The Cromerian Stage or Cromerian Complex, also called the Cromerian (german: Cromerium), is a stage in the

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

glacial history of north-western Europe, mostly occurring more than half a million years ago. It is named after the

East Anglia East Anglia is an area in the East of England, often defined as including the counties of Norfolk, Suffolk and Cambridgeshire. The name derives from the Anglo-Saxon kingdom of the East Angles, a people whose name originated in Anglia, in ...

n town of Cromer in

Great Britain Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It ...

where interglacial deposits that accumulated during part of this stage were first discovered. The stratotype for this

interglacial An interglacial period (or alternatively interglacial, interglaciation) is a geological interval of warmer global average temperature lasting thousands of years that separates consecutive glacial periods within an ice age. The current Holocene i ...

is the

Cromer Forest Bed The Cromer Forest Bed is a geological formation in Norfolk, England. It consists of river gravels, estuary and floodplain sediments predominantly clays and muds as well as sands along the coast of northern Norfolk. It is the type locality for th ...

situated at the bottom of the coastal cliff near

West Runton West Runton is a village in North Norfolk, England, on the North Sea coast. Toponymy The villages name means either, Runa's farm/settlement' or 'Runi's farm/settlement'. Overview West Runton and East Runton together form the parish of Runton ...

. The Cromerian stage preceded the Anglian and Elsterian glacials and show an absence of glacial deposits in western Europe, which led to the historical terms Cromerian interglacial and the Cromerian warm period (german: Kromer-Warmzeit). It is now known that the Cromerian consisted of multiple glacial and interglacial periods.Böse et al. (2012), Quaternary Glaciations of Northern Europe, Quaternary Science Reviews 44, 1-25.
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Chronology

The core of the Cromerian is the first half of the

Middle Pleistocene The Chibanian, widely known by its previous designation of Middle Pleistocene, is an age in the international geologic timescale or a stage in chronostratigraphy, being a division of the Pleistocene Epoch within the ongoing Quaternary Period. Th ...

stage (Ionian) approximately 800-500 ka ago, just before the Anglian glaciation. In terms of Marine isotope stages (MIS) this 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 Calabrian is a subdivision of the Pleistocene Epoch of the geologic time scale, defined as 1.8 Ma—774,000 years ago ± 5,000 years, a period of ~. The end of the stage is defined by the last magnetic pole reversal (781 ± 5 Ka) and plunge int ...

, after the Beestonian Stage.Lee et al. (2011), The Glacial History of the British Isles during the early and Middle Pleistocene: Implications for the long-term development of the British Ice Sheet, Quaternary Glaciations-Extent and Chronology, pages 59-74, Elsevier.
/ref> 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. The result is 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 main valleys of the Alps, orographically by drainage basin. Rhine basin (North Sea) High Rhine *Aare **Limmat ***Linth (Glarus) ****Lake Walen *****Seeztal **** Klöntal ****Sernftal **Reuss *** Lake Lucerne **** Sarner Aa (Brünig Pass co ...

the corresponding stage is called

Günz The Günz is a river in Bavaria, Germany. It is formed near Lauben by the confluence of its two source rivers: the Östliche Günz (eastern Günz) and the Westliche Günz (western Günz). It is approx. long (including its western source riv ...

. The Cromerian had been equated to the

Aftonian The Pre-Illinoian Stage is used by Quaternary geologists for the early and middle Pleistocene glacial and interglacial periods of geologic time in North America from ~2.5–0.2 Ma (million years ago). North America As the oldest stage in th ...

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...

. However, the Aftonian, along with the Yarmouthian (Yarmouth), Kansan, and Nebraskan, have been abandoned by North American Quaternary geologists and merged into the

Pre-Illinoian The Pre-Illinoian Stage is used by Quaternary geologists for the early and middle Pleistocene glacial and interglacial periods of geologic time in North America from ~2.5–0.2 Ma (million years ago). North America As the oldest stage in th ...

.Hallberg, G.R., 1986, ''Pre-Wisconsin glacial stratigraphy of the Central Plains region in Iowa, Nebraska, Kansas, and Missouri'', Quaternary Science Reviews. vol. 5, pp. 11-15.Richmond, G.M. and D.S. Fullerton, 1986, ''Summation of Quaternary glaciations in the United States of America'', Quaternary Science Reviews. vol. 5, pp. 183-196. 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.Walker, M., 2005, ''Quaternary Dating Methods'', John Wiley & Son, Chichester, United Kingdom. Proposals for structuring the Cromerian complex have become quite confusing. Great potential for a full breakdown has been provided by the extensive, continental series at Gorleben.

Glacial cycles

Based on a lack of glacial evidence in Western Europe for the

(Ionian) before the Anglian glaciation, the Cromerian was originally thought to be a period without major glaciations. However, there is evidence for ice-rafting of material across the North Sea from this period. Investigations in the 1950s of oxygene isotopes in deep sea core samples revealed five glacial cycles during MIS 22 - MIS 13. The

Mid-Pleistocene Transition The Mid-Pleistocene Transition (MPT), also known as the Mid-Pleistocene Revolution (MPR), is a fundamental change in the behaviour of glacial cycles during the Quaternary glaciations. The transition happened approximately 1.25–0.7 mill ...

to the 100,000 year glacial cycle became established during the Cromerian. Four of the glaciations (MIS 22, MIS 20, MIS 18, MIS 14) were moderate, probably involving low-land glaciation in Scandinavia, but not spreading to England and northern Germany. One of the glaciations,

Marine Isotope Stage 16 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 Isotop ...

(MIS 16), is globally as strong as the most recent glaciations, MIS 6 (main

Saale The Saale (), also known as the Saxon Saale (german: Sächsische Saale) and Thuringian Saale (german: Thüringische Saale), is a river in Germany and a left-bank tributary of the Elbe. It is not to be confused with the smaller Franconian Saal ...

) and MIS 2 ( Weichsel/Devensian). There is plenty of evidence in Russia for a major glaciation during this stage, which is called the Don Glaciation and believed to correspond to MIS 16. It is not clear why western Europe seems so unaffected by this major glacial.

Fossils

In 1990 the

West Runton Mammoth The West Runton Mammoth is a fossilized skeleton of a steppe mammoth (''Mammuthus trogontherii'') found in the cliffs of West Runton in the county of Norfolk, England in 1990. The find is the largest nearly complete mammoth skeleton known, and is ...

skeleton was found, the best example of the species

Mammuthus trogontherii The steppe mammoth (''Mammuthus trogontherii'', sometimes ''Mammuthus armeniacus'') is an extinct species of Elephantidae that ranged over most of northern Eurasia during the late Early and Middle Pleistocene, approximately 1.8 million-200,00 ...

to be unearthed so far. A significant

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

site, with animal remains dating about 600,000 years ago, is the Mosbach Sands, named after an abandoned village near

Wiesbaden Wiesbaden () is a city in central western Germany and the capital of the state of Hesse. , it had 290,955 inhabitants, plus approximately 21,000 United States citizens (mostly associated with the United States Army). The Wiesbaden urban area ...

, Germany.Ernst Probst: ''Deutschland in der Urzeit''. Munich: Bertelsmann, 1986
German National Library catalogue
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References

Sources

www.Stratigraphy.org

{{North German glaciations Quaternary geochronology Ice ages Pleistocene Interglacials

Chronology

Glacial cycles

Fossils

See also

References

Sources