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Hydrothermal alteration of felsic volcanic rocks at the Helen Siderite Deposit, Wawa, Ontario

Journal Article · · Econ. Geol.; (United States)

Felsic lavas and pyroclastic rocks, underlying the Archean Helen iron-formation, have been variably altered by hydrothermal solutions which, when discharged onto the sea floor, formed the Helen siderite deposit. Within the footwall volcanic sequence five chemically and mineralogically distinct alteration types have been defined: least altered, sericite, chlorite chloritoid, and ankerite. Based on mineralogy and chemistry of the altered rocks and on the geometry of the alteration zones, an alteration model is proposed.

Research Organization:
Department of Geology, University of Minnesota-Duluth, Duluth, Minnesota
OSTI ID:
5240491
Journal Information:
Econ. Geol.; (United States), Journal Name: Econ. Geol.; (United States) Vol. 79:6; ISSN ECGLA
Country of Publication:
United States
Language:
English