STRUCTURAL AND COMPOSITION CHARACTERISTICS OF IMPACTITES OF COPTOMICT FACIES OF THE KARA ASTROBLEME RIM
N.I. Maksimenko1, T.G. Shumilova1
1N.P. Yushkin Institute of Geology, FRC Komi SC UB RAS, Syktyvkar, Russia
Keywords: Suevite, impactite, Kara astrobleme, impact facies, shock metamorphism, impactogenesis
Abstract
The impact facies are subdivided to coptogenic (primarily deposited) and coptomictic (redeposited) units. The redeposited impact facies remain poorly studied at present. In this work, the deposits of the coptomictic facies on the basis of the Kara astrobleme are characterized in detail for the first time. Structural and textural features of impactites at the macrolevel and microscopic structural and material features of the constituent components (lithoclasts, vitroclasts and matrix) of lapilli and agglomerate suevites of the Sayakha River area are considered. According to the reconstruction, the breccia impactites of the crater rim at the northwestern sector of the Kara astrobleme were formed under conditions of the landslides facies from the crater wall at the stage of early modification of the astrobleme. The results obtained can be used to reconstruct a model of the Kara impact structure formation and to improve the unified model of the breccia impactites formation of coptomictic facies in a large meteorite crater.
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