Obolon - Hypervelocity Impact Crater

Alternate Names
Local Language
Coordinates 49° 34' 19" N; 32° 55' 34" E
Notes
  1. Near the village of Obolon in the Poltava Province, on the NE flank of the Ukrainian Shield.
Country Ukraine
Region Poltava
Date Confirmed 1977
Notes
  1. PDFs in quartz and shatter cones found (Val'ter et al., 1977).
Buried? Yes
Notes
  1. Filled and buried by up to 350 m of Middle Jurassic to Quaternary sandstones, siltstones and shales (Val'ter et al., 1977).
Drilled? Yes
Notes
  1. Two holes were drilled through 270 m of Palaeozoic sedimentary cover and penetrate (the first, to depth of 860 m, the second, to a depth of 1033 m) Jurassic sedimentary fill, allogenic breccia and into fractured Proterozoic crystalline basement (Val'ter et al., 1977).
Target Type Mixed
Notes
  1. Lower Proterozoic gneisses and granitoids (Val'ter et al., 1977). Lower Triassic clays and sandstones and Middle Carboniferous claystones, sandstones and limestones (Masaitis et al., 1976). Formed in a shallow marine basin (Gurov and Gurova, 1995). Carboniferous and Lower Triassic platform sediments covered the crystalline, Precambrian basement to a depth of ~0.3km (Gurov et al., 2009).
Sub-Type Claystone, Gneiss, Granitoid, Limestone, Sandstone
Apparent Crater Diameter (km) 19 km
Age (Ma) 169 ± 7
Notes :
  1. 169 ± 7 Ma determined by K-Ar of impact melt rocks (Gurov et al., 2009). Additional age constraints: 160 ± 15 Ma based on stratigraphy (Krayushkin et al. 1989).

Method :
  1. K-Ar
Impactor Type Iron
Notes
  1. Weakly magnetic metallic particles containing a phase equivalent in structure to taenite and kamacite (Val'ter et al., 1972).

Advanced Data Fields

Notes

Erosion
4
  1. Rim may be largely eroded, with partial preservation of the crater-fill products (Val'ter et al., 1977).
Final Rim Diameter
Unknown
Apparent Rim Diameter
19 km
  1. Dimensions are ~19 km in E-W direction and ~17 km in N-S direction for an average diameter of 18 km (Gurov et al., 2009). Dimensions from diagram in (Masaitis et al., 1980). Diameter found in (Gurov and Gurova, 1995).
Rim Reliability Index
2
  1. Consists of a central uplift surrounded by an annular depression partially filled with breccia (Masaitis et al., 1980).
Crater Morphology
Complex
Central Uplift Diameter
5km
Central Uplift Height
250 m
Uplift Reliability Index
Structural Uplift
Unknown
Thickness of Seds
0.3
Target Age
Precambrian Palaeozoic Mesozoic
Marine
No
Impactor Type
Iron
  1. Weakly magnetic metallic particles containing a phase equivalent in structure to taenite and kamacite (Val'ter et al., 1972).
Other Shock Metamorphism
Maskelynite Impact diamonds
  1. Maskelynite (Masaitis et al., 1980) and impact diamonds (Gurov et al., 1995).
Shatter Cones
Yes
  1. Shatter cones, 4 to 5 cm in size, occur in fragments of Carboniferous limestone and crystalline basement rocks (from a within crater drillcore; (Val'ter et al., 1977). Shatter cones occur in large clasts of crystalline rocks (i.e., gneiss and granite) from the allogenic breccia (i.e., within-crater impact breccia) (Gurov et al., 2009).
Planar Fractures
No
Planar Deformation Features
Yes
  1. PDF in quartz grains (Val'ter et al., 1977) (Masaitis et al., 1980).
Diaplectic Glass
No
Coesite
Yes
  1. (Gurov et al., 1978) (Masaitis et al., 1980) Found via X-ray diffractometry of shockmetamorphosed quartz fractions after partial solution in hydrofluoric acid (Gurov et al. 1980).
Stisovite
No
Crater Fill
LB, MB
  1. Polymict lithic breccias occur, as well as melt (glass)-bearing breccias (referred to as suevites). Found in a drill core at about 3 km west of the crater center (Valter et al., 1977) (Gurov & Gurova, 1995) (Masaitis, 1999) (Schmieder & Buchner, 2008). A drill core close to the crater rim contains a two-layer ejecta stratigraphy: 22.5 m of lithic breccias overlain by 14 m of melt-bearing breccias (Gurov et al., 2009).
Proximal Ejecta
LB, MB
Distal Ejecta
Dykes
Volume of Melt
Depth of Melting

References

Spot a missing reference? Submit Reference

A A Val'ter, Y P Gurov, V A Ryabenko (1977) The Obolon' fossil meteorite crater (astrobleme) on the northeast flank of the Ukrainian Shield, Doklady. Earth Science Sections 232(1-6), p. 37-40, Scripta Publishing, Silver Spring, MD, url

A A Valter, V A Ryabenko (1977) Explosion Craters on the Ukrainian Shield, Kiev: Naukova Dumka

E P Gurov, E P Gurova, R B Rakitskaya (1995) Impact diamonds in the craters of the Ukrainian shield (abstract), Meteoritics 30, p. 515-516

E P Gurov, E P Gurova (1995) Impact-melt composition of the Obolon crater: Chlorine as a possible indicator of the submarine crater formation, Meteoritics & Planetary Science 30(5), Derek W G Sears (ed.), p. 515, Meteoritical Society, Fayetteville, AR, url

Y P Gurov, O P Gurova, R B Rakitskaya, A Y Yamnichenko (1997) Obolonskaya impact structure; some petrochemical and structural peculiarities of impactites, Geologichnyy Zhurnal (1995) = Geological Journal 1997(1-2), p. 114-118, Natsional'na Akademiya Nauk Ukrayini, Institut Geologichnikh Nauk, Kiev, url

J G Spray, S P Kelley, D B Rowley (1998) Evidence for a late Triassic multiple impact event on Earth, Nature 392(6672), p. 171-173, url, doi:10.1038/32397

Y P Gurov, Y P Gurova, A Y Yamnichenko, Y A Chernenko (2007) Rocks in the Obolon impact crater and adjacent areas, Geologichnyy Zhurnal (1995) = Geological Journal 2007(4), p. 48-59, Natsional'na Akademiya Nauk Ukrayini, Institut Geologichnikh Nauk, Kiev, url

E Gurov, E Gurova, Y A Chernenko, A Y Yamnichenko (2009) The Obolon impact structure, Ukraine, and its ejecta deposits, Meteoritics & Planetary Science 44(3), p. 389-404, Meteoritical Society, Fayetteville, AR, url, doi:http://dx.doi.org/10.1111/j.1945-5100.2009.tb00740.x

A A Valter, M S Maschak (2012) About the same geological age and possible simultaneous formation of Obolon' (Ukraine) and Puchezch-Katun' (Russia) impact structures, Abstracts of Papers Submitted to the Lunar and Planetary Science Conference 43, p. Abstract 1080, Lunar and Planetary Science Conference, Houston, TX