Latent volcanic heat and further unique aspects of early diagenetic stratiform copper mineralization in the White Pine-Presque Isle District, northern Michigan
Autor: | Alex C. Brown |
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Rok vydání: | 2017 |
Předmět: |
geography
Mineralization (geology) geography.geographical_feature_category Chalcocite 020209 energy Geochemistry 02 engineering and technology engineering.material 010502 geochemistry & geophysics 01 natural sciences Diagenesis Conglomerate Volcanic rock Geophysics Geochemistry and Petrology 0202 electrical engineering electronic engineering information engineering engineering Bornite Economic Geology Pyrite Pseudomorph Geology 0105 earth and related environmental sciences |
Zdroj: | Mineralium Deposita. 53:721-728 |
ISSN: | 1432-1866 0026-4598 |
Popis: | The curious occurrence of copper-rich early diagenetic sediment-hosted stratiform copper mineralization in the finest-grained facies of Nonesuch greybeds in northern Michigan has been previously attributed to the warming of cupriferous brines in the footwall Copper Harbor Conglomerate by latent volcanic heat from the subjacent Porcupine Volcanics shield volcano. That anomalous footwall warming is employed here to explain other unique aspects of the White Pine-Presque Isle mineralization: the abrupt downward sulfide zoning from disseminated pyrite to chalcocite across the top of the cupriferous zone; the absence of bornite and chalcopyrite in the cupriferous zone proper; and the essential absence of pseudomorphs after pyrite euhedra and framboidal aggregates within the cupriferous zone proper, as well as the relatively coarse-grained character of disseminated chalcocite in the cupriferous zone. |
Databáze: | OpenAIRE |
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