Large-scale fluid flow patterns within the Corsican Ophiolite

Veins are a ubiquitous feature within the Corsican Ophiolite and attest to the production and movement of fluids at all metamorphic grades. However ox ygen isotope data for the ophiolite indicates that there has been little fl uid flow between different units of the ophiolite. In contrast, oxygen and carbon isotope data for matrix and vein calcite in the ophiolite suggest th at the calcite is probably derived from CO2-bearing fluids from the surroun ding Schistes Lustres. There does not appear to be any fluid flow in the op posite direction, from the ophiolite to the Schistes Lustres. Thus, whilst large-scale fluid flow from the Schistes Lustres to the ophiolite probably occurred, this fluid how was not pervasive. The disequilibration between th e calcite and the whole rock suggests that fluid flow may have been rapid o r confined to fracture systems. (C) 2000 Elsevier Science B.V. All rights r eserved.