventually destroyed by the fire at about 4200 BP; its remains were sealed with sand. Judging from the pollen evidence, at that time, mixed coniferous forests were restricted to morainic hills, with pine forests on sandy plains and rich aquatic flora in the immediate vicinity of the sites. The deposits contain 40 species of animals and fishes including large mammals: elk, brown bear and boar being the most common, and also fur animals: marten, otter and squirrel. Judging by the age groups, the elk was huntered throughout the year. Pike and perch were the most common among the fish. At least 30 edible plants were identified in the deposits of pile-dwellings; hazel-nut and water chestnut (Trapa natans) were allegedly the main source of plant protein. Rich cultural assemblage found in these levels is referred to as Usvyatian. A short-lived regression marked the end of this stage."

"Part of the Heart of Neolithic Orkney World Heritage Site, the Ring of Brodgar is found in the West Mainland parish of Stenness. It stands on an eastward-sloping plateau on the Ness of Brodgar - a thin strip of land separating the Harray and Stenness lochs."

"Because the interior of the Ring of Brodgar has never been fully excavated, or scientifically dated, the monument's actual age remains uncertain. However, it is generally assumed to have been erected between 2500 BC and 2000 BC, and was, therefore, the last of the great Neolithic monuments built on the Ness."

"With a diameter of 103.6 metres (340 ft), the Brodgar ring is the third largest stone circle in the British Isles. Covering an area of 8,435 square metres (90,790 square feet), it is beaten only by the outer ring of stones at Avebury and the Greater Ring at Stanton Drew in England. Incidentally, the Brodgar ring is exactly the same size as Avebury's two inner rings."

"In fact, when the ring was erected, between 2500BC and 2000BC, the Stenness loch didn't exist. Instead the area was wet, marshy bog, surrounding pools of water or lochans."

Subboreal-1
Subboreal-1 is 5700-5500 BP.

"This stage started with an abrupt fall of the lake levels during which the lake at Rudnya-Serteya turned into mire with accumulation of detritus gyttja, rich in plant remains, mostly reed, sedge and scirpus, dark brown gyttja rich in decomposed plant remains and peat. Simultaneously the pile dwellings started emerging on lower levels of several lakes. The initial stage of pile dwellings is particularly well repre- sented at the site of Usvyaty 4, in the levels dated: 5570±40, 5530±40, 5490±65, 5480±60 BP etc."

Atlantic history
The "Atlantic period [is] 4.6–6 ka [4,600-6,000 b2k]."

"Starting with the Atlantic period (8-5 ka BP), in conditions of general temperature increase (by 1.5 °C annually) and rainfall (by 80-100 mm annually), one notes a substantial rise in the lake-level throughout Northern and North-Eastern Europe."

"In the 1970s and 1980s a site called Tybrind Vig, a few hundred yards off the coast of a Danish island in the Baltic Sea, yielded evidence of a surprisingly advanced late Mesolithic fishing culture, including finely decorated canoe paddles and several long, thin canoes, one of them over 30 feet long. More recently, [others] have excavated a series of underwater settlements in Wismar Bay, on the German Baltic coast, dating between 8,800 and 5,500 years ago. The sites vividly document the people’s shift in diet from freshwater fish to marine species, as the sea rise transformed their land over centuries from inland lakes surrounded by forests, to reedy marshes, to fjords, and eventually to the open bay there now."

Late-Atlantic-2
The Late-Atlantic-2 period is 6000-5700 BP.

"Following the rise of the lake-level, the previous settlement was abandoned and covered with yellow medium-grained sand. A new site was found in the level of olive-coloured gyttya. This level includes the pottery of the previous type combined with new varieties which have analogies in the Narvian (eastern Peribaltic) as well as in the Upper Volga and Upper Dniper cultures. Remains of a wishweir lie directly above this level; they were radiocarbon dated to 5780±50 (LE-2577) and 5770±50 (LE-2570) BP. The pollen spectra show the highest content in thermophylous broad-leaved species reaching 34 % and suggesting a significant rise in temperature. The level includes numerous seeds and macrofossil remains of aquatic plants, including Nymphaea sp. and Ceratiophyllum sp."

"Then, around 6,000 years ago, a new people from the south arrived on the thickly forested shores of the British Isles. They came in boats, with sheep, cattle, and cereals. Today the living descendants of these early Neolithic farmers, equipped with vastly more sophisticated technology than their Mesolithic counterparts, once again look to a future contending with a rising sea."

"The last remains of the American ice sheet disappeared about 6000 years ago [6,000 b2k]".

Late-Atlantic-1
The Late-Atlantic-1 period is 6500-6000 BP.

"After a short-lived rise, a new regression followed with the accumulation of olive-colored gyttja. A new settlement arose the material culture of which is considered as Rudnyaian. The pottery shows a continuity in relation to the Serteyan with the appearance of new elements: the pointed “thorn-bottomed” vessels with S-like profiles, made of clay tempered with crushed shells, organic matter and a small admixture of sand. The stone inventory was dominated by scrapers manufactured from flakes, and includes the arrowheads and the fragments of axes and adzes. The rich bone and antler industry has analogies in the early Neolithic of eastern Peribaltic. A large series of radiocarbon dates falls within a time-span of 6200-6000 BP."

Copper Age
The copper age history period began from 6990 b2k.

Middle Atlantic
The Middle Atlantic period is 7000-6500 BP.

"The period of low level during which the calcareous gyttja with shells was deposited on top of the silt at the site of Rudnya Serteyskaya. These deposits for which no radiocarbon dates are available include the materials of the oldest pottery-bearing tradition in that area referred by Miklyaev to the Serteyan. The conic pottery vessels ornamented with rows of triangular impressions were made of clay tampered with coarse sand and organic matter. The stone industry consisted of fragmented implements made on blades and flakes. The pollen spectra reflect a relatively cool episode within the Atlantic climatic optimum, with the total amount of broad-leaved species (oak, elm and lime) being less than 7 %; among the macrofossils were identified: alder, birch, willow and horsetail."

Ancient history
The ancient history period dates from around 8,000 to 3,000 b2k.

The "Scandinavian one 2000 years earlier [8,000 b2k]."

Full Atlantic
The Full Atlantic period is 6000-3800 BC, 8000-5800 b2k.

"In Roskilde Fjord the Full Atlantic period is characterised by the formation of oyster banks in the narrows of the fjord. 14C datings of oysters range from 5700 BC for the lowermost and oldest to 3700 BC for oysters from the top of the oyster banks (Bondesen 2002)."

"In the beginning of the Full Atlantic, the sea reached its present level and by the end of the period it was three meters above the present sea level."

"In this period, the salinity of the fjord must have been above 2.2%, the lowest salinity at which the oyster can breed. Moreover, the summer temperature is critical for the oysters’ ability to breed, thus it must have been warmer than today (Spärck 1936)."

"The high salinity is also indicated by the Mg/Ca ratio in the gyttja of RF6 [...]."

"The high productivity of the oyster in the narrows of the fjord (thickness of oyster banks often more than 10 meters) also indicates the presence of tides in the Atlantic times."

"The strand lines from the Full Atlantic are characterised by a high abundance of iron concretions (local name: “dværgkrukker” = gnome pots)."

"During the Full Atlantic, humans expanded their dwellings on the coast (the Ertebølle culture) [...]. Leaving the Kongemose culture sites flooded by the rising sea."

Early Atlantic
"A rise of the lake-level is acknowledged at the end of the Boreal – beginning of the Atlantic period. The pollen show gradual spread of pine dominated forest with hazel in underwood, and an increasing admixture of broad-leaf species starting with the beginning of the Atlantic. No authentic Mesolithic sites attributable to this period have ever been found in the area. There are unconfirmed reports about the finds of Kunda-like implements in deep layers of a peat bog near the Lake of Zhizhitsa."

The Early Atlantic is 7000-6000 BC, 9000-8000 b2k.

"Around 7000 BC the sea invaded the lowland, flooding lakes and bogs, creating the Roskilde Fjord. As shown by 14C datings (Bondesen 2002), the transgression was almost simultaneous over the entire fjord, and the Boreal bog in RF6 (10.20 m below present sea level) is covered by 20 cm of littoral shell deposits, which were later followed by five meters of marine gyttja."

"Also in the Early Atlantic period considerable erosion took place in the narrow parts. The configuration of the Early Atlantic fjord [...] was extreme, with very narrow passages. The configuration of the former coastlines is based partly on drill hole information (Bondesen 1988), but the details mainly come from the geoelectrical mapping [...] of Roskilde Fjord and Isefjord, where more than 500 km of profiling has been measured in the map area (seismic profiles are unable to establish the thickness of the Holocene deposits due to the high gas content (Bondesen et al. 1979))."

"The pollen curves shown [below] illustrate how the climax trees oak (Quercus) and lime (Tilia) oust the pioneer trees birch (Betula) and pine (Pinus). Also the grass-pollen decreases due to the increasing shade of the climax trees (this could however also be due to varying size of the swamp)."

"During the Early Atlantic, humans (the Kongemose culture) moved their dwellings to the coast [...]."

"In many places, archaeologists found traces of the catastrophe: in the East of Scotland, near Inverness, the wave surprised people by a camp fire, as shown by a 25cm layer of sand and gravel ten meters above sea level. Remains of urchins, sea mussels and seaweed testify to the rush of water which carried everything along. In Norway, on the Shetland Islands, and the Faroe Islands, traces of devastation lay even higher above the sea level of that time, waves above 20m crashed onto the land. The age of the desposits yielded a consistant value of 8,150 years."

"The decisive clues for the mesolithic mass death are mosses, especially Hylocomium splendens, known today as glittering wood-moss, or mountain fern moss. After the tsunamis of 8,150 years ago, they were buried under sea mud so that they remained sealed up and preserved. The state of growth they have been found in reveals at what season the monster waves hit."

"Every Spring fresh new green shoots of Hylocomium splendens appear, which branch out every subsequent month. The mosses in the destroyed Mesolithic settlements betray the fact that they were buried in late fall."

The "stone age hunters must have all returned to the coasts by then. Therefore the tsunamis must have caught most of the people off-guard, it must have been terrible. The loss of their reserves, tools and dwellings must have been a grave problem for them. Many probably didn’t make it through the winter."

Boreal transition
"During the Boreal (9-8 ka BP) the lake-level rose and intense accu- mulation of organic matter took place in many lakes of central and North-Western Russia as well as in the Peribaltic area and Byelorussia (Davydova, 1992)."

"Some 8,200 years ago, after millennia of incrementally rising seas, a massive release of meltwater from a giant glacial lake in North America, called Lake Agassiz, caused sea levels to jump by more than two feet. By slowing the circulation of warm water in the North Atlantic, this influx of frigid water triggered a sudden plunge in temperature, causing Doggerland’s coasts—if any remained—to be battered by frigid winds. If that were not enough, around the same time, a landslide on the seafloor off the coast of Norway, called the Storegga slide, [ca 8,150 years ago], triggered a tsunami that flooded the coastlines of northern Europe."

"On a diving expedition off the village of Cley-next-the-Sea in Norfolk, [...] the remains of a mighty Doggerland oak forest [have been discovered], most probably flattened by the tsunami, lying on the ocean floor, in shallow waters, less than half a mile off the coast. It is believed that this huge fossil forest was uncovered by the severe storms which scraped the sea bottom in this area in December 2013."

Whole "oak trees with branches up to eight meters long, which looked like they had been felled at some point.”

“The sea was quite rough by the shore so I decided to dive slightly further out and after swimming over 300 meters of sand I found a long blackened ridge.”

"When I looked more closely I realised it was wood and when I swam further along I started finding whole tree trunks with branches on top, which looked like they had been felled."

"At one time it would have been a full-blown Tolkein-style forest, stretching for hundreds of miles."

"The forest bed is at the start of the chalk reef which forms the proposed Cromer Shoal Marine Conservation Zone just to the East."

"The hazelnut shell was found in a pocket of soil that had survived underneath the Bronze Age burial mound at Longhowe and provides a context for numerous stone arrowheads and other tools, which were found both in the soil below, and in, the matrix of the mound. It is likely that the remains of a small Mesolithic hunting camp were destroyed by the mound builders."

"A charred hazelnut shell recovered during the excavations at Longhowe in Tankerness (Orkney, Scotland), earlier this year, has been dated to 6820-6660 BCE. Although Orkney has plenty of indications of early (pre-farming or Mesolithic) settlement in the form of stone tools, this is the first date to relate to this activity. It pushes back the dated settlement of Orkney by 3,000 years."

"This date relates to the earliest known period of settlement of Scotland when bands of nomadic hunters lived here. Remains from this time are scarce and few sites have been recognised by archaeologists, especially in the north. Longhowe is therefore important both for the light it can shed on this elusive period of Orkney's past as well as for our understanding of the early settlement of Scotland as a whole."

The Boreal period is 8000-7000 BC, or 10,000 to 9,000 b2k.

"The filling up of the Preboreal lake and the results of the sinking Preboreal groundwater level are seen in [the pollen diagram on the right]. [...] the decrease of Pediastrum and the subsequent blooms of Equisetum, Menyanthes and Athyrium [...] shows first the transition of the lake to a bog, and then, at the end of the Boreal period, the swamping of the bog followed by the transgression of the sea to the area."

"The sediment of the Boreal period consists of brown peat in the first half, and black peat in the second half, also indicated by the iron content [...] In the first half of the period, the environment around RF6 was a bog with water supply coming only in the form of rainwater/surface water. Later the sea level /groundwater level rose and groundwater (with iron) seeped into the bog."

"In the Boreal period very few humans lived in the area. [There are known] localities (www. dkconline.dk) of settlements from the Maglemose culture (9000 BC – 6400BC). [There are known] localities (www.dkconline. dk) of settlements from the Kongemose culture (6400 BC - 5400 BC). [There are known] localities (www.dkconline. dk) of settlements from the Ertebølle culture (5400 BC – 3900 BC)."

"But this would have been quite beyond the capacity of these isolated and unorganised tribes! They could only keep fleeing from the advancing sea..."

"...and abandon the tombs of their dead, which for thousands of years, they had protected with the help of indestructible megaliths and barrows? But they had also organized themselves early in order to reinforce the dunes of the coast with embankments. All this would explain the discipline, the emergence of a sense of the common good and the taste for vast public works which one can surmise to have characterized the civilization of the megaliths."

"These people were accustomed to defending their territory. And the circumstances were particularly favorable! The Dogger Bank offered a natural bareer 15m high (or more...) and 300km long! It sufficed to reinforce it on its flanks."

"Imagine the situation. A tribal chief, let's call him Atlas, has put up his hut at the highest point of the Dogger Bank, on top of a vertical cliff, from where he could survey the surroundings. He called on his neighbors: let's stop dispersing our strengths! You see there this enormous river which comes straight towards us to throw itself at our feet in this ravine through which the sea progresses? It suffices to erect, on our side of the river, an embankment, in order to protect in due time the whole plain which is behind. But all the tribes would have to send me a contingent of workers!"

"They all agreed that he was right, and that the realisation was not particularly difficult. An embankment of 3 meters would have brought protection for one hundred years. But there was a worse danger to avert."

"I have explored this mountain until its tip, very far to the north. There too, the sea is beginning to infiltrate the plain through some kind of a valley, beyond which one can see, in the distance, a line of some elevations, which could also protect us. We should build there a big dam, which looks possible to me because, interestingly, there is no river in this valley! I suggest therefore to send a delegation to the tribes in the north so that they associate themselves in a solemn pact for the defense of our Plain!"

"The pact was made. The chief got powers to bring to completion his program on the whole territory. They agreed that they would have to get into the good graces of the god of the sea, whose assaults would have to be brought under control. They would build for him a temple at the highest point, where a collegium of priests would honor him and try to figure out his intentions in order to provide guidance for the work to be done."

"And that's how [...] in 7000 BC, a tremendous struggle might have been engaged in order to counter the rise of the waters!"

"And how an enterprising tribal chief was able to extend his authority over the vast lands of the megaliths."

"To the South of the Dogger Bank, the battle-plan was laid out by the terrain itself. It sufficed to shore up the bank of the river, which was almost rectinilear, flowing on a very flat surface. As the sea rose, it had to be elevated, and prolonged towards the coast of Holland."

"To the north, it was much more difficult to cut through the valley, an ancient bed of the diverted river Elbe. The dam was exposed to the terrible storms of the North Sea and would have to be prolonged by and by over 50 km."

"Beyond, left-over moraines would have offered protection in the direction of the east; but the sea already infiltrated there through numerous ravines. So they decided to put their line of defense further back, on the flat land, which, to the south-east, rose gradually in the direction of Denmark."

"The map of 7000 BC shows the line of these first dykes."

"The Dogger Bank and its three dykes, in full lines, prevented the sea from invading this immense territory which extended all the way to today's coasts. Now, is this not a space which can pretend to the title of a "Great Plain"?"

"Taking a hold on the still emerged Dogger Bank, the Great Plain is spreading at 10 or 20 meters below sea-level, protected by mighty dykes. The continental waters are stopped by the shoring up of the Frisian and Danish islands. Behind this dam, the sea penetrates on the low-lands presently covered by a thick layer of peat. The ground of Denmark has not yet sunk back enough to allow the Elbe to find back to its bed."

Pre-Boreal transition
"Lowering and a partial paludination of lakes during the Preboreal (10-9 ka BP) was identified in the Peribaltic area (Kabailiene et al., 1992) and Byelorussia (Yakushko et al., 1992)."

On Stronsay a thousand pieces of flint have been excavated, tentatively dated to 7000 BC.

"The Stronsay flint cache looks like representing a temporary camp – erected, possibly during a hunting expedition, on a landmass that would eventually become Stronsay."

“We’ve got over a thousand pieces of flint – lots of very fine blades and microliths and the debitage you get from flint knapping."

“Links House, where we were excavating, was the site where we discovered the tanged points last year, but a second location of Millfield, where another tang was discovered in the 1920s, is 2km away. The artefacts we were getting were quite different from the normal Mesolithic artefacts, and this could mean the site might be a bit earlier than we were first anticipating."

“We knew as soon as we started retrieving material that what we were getting was quite a bit earlier than your typical Neolithic material – because it was just so fine. Even the flints we picked up at Longhowe, near Minehowe, last summer were quite different.”

“I think that it is quite early Mesolithic, dating from between 9000BC-7000BC, but we’ll need to wait for dates before we can know for sure. There’s an awful lot more work to do.”

"About 9000 years ago the temperature in Greenland culminated at 4°C warmer than today. Since then it has become slowly cooler with only one dramatic change of climate. This happened 8250 years ago [...]. In an otherwise warm period the temperature fell 7°C within a decade, and it took 300 years to re-establish the warm climate. This event has also been demonstrated in European wooden ring series and in European bogs."

The last glaciation appears to have a gradual decline ending about 12,000 b2k. This may have been the end of the Pre-Boreal transition.

From "sea-level studies in Kattegat (Mörner 1969) [...] the Holocene sea level in the southern part of Kattegat was at it’s lowest just before the Boreal period."

This in the image on the right "is how the north-west of Europe presented itself in 7,000 BC."

"You see that the sea, in grey, 5m below its present level, licked the slopes of the Dogger Bank which dominated it by some 15m. [We might point out that it was probably more, on account of the erosion having occurred since.] Men, who had been moving back for a thousand years on a hopelessly flat terrain, found refuge on this mountain "of a mediocre altitude" but the sea began to encircle it by the north-east, where an outcropping was already almost isolated."

"To the south-west, the sea infiltrated more deeply, penetrating in deep ravines which had been dug by the rivers forced to circumvent the Bank. To the south-east, the terrain found back to the weak slope of the natural soil."

In "the direction of the mouth of the Elbe, the ground reaches a reading of +10, then of +14, to reach a vast outcropping at reading +30m, encompassing the whole valley of the nether Elbe. Beyond, it slopes down rapidly to the present level of the land."

The "bulge" "which had been brought about by the ice-age had forced the Elbe and the Weser to divert their course to the West, probably in the direction of the Zuydersee."

The "map of the mm/y movements shows that the bulge prolonged itself towards the Pas-de-Calais. The +14 curve shows that there subsisted, along the Belgian coast, a "glove finger," which narrowed the access to the English Channel. But above all, this dam protected, in the east, a vast bowl formed, from the Schelde to the Zuydersee, by the natural soil which the thick layer of peat had not yet covered!"

"All these waters formed a huge swamp the exit of which, situated near Texel, the first of the Frisian islands, directed their flow towards the deep ravines observed at the south-west of the Bank, towards the channel of the Pas-de-Calais."

"The Dogger Bank begins to be surrounded by the sea. Level +30 deviates the rivers Elbe, Weser and Ems towards a lake held in by level +14 in the Netherlands. The effluent digs the Silver Pit to the west of the Dogger Bank and, to the south, the ravine towards the Pas-de-Calais."

"Now look at this map [in the image third down on the right] and decide what you would have done if you had lived in this country, ever more eaten up by the sea."

"The solution is known: build dykes!"

Younger Dryas
"The pollen spectra considered as the Alleröd/Younger Dryas transition show the occurrence of spruce and birch forests in an open, herb dominated landscape with high participation of Chenopodiaceae, Artemisia, Poaceae, Cyperaceae, Helianthemum, Dryas sp., and aquatic plants. These deposits may originate from the surface erosion and the subsequent inwash of coastal forms of numerous interconnected post-glacial lakes which existed in that area. The coastal forms were subjected to wind erosion, resulting in formation of wind blown dunes. This period corresponded to the initial human settlement of the area, with several sites consisting of large concentrations of flint tools found on the elevated terraces and dunes (Ivantsov Bor, Lukashenki 1-3, Serteya and others). Lithic assemblages include the tanged points of Ahrensburg, Lyngby and Svidry types, suggesting repeated yet ephemeral settlements of hunting groups."

"The Younger Dryas interval during the Last Glacial Termination was an abrupt return to glacial-like conditions punctuating the transition to a warmer, interglacial climate."

"From former cirque glaciers in western Norway, it is calculated that the summer (1.May to 30.September) temperature dropped 5-6°C during less than two centuries, probably within decades, at the Alleröd/Younger Dryas transition, some 11,000 years ago."

"From the same data the Younger Dryas summer temperature is estimated to have been 8-10°C lower than at present, and from fossil ice wedges the mean annual temperatures 13°C lower than at present in the same area."

"At the time of the Alleröd/Younger Dryas transition, the Scandinavian ice-sheet was still a major element in the climate system. The record from the Younger Dryas is distinct, consisting of ice-marginal deposits that are mapped nearly continuously around Scandinavia [...], showing that the climate turned to a more glacial regime in both the continental climate area of USSR/Finland and the oceanic climate area of Western Norway. This suggests that lower summer temperatures, and not increased winter precipitation, was the climatic factor that determined the major pattern of glacial response."

An "amplification of the re-advance in Western Norway compared to the easterly areas, due to higher winter precipitation along the western flank of the ice-sheet, and topographical and glaciological factors [...] The re-advance also caused a relative rise in sea level in Western Norway through the combination of increased gravitational attraction and a halt in glacio-isostatic uplift (Anundsen, 1985)."

The diagrams on the right show percentages of the planktonic foraminifera Neogloboquadrina pachyderma from two cores: "a" Troll 3.1 (60° 46.7' N, 3° 42.8' E, 332 m water depth) in the Norwegian Trench and "b" V23-81 located off Ireland.

"Annual layer counting through the most recent of these [sudden changes in the temperature of precipitation] indicates that a warming of ~7 °C occurred within a 50-yr period during the transition from the Younger Dryas cold phase (~11-10 kyr BP) to the present interglacial2."

Late Weichselian
"Recent stratigraphical achievements and long time established chronologies exist for the Late Weichselian, i.e. 10-25 ka BP. During this period Denmark experienced the complex Main-Weichselian glaciation from 25 to about 14 ka BP (Jylland stade, Houmark-Nielsen 1989) followed by the Late Glacial climatic amelioration including the interstadial Bølling-Allerød oscillation (13-11 ka BP), finally leading to the interglacial conditions that characterize the Holocene (Hansen 1965)."

Allerød Oscillation
The "Allerød Chronozone, 11,800 to 11,000 years ago".

"Lommel (1) is in northern Belgium, near the border with the Netherlands. At 12.94 ka (2), this site was a large late Glacial sand ridge covered by open forest at the northern edge of a marsh. More than 50 archaeological sites in this area indicate frequent visits by the late Magdalenians, hunter-gatherers who were contemporaries of the Clovis culture in North America. Throughout the Bölling-Allerod, eolian sediments known as the Coversands blanketed the Lommel area. Then, just before the Younger Dryas began, a thin layer of bleached sand was deposited and, in turn, was covered by the dark layer marked "YDB" above. That stratum is called the Usselo Horizon and is composed of fine to medium quartz sands rich in charcoal. The dark Usselo Horizon is stratigraphically equivalent to the YDB layer and contains a similar assemblage of impact markers (magnetic grains, magnetic microspherules, iridium, charcoal, and glass-like carbon). The magnetic grains have a high concentration of Ir (117 ppb), which is the highest value measured for all sites yet analyzed. On the other hand, YDB bulk sediment analyses reveal Ir values below the detection limit of 0.5 ppb, suggesting that the Ir carrier is in the magnetic grain fraction. The abundant charcoal in this black layer suggests widespread biomass burning. A similar layer of charcoal, found at many other sites in Europe, including the Netherlands (3), Great Britain, France, Germany, Denmark, and Poland (4), also dates to the onset of the Younger Dryas (12.9 ka) and, hence, correlates with the YDB layer in North America."

Usselo is the type site for the 'Usselo Soil', the 'Usselo horizon' or 'Usselo layer', a distinctive and widespread Weichselian (Lateglacial) buried soil, paleosol, found within Lateglacial eolian sediments known as 'cover sands' in the Netherlands, western Germany, and western Denmark; classified as either a weakly podzolized Arenosol or as a weakly podzolized Regosol, where numerous radiocarbon dates, optically stimulated luminescence dates, pollen analyses, and archaeological evidence from a number of locations have been interpreted to show that the Usselo Soil formed as the result of pedogenesis during a period of landscape stability during the Allerød oscillation that locally continued into the Younger Dryas stadial as a marker bed.

The abundant charcoal, which is found in the Usselo Soil, and contemporaneous Lateglacial paleosols and organic sediments across Europe, may have been created by wildfires caused by a large bolide impact, based upon the reported occurrence of alleged extraterrestrial impact indicators and hypothetical correlations with Clovis-age organic beds in North America. However, the contemporaneous nature of the Usselo Soil with Clovis-age organic beds in North America, the presence of impact indicators within it, and the impact origin of the charcoal may only be apparent.

Holocene
The Holocene starts at ~11,700 b2k and extends to the present.

Neolithic
The base of the Neolithic is approximated to 12,200 b2k.

Mesolithic
The mesolithic period dates from around 13,000 to 8,500 b2k.

"Bruine Bank, an area in the North Sea, is known to fishermen for mainly two things: the excellent catch rates when the weather is cold – and the bones, mammoth teeth, and even artefacts which frequently get caught in the nets [...] The bones, teeth and artefacts stem from a long lost land, Doggerland. Until the end of the last Ice Age, about 8000 years ago, the North Sea was still a part of the continent, even beyond the British Isles. [...] The oldest find is a fragment of a Neanderthal skull which is at least 35,000 years old – possibly even much older, up to 75,000 would be possible. 35,000 old stone tools of the Paleolithic have more than once been dragged inadvertendly to the surface by the fishermen with their mussel vacuum harvesters."

"The Blytt-Sernander climatic zones have been established with the traditional pollen indicators [diagram on the right], as the distinct elm-fall at the Full Atlantic/ Subboreal transition, and the rise of beech at the Subboreal/Subatlantic transition. In dating the zones we follow the investigations in Store Bælt (Christensen et al.1997). The few samples below 1100 cm seem to have missed the Younger Dryas, so the transition Preboreal/Late Glacial is not drawn up."

"The dominance of pine (Pinus) in the pollen diagram [on the right] and the less abundant hazel (Corylus) compared with standard diagrams for eastern Denmark (Iversen 1973), could be explained by the fact that RF6 is located in a big bog where the environment must be very moist and the pine therefore had much better growth conditions than hazel."

Older Dryas
"Older Dryas [...] events [occurred about 13,400 b2k]".

"Recent stratigraphical achievements and long time established chronologies exist for the Late Weichselian, i.e. 10-25 ka BP. During this period Denmark experienced the complex Main-Weichselian glaciation from 25 to about 14 ka BP (Jylland stade, Houmark-Nielsen 1989) followed by the Late Glacial climatic amelioration including the interstadial Bølling-Allerød oscillation (13-11 ka BP), finally leading to the interglacial conditions that characterize the Holocene (Hansen 1965)."

"During the Late Weichselian glacial maximum (20-15 ka BP) the overriding of ice streams eventually lead to strong glaciotectonic displacement of Late Pleistocene and pre-Quaternary deposits and to deposition of till."

Marine Isotope Stage 1
The Earth is currently experiencing an interglacial period (warming) during the present Quaternary Ice Age, identified as the "Marine Isotope Stage 1" (MIS1) in the Holocene epoch (or recently the Anthropocene epoch).

Dansgaard–Oeschger events are considered switches between states of the climate system.

The Holocene period began around 11,700 years ago and continues to the present. Identified with the current warm period, known as "Marine Isotope Stage 1", or MIS 1, the Holocene is considered an interglacial period in the Quaternary glaciation or current Ice Age.

Bølling Oscillation
"The most rapid global sea-level rise event of the last deglaciation, Meltwater Pulse 1A (MWP-1A), occurred ∼14,650 years ago."

Contributions "from Antarctica, 1.3 m (0–5.9 m; 95% probability), Scandinavia, 4.6 m (3.2–6.4 m) and North America, 12.0 m (5.6–15.4 m), giving a global mean sea-level rise of 17.9 m (15.7–20.2 m) in 500 years. Only a North American dominant scenario successfully predicts the observed sea-level change across our six sites and an Antarctic dominant scenario is firmly refuted by Scottish isolation basin records."

The "intra-Bølling cold period [IBCP is a century-scale cold event and the] Bølling warming [occurs] at 14600 cal [calendar years, ~ b2k] BP (12700 14C BP)".

"The period of time when sea levels shot up at the end of the last glacial period, roughly 14,600 years ago, is known as meltwater pulse 1A (MWP-1A). Ever since this pulse was identified from coral records in 1989, the origins of the meltwater have been the subject of debate. Some researchers have hypothesized that Antarctica was the major source of the meltwater, whereas other scientists have suggested that it came from the Northern Hemisphere."

Melting "ice sheets in North America, followed by Scandinavia, were the dominant drivers of MWP-1A and that the world’s mean sea level rise was 17.9 meters over 500 years."

Seas "rose significantly more in the Southern Hemisphere, indicating that 65%–80% of MWP-1A’s meltwater came from the Northern Hemisphere."

"In this case, the observed low sea level rise in the Northern Hemisphere supports a major northern contribution with a relatively minor Antarctic contribution. Also, during the past 10 years, more and more Antarctic field-based glaciological evidence suggests the Antarctic Ice Sheet was relatively stable during MWP-1A."

"The new research is a possible answer to the question of meltwater sources for MWP-1A, but that the debate is far from over."

"Previous studies that analyzed data from Tahiti, Barbados, and the Sunda Shelf are reliable, because they are based on uranium series dating. Data in the new study that came from the Great Barrier Reef and Scotland are based on a radiocarbon dating method, which requires caution in interpreting the timing, particularly during the deglaciation."

The updated method of calibrating the radiocarbon timescale "will produce some complicated uncertainties regarding the dating results, and we have used some statistical techniques to fully capture those uncertainties. In this case, our results considered those uncertainties carefully."

"In the future, the researchers want to study more sea level sites to better understand MWP-1A. They also want to see how they can use their results to replicate climate changes during the event."

"A better understanding of MWP-1A could yield insights into global ocean circulation behavior under rapid freshwater discharge and could provide better predictions of future climate change."

"We hope that our study will help climate modelers and paleoscientists piece together the impact of this event, with clear parallels for understanding the impact of increasing melt from the Greenland Ice Sheet today."

Marine Isotope Stage 2
Termination I, also known as the Last Glacial Termination, is the end of Marine isotope stage 2.

Oldest Dryas
"Coral reefs drilled offshore of Barbados provide the first continuous [17,000 years] and detailed record of sea level change during the last deglaciation. The sea level was 121 ± 5 metres below present level during the last glacial maximum. The deglacial sea level rise was not monotonic; rather, it was marked by two intervals of rapid rise. Varying rates of melt-water discharge to the North Atlantic surface ocean dramatically affected North Atlantic deep-water production and oceanic oxygen isotope chemistry. A global oxygen isotope record for ocean water has been calculated from the Barbados sea level curve, allowing separation of the ice volume component common to all oxygen isotope records measured in deep-sea cores."

"During the Late Weichselian glacial maximum (20-15 ka BP) the overriding of ice streams eventually lead to strong glaciotectonic displacement of Late Pleistocene and pre-Quaternary deposits and to deposition of till."

"Here [in the image on the right] is what north-western Europe looked like in 18,000 BC, at the end of an ice age which had lasted 70,000 years. You see, the doted line shows the present coastlines. The areas covered by the sea are in grey. The formation of ice at the expense of the oceans brought down the sea level by 120m."

"The polar ice sheet was crushing Scandinavia, reaching Denmark and part of the North Sea, which had dried up all the way to the Orkney Islands, because of the 120 meter drop in sea level. The Scottish glacier covered the west of the North Sea. The retreating of the water pushed the Atlantic back 150 km from the present shores of Brittany."

"We can see that the sea is 100 km to 150 km away from the present coastline of Brittany and Ireland. The English Channel and the Irish Sea were dry, but space is lacking there for our Great Plain. On the other hand, we find that the North Sea is dry all the way to the latitude of Scotland, 800km from the Netherlands, on a breadth of 500km separating England from Denmark."

"The map shows the extreme advance of the ice-sheets, well known from on-land, but less so under the sea. An enormous glacier two to three thousand meters thick covered the mountains of Norway and advanced on the North Sea. It's moraine formed the backbone of Denmark. Another glacier, less huge, crowned the mountains of Scotland and occupied the West of this area. It's only when the climate warmed up considerably in 10,000 BC that the area became inhabitable."

"At the time of the last glacial maximum, 18,000 years ago, sea levels were 340ft (120 metres) lower than they are today."

"They have also found parts of sabre-toothed tigers [the lower jawbone bone is 20,000 years old], the skull of a woolly rhino and the cranium of a reindeer."

Jylland stade
"After c. 22 ka BP during the Jylland stade (Houmark-Nielsen 1989), Late Weichselian glaciers of the Main Weichselain advance overrode Southeast Denmark from the northeast and later the Young Baltic ice invaded from southeasterly directions. Traces of the Northeast-ice are apparently absent in the Klintholm sections, although large scale glaciotectonic structures and till deposits from this advance are found in Hjelm Bugt and Møns Klint (Aber 1979; Berthelsen 1981, 1986). At Klintholm, the younger phase of glaciotectonic deformation from the southeast and south and deposition of the discordant till (unit 9) were most probably associated with recessional phases of the Young Baltic glaciation. In several cliff sections, well preserved Late Glacial (c. 14-10 ka BP) lacustrine sequences are present (Kolstrup 1982, Heiberg 1991)."

The "Allarp Till (Berglund & Lagerlund 1981), was deposited in connection with the first Late Weichselian ice advance in southern Sweden. Petrographic studies (Bose 1990) indicate that the first Late Weichselian ice advance which overrode northern Germany and reached the Brandenburg stage has a composition comparable to the Allarp till and the bedded diamictons from Klintholm."

GIS 2
The weak interstadial corresponding to GIS 2 occurred about 23.2 kyr B.P.

GIS 3
The stronger GIS 3 interstadial occurred about 27.6 kyr B.P.

It begins abruptly at 29 ka and ends about 26 ka.

"GIS 3 (start) 25.571 [to] GIS 3 (end) 25.337 ka BP".

Møn interstadial
The Møn interstadial corresponds to GIS 4.

Klintholm advance
This advance occurred after the Møn and ended with GIS 6.

GIS 5
GIS 5 interstadial occurred during the Klintholm advance about 33.5 kyr B.P.

Ålesund Interstadial
The Ålesund interstadial began with GIS 6 and ended after GIS 8.

Huneborg interstadial
The Huneborg interstadial is a Greenland interstadial dating 36.5-38.5 kyr B.P. GIS 8.

The Denekamp interstadial corresponds to the Huneborg interstadial.

The long-horned (Bison priscus) steppe bison occurred in Britain, from the Denekamp interstadial of the Weichselian glaciation at its most recent.

The image on the right has been identified as the European bison, Bison bonasus, but from its long horns could be Bison priscus.

The European bison occurred in southern Sweden only between 9500 and 8700 b2k, and in Denmark only from the Pre-Boreal.

Hengelo interstadial
The Hengelo interstadial [is] > 35 ka BP".

The "Hengelo Interstadial [is] (38–36 ka ago)."

Hasselo stadial
The "Hasselo stadial [is] at approximately 40-38,500 14C years B.P. (Van Huissteden, 1990)."

The "Hasselo Stadial [is a glacial advance] (44–39 ka ago)".

On the right is an image of Mammuthus primigenus, Bruine Bank North Sea, Pleistocene ca: 40,000 years old, back teeth or molar of mammoth.

"The North Sea may seem a surprising location to discover a woolly mammoth skeleton, but Dutch fossil hunters have hauled ancient bones from its depths."

"When the creature was alive 40,000 years ago, the now watery expanse was a low-lying stretch of icy tundra."

"The group of archaeologists, salvagers and palaeontologists trawled the waters off the east coast of Rotterdam at a depth of 100 feet (30 metres)."

In "2010 bones belonging to an 11ft (3.4 metre) tall woolly mammoth [were discovered]. Collected [were] its skull, tusks and other large bones, and [...] any missing ones [were filled in] with finds from similar beasts discovered nearby of a similar age, to form a complete skeleton after months of work."

Also "uncovered [were] bones belonging to woolly rhinos and Irish elks, plus a prehistoric skull of a European bison, also known as a Wisent on the North Sea bed."

"Most fishermen have found extinct bones [near Rotterdam] by dredging and they're more likely to find something than not,. They often dump the bones back in the sea."

Skjonghelleren Glaciations
The Ebersdorf Stadial may correspond to the earlier two glaciation (I & L) of the Skjonghelleren Glaciations of Scandinavia where ice crosses the North Sea between 50-40 ka BP.

"Two radiocarbon dates on bones [from the Skjonghelleren (cave)] and three Uranium series dates on speleothems from this bed all cluster around 30,000 B.P. [Bed G: 29,600 ± 800, 32,800 ± 800], i.e., the end of the Ålesund interstadial. Above the uppermost laminated bed, bone fragments of birds, fish and mammals, deposited between c. 12,000 and c. 10,000 B.P. [Bed B: 10,360 ± 170, 11,510 ± 190] were found."

"Three sequences of laminated clay [are Beds F, I & L], suggesting that the cave has survived at least three glaciations since its formation. Four blocky units were formed in ice-free periods prior to [Block K], between [Block G], and after the deposition [Block B] of the laminated sequences."

Bed A is travertine, Beds C, H & J are silt, Bed D is granulated clay, Bed E is clay with intraclasts, Block M is above the Bedrock.

Beds A and B "were deposited after the last deglaciation. The date 11,510 ± 190 B.P. [...] gives a minimum age for the last deglaciation in the Skjonghelleeren area. Previous work (Mangerud et al. 1981a), however demonstrates the the deglaciation occurred some time before 12.3 ka."

The sequence from young to old is
 * 1) A - travertine,
 * 2) B - c. 10,000 - 12,000 a, ice-free period,
 * 3) C - silt,
 * 4) D - granulated clay,
 * 5) E - clay with intraclasts,
 * 6) F - glaciation, ~ 20,000 a,
 * 7) G - Block G, c. 29,000 - 34,000 a,
 * 8) H - silt,
 * 9) I - glaciation, ~ 40,000 a,
 * 10) J - silt,
 * 11) K - ice-free period,
 * 12) L - glaciation, ~ 50,000 a,
 * 13) M - ice-free period,
 * 14) N - Bedrock.

Moershoofd interstadial
The Moershoofd interstadial has a 14C date of 44-46 kyr B.P. and corresponds to GIS 12 at 45-47 kyr B.P.

Marine Isotope Stage 3
In archaeology, a bout-coupé is a type of handaxe that constituted part of the Neanderthal Mousterian industry of the Middle Palaeolithic. The handaxes are bifacially-worked and in the shape of a rounded triangle. They are only found in Britain in the Marine Isotope Stage 3 (MIS 3) interglacial between 59,000 and 41,000 years BP, and are therefore considered a unique diagnostic variant.

Lynford Quarry is the location of a well-preserved in-situ Middle Palaeolithic open-air site near Mundford, Norfolk.

The site, which dates to approximately 60,000 years ago, is believed to show evidence of hunting by Neanderthals (Homo neanderthalensis). The finds include the in-situ remains of at least nine woolly mammoths (Mammuthus primigenius), associated with Mousterian stone tools and debitage. The artefactual, faunal and environmental evidence were sealed within a Middle Devensian palaeochannel with a dark organic fill. Well preserved in-situ sites of the time are exceedingly rare in Europe and very unusual within a British context.

The site also produced rhinoceros teeth, antlers, as well as other faunal evidence. The stone tools on the site numbered 600, made up of individual artefacts or waste flakes. Particularly interesting were the 44 hand axes of sub-triangular or ovate form.

The site was dated to Marine Isotope Stage 3 using Optically Stimulated Luminescence dating of the sand from the two layers of deposits within the channel.

Middle Weichselian
"The Middle Weichselian corresponds to the isotope stages MIS-4 and MIS-3 spanning the interval from c. 80 kyr BP to c. 32 kyr BP [...]."

Glinde interstadial
The Glinde interstadial has a 14C date of 48-50 kyr B.P. and corresponds to GIS ?13/14 with a GIS age of 49-54.5 kyr B.P.

Ebersdorf Stadial
"Genetics suggests Neanderthal numbers dropped sharply around 50,000 years ago. This coincides with a sudden cold snap, hinting climate struck the first blow."

Oerel interstadial
The Oerel interstadial has a 14C date of 53-58 kyr B.P. and corresponds to GIS 15/16 with a GIS age of 56-59 kyr B.P.

Karmøy stadial
The Karmøy stadial begins in the high mountains of Norway about 60 kyr B.P. and expands to the outer coast by 58 kyr B.P.

Odderade interstadial
The Odderade interstadial has a 14C date of 61-72 kyr B.P. and corresponds to GIS 21.

"During the Odderade interstadial, the limit of the south-boreal and the mixed forest may be situated at Watten, while the transition from the north-boreal to the middle-boreal forest is found in the Netherlands and northern Germany."

Early Middle Weichselian
"The early Middle Weichselian is assumed to correspond to the period 80-􏰀62kyr BP and to MIS-4. During this interval, average sea levels reached lower values than during the Early Weichselian and ice extent can be expected to have been substantial. But, as the global sea-level oscillations in this interval are also large, substantial ice-volume fluctuations can be anticipated across northern Eurasia within this stage."

Marine Isotope Stage 4
"During the Middle Stone Age of Southern Africa, technological and behavioral innovations led to significant changes in the lifeways of modern humans. The glacial episode of Marine Isotope Stage 4, about 57-71,000 years ago, resulted in cooler and drier climatic conditions and the expansion of grassland vegetation. Sea level dropped by as much as 80 meters below its current level. During this period the cultural phase known as the Howieson’s Poort appeared across much of Southern Africa, peaking at about 60-65,000 years ago, and then disappeared. The lithic industry of the Howieson’s Poort is exemplified by changes in technology, such as the use of the punch technique, an increase in the selection of fine-grained silcrete, and the predominance of retouched pieces including backed tools, segments, scrapers and points. Segments are the type fossil of the Howieson’s Poort and represent multi-purpose armatures that were hafted onto wooden spear shafts. The standardized design and refined style of segments convey information about the behavior of their makers and provide insight about group identity. Increasing use of ochre, the presence of engraved ostrich eggshells, and a bone tool industry are associated with these stone artifacts. Also evident is an intensified use of space. Taken together, these behaviors suggest that the Howieson’s Poort represents a clear marker of modern human culture."

"Using stone tool residue analysis with supporting information from zooarchaeology, we provide evidence that at the Abri du Maras, Ardèche, France, Neanderthals [a skull is imaged on the left from Abri du Maras] were behaviorally flexible at the beginning of MIS 4. Here, Neanderthals exploited a wide range of resources including large mammals, fish, ducks, raptors, rabbits, mushrooms, plants, and wood. Twisted fibers on stone tools provide evidence of making string or cordage."

MIS Boundary 4/5 is at 71 ka.

Wisconsinian glacial
Wisconsinian glacial began at 80,000 yr BP.

Marine Isotope Stage 5
Marine Isotope Stage 5 or MIS 5 is a Marine Isotope Stage in the geologic temperature record, between 130,000 and 80,000 years ago.

"The Neanderthal fossils [from Denisova cave] examined dated from 80,000 to 140,000 years ago. The dates indicate that the two hominin groups crossed paths at the cave and may have even been interbreeding during that time."

Early Weichselian
"The Early Weichselian spans the interval from c. 118 kyr BP to c. 80 kyr BP and corresponds to the two stadials MIS-5d and 5b and the two interstadials MIS-5c and 5a."

Rederstall Stadial
MIS Boundary 5.3 is at 96 ka.

MIS Boundary 5.2 (peak) is at 87 ka.

MIS Boundary 5.1 (peak) is at 82 ka.

Both "the Brørup and Odderade interstadials [occur] near Watten (northern France)".

Vegetation "maps for the Early Weichselian along the North Sea basin [...] show a vegetation gradient from the Scandinavian sites to the more temperate northern France."

"By comparison with the profiles described from northern Germany by Menke and Tynni (1984) and Behre (1989), it is now possible, on stratigraphical grounds, to correlate the stadial phases observed at Watten with the Herning (pollen zone 2) and the Rederstall stadial (pollen zone 4) despite the fact that the floristic composition of the vegetation is not the same."

Brørup interstadial
The "Brørup interstade [is about] 100 ka BP". It corresponds to GIS 23/24.

"A flint handaxe, recovered on a stretch of shore in St Ola, could be the oldest man-made artefact found in Orkney to date."

"Around 14cm long, the Orkney axe was picked up by Evie man, Alan Price, who passed it to county archaeologist, Julie Gibson. The axe has been broken and originally would have tapered to a point opposite the cutting edge. But at some point in antiquity, the point broke off and someone reworked the flint to its present straight edge."

“The problem with the Palaeolithic axes found in Scotland, to date, is that because they were not found ‘in context’ — that is, associated with other finds of the same era — there is some debate as to their authenticity. But we’re not going to find much contextual evidence, as we’re not likely to find sites of that date in Scotland that still have hearths and postholes still in situ.”

“We have to remember that this was an incredibly long time ago — pre-Ice Age, in fact. Britain wasn’t an island but was still connected to mainland Europe, and across this landscape the people of the Palaeolithic, nomadic hunter-gatherers, wandered from season to season.”

“What we can say is that it is definitely older than 100,000 years — so old it’s become geology. Palaeolithic people must have passed through what was later to become Scotland, so we’ve not discounted the possibility that the axe is evidence of people of that era in this area. But, because it’s so early, we need further information first."

“A site visit, to check for the presence of other flint nodules, will be first on the agenda to see whether there is any more evidence of ballast in the area the axe was found, and we’re hoping to take first steps soon.”

“This exciting and intriguing find raises more questions than it answers. It would be useful to know more about ballast deposition practice around Kirkwall Harbour, and we would be very interested in hearing from anyone who has information on local traditions."

"The only other suspected Palaeolithic axe found in Orkney came from Upperborough, in Harray. This axe was discovered in the early years of the 20th century and presented to the National Museum of Antiquities of Scotland in 1913."

It was “picked up. . . on the surface of the ground, in gravel, on the common to the west of the township of Upperborough, Harray, at about half a mile distant from the Loch of Harray, and some five miles from the sea”.

The "Harray artefact was not from the Palaeolithic".

"The Palaeolithic – or Old Stone Age – was a long period of hunter-gatherers, extending from the time when humans first evolved up to about 10,000 BC. In Britain, the earliest evidence of human activity dates from about 700,000 years ago, although there are long periods, of 100,000 years or more, when there appears to have been no human presence. The period is divided up by historians into the Lower (the oldest), Middle and Upper Palaeolithic to indicate when social and technological developments – mainly increasingly sophisticated flint tools – occurred."

"The vegetation observed at Watten during the Brørup interstadial is a mixed forest of conifers and deciduous trees, while at the same time northwestern Europe is covered by a middle- and south-boreal forest."

MIS Boundary 5.4 (peak) is at 109 ka.

Herning Stadial
MIS Boundary 5.5 (peak) is at 123 ka.

"By comparison with the profiles described from northern Germany by Menke and Tynni (1984) and Behre (1989), it is now possible, on stratigraphical grounds, to correlate the stadial phases observed at Watten with the Herning (pollen zone 2)".

Eemian interglacial
The "controversially split Eemian period, the predecessor of our own warm period about 125,000 years ago."

"In the deep sea record the onset of the Last Interglacial and MIS-5e is usually defined as the time when global sea level was midway between its lowest value at the end of the glacial maximum at c. 140 kyr BP and the time at which present sea level was first reached at c. 130􏰀-129 kyr BP (Stirling et al. 1998), or at c. 135 kyr BP. This is not a precise definition, because the time at which the sea-level rise started is not well constrained and the rise may not have been uniform as is indicated by the oscillation that may have occurred during this rise (Esat et al. 1999). In northern Europe the definition of the Eemian period is based on the fossil pollen record, and the relative chronology defined by Müller (1974) and Zagwijn (1996) is adopted here ([above table]). The Eemian is characterized by a uniform vegetation development and similar pollen zones can be identified across the entire region from the Atlantic coast and North Sea to the Arkhangelsk region. In particular, for the early Eemian (the pollen zones E1-E4 of Zagwijn 1983, 1996), differences in arrival time of species across the region appear to have been small and the relative chronology is assumed to be the same across the region (Zagwijn 1996; Grichuk 1984; Eriksson 1993). Beginning with the Carpinus zone (zone E5) differences in the timing of the pollen zones across the region may have been greater, but because most of the evidence discussed here relates to the early period this is not significant for present purposes. Thus we adopt this relative chronology across northern Europe."

"In the pollen diagrams, the interval E2a to E4b is a time when temperatures were higher than at any time during the remainder of the interglacial or at any time during the Holocene. This interval is also characterized by Baltic Sea salinities that were higher than at any other time in either the Eemian or Holocene (Funder et al. 2002). Evidence from The Netherlands (Zagwijn 1983, 1996; Beets & Beets 2003) and northwestern Germany (Caspers et al. 2002) indicates that the warmest conditions occurred shortly before the cessation of the rapid sea-level rise in this region and the usual practice has been to relate the end of E4b to the time of cessation of the global sea-level rise (Funder et al. 2002; Beets & Beets 2003). However, this association needs examination because of differential isostatic contributions among the North Sea and western Baltic locations and with respect to the sites used to establish the global sea-level function. Without knowledge of the Late Saalian ice sheet this lag cannot be evaluated, and in the first instance we adopt the same assumption and return to the relationship between the pollen and U/Th time scale once a satisfactory approximation of the ice model has been derived. Zagwijn (1996) defines the start of the Eemian as the pollen zone E1, c. 3000 years before the end of zone 4b ([above table]), and this places it at 132􏰀-133 kyr BP in the preliminary U/Th time scale (Funder et al. 2002). This is later than in the previous definition of c. 135 kyr BP for the start of MIS-5e, but for the present we adopt the time of onset of the pollen zone E1 at 132.5 kyr BP, implying that this occurred c. 2.5 kyr after the onset of the interglacial as defined by the mid-point between the end of the glacial maximum and the time at which present sea level was first reached. For European Russia and West Siberia we adopt the stratigraphic nomenclature and equivalences summarized by Larsen et al. (1999a) and we assume that the boreal period as far east as the Taymyr Peninsula has the same chronology as its northern European counterpart."

"The end of MIS-5e is defined as the time of onset of the global sea-level fall (c. 119-120 kyr BP) and the observed duration of interglacial sea levels near their present value (c. 10-11 kyr) compares well with the estimated duration of the pollen zones E5-E6b of Müller (1974) and with his inference that the interglacial ended with the end of the E6-b pollen zone. Thus, we fix the end of the pollen zone E6b at 119.5 kyr BP."

"The Eem interglaciation […] lasted from 131 to 117 kyr B.P."

Sangamon Episode interglacial
"OSL dates also suggest that last interglacial (MIS 5; Sangamon Ep.) fluvial deposits are preserved locally."

Age "assignment of Sangamonian (sense alto = 80,000-ca. 220,000 yr BP) [is] to Illinoian (ca. 220,000-430,000 yr BP)".

Illinois Episode glaciation
"Ages of sediments immediately beneath the oldest till (Kellerville Mbr.) in the bedrock valley average 160 ka and provide direct confirmation that Illinois Episode (IE) glaciation began in its type area during marine isotope stage (MIS) 6. The oldest deposits found are 190 ka fluvial sands on bedrock in the deepest part of the valley. These correlate to earliest MIS 6. We now correlate the lowest deposits to the IE (Pearl Fm.)."

"Illinoian [is] (ca. 220,000-430,000 yr BP)".

Marine Isotope Stage 6
The "last two glacial cycles [span] MIS 6 through 2".

The base of the Illinoian stage and the top of the Pre-Illinoian stage correlates with the base of Marine Isotope Stage 6 at 191,000 BP.

"Investigation of isolated landforms on the eastern margin of the East Anglian Fenland at Feltwell and Methwold Hythe, Norfolk has demonstrated that they represent glacifluvial delta-fan and related sediments. Section logging, borehole records and previous descriptions together indicate that the deposits were laid down as an ice-marginal delta complex and feeder channel into a proglacial lake. The internal structure and form of the delta and related feeder channel have also been determined using ground-penetrating radar. The sequence indicates deposition at the ice front, together with minor ice-front movements, a substantial discharge event and repeated solutional collapse of the underlying bedrock. Postdepositional solifluction and cryoturbation also occurred. The glaciomarginal landform complexes form part of a line of delta-fan and associated accumulations (the ‘Skertchly Line’) deposited at the margin of an ice lobe that entered the Fenland. Here the ice dammed westward-aligned rivers to form a lake, here called Lake Paterson. These observations reinforce earlier descriptions of a late Middle Pleistocene glaciation of the Fenland termed the ‘Tottenhill glaciation’. Previous research concluded that the glaciation occurred at c. 160 ka, that is, during the late Wolstonian (= late Saalian) Stage (Drenthe Substage, early Marine Isotope Stage 6), a correlation supported by evidence from the North Sea floor."

MIS Boundary 6/7 is at 191 ka.

Marine Isotope Stage 7
"Optically stimulated luminescence age estimates for the Pleistocene beach at Morston, north Norfolk, UK, obtained by the single-aliquot regenerative-dose protocol, indicate a Marine Isotope Stage (MIS) 7–6 transition date. The view that the beach is of Ipswichian (MIS 5e) age, held virtually unanimously for the last 75 years, may now be discarded. The extant beach sequence lies up to ∼5 m OD, yet global models suggest that MIS 7–6 sea levels were typically substantially below that of today. The explanation may lie with poorly understood regional tectonic movements. The MIS 7–6 date helps to constrain the ages of glacial deposits that bracket the beach sediments at Morston. The underlying Marly Drift till cannot be younger than MIS 8; this may also be true for the complex assemblage of glaciogenic landforms and sediments, including the Blakeney esker, in the adjacent lower Glaven valley. The well-established Late Devensian (MIS 2) age of the Hunstanton Till is not compromised by the date of the Morston beach. There is no indication of a proposed Briton's Lane glaciation during MIS 6 times."

"The potential for Middle Palaeolithic sites to survive beneath the sea in northern latitudes has been established by intensive investigation within Area 240, a marine aggregate licence area situated in the North Sea, 11km off the coast of Norfolk, England. The fortuitous discovery of bifacial handaxes, and Levallois flakes and cores, led to a major programme of fieldwork and analysis between 2008 and 2013. The artefacts were primarily recovered from Marine Isotope Stage 8/7 floodplain sediments deposited between 250 and 200 ka. It is considered that the hand axes and Levallois products are contemporaneous in geological terms with taphonomically complex sedimentary contexts, as observed in several north-west European sites. The Early Middle Palaeolithic (EMP) lithics have survived multiple phases of glaciation and marine transgression. The investigations confirm that the artefacts are not a ‘chance’ find, but indicate clear relationships to submerged and buried landscapes that, although complex, can be examined in detail using a variety of existing fieldwork and analytical methods. The palaeogeographical context of the finds also offers expanded interpretations of the distribution of EMP hominins in the southern North Sea, not predictable from onshore archaeological records."

MIS Boundary 7/8 is at 243 ka.

Marine Isotope Stage 8
"The [Jebel Irhoud site] Moroccan fossils [...] are roughly 300,000 years old. Remarkably, they indicate that early Homo sapiens had faces much like our own, although their brains differed in fundamental ways."

"We did not evolve from a single 'cradle of mankind' somewhere in East Africa. We evolved on the African continent."

MIS Boundary 8/9 is at 300 ka.

Marine Isotope Stage 9
The base of the Pre-Illinoian stage has been correlated to the top of Marine Isotope Stage 9 at 300,000 BP.

"A stalagmite from northern Norway is dated with 12 thermal ionization mass spectrometry U-Th dates, and at least four separate growth periods are identified that correspond with marine isotope stages 9, 11, 13, and probably 15. The calcite is tested for isotopic equilibrium with the Hendy test. Oxygen isotope measurements on 231 subsamples on a vertical transect are used as a paleotemperature proxy. The detailed isotopic record from MIS 9 show apparent similarities to a Holocene record from the same cave, both in the climatic evolution and the overall temperatures: both show temperature oscillations changing from high-frequency, low-amplitude cycles in the beginning of the interglacial period to lower frequency, higher amplitude cycles in the later part of the interglacial period. The isotope record from MIS 11 shows a distinct isotopic event toward heavier values. The isotopic record together with the porous, humus-rich calcite are interpreted as indicating a warmer than present interglacial period with several episodes of heavy rainfall."

MIS Boundary 9/10 is at 337 ka.

Marine Isotope Stage 10
Termination is the period of time during a glacial cycle when there is a relatively rapid transition from full glacial climates to full interglacial climates, numbered for the Quaternary period, using Roman numerals from the most recent termination as “I” and with increasing value, e.g. “II”, “III”, and so forth, into the past, with Termination I, also known as the Last Glacial Termination, is the end of Marine isotope stage 2; Termination II is the end of Illinoian (Marine Isotope Stage 6); Termination III is the end of Marine Isotope Stage 8; Termination IV is the end of Marine Isotope Stage 10, and so forth.

MIS Boundary 10/11 is at 374 ka.

Marine Isotope Stage 11
Marine Isotope Stage 11 is a Marine Isotope Stage in the geologic temperature record, covering the interglacial period between 424,000 and 374,000 years ago. It corresponds to the Hoxnian Stage in Britain.

The Hoxnian Stage was a middle Pleistocene stage of the geological history of the British Isles, an interglacial preceded the Wolstonian Stage and followed the Anglian Stage, equivalent to Marine Isotope Stage 11 (MIS 11). The Hoxnian is divided into sub-stages Ho I to Ho IV.

MIS 11 represents the longest and warmest interglacial interval of the last 500 kyr: it shows the highest-amplitude deglacial warming in the last 5 Myr and possibly lasted twice the other interglacial stages, is characterized by overall warm sea-surface temperatures in high latitudes, strong thermohaline circulation, unusual blooms of calcareous plankton in high latitudes, higher sea level than the present, coral reef expansion resulting in enlarged accumulation of neritic carbonates, and overall poor pelagic carbonate preservation and strong dissolution in certain areas, and is considered the warmest interglacial period of the last 500,000 years.

Carbon dioxide concentration during MIS 11 was possibly similar to that documented in the pre-industrial period, but not especially high when compared to other interglacial periods (for example, concentration was probably higher during MIS 9).

Beach deposits in Alaska,Bermuda and the Bahamas, as well as uplifted reef terraces in Indonesia, suggest that global sea level reached as much as twenty metres above the present.

Sedimentary deposits from Greenland suggest a near-complete deglaciation of south Greenland, and a subsequent sea level rise of 4.5 to 6  metres of sea-level-equivalent volume during MIS 11, around 410,000 to 400,000  years ago.

In contrast to most other interglacials of the late Quaternary, MIS 11 cannot be straightforwardly explained and modelled solely within the context of Milankovitch forcing mechanisms.

MIS Boundary 11/12 is at 424 ka.

Marine Isotope Stage 12
Marine Isotope Stage 12 started about 478,000 years ago and ended about 424,000 years ago.

The strong glacial MIS 12 has been problematic, and has sometimes been identified with the Mindel glaciation, which would imply an end to Gunz already after MIS 13 (480 000 years ago).

Yarmouthian interglacial
"Clay deposition in the Piauí River floodplain around 436 ± 51.5 ka occurred during a warmer period of the [Yarmouthian interglaciation] Aftonian interglaciation, corresponding to isotope stage 12 (Ericson and Wollin, 1968)."

"The extinctions and earliest known first occurrences of the 26 extant and 8 extinct cyst taxa in the three samples (with a minimum 430,000 yr BP Yarmouthian age) corroborate a likely assemblages with a maximum age of Illinoian (ca. 220,000-430,000 yr BP) in Unit I."

Yarmouthian spans 420,000-500,000 yr BP.

MIS Boundary 12/13 is at 478 ka.

Anglian stage
The Anglian Stage is the name used in the British Isles for a middle Pleistocene glaciation that precedes the Hoxnian Stage and follows the Cromerian Stage in the British Isles, correlates to Marine Isotope Stage 12 (MIS 12), which started about 478,000 years ago and ended about 424,000 years ago.

The Anglian stage has often been correlated to the Elsterian Stage of northern Continental Europe and the Mindel Stage in the Alps; however, there is ambiguity regarding the correlation of these two glacials to either MIS 12 or MIS 10, as described in more detail in the article 'Elster glaciation'.

The Anglian was the most extreme glaciation during the last 2 million years, where in Britain the ice sheet reached the Isles of Scilly and the Western Approaches, the furthest south the ice reached in any Pleistocene ice age. In the south-east of England it diverted the River Thames from its old course through the Vale of St Albans south to its present position.

This stage had been equated to the Kansan Stage in North America; however, the terms Kansan Stage, along with Yarmouth, Nebraskan, and Aftonian stages, have been abandoned by North American Quaternary geologists and merged into the Pre-Illinoian stage. The Anglian Stage is now correlated with the period of time which includes the Pre-Illinoian B glaciation of North America.

Marine Isotope Stage 13
Marine Isotope Stage 13 in Britain covering the Cromerian interglacial period between ~524,000 and 474,000 years ago, split into three substages, MIS 13a MIS 13b, and MIS 13c, where some records indicate that MIS 13a was an unstable warm peak with a cold split in the middle at MIS 13.12 - separating warm MIS 13.11 and 13.13. This interglacial follows the relatively warm glacial period associated with Marine Isotope Stage 14, and is followed by the relatively cold glacial period associated with MIS 12.

MIS Boundary 13/14 is at 533 ka.

"The deposits of the Bytham River, that flowed across central England until the Anglian glaciation (Marine Isotope Stage 12) overrode and destroyed it, have been exposed in many places, mostly in the context of gravel extraction, from Waverley Wood near Coventry in the west to Pakefield near Lowestoft on the East Anglian coast. Many of these sites have yielded artefacts. The present paper concentrates on large, detailed samples from Waverley Wood, Feltwell and Warren Hill collected by the late R.J. MacRae and the late Terry Hardaker. These samples draw attention to the fact that during Marine Isotope Stage 13 or earlier, an extensive Lower Palaeolithic population was spread across middle England and those inhabitants made use of whatever raw materials were available on site. The sites reported reflect localities where access to gravel extraction plants was permitted and a long-term watching brief could be maintained. The finds comprise mainly quartzite artefacts from Waverley Wood in the west, quartzite with some flint at Feltwell, and flint at Warren Hill in the east, and provide a perspective on how raw materials influenced artefact design within the region, prior to c. 450,000 yrs BP."

Marine Isotope Stage 14
A relatively warm glacial period having limited extent of Arctic ice sheets.

MIS Boundary 14/15 is at 563 ka.

Kansan glacial
Kansan glacial spans 500,000-600,000 yr BP.

Marine Isotope Stage 15
Deep sea core samples have identified approximately 5 glacial cycles of varying intensity during Gunz.

The detailed stratigraphic table by the German Stratigraphic Commission puts the start of Gunz in the late Calabrian (approximately one million years ago, earlier than MIS 19) and shows a continuity of glacial cycles with the following Mindel stage, with the border arbitrarily put at the start of MIS 10 (approximately 374 000 years ago). Gunz corresponds roughly to the Cromerian stage in the glacial history of Northern Europe.

Deep sea core samples have identified approximately 10 marine isotope stages (at least MIS 21 to MIS 11) during Gunz.

MIS Boundary 15/16 is at 621 ka.

Marine Isotope Stage 16
The most intense glacials of Gunz (MIS 16 and MIS 12) reached similar extents to those of the more recent Riss glaciation and Wurm glaciation glacials. These have not been easy to identify in the geological record of the Alps, but MIS 16 has been identified with the Don Glaciation of Eastern Europe.

MIS 16 is a major glacial stage identified through measurements of oxygene isotopes in deep sea core samples (marine isotope stage) of Cromerian age, approximately 676-621 ka ago. In terms of global ice volume, it ranks as one of the two most extreme glaciations of the Quaternary, on par with MIS 12. However, in terms of sea water temperatures it is a much more modest glaciation, of similar climate intensity to the neighbouring Cromerian glaciations MIS 14 and MIS 18. The atmospheric concentration of was below 180 ppm for 3 ka during MIS 16, the lowest of the last eight glacial cycles.

Don and MIS 16 are usually correlated to each other based on assumption that the most widespread evidence for glaciation in the Cromerian ought to be associated with the largest glaciation on the global scene; however, the time resolution of current age determinations is insufficient for a clear distinction between MIS 14, MIS 16 and MIS 18.

It is unclear why the major glaciation of MIS 16 has left very little evidence in the geological records of Western Europe.

MIS 16 is believed to correspond to Pre-Illinoian D in North America.

Don Glaciation
The Don Glaciation, also known as the Donian Glaciation and the Donian Stage, was the major glaciation of the East European Plain, 0.5–0.8 million years ago, during the Cromerian Stage of the Middle Pleistocene. It is correlated to Marine Isotope Stage 16, approximately 650,000 years ago, which globally contained one of the largest glacial volumes of the Quaternary.

The Don Glaciation shows evidence of the most extensive ice sheet on the East European Plain, extending into the drainage basin of the middle and lower Don River in Russia, reaching 50 degrees north latitude, occurred before the Muchkap interglacial and the Oka and Dnieper glaciations of Eastern Europe.

Aftonian interglacial
Aftonian interglacial spans ca. 600,000-650,000 yr BP.

"N tills [...] show the greatest amount of feldspar and carbonate minerals in the silt fraction. This group includes at least one till unit overlain by the 0.6 Ma Lava Creek ash, thus suggesting that some of these units were deposited between 0.8 and 0.6 Ma, but also later, as indicated by two sites with a till overlying the 0.6 Ma ash (Boellstorff, 1973). The N till group is considered to include the A1, A2, and A3 tills of Boellstorff (1973, 1978b)."

Lava Creek B ash is dated at 602 ka.

The Yellowstone Lava Creek B ash is dated at 639 ± 2 ka ka.

"The Lava Creek B ash bed (0.64 Ma) originated from one of several Yellowstone Plateau plinian eruptions that produced extensive ashfall over much of the west-central United States (Izett and Wilcox, 1982)."

"The second, and geochemically analyzed, occurrence of Lava Creek B ash is in Kelso Gulch, along sloping hillsides slightly above the valley floor (Fig. 2). The tephra layer intermittently follows the contour of the hillslope at an elevation of 1,591 m. It is variably cemented with calcite and up to 5 cm thick. At this locality, geochemical confirmation of the Lava Creek B ash by co-author Wan (Table 1) comes from sample K06CO3, collected from an indurated, ca. 5-cm-thick ash bed exposed on a hillside (Fig. 2). This ash bed is thinly mantled by slope-wash."

"Processing, petrographic analysis, and geochemical fingerprinting of tephra sample K06CO3 and its identification as the Lava Creek B ash was performed at the USGS Tephrochronology Laboratory and the Electron Microprobe Laboratory in Menlo Park, California."

"The age of the [stag moose Cervalces] roosevelti type specimen is pre-Wisconsin (Aftonian)".

"Examples of pre–Illinoian sections [are in the images on the right]. (A) Two till units with paleosols separated by nonglacial silt and clay unit at site 19 (blow-up of units to left). (B) Lava Creek B ash (0.602 Ma) cropping out near site 4. (C) Two-till unit sequence capped by loess deposits at site 15. Lower till is truncated by sand and gravel unit whereas upper till is affected by paleosol development. Sandy diamicton is present between lower till and bedrock."

Marine Isotope Stage 17
"The oxygen isotope profile of Dome Fuji ice core suggests that the deeper part of ice goes back to 720kyr, which corresponds to MIS (Marine Isotope Stage) 17."

"The uppermost occurrence of L. rectilatus was in marine strata deposited during marine isotope stage 17, which has an estimated age of ca 0.7 Ma."

"The lowest occurrence of L. rectilatus in the five cores was in the marine strata between the Kd25 and Kd12-Type tephra layers, and was dated at ca 1.45 Ma."

In the image on the right is a "marine notch at about 350 m in altitude ascribed to marine isotope stage 17 (estimated about 730 ka) from Sumba Island, Indonesia."

"Tidal notches generally appear as undercuts on rock cliffs. Their height corresponds roughly to that of the local midlittoral zone (i.e.: tidal range plus average wave height). They typically form a recumbent V-shaped or U-shaped profile with a vertex (apex, retreat point) located near Mean Sea Level (MSL) (Fairbridge, 1952; Hodgkin, 1964), a roof near the highest tide level and a base near the lowest tide level."

"An archeological site between Pakefield and Kessingland on the coast of eastern England that has been exposed by a fall in the level of the North Sea. It consists of sediments of the Cromer Forest-bed formation (CF-bF) that probably belong to Marine Isotope Stage 17 (but they could be as old as Marine Isotope Stage 19) Thirty-two worked flints, including a simply flaked core and a crudely retouched flake, were found in situ. (Location 52°25.9'N, 01°43.8'E, England.)"

Marine Isotope Stage 18
Core "MV0508-20JPC dated to 735000±5000 years ago (Marine Isotope Stage 18) [is] a "floating window" of millennial-scale ecological variability."

"Core MV0508-20JPC is an intermittently laminated archive, strongly influenced by the California Current OMZ, with continuously preserved benthic foraminifera and discontinuously preserved micro-invertebrates, including ophiuroids, echinoderms, ostracods, gastropods, bivalves and scaphopods."

"Samples were obtained from Core C9001C, which was recovered at a water depth of 1180 m, east of the Shimokita Peninsula in the Tohoku region of Japan. The core contained a continuous stratigraphic succession down to marine isotope stage 18 (740 ka). Abundance peaks exceeding 5% of the total radiolarian fauna were defined as Davisiana event (DAE), and a total of 20 DAEs were observed over the last 740 kyr. The DAEs were generally near interglacial/glacial period boundary whereas peaks in the radiolarian total abundance, reflecting warm surface radiolarian productivity, occur mainly within the interglacial intervals."

"The age for the Fulton member is "tuned" to dates for Marine Isotope Stage 18, based on its normal magnetic remanence."

"The Matuyama-Brunhes reversal (0.78 Ma) is a paleomagnetic datum within the pre-Illinoian stratigraphic sequence of the North American midcontinent that marks the boundary between the Early and Middle Pleistocene. In eastern Iowa this datum separates Wolf Creek Formation deposits with normal remanent polarity from older glacial diamictons of the Alburnett Formation with reversed polarity."

"Based on fission-track dating of tephra in western Iowa and cosmogenic-isotope burial dating in northern Missouri, the normal- polarity tills are younger than the M/B boundary, whereas the reversely magnetized tills are older. Therefore, this paleomagnetic datum is the M/B reversal, which is the new boundary between the Early and Middle Pleistocene (Gibbard et al., 2010). Rovey and Kean (2001) further suggested that this reversal followed shortly after the maximum expansion of the second major pre-Illinoian glaciation that is recorded widely in the midcontinent of North America."

Evidence "from Conklin Quarry [show] this second major glaciation actually is significantly older than the M/B reversal, but did occur shortly before a brief reversal of the earth’s magnetic field."

"Locally preserved valley-fill and slope sediments, inset into the reversely magnetized Alburnett Formation tills, and capped by the Westburg Geosol at Conklin Quarry, have a normal detrital remanent magnetization. Therefore, a magnetic reversal (reverse to normal) is present within the Alburnett Formation. However, based on cosmogenic isotope dates and correlation to other dated sections, this reversal is too old to be the M/B transition. Instead, the normal remanence within the upper Alburnett alluvial/colluvial facies probably indicates deposition during either the Cobb Mountain or the Jarimillo Normal Polarity Subchron."

Cromerian
The core of the Cromerian is the first half of the Middle Pleistocene stage (Ionian) approximately 800-500 ka ago, just before the Anglian glaciation which corresponds to MIS 19 to MIS 13. Some authors instead put the start at MIS 22, corresponding to a start 900 ka ago, which includes the last 100 ka of the Calabrian stage, after the Beestonian Stage. Some sources today correlate the Elster glaciation to MIS 10 instead of MIS 12, while keeping the Cromerian running up to the start of the Elsterian, with the result being an end to the Cromerian stage in continental Europe at the end of MIS 11 (400 ka ago), and that the continental Cromerian continues beyond its end in Britain and Ireland and runs in parallel to the Anglian and Hoxnian Stages (MIS 12-11).

In the Alpine region the corresponding stage is called Günz.

The Cromerian had been equated to the Aftonian in North America; however, the Aftonian, along with the Yarmouthian Interglacial, Kansan glaciation, and Nebraskan, have been abandoned by North American Quaternary geologists and merged into the Pre-Illinoian. At this time, the Cromerian is correlated with the period of time, which includes the Pre-Illinoian C, Pre-Illinoian D, and Pre-Illinoian E glaciations of North America.

Marine Isotope Stage 19
"Climatostratigraphical stages for Great Britain and north-west Europe are based on inferences from biostratigraphical (pollen) and lithological evidence for ‘temperate’ and ‘cold’ events. Ages: bases of series and subseries are taken from the Phanerozoic time scale of Gradstein and Ogg (1996). The early/middle Pleistocene boundary is correlated with the Bruhnes — Matuyama magnetic reversal, correlated with Marine Isotope Stage 19. The base of the Pleistocene Series is defined at the base of the marine claystones conformably overlying the marker bed sapropel layer ‘e’ in the Vrica section, Calabria, Italy (Aguirre and Passini, 1985). Suggested correlation with marine isotope stages for Early to Middle Pleistocene is after Zagwijn (1992) and Funnell (1996), based on the stages of Shackleton et al. (1990)."

Calabrian
"The [Calabrian] GSSP occurs at the base of the marine claystone conformably overlying sapropelic bed ‘e’ within Segment B in the Vrica section. This lithological level represents the primary marker for the recognition of the boundary, and is assigned an astronomical age of 1.80 Ma on the basis of sapropel calibration."

There are "artifacts excavated from coastal exposures, dating back to 700,000 years."

Prehistory
The prehistory period dates from around 7 x 106 b2k to about 7,000 b2k.

"The German Bight and the area around the island is known to have been inhabited since prehistoric times. Tools made of flint have been recovered from the bottom of the sea surrounding Heligoland."

"On the Oberland prehistoric burial mounds were visible until the late 19th century and excavations showed skeletons and artefacts. Moreover, prehistoric copper plates have been found under water near the island; those plates were almost certainly made on the Oberland (see Alex Ritsema, Heligoland, Past and Present, 2007, pp.21-23)."