Diamonds from the iridium-rich K-T boundary layer at Arroyo el Mimbral, Tamaulipas, Mexico

Abstract

Research Article| November 01, 1997 Diamonds from the iridium-rich K-T boundary layer at Arroyo el Mimbral, Tamaulipas, Mexico R. M. Hough; R. M. Hough 1Planetary Sciences Research Institute, The Open University, Milton Keynes, MK7 6AA, United Kingdom Search for other works by this author on: GSW Google Scholar I. Gilmour; I. Gilmour 1Planetary Sciences Research Institute, The Open University, Milton Keynes, MK7 6AA, United Kingdom Search for other works by this author on: GSW Google Scholar C. T. Pillinger; C. T. Pillinger 1Planetary Sciences Research Institute, The Open University, Milton Keynes, MK7 6AA, United Kingdom Search for other works by this author on: GSW Google Scholar F. Langenhorst; F. Langenhorst 2Institut für Mineralogie, Museum für Naturkunde, Humboldt-Universität zu Berlin, Invalidenstrasse 43, D-10115 Berlin, Germany Search for other works by this author on: GSW Google Scholar A. Montanari A. Montanari 3Osservatorio Geologico di Coldigioco, I-62020, Frontale di Apiro (MC), Italy4École des Mines de Paris, Boulevard Saint-Michel, 75272, Paris Cedex 06, France Search for other works by this author on: GSW Google Scholar Author and Article Information R. M. Hough 1Planetary Sciences Research Institute, The Open University, Milton Keynes, MK7 6AA, United Kingdom I. Gilmour 1Planetary Sciences Research Institute, The Open University, Milton Keynes, MK7 6AA, United Kingdom C. T. Pillinger 1Planetary Sciences Research Institute, The Open University, Milton Keynes, MK7 6AA, United Kingdom F. Langenhorst 2Institut für Mineralogie, Museum für Naturkunde, Humboldt-Universität zu Berlin, Invalidenstrasse 43, D-10115 Berlin, Germany A. Montanari 3Osservatorio Geologico di Coldigioco, I-62020, Frontale di Apiro (MC), Italy4École des Mines de Paris, Boulevard Saint-Michel, 75272, Paris Cedex 06, France Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1997) 25 (11): 1019–1022. https://doi.org/10.1130/0091-7613(1997)025<1019:DFTIRK>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation R. M. Hough, I. Gilmour, C. T. Pillinger, F. Langenhorst, A. Montanari; Diamonds from the iridium-rich K-T boundary layer at Arroyo el Mimbral, Tamaulipas, Mexico. Geology 1997;; 25 (11): 1019–1022. doi: https://doi.org/10.1130/0091-7613(1997)025<1019:DFTIRK>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Diamonds, up to 30 µm in size, were found in the iridium-rich layer from the K-T boundary site at Arroyo El Mimbral and the spherule bed from Arroyo El Peñon, northeastern Mexico. Stepped heating experiments indicate two or more isotopically distinct diamond components with carbon isotopic compositions characteristic of a mixture of carbon sources. The diamonds' crystal form is cubic—not the hexagonal polymorph of diamond, lonsdaleite, which has been used previously to infer formation due to shock transformation of graphite. The size, crystallography, and mineralogic associations of K-T diamonds are similar to those of impact-produced diamonds from the Ries crater in Germany where both shock transformation of graphite and a mode of formation by condensation from a vapor plume have been inferred. The discovery of impact-produced diamonds in association with high Ir contents for these sediments supports their impact origin, K-T age, and the inference that their source was from the buried impact crater of Chicxulub on the Yucatan peninsula, Mexico. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.