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Lower Triassic large sea-floor carbonate cements: Their origin and a mechanism for the prolonged biotic recovery from the end-Permian mass extinction

1999; Geological Society of America; Volume: 27; Issue: 7 Linguagem: Inglês

10.1130/0091-7613(1999)027 2.3.co;2

1943-2682

A.D. Woods, David J. Bottjer, Maria Mutti, Jean M. Morrison,

Geological and Geophysical Studies Worldwide

Research Article| July 01, 1999 Lower Triassic large sea-floor carbonate cements: Their origin and a mechanism for the prolonged biotic recovery from the end-Permian mass extinction Adam D. Woods; Adam D. Woods 1Department of Earth Sciences, University of Southern California, Los Angeles, California 90089-0740, USA Search for other works by this author on: GSW Google Scholar David J. Bottjer; David J. Bottjer 1Department of Earth Sciences, University of Southern California, Los Angeles, California 90089-0740, USA Search for other works by this author on: GSW Google Scholar Maria Mutti; Maria Mutti 1Department of Earth Sciences, University of Southern California, Los Angeles, California 90089-0740, USA Search for other works by this author on: GSW Google Scholar Jean Morrison Jean Morrison 1Department of Earth Sciences, University of Southern California, Los Angeles, California 90089-0740, USA Search for other works by this author on: GSW Google Scholar Geology (1999) 27 (7): 645–648. https://doi.org/10.1130/0091-7613(1999)027 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 Adam D. Woods, David J. Bottjer, Maria Mutti, Jean Morrison; Lower Triassic large sea-floor carbonate cements: Their origin and a mechanism for the prolonged biotic recovery from the end-Permian mass extinction. Geology 1999;; 27 (7): 645–648. doi: https://doi.org/10.1130/0091-7613(1999)027 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 Precipitation of inorganic calcium carbonate is a common occurrence in both modern and ancient marine environments. However, synsedimentary growth of large (>5–10 cm) crystalline carbonate cements directly onto the sea floor has been thought to be limited to the Proterozoic, when seawaters were highly oversaturated with calcium carbonate compared to average Phanerozoic values. Outer shelf to slope deposits of the Lower Triassic Union Wash Formation in east-central California, deposited in oxygen-restricted settings, contain crystalline calcium carbonate cements that appear to have grown directly on the sea floor. Paleoenvironmental analyses indicate that these large calcium carbonate cements grew under conditions that were similar to those proposed for the precipitation of inorganic calcite in the Black Sea. Sulfate reduction of organic matter led to an increase in the amount of bicarbonate ion in deep waters and a concomitant increase in ΣCO2 and alkalinity. Mixing with surface waters led to CO2 degassing, and precipitation of cements from waters supersaturated with calcium carbonate. The presence of these cements and associated facies thus provides evidence of harsh environmental conditions in the Early Triassic at the regional level, which may have acted in concert with biotic effects of the end-Permian mass extinction, as well as similar deleterious conditions (e.g., shelf anoxia) in other regions, to produce a prolonged as well as temporally and geographically variable biotic recovery from this mass extinction. 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.