Pomeranian phase
|
Glacial / interglacial |
Stadiale / Interstadiale |
Period (BC) |
|---|---|---|
| Vistula late glacial | ||
| Younger dryas period | 10,730-9,700 | |
| Alleröd Interstadial | 11,400-10,730 | |
| Older dryas period | 11,590-11,400 | |
| Bölling-Interstadial | 11,720-11,590 | |
| Oldest dryas period | 11,850-11,720 | |
| Meiendorf-Interstadial | 12,500-11,850 | |
| Vistula high glacial | ||
| Mecklenburg phase | 15,000-13,000 | |
| Pomeranian phase | 18,200-15,000 | |
| Lascaux-Interstadial | 19,000-18,200 | |
| Laugerie-Interstadial | 21,500-20,000 | |
| Frankfurt phase | 22,000-20,000 | |
| Brandenburg phase | 24,000-22,000 | |
| Tursac Interstadial | 27,000-25,500 | |
| Maisières-Interstadial | 30,500-29,500 | |
| Denekamp-Interstadial | 34,000-30,500 | |
| Huneborg Stadium | 39,400-34,000 | |
| Hengelo Interstadial | 41,300-39,400 | |
| Moershoofd Interstadial | 48,700 | |
| Glinde Interstadial | 51,500 | |
| Ebersdorf Stadium | 53,500 | |
| Oerel-Interstadial | 57,700 | |
| Vistula early glacial | ||
| Schalkholz Stadium | 60,000 | |
| Odderade Interstadial | 74,000 | |
| Rederstall-Stadial | ? | |
| Brörup-Interstadial | ? | |
| Amersfoort-Interstadial | ? | |
| Herning Stadium | 115,000 | |
| Eem warm period | ||
| 126,000 |
The penultimate ice advance of the Scandinavian inland ice towards the end of the Vistula high glacial is known as the Pomeranian phase . It dates roughly to the period 18,000 to 15,000 BC. Chr.
Naming and conceptual history
The term Pommern-Phase, also known as Pommersche Phase , Pommersches Stadium or Pommerscher Advance , was introduced in 1925 by Paul Woldstedt . He identified as Pomeranian phase, the last large, contiguous terminal moraines education phase northern Germany . In 1928 he changed the term to Pommersches Stadium in order to align it with the practice common in the Alpine region.
The type region of the Pomeranian phase is Pomerania , there is no separate type locality .
Geographical course
The Pomeranian main ice edge begins in northeast Germany east of Lübeck , goes around the south of Wismar , then turns in a south-easterly direction and passes 20 kilometers south of Neubrandenburg . You continue through the Uckermark to Pomerania via the villages of Neuenhagen - Stara Rudnica - Moryn - Babin - Trzcinna - Barlinek . It then crosses northern Poland at Szczecinek , north Grudziądz , south Olsztyn and Ełk . In southern Lithuania , it probably follows the Baltija-Morrane passing by Vilnius . It then moves through northern Belarus and, according to Woldstedt (1958), can be traced in northern Russia to the east of Arkhangelsk . At this point in time, the connection to the Barents Sea Ice Sheet should also have existed.
The continuation to the northwest and north via Schleswig-Holstein and Denmark is controversial. Müller u. a. (1995) advocate a continuation around the Fördenende in Schleswig-Holstein over the Sehberg-Randlage ( qw5 ) north to the East Jutian peripheral area of Denmark and further through the Kattegat to the Norwegian shelf edge . Studies by Smed (1997), for example, based on historical bedrock , assign these two peripheral locations to the later glacier advance of the Mecklenburg phase ( young Baltic phase ). It is possible that the central Jutland ice edge was reached.
Stratigraphy and Correlation
The Pomeranian phase ( W2 ) belonging to marine isotope stage 2 stratigraphically follows the Frankfurt phase W1F . In turn, it will be replaced by the Mecklenburg phase . Based on the GRIP ice core, there is a correlation with Greenland Stadial 2b ( GS-2b ). Usually the Pomeranian phase can be divided in two. Upstream of the main edge of the ice, W2 (or W2o ), the maximum advance W2max (or W2u ) is only a few kilometers further southwest . In the main basin of the Oder Glacier, the main ice edge is followed by four more seasons (from young to old):
- Ücker relay
- Gerswalder relay
- Zichow Golmer relay
- Angermünder relay
Dating
In the Oder Glacier area, Liedtke (1996) provided a conventional, calibrated radiocarbon age of <17,600 years vh, corresponding to <15,650 v. Chr. Kozarski (1995) extrapolated a slightly older radiocarbon age of 16,200 years BC (or calibrated 17410 BC) from lying sediments for the Pomeranian fringe. Lüthgens, Böse & Preusser (2011) recently determined an age of around 18,000 BC using OSL data . For the outskirts. Sand areas emanating from the ice edge were identified by the same authors with 18150 ± 1600 years BC. Chr. In Althüttendorf v and 17450 ± 2400 years. Dated near Eberswalde . The final stabilization of the debris fraction in the terminal moraine took place according to Heine et al. (2009) on the basis of SED data, however, only around 14450 ± 700 years BC. Rinterknecht et al. (2010) found an age of> 15,000 BC for the melting of the ice masses north of the peripheral location. The same authors assign the stabilization process of the Gerswalder Retreat Squadron crossing 30 kilometers further north to an age of 13,250 ± 500 years BC. Chr. To.
Overall, the Pomeranian phase is likely to run from 18,200 to 15,000 BC. Be classified. However, if stabilization processes are taken into account, it ended after a general periglacial stabilization phase around 13000 BC. BC only around 12,750 ± 1000 years BC. With the melting of dead ice in the Angermünder Staffel.
The advance of the Pomeranian ice masses from 18,200 BC. Chr. Correlated with LGM-2 , the last maximum of the Weichselian ( engl. Load Glacial maximum or LGM ), which was determined on the basis of marine isotope records (The LGM-1 correlated with the Brandenburg-phase ).
geology
In Mecklenburg-Western Pomerania , based on the arrangement of the ice edge layers of the Vistula high glacial, a chronological sequence can be recognized that shows an age decreasing from southwest to northeast. For example, the W1B peripheral location of the Brandenburg phase, which moves from Schwerin to the southeast, is roughly paralleled by the peripheral location of the Frankfurt W1F phase only a few kilometers away .
The morphologically most outstanding element, however, is the Pomeranian main ice edge layer W2 of the two-part Pomeranian phase , which is divided into praises . Its associated ground moraine is extensive in the north-eastern backland and is also widespread in greater thicknesses, except for channel and basin areas. The landscape of Western Pomerania, which adjoins it to the north and is dominated by ground moraines, is counted among the flat, undulating North Mecklenburg clay plates , in which the edge of the inland ice, which was contiguous during the main Pomeranian advance, dissolved or subsequently oscillated due to climatic fluctuations. The maximum advance of the Pomeranian phase W2max runs parallel to the main margin line and is only a few kilometers in front of it to the southwest; However, when it reaches the Warnow, it turns to the west in the direction of Schwerin and there approaches the edge of the Frankfurt phase.
Following the Pomeranian Haupteisrandlage Rosenthaler outskirts W3R of Mecklenburg-phase with their model-like edging walls and individual Sander distributions.
Heinrich event
The Heinrich event H1 , dated around 15,000 years BC. BC, located at the transition from the Pomeranian phase to the Mecklenburg phase. With him perhaps the widespread formation of periglacial correlated cover sands (Engl. Cover sands ), such as in the southern Netherlands of rubble horizon of Beuningen Gravel Bed , the v at 15.250. Came to the deposit.
Environmental parameters
Oxygen isotopes
According to the GRIP ice core , the δ- 18 O values at the beginning of the Pomerania phase were at a very low level of −42 ‰ SMOW . They then rose steadily in the further course to -38 ‰ SMOW. As a temperature proxy, they indicate very cold conditions at the beginning of the phase (maximum advance) followed by successive warming (main ice edge and retreat echelons).
Individual evidence
- ↑ Thomas Litt, Achim Brauer , Tomasz Goslar, Josef Merkt, Krystyna Bałaga, Helmut Müller, Magdalena Ralska-Jasiewiczowa, Martina Stebich, Jörg FW Negendank: Correlation and synchronization of Lateglacial continental sequences in northern central Europe based on annually laminated lacustrine sediments. In: Quarternary Science Reviews. vol. 20, No. 11, May 2001, pp. 1233-1249.
- ↑ For the sake of standardization, the age data for the climatic stages of the Vistula Late Glacial were converted to v. With the dendrochronological and warven chronological data, the reference point is the year 1950, ie 1950 years have to be subtracted to get BC. Chr. Indications to receive. The ice core data, on the other hand, relate to the reference year 2000. The age information from the Vistula high glacial is the approximate start of the corresponding time interval vh
- ↑ Lundqvist, J. and Saarnisto M .: Summary of project IGCP 253 . In: Quaternary International . tape 28 , 1995, pp. 9-18 .
- ↑ Müller, U. among others: The Pleistocene sequence in Mecklenburg-Western Pomerania . Ed .: Ehlers, J., Kozarski, S. & Gibbard, P .: Glacial deposits of North-East Europe. Rotterdam (Brookfield: Balkema) 1995, p. 626 .
- ↑ Liedtke, H .: The Ice Age design of the Oderbruch . In: Heidelberg Geographical Works . tape 104 , 1996, pp. 327-351 .
- ^ Marks, L .: Last Glacial Maximum in Poland . In: Quaternary Science Reviews . tape 21 , 2002, p. 103-110 .
- ↑ Kozarski, S .: Deglacjacja pólnocno-zachodniej Polski: womki i trasformacja geosystema (~ 20 ka – 10 ka) . In: Documentacja Geograficzna . tape 82 , 1995.
- ↑ Lüthgens, C., Böse, M. & Preusser, F .: Age of the Pomeranian ice marginal position in north-eastern Germany determined by Optically Stimulated Luminescence (OSL) dating of glaciofluvial sediments . In: Boreas . 2011, doi : 10.1111 / j.1502-3885.2011.00211.x .
- ↑ Heine, K., Reuther, AU, Thieke, HU, Schulz, R., Schlaak, N. and Kubik, PW: Timing of Weichselian ice marginal positions in Brandenburg (northeastern Germany) using cosmogenic in situ 10Be . In: Journal of Geomorphology NF . tape 53 (4) , 2009, pp. 433-454 .
- ↑ Rinterknecht, VR, Braucher, R., Evil, M., Bourlès, D. and Mercier, J.-L .: Late Quaternary ice sheet extents in northeastern Germany inferred from surface exposure dating . In: Quaternary Science Reviews . 2010, doi : 10.1016 / j.quascirev.2010.07.026 .
- ↑ Lüthgens, Christopher: The age of Weichselian main ice marginal positions in north-eastern Germany inferred from Optically Stimulated Luminescence (OSL) dating. Dissertation, Free University of Berlin . Berlin 2011.
- ↑ Bard, E .: Ice Age Temperatures and Geochemistry . In: Science . tape 284 , 1999, pp. 1133-1134 .
- ↑ Börner, A. et al.: Geoscientific investigations on the OPAL route in Mecklenburg-Western Pomerania - field work and first results . In: Brandenburg. geowiss. Contrib . tape 18, 1/2 . Cottbus 2011, p. 9-28 .
- ^ Hurtig, T .: Physical geography of Mecklenburg . Berlin 1957, p. 252 .
- ↑ Checkout, C., Vandenberghe, J., de Corte, F. and van den Haute, P .: Late Weichselian fluvio-aeolian sands and cover sands of the type locality Grubbenvorst (southern Netherlands): sedimentary environments, climate record and age . In: Journal of Quaternary Science . tape 22/7 , 2007, p. 695-708 .