Characterization of diagenetic fluids of the Upper Jurassic-Lower Cretaceous carbonate platform of the Galicia margin at Ocean Drilling Program Site 639: evidence for dolomitization by hypersaline brines

Abstract

Describes a carbonate platform on a tilted fault block along the Galicia margin off the northwest Iberian Peninsula, composed primarily of a sequence of dolomite overlying limestone. The dolomite formed during shallow burial from sulfate-bearing, hypersaline brines at slightly elevated temperatures. Hypersalinity is interpreted to be associated with a nearby, shallow restricted basin that formed during rifting of the Iberian margin from Newfoundland. The dolomitization of the platform is therefore a by-product of the rifting. -from Authors