Blue earth

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system series step ≈ age ( mya )
higher higher higher younger
Paleogene Oligocene Chattium 23.03
⬍
28.1
Rupelium 28.1
⬍
33.9
Eocene Priobonium 33.9
⬍
38
Bartonium 38
⬍
41.3
lutetium 41.3
⬍
47.8
Ypresium 47.8
⬍
56
Paleocene Thanetium 56
⬍
59.2
Seelandium 59.2
⬍
61.6
Danium 61.6
⬍
66
deeper deeper deeper older

A sediment in the area of ​​the Gdańsk Bay , which is known for its high content of Baltic amber , is called blue earth .

geology

The formation was placed in the Lower Oligocene / Upper Eocene for a long time. More recent radiometric examinations, however, have shown a Middle Eocene age ( Lutetium ). In addition to this formation, further amber-bearing layers occur below the blue earth, which lithologically are not dissimilar to the blue earth. These formations (“Wilde Erde” and “Lower Blue Earth”) belong to the Ypresium according to radiometric dating. The regional lithostratigraphic units of the actual blue earth of the Lutetium carry the designations "Prussian Formation" (in Samland ) and "Lower Mosina Formation" (in the vicinity of Chłapowo , Poland). The Blue Earth is usually divided into the approximately equally powerful units of the lower and upper banks. The lower bench in turn consists of the sequence of layers (from top to bottom):

  • Colorful stitch
  • Stone engraving
  • Hard stitch

The clearly highest amber concentration can be found in the so-called stone engraving.

The blue earth is a clayey to sandy silt with a high glauconite content . The glauconite gives the sediment a bluish-greenish appearance when moist. The layers of the blue earth in Samland and in the subsoil of the Gdańsk Bay reach a thickness of up to 14 meters in places. The deposits are between about 10 and 100 meters below the surface of the earth (or below the sea floor).

The Bay of Gdańsk

The mid- to upper-Ocene marine sediment near the coast formed in calm water, most likely in lagoons and in the extensive delta of the hypothetical river Eridanus , which, coming from the north, flowed into the area of ​​today's Gdańsk Bay (Chłapowo-Samland Delta).

The wild earth lying directly under the blue earth also contains amber, but not in the same concentration as the blue earth. The same applies to the Striped Sands lying above the Blue Earth. In contrast, the local formations of the Upper Triebsand, Gray Wall and Green Wall in this sequence of layers contain no or only very small amounts of amber.

geography

Blue earth has been found particularly on the west coast of Samland, where it is also removed in open-cast mining for the purpose of amber extraction. The formation extends far into the Gdańsk Bay and also appears relatively close to the surface in the west of the Gdańsk Bay, especially on the sea side ( Hel peninsula ), in the vicinity of Gdańsk but also far inland (e.g. near Lębork ).

Reports of blue earth from central and southern Poland or from the east of Germany refer to glacial clods of this sediment in Quaternary deposits of the Vistula glacial .

Amber mining and extraction

Amber mining near Jantarny

All parts of the Blue Earth contain significant amounts of Baltic amber. The reserves are estimated at well over 600,000 tons. The concentration generally fluctuates between 0.5 kilograms and 6.0 kilograms per cubic meter of blue earth. Where the blue earth lies just below the surface of the mainland, the amber in it is extracted in open-cast mining. In 2010, in the immediate vicinity of the coast near Jantarny (formerly Palmnicken) in the "Primorskoje" mine 341 tons were extracted. In the period from 1951 to 1988, production in the pits that are now closed at the same location totaled around 17,700 tons.

literature

  • M. Ganzelewski: Formation and deposits of Baltic amber. In: Amber - Tears of the Gods. Bochum 1996, ISBN 3-921533-57-0 , pp. 11-18.
  • JR Kasinski, R. Kramarska: Sedimentary environment of amber-bearing association along the polish-russian baltic coastline. Hanover 2008, ISBN 978-3-936617-86-3 , pp. 46-57. (Excursion guide and publications of the German Society for Geosciences, 236)
  • B. Kosmowska-Ceranowicz: Amber - The deposit and its formation. In: Amber - Tears of the Gods. Bochum 1996, ISBN 3-921533-57-0 , pp. 161-168.
  • R. Slotta , M. Ganzelewski: Today's amber extraction and processing in Jantarnyi. In: Amber - Tears of the Gods. Bochum 1996, pp. 249-268.
  • G. Standke: Bitterfeld amber equals Baltic amber? - A geological space-time consideration and genetic conclusions. Hanover 2008, ISBN 978-3-936617-86-3 , pp. 11-33. (Excursion guide and publications of the German Society for Geosciences, 236)

Individual evidence

  1. ↑ S. Ritzkowski: Age determination of the amber-bearing sediments of the Samland (Paleogene, Kaliningrad district). In: Metalla , special issue 66, pp. 19-23, Bochum 1997
  2. ↑ Standke 2008
  3. ↑ Barbara Kosmowska-Ceranowicz: Bernstein - the deposit and its formation. In: Amber - Tears of the Gods. Bochum 1996, ISBN 3-921533-57-0 .
  4. ↑ Königsberger Express online 5/2011