Cromer complex

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system series step ≈  age  ( mya )
quaternary Holocene Meghalayum 0
⬍
0.012
Northgrippium
Greenlandium
Pleistocene Young Pleistocene
(Tarantium) 		0.012
⬍
0.126
Middle Pleistocene
(Ionian) 		0.126
⬍
0.781
Calabrium 0.781
⬍
1.806
Gelasium 1,806
⬍
2,588
deeper deeper deeper older

The Cromer complex ( synonym : Cromerium) is similar to the Saale complex, a period of the Pleistocene that encompasses several warm and cold periods , the structure of which is still uncertain. It is the older part of the Middle Pleistocene (Ionian) and ranges from the Bruhnes-Matuyama reversal of the earth's magnetic field at the border with the Calabrian, younger part of the Lower Pleistocene , around 0.786 million years ago to the beginning of the Holstein Warm Period 0.300 million years ago. The Günz glacial period , the first glaciation of the Alps, is set in the period of the Cromer complex .

From Clement Reid was a near the village of Cromer in the county of Norfolk of East Anglia on the coastal cliff under a moraine upcoming low powerful präglaziale layer sequence of lacustrine and marine sediments , the term "Cromer Forest-bed" than in 1882 stratigraphic used unit. This term quickly found widespread use in the Netherlands and Northern Germany as a term for interglacial sediments that were deposited immediately before the oldest Nordic inland glaciation of the Quaternary , the Elster Glaciation . According to the further investigations of the Cromer Forest-bed, which only began in the 1960s, only sediments of a warm period Middle Pleistocene age are present at the localities in eastern England, but these could be of different ages.

In the Netherlands, the Cromer complex is now divided into four independent interglacials , Interglacials I (Waardenburg) to IV (Noordbergum). The oldest Interglacial I, however, probably still belongs to the Old Pleistocene and it is uncertain which of the interglacial series of eastern England is of the same age. In addition, only parts of the interglacials are usually present, so that the correlation with the occurrences in the adjacent north-west German area is uncertain.

Includes in North-West Germany, based on the above the salt dome of Gorleben according to current state of drilled vertical sequence, the Cromer complex five warm periods and four cold periods. The oldest warm-time layers encountered are said to be of the same age as the Osterholz warm-time drilled near Elze . Overlying layers with a warm period vegetation sequence could be parallelized with the Hunteburg warm period drilled near Hunteburg . Two more layer sequences follow higher up with a warm period vegetation pattern, which have not yet been given names. The upper end is formed by sediments, which are paralleled with the Rhume warm period encountered near Bilshausen .

The Ice Age large mammal fauna discovered in the Mosbach Sands in 1845 near the former village of Mosbach, today part of the urban area of Wiesbaden , also has a Cromerian age, it is one of the most important fossil deposits in Germany. The Mosbach sands are part of a complicated sequence of deposits from the Rhine and Main . The main find layer was deposited in “Cromer-Interglacial III” after the investigations of the small mammal fauna.

In Central Germany , only two occurrences from the Cromer complex are known to date. The Voigtstedt warm period in the Voigtstedt brickworks mine near Artern, palynologically only incompletely preserved, is uncertain in its age, mostly it is placed in the older period of the Cromer complex. The 10 m thick loess , which was examined in more detail in the Mahlis brickworks near Wermsdorf in the 1970s, comprises larger parts of the Cromer complex. According to the palynological findings, the basal clay mud was deposited under a cold-age climate and it contains the carpological remains of a rich flora . The Bruhnes-Matuyama reversal has been demonstrated in the basal layers and the loess series, which is divided by fossil soils, is covered by ground moraine. While the loess layers were deposited in cold ages, the characteristics of the three embedded paleo soils speak for a warm period climate. The threefold structure that results from this cannot currently be reconciled with the Dutch and northwest German structures of the Cromer complex.

Web links

Individual evidence

  1. ↑ a b German Stratigraphic Commission, Ed .; Editing, coordination and design: M. Menning, A. Hendrich: Stratigraphische Tisch von Deutschland 2016 . Potsdam 2016 (bib.telegrafenberg.de)
  2. ^ C. Reid: The geology of the country around Cromer. In: Memoirs of the Geological Survey of England and Wales. Sheet 68 E, London 1882, pp. 1-143 (pubs.bgs.ac.uk)
  3. ^ RG West, DG Wilson: Cromer Forest Bed Series. In: Nature. Volume 209, London 1966, pp. 497-498.
  4. ↑ PL Gibbard, RG West, WH Zagwijn, PS Balson, AW Burger, BM Funell, DH Jeffrey, DH De Jong, T. Van Kolfhofen, AM Lister, T. Meijer, PEP Norton, RC Preece, J. Rose, AJ Stuart , CA Whiteman, JA Zalasiewicz: Early and Middle Pleistocene correlations in the southern North Sea Basin. In: Quaternary Science Reviews. Volume 10, Amsterdam 1991, pp. 23-52.
  5. ↑ a b T. Litt, K.-E. Behre, K.-D. Meyer, H.-J. Stephan, S. Wansa: Stratigraphic terms for the Quaternary of the north German glaciation area. In: Ice Age and the Present, Quaternary Science Journal. Volume 56, Issue 1-2, Hannover 2007, pp. 7-65, 116-138.
  6. ^ WH Zagwijn, HM Van Montfrans, JG Zandstra: Subdivision of the "Cromerian" in The Netherlands, pollenanalysis, palaeomagnetism and sedimentary petrology. In: Geology en Mijenbow. Volume 50, Amsterdam 1971, pp. 41-58.
  7. ^ WH Zagwijn: The Cromerian Complex Stage of the Netherlands and correlation with other areas in Europe. In: C. Turner (Ed.): The Middle Pleistocene in Europe. Balkema, Rotterdam 1996, pp. 145-172.
  8. ↑ H. Müller: Old Quaternary sediments in the overburden of the Gorleben salt dome. In: Journal of the German Geological Society. Volume 137, Hannover 1986, pp. 85-95.
  9. ↑ E. Grüger: Vegetation-historical studies on Cromer-period deposits in the northern edge of the German low mountain range. In: Ice Age and the Present. Volume 18, Hannover 1968, pp. 204-235.
  10. ↑ J. Hahne, H. Mengeling, J. Merkt, F. Grahmann: The Hunteburg warm period (“Cromer complex”) and deposits of the Elster, Saale and Weichsel glacial periods in the Hunteburg GE 58 research well near Osnabrück. In: Geological Yearbook. Volume A 134, Hannover 1994, pp. 117-166.
  11. ^ H. Müller: A pollen analysis revision of the interglacial profile of Bilshausen (Unter-Eichsfeld). In: Geological Yearbook. Volume 83, Hannover 1965, pp. 327-352.
  12. ↑ C. Hoselmann, T. Laupenmühlen, J. Bohaty, G. Radtke, G. Weber, M. Weidenfeller: Field Trip C (September 27, 2018): Fluviatile and aeolian deposits in the Rhine-Main area. In: DEUQUA Special Publications. Volume 1, Hannover 2018, pp. 29–52 (deuqua-spec-pub.net)
  13. ↑ L. Maul, LI Rekovets, W.-D. Heinrich, T. Keller, G. Storch: Arvicola mosbachensis (Schmidtgen 1911) of Mosbach 2: abasic sample for the early evolution of the genus and a reference for further biostratigraphical studies. In: Senckenbergiana lethaea. Volume 80, Stuttgart 2000, pp. 129-147.
  14. ↑ K. Erd: Pollen analysis studies in the Old Pleistocene by Voigtstedt in Thuringia. In: Paleontological Treatises. Volume A 2, Berlin 1965, pp. 259-272.
  15. ^ R. Fuhrmann: The stratigraphic position of the loess in central and west Saxony. In: Journal of Geological Sciences. Volume 4, Issue 9, Berlin 1976, pp. 1241-1270. (researchgate.net)
  16. ↑ R. Fuhrmann, W.-D. Heinrich, DH Mai, F. Wiegangk: Investigations on the pre-Cold Age loess from Mahlis (Leipzig district). In: Journal of Geological Sciences. Volume 5, Issue 6, Berlin 1977, pp. 717-743. (researchgate.net)
  17. ↑ L. Eissmann: Fundamentals of the Quaternary Geology of Central Germany (Saxony, Saxony-Anhalt, South Brandenburg, Thuringia). In: Altenburger Scientific Research. Issue 7, Altenburg 1994, pp. 55-135.