The '''Cromerian Stage''' or '''Cromerian Complex''', also called the '''Cromerian''' ({{langx|de|Cromerium}}), is a stage in the [[Pleistocene]] glacial history of north-western Europe, mostly occurring more than half a million years ago. It is named after the [[East Anglia]]n town of [[Cromer]] in [[Great Britain]] where interglacial deposits that accumulated during part of this stage were first discovered. The [[stratotype]] for this [[interglacial]] is the [[Cromer Forest Bed]] situated at the bottom of the coastal cliff near [[West Runton]]. The Cromerian stage preceded the [[Anglian stage|Anglian]] and [[Elster glaciation|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''' ({{langx|de|Kromer-Warmzeit}}). It is now known that the Cromerian consisted of multiple glacial and interglacial periods.<ref name="Böse 2012">[http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.734.1691&rep=rep1&type=pdf Böse et al. (2012), Quaternary Glaciations of Northern Europe, Quaternary Science Reviews 44, 1-25.]</ref>
== Chronology == The core of the Cromerian is the first half of the [[Middle Pleistocene]] stage (Ionian) approximately 800-500 ka ago, just before the [[Anglian stage|Anglian glaciation]]. In terms of [[Marine isotope stage]]s (MIS) this corresponds to MIS 19 to MIS 13.<ref>{{cite journal|doi=10.1029/2004PA001071|url=http://www.lorraine-lisiecki.com/LR04_MISboundaries.txt|title=A Pliocene-Pleistocene stack of 57 globally distributed benthic δ18O records|journal=Paleoceanography|volume=20|author1= Lisiecki, Lorraine E.| author2= Raymo, Maureen E.|issue=1|authorlink = Lorraine Lisiecki|authorlink2 = Maureen Raymo|year=2005|pages=n/a|bibcode=2005PalOc..20.1003L|hdl=2027.42/149224|s2cid=12788441 |hdl-access=free}}</ref> 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 stage]], after the [[Beestonian stage|Beestonian Stage]].<ref name="Lee 2011">[http://nora.nerc.ac.uk/id/eprint/16048/1/16048.pdf 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 stage|Anglian]] and [[Hoxnian Stage]]s (MIS 12-11).<ref name="STD 2016">{{Cite web |url=http://www.stratigraphie.de/std/Bilder/5_2.pdf |title=German Stratigraphic Commission: Stratigraphische Tabelle von Deutschland 2016 |access-date=2019-03-31 |archive-url=https://web.archive.org/web/20181123154421/http://www.stratigraphie.de/std/Bilder/5_2.pdf |archive-date=2018-11-23 |url-status=dead }}</ref>
In the [[Alpine region]] the corresponding stage is called [[Gunz (geology)|Günz]].
The Cromerian had been equated to the [[Aftonian]] in [[North America]]. However, the Aftonian, along with the [[Yarmouthian Interglacial (Stage)|Yarmouthian (Yarmouth)]], [[Kansan glaciation|Kansan]], and Nebraskan, have been abandoned by North American Quaternary geologists and merged into the [[Pre-Illinoian]].<ref name="Hallberg1">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.</ref><ref name="RichmondOther1">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.</ref> 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.<ref name="Walker1">Walker, M., 2005, ''Quaternary Dating Methods'', John Wiley & Son, Chichester, United Kingdom. {{ISBN|0 470 86927 5}}</ref><ref name="RichmondOther1"/>
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]].<ref>Thomas Litt, Karl-Ernst Behre, Klaus-Dieter Meyer, Hans-Jürgen Stephan und Stefan Wansa: ''Stratigraphische Begriffe für das Quartär des norddeutschen Vereisungsgebietes.'' Eiszeitalter und Gegenwart (Quaternary Science Journal), 56(1/2), 2007, pp. 22-23 {{ISSN|0424-7116}} </ref>
== Glacial cycles == Based on a lack of glacial evidence in Western Europe for the [[Middle Pleistocene]] (Ionian) before the [[Anglian stage|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.<ref name="Lee 2011"/> 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]] to the 100,000 year glacial cycle became established during the Cromerian.<ref name="Lee 2011"/> 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.<ref name="Böse 2012"/> One of the glaciations, [[Marine Isotope Stage 16]] (MIS 16), is globally as strong as the most recent glaciations, MIS 6 (main [[Saale glaciation|Saale]]) and MIS 2 ([[Weichselian glaciation|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.<ref name="Böse 2012"/><ref>[https://www.qpg.geog.cam.ac.uk/research/projects/nweurorivers/donglaciation.html Cambridge Quaternary Palaeoenvironments Group: Don Glaciation]</ref>
== Fossils == In 1990 the [[West Runton Mammoth]] skeleton was found, the best example of the species [[Mammuthus trogontherii]] to be unearthed so far.
A significant [[fossil]] site, with animal remains dating about 600,000 years ago, is the [[Mosbach Sands]] in Germany, named after an abandoned village near [[Wiesbaden]], Germany.<ref>Ernst Probst: ''Deutschland in der Urzeit''. Munich: Bertelsmann, 1986. [http://d-nb.info/958229643 German National Library catalogue]</ref>
== See also == * [[Timeline of glaciation]] * [[Quaternary]] * [[Cromer Forest Bed]]
== References == {{Reflist}}
== Sources == * [https://web.archive.org/web/20080910122430/http://www.quaternary.stratigraphy.org.uk/correlation/POSTERSTRAT_v2007b_small.jpg www.Stratigraphy.org] * [http://www.zum.de/Faecher/G/BW/Landeskunde/rhein/geschichte/urundfrueg/quartaer.htm www.zum.de]
{{North German glaciations}}
[[Category:Quaternary geochronology]] [[Category:Ice ages]] [[Category:Pleistocene]] [[Category:Interglacials]]