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Mineralogy of the silt fraction in surficial sediments from the United States mid-Atlantic shelf, slope and rise

Marine Geology

By:
and
https://doi.org/10.1016/0025-3227(92)90015-A

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Abstract

An analysis of the abundances and distributions of silt-sized heavy minerals from the U.S. mid-Atlantic outer continental shelf, slope, and rise shows that heavy minerals constitute a substantially greater weight percent of the silt fraction than that of the sand fraction regardless of environment and sediment texture. Concentrations of silt-sized heavy minerals progressively decrease from the shelf where they average 6.94%, to the slope and rise where they average 4.45% and 3.45%, respectively. A mixed amphibole-garnet+staurolite-epidote-pyroxene association dominates the silt-sized heavy mineral assemblage on the slope and rise; an ilmenite-amphibole-epidote association predominates on the shelf. Downslope trends in detrital nonmicaceous silt-sized heavy mineral abundances are related to hydraulic sorting rather than to chemical weathering. Elevated concentrations of the authigenic pyrite, siderite, dolomite+ankerite, and, possibly, phosphorite in the surficial slope sediment suggests that formation of silt-sized heavy minerals by diagenetic processes is relatively more important there than on the continental shelf or rise. 

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Additional publication details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Mineralogy of the silt fraction in surficial sediments from the United States mid-Atlantic shelf, slope and rise
Series title:
Marine Geology
DOI:
10.1016/0025-3227(92)90015-A
Volume:
103
Issue:
1-3
Year Published:
1992
Language:
English
Contributing office(s):
Woods Hole Coastal and Marine Science Center
Description:
13 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Marine Geology
First page:
185
Last page:
197
Country:
United States