Biber or the Biber Complex (german: Biber-Komplex) is a timespan approximately 2.6–1.8 million years ago in the glacial history of the

Alps The Alps () ; german: Alpen ; it, Alpi ; rm, Alps ; sl, Alpe . are the highest and most extensive mountain range system that lies entirely in Europe, stretching approximately across seven Alpine countries (from west to east): France, Swi ...

. Biber corresponds to the

Gelasian The Gelasian is an age in the international geologic timescale or a stage in chronostratigraphy, being the earliest or lowest subdivision of the Quaternary Period/System and Pleistocene Epoch/Series. It spans the time between 2.58 Ma (million ye ...

age in the international

geochronology Geochronology is the science of determining the age of rocks, fossils, and sediments using signatures inherent in the rocks themselves. Absolute geochronology can be accomplished through radioactive isotopes, whereas relative geochronology is ...

, which since 2009 is regarded as the first age of the Quaternary period. Deep sea core samples have identified approximately 20 glacial cycles of varying intensity during Biber.German Stratigraphic Commission: Stratigraphische Tabelle von Deutschland 2016
/ref>

History of the term

In 1953, Schaefer defined the Biber glaciation (german: Biber-Kaltzeit), Biber Glacial (''Biber-Glazial''), or Biber Ice Age (''Biber-Eiszeit'') from gravel landforms of the Stauden Plateau in the area of the Iller-Lech Plateau and in the Aindling terrace sequence, by grouping together the so-called Middle and Upper Cover Gravels or ''Deckenschotter''. This corresponded to the Staufenberg Gravel Terrace on the Iller-Lech Plateau, identified in 1974 by Scheunenpflug, and the so-called High Gravels (''Hochschottern'') of the Aindling region. The rich crystalline sedimentary facies (''Kristallinreiche Liegendfazies''), that Löscher distinguished in 1976 in the area of the Rhine Glacier of the western Riß-Iller Plateau may also be paralleled with these glacial landforms. The gravels in the Iller-Lech region ascribed to the Biber glaciation are generally heavily weathered and originate from the

Northern Limestone Alps The Northern Limestone Alps (german: Nördliche Kalkalpen), also called the Northern Calcareous Alps, are the ranges of the Eastern Alps north of the Central Eastern Alps located in Austria and the adjacent Bavarian lands of southeastern Germa ...

. Löscher's ''Kristallinreiche Liegendfazies'', by contrast, originates from the bedrock of the

molasse __NOTOC__ The term "molasse" () refers to sandstones, shales and conglomerates that form as terrestrial or shallow marine deposits in front of rising mountain chains. The molasse deposits accumulate in a foreland basin, especially on top of flysc ...

zone. The term Biber glaciation was not part of the traditional four-stage glaciation schema of the

Albrecht Penck Albrecht Penck (25 September 1858 – 7 March 1945) was a German geographer and geologist and the father of Walther Penck. Biography Born in Reudnitz near Leipzig, Penck became a university professor in Vienna, Austria, from 1885 to 1906, a ...

and Eduard Brückner, but was named after the Biberbach river north of

Augsburg Augsburg (; bar , Augschburg , links=https://en.wikipedia.org/wiki/Swabian_German , label=Swabian German, , ) is a city in Swabia, Bavaria, Germany, around west of Bavarian capital Munich. It is a university town and regional seat of the ...

in 1953 by Ingo Schaefer, based on the naming system of the traditional Penck schema. Its type region is the ''Stauden Plateau'' in the

Iller-Lech Plateau The Iller-Lech Plateau (german: Donau-Iller-Lech-Platte), also known as the Upper Swabian Plateau (''Oberschwäbische Hochebene''), is one of the natural regions of Germany. Boundaries In the northwest the Iller-Lech Plateau borders on the Sw ...

x and the Staufenberg Gravel Terrace in the area of

Aindling Aindling is a market town in Aichach-Friedberg district, in Bavaria, southern Germany. Partner cities * Avord, France, since 1977 * Fürstenfeld, Austria Austria, , bar, Östareich officially the Republic of Austria, is a country i ...

. The Biber glaciation was thought to be followed by the

Biber-Danube interglacial The Biber-Danube interglacial (german: Biber-Donau-Interglazial) or Biber-Danube warm period (''Biber-Donau-Warmzeit'') is a historical term for a hypothetical warm period of the Pleistocene epoch in the Alps, between the Biber and Danube glaciati ...

and the Danube glacial. The absolute timing and the connexion with the glacial classification of North Germany and the Netherlands has been problematic. The Biber glacial was thought to correlate either to the

Eburonian The Eburonian (german: Eburon or ''Eburonium''), or, much less commonly, the Eburonian Stage, is a glacial complex in the Calabrian age of the Pleistocene epoch and lies between the Tegelen and the Waalian interglacial. The transition from the T ...

complex or the Pre-Tiglian complex in the Netherlands. In the former case it would correspond to

MIS MIS or mis may refer to: Science and technology * Management information system * Marine isotope stage, stages of the Earth's climate * Maximal independent set, in graph theory * Metal-insulator-semiconductor, e.g., in MIS capacitor * Minimally ...

56 to 62, which would place it in the period between 1.6 and 1.8 million years ago, in the latter case it would roughly correspond to MIS 96 to 100, and would therefore have taken place about 2.4 to 2.588 million years ago. The correlation was fraught with problems however due to the fact that the corresponding depositions in the Netherlands were probably not governed by climatic changes. Similar doubts on climatic grounds for the depositions assessed as Biber-related also exist in the Alpine region. It is possible that there were

tectonic Tectonics (; ) are the processes that control the structure and properties of the Earth's crust and its evolution through time. These include the processes of mountain building, the growth and behavior of the strong, old cores of continents ...

influences perhaps in the wake of the uplift phases of the Alps. The succession and appearance of the gravel bodies makes it possible that during their formation there were several periods of alternating

fluvial erosion In geography and geology, fluvial processes are associated with rivers and streams and the deposits and landforms created by them. When the stream or rivers are associated with glaciers, ice sheets, or ice caps, the term glaciofluvial or fluviogl ...

and

accumulation Accumulation may refer to: Finance * Accumulation function, a mathematical function defined in terms of the ratio future value to present value * Capital accumulation, the gathering of objects of value Science and engineering * Accumulate (hi ...

. The Biber cold period at least corresponds partly with the Swiss cover gravel glaciations (''Deckenschotter-Vergletscherungen''). The 2016 version of the detailed stratigraphic table by the German Stratigraphic Commission firmly places Biber in the

and gives a correspondence to Pre-Tegelen and Tegelen in the glacial geology of northern Europe. There is continuity between Biber and the glacial cycles of the following

Danube The Danube ( ; ) is a river that was once a long-standing frontier of the Roman Empire and today connects 10 European countries, running through their territories or being a border. Originating in Germany, the Danube flows southeast for , p ...

stage

Glacial cycles

Deep sea core samples have identified approximately 40

marine isotope stage Marine isotope stages (MIS), marine oxygen-isotope stages, or oxygen isotope stages (OIS), are alternating warm and cool periods in the Earth's paleoclimate, deduced from oxygen isotope data reflecting changes in temperature derived from data f ...

s (MIS 103 – MIS 64) during Biber. Thus, there have probably been about 20 glacial cycles of varying intensity during Biber. The dominant trigger is believed to be the 41 000 year

Milankovitch cycles Milankovitch cycles describe the collective effects of changes in the Earth's movements on its climate over thousands of years. The term was coined and named after Serbian geophysicist and astronomer Milutin Milanković. In the 1920s, he hypot ...

of axial tilt.Encyclopedia of Quaternary Science
/ref>

Occurrence

Gravels ascribed to Biber (also called the Highland Gravel or Oldest Gravel (''Ältester Deckenschotter'') occur northwest of

as the Stauffenberg Gravel (''Stauffenberg-Schotter''), as well as northeast as the Hohenried Gravel (''Hohenrieder Schotter'') and southwest of Augsburg as the Stauden Plateau Gravel (''Schotter der Stauden-Platte''). Also included are isolated gravels of the Hochfirst near

Mindelheim Mindelheim (; Swabian: ''Mindelhoi'') is a town in Swabia, Bavaria, Germany. The town is the capital of the Unterallgäu district. At various points in history it was the chief settlement of an eponymous state. Geography Mindelheim is locate ...

and the Stoffersberg near

Landsberg am Lech Landsberg am Lech (Landsberg at the Lech (river), Lech) is a Town#Germany, town in southwest Bavaria, Germany, about 65 kilometers west of Munich and 35 kilometers south of Augsburg. It is the capital of the district of Landsberg (district), Lands ...

. There may also be gravels in the Sundgau from the Biber ice age.

References

Literature

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External links