Ilyinets - Hypervelocity Impact Crater

Alternate Names
Local Language Illintsi (Kvasnytsya, 2018); Il'inets.
Coordinates 49° 7' 0" N; 29° 6' 0" E
Notes
  1. On the Ukrainian Shield 45 km SE of the city of Vinnitsa.
Country Ukraine
Region Vinnytsia
Date Confirmed 1980
Notes
  1. Initially confirmed by coesite (Gurov et al., 1978). PDFs in quartz and feldspar as well as shatter cones later confirmed (Masaitis et al., 1980).
Buried? Yes
Notes
  1. Up to 80 m of Quaternary sediments and alluvium cover the structure (Gurov and Ryabenko, 1984).
Drilled? Yes
Notes
  1. Core from 12 boreholes, located from one side of the crater to the other penetrate sedimentary cover, breccias, and fractured country rocks. Devonian clays crater lake sediments are distributed in the buried depression (Masaitis et al., 1980).
Target Type Mixed
Notes
  1. Charnokites and gneisses of Lower Proterozoic age (Gurov and Ryabenko, 1984). Sedimentary formation overlying the crystalline basement, Devonian or older in age (Masaitis et al., 1980).
Sub-Type Gneiss
Apparent Crater Diameter (km) 4.5 km
Age (Ma) 445 ± 10
Notes :
  1. The most recent, recommended age of 445 ± 10 Ma was obtained using 40Ar/39Ar of clast-rich impact melt rocks (Pesonen et al., 2004). Previous isotopic studies on the impactite provides an age of 395 ± 5 Ma (Nikolsky, 1975).

Method :
  1. 40Ar/39Ar
Impactor Type Not determined
Notes
  1. Ni content in the impactites 3 times that of the host rocks indicates contamination by meteoritic material (Val'ter, 1975).

Advanced Data Fields

Notes

Erosion
5
  1. Ejecta and rim completely eroded, with only partial preservation of the crater-fill products (Masaitis et al., 1980) (Koeberl et al., 1996) (Gurov et al.,1998).
Final Rim Diameter
Unknown
Apparent Rim Diameter
4.5 km
  1. (Gurov and Ryabenko, 1984); diagram from (Masaitis et al., 1980). Geophysics suggest structure may be 8 km. See also (Val'ter, 1975).
Rim Reliability Index
2
  1. Consists of a central uplift of brecciated rocks surrounded by a sediment filled annular depression, an outer ring of suevites and breccia and dislocated, faulted, and crystalline rocks around the periphery (Gurov and Ryabenko, 1984).
Crater Morphology
Complex
Central Uplift Diameter
1km
Central Uplift Height
Unknown
Uplift Reliability Index
3
Structural Uplift
300 m
Thickness of Seds
Target Age
Precambrian
Marine
No
Impactor Type
Not determined
  1. Ni content in the impactites 3 times that of the host rocks indicates contamination by meteoritic material (Val'ter, 1975).
Other Shock Metamorphism
Impact diamonds Planar features
  1. Impact diamonds are present in some impact-melt rock (Gurov et al., 1998). Shock metamorphism mentioned (Gurov and Gurova, 1984). The impact diamonds of the rocks of the Ilyinets (Gurov et al., 1995). planar elements have been observed in quartz with preferable orientation of {1013}. (Gurov and Ryabenko, 1984)."
Shatter Cones
Yes
  1. Shatter cones in granite from the central uplift (Masaitis, 1999). Shatter cones occur in autochthonous breccia of the crater basement; they rarely occur in boulders and fragments of crystalline rocks in suevite. They are abundant in drill core samples of core 5008 (drilled near the northern flank of the central uplift) at depths of 120.0, 152.5, and 166.0 m in suevites and at depth intervals of 270.0-282.4, 300.0-307.2, and 311.0-332.5 m in autochthonous granite breccias (Gurov et al., 1998). See also (Masaitis et al., 1980) and (Gurov and Ryabenko, 1984). Observed as radial scratches, similar to shatter cones in more tough rocks (Gurov and Ryabenko, 1984). Everywhere up to the depth of 325 m the shatter cones in rocks, which are oriented at various angles to the axis of the core, are observed.
Planar Fractures
No
  1. Did not find in literature.
Planar Deformation Features
Yes
  1. PDF in quartz grains and feldspars (Masaitis et al., 1980) (Gurov and Ryabenko, 1984) (Gurov et al., 1998). Many mentions of PDF in quartz, feldspar, plagioclase, etc in: Table 2. Petrographic observations for analyzed samples (Gurov et al., 1998). Shocked quartz is rare in granites of the brecciated basement, where PDFs have (mainly, 0001), {1013}, and {1014} (Gurov et al., 1998). Multiple sets of planar deformation (PDFs) are common in quartz, K-feldspar, and plagioclase (Koeberl et al., 1996). **see quartz PDF in Fig. 2.
Diaplectic Glass
Yes
  1. Breccia consists mostly of crushed crystalline rocks, with diaplectic minerals, diaplectic glasses, and coesite (Masaitis, 1999). Diaplectic quartz glass in sample I-26: Table 2. Petrographic observations for analyzed samples (Gurov et al., 1998). Some diaplectic glass (Koeberl et al., 1996). Diaplectic glasses on quartz and feldpars (Gurov and Ryabenko, 1984).
Coesite
Yes
  1. Coesite in breccia mentioned (Masaitis, 1999). Impact-induced high pressure phases in the rocks from the Ilyinets structure include coesite (Gurov et al., 1998). Coesite mentioned (Gurov and Ryabenko, 1984).
Stisovite
No
  1. Did not find in literature.
Crater Fill
LB, MB, M
  1. The crater-fill impactites comprise polymict lithic breccias, melt-bearing breccias (referred to as suevites by the authors) with variable amounts of shocked clasts and glass, and melt rocks (Koeberl et al., 1996). (Gurov et al., 1998) describe a sequence from base to top of "glass-poor suevitic breccia", "glass-rich suevite" and melt rocks; i.e., impact melt rocks and melt (glass)-bearing breccias with different proportions of clasts. Melt rocks also occur as dykes. Volume of melt via Table 1 of (Grieve and Cintala, 1992).
Proximal Ejecta
Distal Ejecta
Dykes
M
Volume of Melt
7x10^-1 km3
Depth of Melting

References

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A A Valter, V A Ryabenko (1977) Explosion craters on the Ukrainian shield (in Russian), p. 1-154, Kiev: Naukova Dumka Press

E P Gurov, E P Gurova (1984) Formation of Ilyinets crater bombs: The role of high-temperature condensation, Abstracts of Papers Submitted to the Lunar and Planetary Science Conference 15, p. 335-336, Lunar and Planetary Science Conference, Houston, TX, url

C Koeberl, W U Reimold, E P Gurov (1996) Petrology and geochemistry of target rocks, breccias, and impact melt rocks from the Ilyinets Crater, Ukraine, Abstracts of Papers Submitted to the Lunar and Planetary Science Conference 27, Part 2, p. 681-682, Lunar and Planetary Science Conference, Houston, TX, url

E P Gurov, C Koeberl, W U Reimold (1998) Petrography and geochemistry of target rocks and impactites from the Ilyinets Crater, Ukraine, Meteoritics & Planetary Science 33(6), p. 1317-1333, Meteoritical Society, Fayetteville, AR, url

C A Lorenz, E P Gurov, G J Consolmagno (2001) Trace element geochemistry and origin of Ilyinets crater bombs, Meteoritics & Planetary Science 36(9, Suppl.), p. 116, Meteoritical Society, Fayetteville, AR, pdf

L J Pesonen, D Mader, E P Gurov, C Koeberl, K A Kinnunen (2004) Paleomagnetism and Ar-39/Ar-40 age determinations of impactites from the Ilyinets impact structure, Ukraine, Cratering in Marine Environments and on Ice, Juri Plado, Lauri J Pesonen (ed.), p. 251-280, Geological Survey of Finland, Espoo, url

E P Gurov, S I Klimovskiy, A Y Yamnichenko (2006) Suevites in the Ilyinets impact structure, Geologichnyy Zhurnal (1995) = Geological Journal 2006(4), p. 105-116, Natsional'na Akademiya Nauk Ukrayini, Institut Geologichnikh Nauk, Kiev

S Staffieri, A Coletta, M L Battagliere, M Virelli (2019) Ilyinets, Ukraine, Encyclopedic Atlas of Terrestrial Impact Craters, p. 343-345, Springer, Cham, url, doi:https://doi.org/10.1007/978-3-030-05451-9_90