Geology of the El Recodo Cu-Mo prospect, SE. Cordille-ra central, Dominican Republic
The main intrusive phase in the El Recodo area is a small stock of leucocractic quartz diorite which intrudes an unmetamorphosed Upper Cretaceous sequence of andesites, tuffs, agglomerates, breccias and minor interbedded limestones. At least three other intrusive phases might be related to the emplacement of the main quartz diorite stock: 1) porphyritic andesites, 2) a series of gabbros and hornblende gabbros and 3) late stage aplite, porphyritic dacite and mineralized quartz-epidote veins. Emplacement of this last phase was accompanied by extensive brecciation and hydrothermal alteration.Three distinct stages of hydrothermal alteration are recognized in the andesites an associated basic to intermediate intrusives: 1) pyroxene-hornblende alteration to chlorite +/- epidote-magnetite, 2) incipient plagioclase alteration to kaolinite-quartz and 3) advanced plagioclase alteration to sericite-quartz +/- chamosite. In altered quartz diorite and dacite porphyries the association K-feldspar-biotite indicates the highest grade of hydrothermal alteration. Mineralization is ubiquitous. Pyrite, chalcopyrite and bornite occur as thin stringers, disseminations and replacements of original mafic minerals. Throughout the area mineralized outcrops are thoroughly stained with a mixture of secondary limonite-hematite and minor chalcocite-malachite. The strongest mineralized areas correspond with significant soil, rock and stream sediment Cu and Mo Anomalies.
- Research Organization:
- George Washington Univ., Washington, DC (USA)
- OSTI ID:
- 6900682
- Report Number(s):
- CONF-8510489-
- Journal Information:
- Geol. Soc. Am., Abstr. Programs; (United States), Journal Name: Geol. Soc. Am., Abstr. Programs; (United States) Vol. 17; ISSN GAAPB
- Country of Publication:
- United States
- Language:
- English
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54 ENVIRONMENTAL SCIENCES
ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM SILICATES
AMPHIBOLE
ANDESITES
CALCIUM COMPOUNDS
CALCIUM SILICATES
CHALCOGENIDES
CHLORITE MINERALS
COPPER COMPOUNDS
CRETACEOUS PERIOD
DEVELOPING COUNTRIES
DIORITES
DOMINICAN REPUBLIC
ENERGY SYSTEMS
EPIDOTES
GABBROS
GEOLOGIC AGES
GEOLOGY
GEOTHERMAL SYSTEMS
GREATER ANTILLES
HISPANIOLA
HYDROTHERMAL ALTERATION
HYDROTHERMAL SYSTEMS
IGNEOUS ROCKS
IRON COMPOUNDS
IRON ORES
IRON OXIDES
IRON SILICATES
ISLANDS
KAOLINITE
MAGNETITE
MESOZOIC ERA
METAMORPHISM
MINERALIZATION
MINERALOGY
MINERALS
MOLYBDENUM COMPOUNDS
ORES
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PLUTONIC ROCKS
PYROXENES
QUARTZ
REFRACTORY METAL COMPOUNDS
ROCK-FLUID INTERACTIONS
ROCKS
SILICATE MINERALS
SILICATES
SILICON COMPOUNDS
SILICON OXIDES
TRANSITION ELEMENT COMPOUNDS
VOLCANIC ROCKS
WEST INDIES