Fluid circulation in the oceanic crust; contrast between volcanic and plutonic regimes

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doi: 10.1029/93JB02035
Author(s): Hart, Stanley R.; Blusztajn, Jerzy; Dick, Henry J. B.; Lawrence, James R.
Author Affiliation(s): Primary:
Woods Hole Oceanographic Institution, Department of Geology and Geophysics, Woods Hole, MA, United States
Other:
University of Houston, United States
Volume Title: Journal of Geophysical Research
Source: Journal of Geophysical Research, 99(B2), p.3163-3173. Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0148-0227
Note: In English. 75 refs.; illus., incl. 3 tables
Summary: Vein carbonates from a variety of ocean crust environments have been analyzed for Sr contents and Sr and oxygen isotopic compositions. Veins from upper crustal lithologies typically have low formation temperatures (<100°C) and form within 10-15 m.y. after crust formation, from solutions containing a basaltic component of very high Ca/Sr (>30 times that of hot smoker vent fluids). Veins from the gabbro lithologies at site 735B show both high (>150°C) and very low (<10°C) formation temperatures. The high-temperature carbonate veins have a large basaltic component (low 87Sr/86Sr) with low Ca/Sr and probably formed before unroofing of this deep crustal block. The low-temperature veins have only a minor basaltic component, and formed after unroofing, but within 0-10 m.y. of crust formation. Hot smoker vent fluids represent the low Ca/Sr limit of fluids recorded by carbonate veins and thus cannot describe the totality of the seawater-ocean crust Ca/Sr exchange budget. Copyright 1994 by the American Geophysical Union.
Year of Publication: 1994
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 05 Petrology, Igneous and Metamorphic; Alkaline earth metals; Calcium; Carbonates; Chemical composition; Crust; Extrusive rocks; Gabbros; Genesis; Hydrothermal conditions; Igneous rocks; Indian Ocean; Isotope ratios; Isotopes; Leg 118; Metals; ODP Site 735; Ocean Drilling Program; Oceanic crust; Oxygen; P-T conditions; Plutonic rocks; Sea water; Solutions; Sr-87/Sr-86; Sr/Ca; Stable isotopes; Strontium; Veins; Volcanic rocks; Water-rock interaction
Coordinates: S324327 S324318 E0571618 E0571557
Record ID: 1995037378
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