Geological perspectives of metalliferous sulfides: offshore exploration in the Gorda Ridge area

Conference · Tue May 01 04:00:00 EDT 1984 · Proc., Annu. Offshore Technol. Conf.; (United States)

OSTI ID:6451790

Beauchamp, R G

The Gorda Ridge is a submarine mountain range located between 86 nautical miles (160km) and 178 nautical miles (330km) off the coasts of northern California and Oregon. Preliminary results from recent investigations of samples from the Ridge suggest both low and high temperature hydrothermal activity. Sea Marc II (Sea Mapping and Remote Characterization) maps of the Gorda Ridge assist in the identification of the central rift valley, seamounts, continuous and discontinuous ridges, and ridge offsets. Volcanic samples dredged from the Gorda Ridge contain traces of sulfide minerals (e.g., pyrite, pyrrhotite, and sphalerite). Fresh volcanic glass occurred in most of the dredge samples. Other samples showed evidence of hydrothermal activity including the occurrence of geothite and nontronite. Manganese minerals todorokite and birnessite occur as encrustations over basalt. Abundant worm tubes were found in association with nontronite. Agglutinated benthic foramifera, some with tests constructed of volcanic glass, are abundant and found in a majority of dredge hauls.

• Research Organization: Minerals Management Service, U.S. Interior Dept.
• OSTI ID: 6451790
• Report Number(s): CONF-8405208-
• Conference Information: Journal Name: Proc., Annu. Offshore Technol. Conf.; (United States) Journal Volume: 3
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
423000* -- Engineering-- Marine Engineering-- (1980-)
ANIMALS
CHALCOGENIDES
DREDGING
ELEMENTS
ENERGY SYSTEMS
EXPLORATION
FORAMINIFERA
GEOLOGICAL SURVEYS
GEOTHERMAL SYSTEMS
HYDROTHERMAL SYSTEMS
IGNEOUS ROCKS
INVERTEBRATES
MAPS
MARINE SURVEYS
METALS
MICROORGANISMS
MINERAL RESOURCES
OFFSHORE SITES
PACIFIC OCEAN
PROTOZOA
RESOURCES
ROCKS
SAMPLING
SARCODINA
SEAS
SULFIDES
SULFUR COMPOUNDS
SURFACE WATERS
SURVEYS
VOLCANIC ROCKS