Are the alteration halos of massive sulfide deposits syngenetic Evidence from U-Pb dating of hydrothermal rutile at the Kidd volcanic center, Abitibi subprovince, Canada

Journal Article · Fri Jun 01 00:00:00 EDT 1990 · Geology; (USA)

DOI:https://doi.org/10.1130/0091-7613(1990)018<0505:ATAHOM>2.3.CO;2· OSTI ID:6419177

Schandl, E S; Davis, D W; Krogh, T E ^[1]

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1. Royal Ontario Museum, Toronto, Ontario (Canada)

The Kidd volcanic complex is composed of felsic volcanic and subvolcanic rocks of Archean age. Metasomatic events affecting the lithology of the Kidd volcanic complex include silicification, extensive CO{sub 2} metasomatism (carbonate), K-metasomatism (sericite-fuchsite), and chlorite and minor carbonate alterations. Petrographic evidence, supported by stable isotope and fluid inclusion studies, suggests that silicification and early carbonate alteration were synvolcanic, and therefore related to ore deposition. During subsequent extensive K-metasomatism, sericite precipitated in the rhyolite, and fuschsite precipitated in the ultramafic rocks. Although chlorite postdates K-metasomatism, the micas and chlorite are both found in anastomosing microfissures, commonly occupying the same set of fractures. Hydrothermal rutile formed by the breakdown of magnetite-ilmenite during K-metasomatism and chlorite alteration gives an age of 2624 {plus minus} 62 Ma (95% confidence level). It is therefore approximately 100 m.y. younger than syngenetic massive sulfide mineralization (2712 {plus minus} 2 Ma). Sulfide stringers within sericite and chlorite veins suggest some remobilization of the ores during these later events. This alteration assemblage, is identical to that found associated with many lode-gold deposits in the Superior province. Recent dating of micas and rutile associated with gold deposits in the Abitibi subprovince gives comparable ages to the rutile in the Kidd volcanic complex, which must therefore record a widespread, late hydrothermal event affecting mineralized rocks.

• OSTI ID: 6419177
• Journal Information: Geology; (USA), Vol. 18:6; ISSN 0091-7613
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
58 GEOSCIENCES
CANADA
VOLCANIC REGIONS
SULFIDES
MINERALIZATION
AGE ESTIMATION
BASALT
CARBONATE ROCKS
CHLORITE MINERALS
DEPOSITION
GEOLOGIC DEPOSITS
GEOLOGIC FISSURES
GEOLOGIC FRACTURES
GOLD ORES
HYDROTHERMAL ALTERATION
ILMENITE
ISOTOPE DATING
ISOTOPE RATIO
LEAD ISOTOPES
LITHOLOGY
MAGNETITE
METAMORPHISM
MICA
ORES
ORIGIN
PETROGRAPHY
PLUTONIC ROCKS
RESERVOIR FLUIDS
RHYOLITES
RUTILE
SEDIMENTARY ROCKS
URANIUM ISOTOPES
ACTINIDE ISOTOPES
CHALCOGENIDES
FLUIDS
GEOLOGIC STRUCTURES
IGNEOUS ROCKS
IRON COMPOUNDS
IRON ORES
IRON OXIDES
ISOTOPES
MATERIALS
MINERALS
NORTH AMERICA
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
RADIOACTIVE MATERIALS
RADIOACTIVE MINERALS
ROCKS
SILICATE MINERALS
SULFUR COMPOUNDS
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
VOLCANIC ROCKS
150200* - Geology &amp; Hydrology of Geothermal Systems
580000 - Geosciences