Formation of deep-sea chert; role of the sedimentary environment

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doi: 10.1002/9781444304855.ch15
Author(s): Lancelot, Yves
Author Affiliation(s): Primary:
Lamont-Doherty Geological Observatory, Palisades, New York, 10964, United States
Volume Title: Special Publication of the International Association of Sedimentologists
Source: Special Publication of the International Association of Sedimentologists, 1, p.349. Publisher: Blackwell, Oxford, International. ISSN: 0141-3600. ISBN: 978-1-444-30485-5 CODEN: SPISDS
Note: In English
Summary: The mineralogy of chert recovered in the central Pacific at several Deep Sea Drilling sites appears strongly influenced by the lithology of host sediments. Chert in clayey sediments is porcelanitic, while quartzose chert nodules are found exclusively in calcareous oozes and rocks. This composition is related to the amount of clay minerals in the sediment. Poor permeability and abundant foreign cations in clay-rich layers lead to precipitation of disordered cristobalite while good circulation and lack of exchangeable cations in carbonates favour direct precipitation of quartz. Chert formation results from a transfer from the highly soluble amorphous silica of biogenic origin into much less soluble crystalline forms. This transfer may be controlled by silico-aluminates present in the sediments. In most of the post-Lower Tertiary sediments these minerals might have been able to take up enough silica from interstitial waters to prevent chert formation. Abstract Copyright (1974), The International Association of Sedimentologists.
Year of Publication: 1974
Research Program: DSDP Deep Sea Drilling Project
Key Words: 06 Petrology, Sedimentary; Amorphous; Calcareous; Central; Chemically precipitated rocks; Chert; Clastic rocks; Clastic sediments; Clay; Cristobalite; Deep Sea Drilling Project; Diagenesis; Environment; Framework silicates; Marine; Mineralogy; Nodules; Ooze; Pacific Ocean; Porcellanite; Quartz; Sedimentary petrology; Sedimentary rocks; Sediments; Silica; Silica minerals; Silicates
Record ID: 1975026002
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute.

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