Earth:Obukhov Formation
| Obukhov Formation Stratigraphic range: Late Eocene | |
|---|---|
| Type | Geological formation |
| Underlies | Mezhigorje Formation |
| Overlies | Early Eocene Basement |
| Thickness | 2–7 m (6.6–23.0 ft) |
| Lithology | |
| Other | Sand, Clay, Amber, Glauconite, Quartz |
| Location | |
| Location | Ukrainian Crystalline Shield |
| Region |
|
The Obukhov Formation is a geologic formation in Belarus and Ukraine that dates to the Late Eocene;[1] the Obukhov Formation is equivalent to the Prussian Formation of Russia.
Rovno amber is found in this formation,[2] and 90% of amber collected from the Obukhov Formation is extracted illegally and the trade is controlled by armed organised crime groups, although the Ukrainian government has begun to oversee excavations since 1993.[2]
Geological context
The Late Eocene Rovno amber is hosted in the Obukhov Formation, and it underlies the Early Oligocene Mezhigorje Formation.[3][2] The formation is found along the northwestern margin of the Ukrainian Crystalline Shield[1] exposed in the Rivne region of Ukraine and across the border near Rechitsa in the Gomel Region of Belarus.[4] The granite basement rock was overlain by sandy to clayey deposits that were host to alluvial amber.[2]
The two formations total between 2–7 m (6.6–23.0 ft) in thickness, both containing interbeds or mixtures of brown coals and carbonized vegetation. Both formations are sandy to clayey in texture, with the Obukhov Formation having more clayey glauconite-quartz plus sandy loess.[5]
References
- ↑ 1.0 1.1 Engel, M.S.; Perkovsky, E.E. (2006). "An Eocene bee in Rovno amber, Ukraine (Hymenoptera, Megachilidae)". American Museum Novitates (3506): 1–11. doi:10.1206/0003-0082(2006)506[0001:aebira2.0.co;2]. http://digitallibrary.amnh.org/bitstream/handle/2246/5685/N3506.pdf?sequence=1.
- ↑ 2.0 2.1 2.2 2.3 Perkovsky, E. E.; Zosimovich, V. Y.; Vlaskin, A. P. (2010). "Chapter 7: Rovno amber". in Penney, D.. Biodiversity of Fossils in Amber from the Major World Deposits. Siri Scientific Press. pp. 116–136. ISBN 978-0-9558636-4-6.
- ↑ Perkovsky, E. E.; Rasnitsyn, A. P.; Vlaskin, A. P.; Taraschuk, M. V. (2007). "A comparative analysis of the Baltic and Rovno amber arthropod faunas: representative samples". African Invertebrates 48 (1): 229–245.
- ↑ Perkovsky, E. E. (2017). "Rovno Amber Caddisflies (Insecta, Trichoptera) from Different Localities, with Information about three New Sites". Vestnik Zoologii 51 (1): 15–22. doi:10.1515/vzoo-2017-0003.
- ↑ Perkovsky, E. E.; Zosimovich, V. Y.; Vlaskin, A. P. (2003). "A Rovno amber fauna: a preliminary report.". Acta Zoologica Cracoviensia 46(Supplemental): 423–430.
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