Weathered spheroids in a Cretaceous/Tertiary boundary shale at Woodside Creek, New Zealand

Abstract

Research Article| October 01, 1985 Weathered spheroids in a Cretaceous/Tertiary boundary shale at Woodside Creek, New Zealand Robert R. Brooks; Robert R. Brooks 1Department of Chemistry, Biochemistry and Biophysics, Massey University, Palmerston North, New Zealand Search for other works by this author on: GSW Google Scholar Paul L. Hoek; Paul L. Hoek 1Department of Chemistry, Biochemistry and Biophysics, Massey University, Palmerston North, New Zealand Search for other works by this author on: GSW Google Scholar Roger D. Reeves; Roger D. Reeves 1Department of Chemistry, Biochemistry and Biophysics, Massey University, Palmerston North, New Zealand Search for other works by this author on: GSW Google Scholar R. Cleland Wallace; R. Cleland Wallace 2Department of Soil Science, Massey University, Palmerston North, New Zealand Search for other works by this author on: GSW Google Scholar James H. Johnston; James H. Johnston 3Department of Chemistry, Victoria University, Wellington, New Zealand Search for other works by this author on: GSW Google Scholar Douglas E. Ryan; Douglas E. Ryan 4Trace Analysis Research Centre, Dalhousie University, Halifax, Nova Scotia B3H 4JI, Canada Search for other works by this author on: GSW Google Scholar Jiri Holzbecher; Jiri Holzbecher 4Trace Analysis Research Centre, Dalhousie University, Halifax, Nova Scotia B3H 4JI, Canada Search for other works by this author on: GSW Google Scholar John D. Collen John D. Collen 5Department of Geology, Victoria University, Wellington, New Zealand Search for other works by this author on: GSW Google Scholar Author and Article Information Robert R. Brooks 1Department of Chemistry, Biochemistry and Biophysics, Massey University, Palmerston North, New Zealand Paul L. Hoek 1Department of Chemistry, Biochemistry and Biophysics, Massey University, Palmerston North, New Zealand Roger D. Reeves 1Department of Chemistry, Biochemistry and Biophysics, Massey University, Palmerston North, New Zealand R. Cleland Wallace 2Department of Soil Science, Massey University, Palmerston North, New Zealand James H. Johnston 3Department of Chemistry, Victoria University, Wellington, New Zealand Douglas E. Ryan 4Trace Analysis Research Centre, Dalhousie University, Halifax, Nova Scotia B3H 4JI, Canada Jiri Holzbecher 4Trace Analysis Research Centre, Dalhousie University, Halifax, Nova Scotia B3H 4JI, Canada John D. Collen 5Department of Geology, Victoria University, Wellington, New Zealand Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1985) 13 (10): 738–740. https://doi.org/10.1130/0091-7613(1985)13<738:WSIACB>2.0.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Robert R. Brooks, Paul L. Hoek, Roger D. Reeves, R. Cleland Wallace, James H. Johnston, Douglas E. Ryan, Jiri Holzbecher, John D. Collen; Weathered spheroids in a Cretaceous/Tertiary boundary shale at Woodside Creek, New Zealand. Geology 1985;; 13 (10): 738–740. doi: https://doi.org/10.1130/0091-7613(1985)13<738:WSIACB>2.0.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 Three types of spheroids are found in the iridium-rich shale layer at the Cretaceous/Tertiary boundary at Woodside Creek, South Island, New Zealand. Two of the types (A and B) consist mainly of microcrystalline goethite, whereas the third type (F) contains an appreciable quantity of hematite. There is a strong correlation between the iridium content of the spheroids and their matrices and the concentrations of other siderophiles such as chromium, cobalt, iron, and nickel. A similar pattern was observed for the chalcophiles arsenic, copper, and zinc. It is suggested that spheroids of types A and B are weathering products derived from diagenetic pyrite clumps and that type F, which contains hematite, represents a further stage in the weathering process and was derived from goethite. The original pyritic material could have readily scavenged arsenic and other siderophiles from the sea-water column under organic-rich reducing conditions at the end of the Cretaceous, and the siderophiles including iridium could have been incorporated into the original meteoritic material. It was concluded, therefore, that types A, B, and F spheroids are weathering products and do not represent original meteoritic material. 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.