Ikaite pseudomorphs in the Zaire deep-sea fan: An intermediate between calcite and porous calcite

Abstract

Research Article| March 01, 1987 Ikaite pseudomorphs in the Zaire deep-sea fan: An intermediate between calcite and porous calcite J.H.F. Jansen; J.H.F. Jansen 1Netherlands Institute for Sea Research, P.O. Box 59, 1790 AB Den Burg, Texel, Netherlands Search for other works by this author on: GSW Google Scholar C. F. Woensdregt; C. F. Woensdregt 2Institute of Earth Sciences, Utrecht State University, P.O. Box 80.021, 3508 TA Utrecht, Netherlands Search for other works by this author on: GSW Google Scholar M. J. Kooistra; M. J. Kooistra 3Netherlands Soil Survey Institute (Stiboka), P.O. Box 98, 6700 AB Wageningen, Netherlands Search for other works by this author on: GSW Google Scholar S. J. van der Gaast S. J. van der Gaast 4Netherlands Institute for Sea Research, P.O. Box 59, 1790 AB Den Burg, Texel, Netherlands Search for other works by this author on: GSW Google Scholar Author and Article Information J.H.F. Jansen 1Netherlands Institute for Sea Research, P.O. Box 59, 1790 AB Den Burg, Texel, Netherlands C. F. Woensdregt 2Institute of Earth Sciences, Utrecht State University, P.O. Box 80.021, 3508 TA Utrecht, Netherlands M. J. Kooistra 3Netherlands Soil Survey Institute (Stiboka), P.O. Box 98, 6700 AB Wageningen, Netherlands S. J. van der Gaast 4Netherlands Institute for Sea Research, P.O. Box 59, 1790 AB Den Burg, Texel, Netherlands Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1987) 15 (3): 245–248. https://doi.org/10.1130/0091-7613(1987)15<245:IPITZD>2.0.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Tools Icon Tools Get Permissions Search Site Citation J.H.F. Jansen, C. F. Woensdregt, M. J. Kooistra, S. J. van der Gaast; Ikaite pseudomorphs in the Zaire deep-sea fan: An intermediate between calcite and porous calcite. Geology 1987;; 15 (3): 245–248. doi: https://doi.org/10.1130/0091-7613(1987)15<245:IPITZD>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 Translucent brown aggregates of calcium-carbonate crystals have been found in cores from the Zaire deep-sea fan (west equatorial Africa). The aggregates are well preserved but very friable. Upon storage they become yellowish white and cloudy and release water. Chemical, mineralogical (XRD), petrographical, crystal-morphological, and stable-isotope data demonstrate that the crystals have passed through three phases: (1) an authigenic carbonate phase, probably calcium carbonate, which is represented by the external habit of the present crystals; (2) a translucent brown ikaite phase (CaCO3·6H2O), unstable at temperatures above 5 °C; and (3) a phase consisting of calcite microcrystals that are poorly cemented and form a porous mass within the crystal form of the morphologically unchanged first phase. The transformation from the first phase into ikaite was probably a kinetic replacement. The transformation from ikaite into the third phase occurred because of storage at room temperature. The presence of ikaite is indicative of a low-temperature, anaerobic, organic-carbon-rich marine environment. Ikaite is probably the precursor of a great number of porous calcite pseudomorphs, and possibly also of many marine authigenic microcrystalline carbonate nodules. 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.