Porphyry Tungsten Zones at Mt. Pleasant, N.B.

CIM Bulletin, Vol. 71, No. 794, 1978

I. S. Parrish, Senior Associate, Derry, Michener & Booth, Inc., and J. V. fully*"", Senior Engineer, Union Carbide Corporation

The Sullivan Mining Group has been exploring the mineral deposits of the Mount Pleasant area of southern New Brunswick since 1967. Sullivan geologists have logged over sixty miles of drill core, mapped over five miles of underground workings and studied numerous surface exposures. Several mineralized zones have been defined and two higher-grade porphyry-tungsten bodies delineated. Within these bodies, wolframite occurs as disseminated specks and grains up to one-half inch in diameter. The host rock is a brecciated rhyolite porphyry that has intruded quartz-feldspar porphyry of Mississippian age. The host rock is itself intruded by an acid porphyry called transition rock and is underlain by a microgranite. The mineralized zones, host rock, transition rock and microgranite are all thought to be derived from the same magma, and to represent progressive fractions from that magma.

Keywords: Economic geology, Mineralogy, Mount Pleasant, Sullivan Mining Group, Brunswick Tin Mines, Porphyry deposits, Tungsten, Metallogenesis.