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), Vol. 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
54 ENVIRONMENTAL SCIENCES
ANDESITES
HYDROTHERMAL ALTERATION
MINERALOGY
ROCK-FLUID INTERACTIONS
DIORITES
DOMINICAN REPUBLIC
HYDROTHERMAL SYSTEMS
GABBROS
AMPHIBOLE
CHLORITE MINERALS
COPPER COMPOUNDS
CRETACEOUS PERIOD
EPIDOTES
GEOLOGY
KAOLINITE
MAGNETITE
METAMORPHISM
MINERALIZATION
MOLYBDENUM COMPOUNDS
PYROXENES
QUARTZ
ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM SILICATES
CALCIUM COMPOUNDS
CALCIUM SILICATES
CHALCOGENIDES
DEVELOPING COUNTRIES
ENERGY SYSTEMS
GEOLOGIC AGES
GEOTHERMAL SYSTEMS
GREATER ANTILLES
HISPANIOLA
IGNEOUS ROCKS
IRON COMPOUNDS
IRON ORES
IRON OXIDES
IRON SILICATES
ISLANDS
MESOZOIC ERA
MINERALS
ORES
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PLUTONIC ROCKS
REFRACTORY METAL COMPOUNDS
ROCKS
SILICATE MINERALS
SILICATES
SILICON COMPOUNDS
SILICON OXIDES
TRANSITION ELEMENT COMPOUNDS
VOLCANIC ROCKS
WEST INDIES
152003* - Geothermal Data & Theory- Rock-Water-Gas Interactions
520300 - Environment
Aquatic- Radioactive Materials Monitoring & Transport- (1989)