Madygen formation

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The Madygen Formation (also Madygen Svita ) describes a lithostratigraphic unit , that is, a sequence of sedimentary rocks , the formation of which is related in time, space and environmental conditions. The sediments of the Madygen Formation were deposited during the Middle or Late Triassic in one or more lakes and on an adjacent flood plain and are now exposed in several separate areas in south-west Kyrgyzstan .

History of discovery and exploration

The Madygen Formation was first delimited by Kochnev (1934) as a separate rock unit and named after the village of Madygen located in the strike area. While most of the authors assumed a Triassic age, Sixtel (1960) assigned a Permian age to the sequence on the basis of plant fossils . Inna Dobruskina (1970, 1995), on the other hand, interpreted the flora as Middle to Late Triassic (approx. 230-220 million years old), which corresponds to the presumed level of evolution of the insect fauna (see Shcherbakov 2008).

Fossil deposit for fossil insects

Since research by Moscow paleontologists in the 1960s under the direction of Alexander Sharov , Madygen has become known as a fossil deposit for insects whose wings and body outlines have been preserved in fossil form. Some of the wings show a color pattern that apparently reflects the original color scheme. The oldest evidence of hymenoptera comes from the Madygen Formation, which also produced some of the oldest two-winged fossils (Shcherbakov 2008).

literature

  • Dobruskina, IA 1970. Age of the Madygen Formation in the context of Permian / Triassic boundary in Middle Asia. Sovetskaya geologiya, 3 (12): 16-28 [in Russian].
  • Dobruskina, IA 1995. Keuper (Triassic) Flora from Middle Asia (Madygen, Southern Fergana). New Mexico Museum of Natural History and Science Bulletin, 5: 1-49.
  • Kochnev, EA 1934. On the study of Jurassic coal-bearing deposits of Fergana. Materials on geology of coal deposits of Middle Asia, no. 5-6 [in Russian].
  • Shcherbakov, DE 2008. Madygen, Triassic deposit number one, before and after Sharov. Alavesia 2: 113-124.
  • Sixtel, TA 1960. On the presence of continental Upper Permian deposits in southern Fergana. Trudy Uzbekskogo geologoicheskogo upravleniya, Sbornik no. 1, Geologiya: 29–38.