[meteorite-list] K/T Boundary Clay at Stevns Klint
From: Paul H. <oxytropidoceras_at_meteoritecentral.com>
Date: Tue, 16 Mar 2010 10:25:41 -0500 Message-ID: <20100316112541.0793B.1049545.imail_at_eastrmwml28> In http://six.pairlist.net/pipermail/meteorite-list/2010-March/062190.html , (?K/T Boundary Clay?), Ed Majden wrote: ?There is some dispute with this material, as some think it may be of volcanic origin, rather than a meteorite impact, K/T boundary layer material? The volcanic origin is an old hypothesis that has been largely abandoned. The Fish Clay at Klint now is largely regarded to consist of terrigenous sediments that accumulated in the absence of biogenic carbonate during the aftermath of the terminal Cretaceous impact. There is an extraterrestrial component that has been mixed with detrital terrestrial sediments by bioturbation and reworking and redeposition of pre-existing sediments. For example, Premovi (2009) concluded: 1. ?IIIA smectite is probably mainly detrital and redeposited from adjacent coastal and/or marine areas.? 2. ?The goethite-/FeS2-rich microspherules of layer IIIA were initially enriched in Fe-oxides which were replaced by goethite or FeS2 during early diagenesis and 3. ?Most of the microspherules and glasses of layer IIIA are also probably detrital and simultaneously redeposited with the smectite.? The Fish Clay contains goethite-rich microspherules. Currently, are argued as being authigenic in origin and unrelated to any Cretaceous-Paleogene ejecta. Premovi (2009) regards these microspherules to have been created by pseudomorphic replacement of FeS2 rich biogenic spherules. Locality: Stevns Klint, Description of a Danish GeoSite http://geosites.dk/lokaliteter/sjaelland/stevns_klint.html Some papers about this are: Bauluz, B., D. R. Peacor, and W. C. Elliott, Coexisting Altered Glass and Fe-Ni Oxides at the Cretaceous- Tertiary Boundary, Stevns Klint (Denmark): Direct Evidence of Meteorite Impact,? Earth Planet. Science Letters. vol. 182, pp. 127?136. Christensen, L., S. Fregerslev, A. Simonsen, and J. Thiede, 1973, Sedimentology and depositional environment of Lower Danian fish clay from Stevns Klint, Denmark. Bulletin of the geological Society of Denmark. vol. 22, pp. 193-212. http://2dgf.dk/xpdf/bull22-03-193-212.pdf Drits, V. A., H. Lindgreen, B. A. Sahaov, H. J. Jakonson, and B. B. Zviagina, 2004, The detailed structure and origin of clay minerals at the Cretaceous/Tertiary boundary, Stevns Klint (Denmark). Clay Minerals. vol. 39, no. 4, pp. 367-390; DOI: 10.1180/0009855043940141 http://claymin.geoscienceworld.org/cgi/content/abstract/39/4/367 http://cat.inist.fr/?aModele=afficheN&cpsidt=16450276 Ekdale, A. A., and R. G. Bromley, 1984, Sedimentology and ichnology of the Cretaceous-Tertiary boundary in Denmark; implications for the causes of the terminal Cretaceous extinction. Journal of Sedimentary Research. vol. 54, no. 3, p. 681-703 http://jsedres.sepmonline.org/cgi/content/abstract/54/3/681 Note: The above paper is a strong supporter of volcanic origin. Hart, M. B., S. E. Feist, G. D. Price and M. J. Leng, 2004, Reappraisal of the K/T boundary succession at Stevns Klint, Denmark. Journal of the Geological Society. vol. 161, no. 5, pp. 885-892; http://jgs.lyellcollection.org/cgi/content/abstract/161/5/885 Kastner, M., F. Asaro, H. V. Michel, W. Alvarez, and L. W. Alvarez, 1984, The Precursor of the Cretaceous-Tertiary Boundary Clays at Stevns Klint, Denmark, and DSDP Hole 465A. Science. vol. 226. no. 4671, pp. 137-143 DOI: 10.1126/science.226.4671.137 http://www.sciencemag.org/cgi/content/abstract/226/4671/137 ?Formation from impact rather than from volcanic glass is supported by its major element chemistry.? Ortega-Huertas, M., F. Martinez-Ruiz, I. Palomo-Delgado, and H. Camley, 2002, Review of the mineralogy of the Cretaceous-Tertiary boundary clay: evidence supporting a major extraterrestrial catastrophic event. Clay Minerals. vol. 37, no. 3, pp. 395-411; DOI: 10.1180/0009855023730054 http://claymin.geoscienceworld.org/cgi/content/abstract/37/3/395 Premovi, P. I., 2004, Cretaceous-Tertiary boundary deposits in Denmark: A diachroneity. Journal Serbian Chemical Society. vol. 71, no.7, pp. 793-806. http://www.doiserbia.nb.rs/img/doi/0352-5139/2004/0352-51390407555P.pdf Premovic, P. I., 2009, The conspicuous red ?impact? layer of the Fish Clay at H?jerup (Stevns Klint, Denmark). Geochemistry International. vol. 47, no. 5, pp. 513-521. http://www.springerlink.com/content/2tq1551k02800715/ ?Smectite of the red layer of the KPB section at H?jerup is probably detrital and redeposited from adjacent coastal or marine areas. This clay mineral is likely mixed with a small amount of smectite derived from impact glasses. Most of the microspherules and nano-size glasses of the red layer at Hojerup are probably detrital and simultaneously redeposited with smectite.? Premovi, P. I., B. Z. Todorovi, and M. S. Pavlovi, 2007, Cretaceous Paleogene boundary Fish Clay at Hojerup (Stevns Klint, Denmark): trace metals in kerogen. Bulletin de la Societe Geologique de France. vol. 178, no. 5, p. 411-421; DOI: 10.2113/gssgfbull.178.5.411 http://bsgf.geoscienceworld.org/cgi/content/abstract/178/5/411 http://www.doiserbia.nb.rs/img/doi/0352-5139/2008/0352-51390804453P.pdf Premovic, P. I., B. Z. Todorovic, and M. S. Pavlovic, 2008, Cretaceous-Paleogene boundary (KPB) Fish Clay at Hojerup (Stevns Klint, Denmark): Ni, Co, and Zn of the black marl Geologica Acta, vol. 6, no. 4, pp. 369-382. DOI: 10.1344/105.000000264 http://www.geologica-acta.com/pdf/vol0604a07.pdf Premovi, P. I., M. M. Krsmanovic, B. Z. Todorovi, M. S. Palovi, N. D. Nikolic, and D. M. Djordjevi, 2006, Geochemistry of the Cretaceous-Tertiary boundary (Fish Clay) at Stevns Klint (Denmark): Ir, Ni and Zn in kerogen. Journal Serbian Chemical Society. vol. 71, no.7, pp. 793-806. http://www.doiserbia.nb.rs/img/doi/0352-5139/2006/0352-51390607793P.pdf Surlyk, F., T. Damholt, and M. Bjerager, 2006, Stevns Klint, Denmark: Uppermost Maastrichtian Chalk, Cretaceous? Tertiary Boundary, and Lower Danian Bryozoan Mound Complex. Bulletin of the Geological Society of Denmark. vol. 4, pp. 1?48. http://2dgf.dk/xpdf/bull54.pdf Yours, Paul H. Received on Tue 16 Mar 2010 11:25:41 AM PDT |
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