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Science 29 October 1965:
Vol. 150. no. 3696, pp. 605 - 610
DOI: 10.1126/science.150.3696.605
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Articles

Igneous Rocks of the Indian Ocean Floor

Celeste G. Engel 1, Robert L. Fischer 2, and A. E. J. Engel 3

1 U. S. Geological Survey, La Jolla
2 Scripps Institution of Oceanography
3 Department of Earth Sciences, University of California, La Jolla 92038

Four dredge hauls from near the crest and from the eastern flank of the seismically active Mid-Indian Ocean Ridge at 23° to 24°S, at depths of 3700 to 4300 meters, produced only low-potassium tholeiitic basalt similar in chemical and mineralogic composition to basalts characteristic of ridges and rises in the Atlantic and Pacific oceans. A fifth haul, from a depth of 4000 meters on the lower flank of a seamount on the ocean side of the Indonesian Trench, recovered tholeiitic basalt with higher concentrations of K and Ti and slightly lower amounts of Si and Ca than the typical-oceanic tholeiite of the ridge. The last sample is vesicular, suggesting depression of the area since the basalt was emplaced. Many of the rocks dredged are variously decomposed and hydrated, but there is no evidence of important chemical modification toward conversion of the lava flows to spilite during extrusion or solidification.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Lherzolite, Anorthosite, Gabbro, and Basalt Dredged from the Mid-Indian Ocean Ridge.
C. G. Engel, C. G. Engel, and R. L. Fisher (1969)
Science 166, 1136-1141
   Abstract »    PDF »
Genetic Relations of Oceanic Basalts as Indicated by Lead Isotopes.
M. Tatsumoto and M. Tatsumoto (1966)
Science 153, 1094-1101
   Abstract »    PDF »


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