Ocean crust vein mineral deposition: Rb/Sr ages, U-Th-Pb geochemistry, and duration of circulation at DSDP sites 261, 462 and 516

Journal Article · Mon Dec 01 00:00:00 EST 1986 · Geochim. Cosmochim. Acta; (United States)

DOI:https://doi.org/10.1016/0016-7037(86)90224-3· OSTI ID:6712387

Hart, S R; Staudigel, H

Cation exchange experiments (ammonium acetate and cation resin) on celadonite-smectite vein minerals from three DSDP holes demonstrate selective removal of common Sr relative to Rb and radiogenic Sr. Celadonites show U and Pb contents and Pb isotopic compositions little changed from their basalt precursors, while Th contents are significantly lower. Celadonites thus have unusually high alkali/U,Th ratios and low Th/U ratios. If this celadonite alteration signature is significantly imprinted on oceanic crust as a whole, it will lead to very distinctive Pb isotope signatures for any hot spot magmas which contain a component of aged subducted recycled oceanic crust. Initial Sr isotope ratios of ocean crust vein minerals (smectite, celadonite, zeolite, calcite) are intermediate between primary basalt values and contemporary sea water values, and indicate formation under seawater-dominated systems with effective water/rock ratios of 20-200.

• Research Organization: Massachusetts Institute of Technology, Cambridge
• OSTI ID: 6712387
• Journal Information: Geochim. Cosmochim. Acta; (United States), Vol. 50:12
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
DOLOMITE
ORIGIN
GEOCHEMISTRY
ISOTOPE RATIO
LEAD ISOTOPES
RUBIDIUM ISOTOPES
SEAS
STRONTIUM ISOTOPES
THORIUM ISOTOPES
URANIUM ISOTOPES
ACTINIDE ISOTOPES
ALKALI METAL ISOTOPES
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METAL COMPOUNDS
CALCIUM CARBONATES
CALCIUM COMPOUNDS
CARBON COMPOUNDS
CARBONATE MINERALS
CARBONATES
CHEMISTRY
ISOTOPES
MAGNESIUM CARBONATES
MAGNESIUM COMPOUNDS
MINERALS
OXYGEN COMPOUNDS
SURFACE WATERS
580400* - Geochemistry- (-1989)