Miller, D. Jay and Kelley, J. (2004): Low-temperature alteration of basalt over time; a synthesis of results from Ocean Drilling Program Leg 187

Leg/Site/Hole:
ODP 187
Identifier:
2005-011569
georefid

10.2973/odp.proc.sr.187.206.2004
doi

Creator:
Miller, D. Jay
Texas A&M University, Department of Geology and Geophysics, College Station, TX, United States
author

Kelley, J.
Oregon State University, United States
author

Identification:
Low-temperature alteration of basalt over time; a synthesis of results from Ocean Drilling Program Leg 187
2004
In: Pedersen, Rolf B., Christie, David M., Miller, D. Jay, Balzer, Vaughn G., Einaudi, Florence, Gee, M. A. Mary, Hauff, Folkmar, Kempton, Pamela D., Liang, Wen-Tzong, Lysnes, Kristine, Meyzen, Christine M., Pyle, Douglas G., Russo, Christopher J., Sato, Hiroshi, Thorseth, Ingunn H., Proceedings of the Ocean Drilling Program; scientific results; mantle reservoirs and migration associated with Australian Antarctic rifting; covering Leg 187 of the cruises of the drilling vessel JOIDES Resolution; Fremantle, Australia, to Fremantle, Australia, Sites 1152-1164; 16 November 1999-10 January 2000
Texas A&M University, Ocean Drilling Program, College Station, TX, United States
187
Shipboard studies during Ocean Drilling Program Leg 187 (Australian Antarctic Discordance, AAD) suggested that there was no discernible coincidence between the interpreted age of rocks recovered and the intensity of alteration observed. Samples from the oldest sites occupied appeared to exhibit the least overall effects of alteration, and the intensity of alteration varied from site to site. Previous investigations of low-temperature alteration in oceanic basement samples have been restricted by the myopic perspective provided by single drill holes or dredge collections. Combining core samples from Leg 187 and dredge samples from the AAD collection at Oregon State University (USA) offers the unique opportunity to investigate mineral and bulk chemical changes attending alteration of basalt over a range of ages from 0 to 28 Ma. Results of this research indicate that there is a general increase in the intensity of alteration as the basalts age and move off axis, but that this relationship is somewhat veiled by the dominating control on alteration intensity dictated by variations in permeability.
English
Coverage:Geographic coordinates:
North:-41.1500
West:126.0000East: 135.0000
South:-46.0000

Igneous and metamorphic petrology; alteration; Australian-Antarctic discordance; basalts; Cenozoic; cores; glasses; hydrothermal alteration; ICP mass spectra; igneous rocks; Indian Ocean; Leg 187; low temperature; mass spectra; metasomatism; Mid-Indian Ridge; mineral composition; Ocean Drilling Program; permeability; Quaternary; Southeast Indian Ridge; spectra; temperature; Tertiary; volcanic rocks; whole rock;

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