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Berlin Environmental Atlas

01.17 Geological Outline (Edition 2013)

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Geological overview of Tertiary and Quaternary formations

The earth’s surface and the near-surface segment in the area of the city of Berlin were formed by deposits during the Tertiary, the Pleistocene and the Holocene, with the tertiary and quaternary sediments having a certainly decisive significance for the life of the city. For instance, all the water from the public water supply system comes largely from the Quaternary and to some extent from the tertiary groundwater aquifers. Some 90% of the groundwater used in Berlin is withdrawn within the city limits.

The Tertiary

The Tertiary, also known as the Lignite Era, began 65 million years ago, at the end of the Cretaceous period and ended at the beginning of the Quaternary, some 2.6 million years ago.

Sediments from the Tertiary are found in Berlin in a discordant pattern, with a time gap, above older strata of material from the Cretaceous, Jurassic or Keupers eras, and constitute a virtually complete underlying, older level beneath the quaternary strata (Fig. 3). In areas of deeper quaternary erosion, such as e.g. in sections of quaternary removal zones (tunnel valleys), tertiary deposits are entirely missing. Tertiary sediments constitute the surface layer at only one site in Berlin, in Lübars.

The clayey/silty rupelton, which is some 80 m thick, has a particular position within the tertiary layer. Due to its very broad dissemination, it is not only an important geological guide horizon within the covering hills from the Tertiary and Quaternary, it is also of considerable hydrogeological significance, since its constitutes a barrier between the saltwater in the underlying stratum and the freshwater in the younger, covering strata. In areas in which rupelton strata are partially or completely absent due to quaternary erosion, dissemination pathways, in some cases extending to the surface, were created for the rise of mineralized deep water, and for its spread into the freshwater strata (Fig. 3).

Abbildung 3
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Fig. 3: Simplified geological profile through the tertiary and quaternary strata, extending from Wilmersdorf through Schöneberg to Neukölln

The Quaternary

The Quaternary began with a global climate change, the Pleistocene Ice Age, some 2.6 million years ago, and ended with the Holocene at the end of the Ice Age. In Berlin, Pleistocene deposits from the three Nordic glaciations, the Elsterian, the Saalian and the Weichselian Glaciations, occurred. These deposits consist of meltwater sands and gravels of Nordic origin, laminated clays and stilts, and the glacial till of the ground moraines.

In addition, there are sediments from the Holstein and Eemian interglacials, with gyttjas, silts, clays and peats, and also river sands and gravels provided from areas further south (Tab. 1).

Tab. 1: Schematic structure of the Quaternary, by Stackebrandt & Manhenke (2010)
Stage (north German system) Typical deposits Began years before present
Holocene
  Peats, gyttjas, dune and river sands, bog-associated sands 12,000
Pleistocene
Weichselian Glaciation Meltwater sands, boulder clay, glacial till 115,000
Eemian Interglacial Peats, gyttjas, bog-associated sands 127,000
Saalian Glaciation Meltwater sands, boulder clay, glacial till, basin clays and silts 304,000
Holstein Interglacial Peats, gyttjas, clays and silts with snails, river sands and gravels 320,000
Elsterian Glaciation Meltwater sands, boulder clay, glacial till, basin clays and silts 400,000
Older glaciations and interglacials None observed in Berlin 2,600,000
Tab. 1: Schematic structure of the Quaternary, by Stackebrandt & Manhenke (2010)

The glaciers, particularly those of the Elsterian glaciation, eroded channels in the existing tertiary surface, in some cases very deep, which were then filled with glacial rock material. In some cases, the tertiary layer, particularly the rupelton clay, was completely eroded away, so that the protective barrier between the freshwater and saltwater strata was destroyed.

The thickness of the Pleistocene layers in Berlin is usually between 20 and 100 m; in the channels from the Elsterian period, however, they can be up to 250 m thick (Fig. 3).

After the end of the Pleistocene some 12,000 years ago, the Holocene began. Peats, gyttjas, and dune and river sands were deposited, which in some localities had very great thicknesses, often of more than 10 m.

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