Ovenshine, A. T. et al. (1975): Bottom water conditions indicated by surface features of detrital silicate grains at Site 276

Leg/Site/Hole:
DSDP 29
DSDP 29 276
Identifier:
1976-016985
georefid

10.2973/dsdp.proc.29.132.1975
doi

Creator:
Ovenshine, A. T.
U. S. Geol. Surv., Menlo Park, Calif., United States
author

Margolis, S. V.
Univ. Hawaii, United States
author

Larson, R. R.
author

Identification:
Bottom water conditions indicated by surface features of detrital silicate grains at Site 276
1975
Initial Reports of the Deep Sea Drilling Project
Texas A & M University, Ocean Drilling Program, College Station, TX, United States
29
Lyttleton, N. Z. to Wellington, N. Z.; March-April 1973
1065-1069
Many of the sand-sized silicate grains recovered during the abortive drilling at Site 276 are polished, iron stained, or coated with black or brown ferruginous material. Examination of eight representative grains with the scanning electron microscope and energy-dispersive X-ray analyzer shows that the ferruginous coatings are of two types: (1) black scale generally preferentially developed in grain surface depressions, and (2) smooth brown sheaths of hydroust(?) iron that completeley envelope grains. The black scale typically contains major amounts of Fe, minor Si, and traces of Al, K, Ca, Ti, and Mn. The polish exhibited by many quartz and feldspar grains results from development of a smooth coating of silica containing minor or trace Fe. The coatings on the detrital silicate grains at Site 276 indicate that the western boundary current, which impinges on the site, is oxygenated, and silica rich. The results of the study show that iron staining, and the formation of siliceous and ferruginous coatings, can occur at oceanic depths (4671 m).
English
Coverage:Geographic coordinates:
North:-46.0000
West:146.0000East: 176.4824
South:-60.0000

Oceanography; Campbell Plateau; chemical composition; coatings; Deep Sea Drilling Project; DSDP Site 276; environmental analysis; geochemistry; grains; interpretation; iron; Leg 29; metals; oxygenation; Pacific Ocean; sediments; silica; silicates; South Pacific; southwest; Southwest Pacific; West Pacific;

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