El´gygytgyn impact structure, Siberia: Investigation of a mid-size impact structure in volcanic target.

• Applicant: Professor Dr. Wolf Uwe Reimold
• Subject Area: Mineralogy, Petrology and Geochemistry
• Term: from 2010 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 166977551

The young (3.6 Ma), 18 km diameter El´gygytgyn crater in Chukotka, NE Russia, is one of the best-preserved impact structures on Earth. The complex crater structure was formed in a silicious volcanic target, which makes it a rare terrestrial equivalent to the abundant impact structures in volcanics on other planetary surfaces (e.g., on Mars). After the impact a crater lake formed – within which undisturbed and continued lacrustrine sedimentation took place to establish a continuous, long-term reservoir of paleoenvironmental information. The crater was never covered by glaciers or ice shields, which allowed the development of a unique arctic climate archive. In spring 2009 a drilling campaign by the “International Continental Drilling Project (ICDP)” recovered a complete (517 m) sequence of lake sediments and impactites (317 m of lacustrine, post-impact sediments, a several m wide transition zone to the underlying impact breccias - 25 m suevite above 170 m monomict lithic breccia). The goals for drilling were: (1) to collect an unprecedented record of climate history in the terrestrial arctic, and (2) to facilitate study of the crater fill and the crater floor geology of this unique impact structure in a rare geological setting. Here we propose a petrographic (incl. shock deformation) and chemical (incl. projectile identification) project aimed at elucidating the formation of the impactite sequence in this drill core, and – in conjunction with numerical modeling based on these results (during phase 2) – at a better understanding of the impact processes involved in generation of this complex impact structure.

• DFG Programme: Infrastructure Priority Programmes
• Subproject of: SPP 1006: International Continental Scientific Drilling Program (ICDP)
• Participating Person: Dr. Ralf Thomas Schmitt