Abstract
We present a paleohydrologic model of stratiform copper mineralization in the Keweenawan Midcontinent Rift System. We attribute regional-scale mineralization in the basal facies of the transgressive Nonesuch Formation to compaction of the subjacent fluvial Copper Harbor Formation in response to deposition of the superjacent fluvial Freda Formation. The transgressive sequence focused compaction-driven discharge of cupriferous brines in the Copper Harbor Formation to the basin margins, where leakage into the overlying Nonesuch Formation drove redox-controlled copper precipitation. Intense fluid focusing atop a basement high formed the White Pine ore body. The timing of this simulated event is consistent with the inferred timing of stratiform mineralization. Our model satisfies mass-balance constraints at White Pine for a geologically plausible range of permeabilities and copper concentrations. (C) 2000 Elsevier Science B.V. All rights reserved.
Original language | English (US) |
---|---|
Pages (from-to) | 239-243 |
Number of pages | 5 |
Journal | Journal of Geochemical Exploration |
Volume | 69-70 |
DOIs | |
State | Published - Jun 2000 |
Event | Geofluids III - 3rd International Conference on Fluid Evolution, Migration and Interaction in Sedimentary Basins and Orogenic Belts - Barcelona, Spain Duration: Jul 12 2000 → Jul 14 2000 |
Keywords
- Midcontinent Rift System
- Numerical modeling
- Paleohydrogeology
- Stratiform copper deposit