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Heavy-mineral variability in the Baltimore Canyon trough area

March 1, 1978

Petrographic analyses of bottom sediments from 87 stations within a relatively large subarea (1700 square kilometers) define the local variability and the distributional processes of heavy minerals in the Baltimore Canyon Trough area (13500km2 ). Of the 29 mineral groups that were identified, those most diagnostic of differences between stations were opaque minerals, garnet, hornblende, orthopyroxene, other amphiboles, and staurolite. Some of the common components cannot be used to define areal trends. The association of minerals by their specific gravities reflects the modern reworking and sorting of sediments in this area. The poor correlation between mineral abundance and the ridge-and trough topography suggests either that our analyses and samples did not resolve bathymetrically induced changes or that smaller bed forms (such as ripples) largely control the heavy-mineral distribution. Data from this study provide a baseline for evaluating manmade disturbances of the bottom sediments and show that relatively large changes in the heavy mineral composition can take place over small distances on this part of the Continental Shelf.

Citation Information

Publication Year 1978
Title Heavy-mineral variability in the Baltimore Canyon trough area
Authors H. J. Knebel, David C. Twichell
Publication Type Article
Publication Subtype Journal Article
Series Title Journal of Research of the U.S. Geological Survey
Index ID 70232935
Record Source USGS Publications Warehouse