Discovery of microscopic evidence for shock metamorphism at the Serpent Mound structure, south-central Ohio: confirmation of an origin by impact

Shock‐metamorphic microfeatures in chert from the Jebel Waqf as Suwwan impact structure, Jordan

“…Cherts are known to occur in the sedimentary target rocks of a number of terrestrial impact sites, such as Steinheim, Germany (e.g., Buchner and Schmieder 2010); Kentland, Indiana, USA (Koeberl and Sharpton 1993); Newporte, North Dakota, USA (Koeberl and Reimold 1995); Serpent Mound, Ohio, USA (Carlton et al. 1998); Slate Islands, Canada (Dressler et al.…”

“…Cherts are known to occur in the sedimentary target rocks of a number of terrestrial impact sites, such as Steinheim, Germany (e.g., Buchner and Schmieder 2010); Kentland, Indiana, USA (Koeberl and Sharpton 1993); Newporte, North Dakota, USA (Koeberl and Reimold 1995); Serpent Mound, Ohio, USA (Carlton et al 1998); Slate Islands, Canada (Dressler et al 1998); Haughton, Canada (Osinski and Spray 2005); Amelia Creek, Australia (Macdonald et al 2005), and others, as well as in the impact-produced Alamo breccia, Nevada, USA (e.g., Morrow et al 2005). For example, PDFs in quartz have been recognized in recrystallized chert clasts within the Kentland impact breccia, whereas conspicuous fracture patterns similar to those observed in the Jebel Waqf as Suwwan chert occur at Steinheim .…”

Re‐Os isotope systematics in carbonates from Serpent Mound, Ohio: Implications for Re‐Os dating of crustal rocks and the osmium isotopic composition of Ordovician seawater

“…The samples analyzed in this study were obtained from the Ohio Department of Natural Resources Division of Geological Survey (DGS), and include core samples from the Serpent Mound central uplift area (DGS core 3274, 39°01′59″N, 83°24′11″W [ Carlton et al , 1998]) and samples from outside the Serpent Mound structure approximately 11.6 miles west of the central uplift area (core 2626). The samples include Middle‐ and Upper‐Ordovician carbonates and one shale clast, from the following formations: Grant Lake Limestone (Maysvillian, 442–446 Ma [ Martin , 1975; Sloan , 1987; Pope and Martin , 1998]), Lexington Limestone (Mohawkian stage 5b, 445–454 Ma [ Sloan , 1987; Pope and Martin , 1998; Shields et al , 2003]), Black River Group (Blackriveran, 454–458 Ma [ Sloan , 1987; Pope and Martin , 1998]) and Wells Creek (Whiterockian, 460–472 Ma [ Sloan , 1987; Pope and Martin , 1998; Shields et al , 2003]).…”

“…The Serpent Mound structure in southwestern Ohio is an anomalous geologic feature that exhibits many characteristics consistent with a meteorite impact, although the origin of the structure remains highly controversial [ Reidel and Koucky , 1981; Reidel et al , 1982; Carlton et al , 1998; Baranoski et al , 2003]. The structure is characterized by a nearly circular region 8 km in diameter of intensely folded, faulted and brecciated Paleozoic carbonates, sandstones, and shales, with a central core that experienced ∼300 m of vertical uplift followed by erosion [ Reidel and Koucky , 1981; Reidel et al , 1982].…”

“…Although the presence of coesite at Serpent Mound has been reported in the literature [ Cohen et al , 1961, 1962], the identification was based on a single poor quality x‐ray diffraction pattern, and no subsequent studies have been able to confirm the presence of coesite in these samples [ Gaddis , 2001]. A recent study of subsurface core samples from the central uplift area reported planar deformation features (PDFs) in quartz and elevated platinum‐group element abundances in brecciated relative to unbrecciated samples from the Serpent Mound structure, which were interpreted as evidence for a meteorite impact origin for the structure [ Carlton et al , 1998].…”