Mississippi Valley-type sulfide mineralization, Sheffield Channel, and implications for Delaware basin evolution

Conference · Sat Mar 01 04:00:00 EST 1986 · Am. Assoc. Pet. Geol., Bull.; (United States)

OSTI ID:7013681

Mazzullo, S J

A zinc-lead deposit of Mississippi Valley-type character occurs in the subsurface (1312 m) Sheffield channel, in basal Leonardian (Permian) dolomites along the southern Central Basin platform, Pecos County, Texas. The host dolomites represent shelf-marginal facies that pass landward into an inner shelf-carbonate/evaporite province (Lower Clear Fork), and abruptly seaward adjoining a prominent basement fault into equivalent basinal facies of the Bone Spring formation. Zoned sphalerite, accessory gypsum, and abundant pyrite are the major sulfide species present in the deposit. Sulfur isotope and fluid inclusion data, in conjunction with reconstructions of Delaware basin geothermal history, suggest that sulfide mineralization occurred during or subsequent to a burial-temperature maxima in the late Mesozoic to early Tertiary. Mineralizing fluids appear to have been derived from basinal rocks older than the Bone Spring (3355-m depths), and migrated upward along the platform bounding fault system. Sulfide precipitation at temperatures of 96/sup 0/ +/- 10/sup 0/C resulted from mixing of basinal brines and ambient host fluids that were charged with sulfur derived locally. Burial paragenesis sequentially involved a major period of pre-ore dolomitization, minor carbonate dissolution, complex sulfide-mineral emplacement, and post-ore dolomite and calcite cementation. Similar carbonate diagenetic sequences found elsewhere in the Delaware basin may be evidence of a common regional hydrodynamic history of the basin.

• OSTI ID: 7013681
• Report Number(s): CONF-8604186-
• Conference Information: Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Journal Volume: 70:3
• Country of Publication: United States
• Language: English

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CARBON COMPOUNDS
CARBONATE MINERALS
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