Publication Type:

Journal Article

Authors:

McCormick, Kelli A.; McDonald, Andrew M.

Source:

The Canadian MineralogistThe Canadian Mineralogist, Mineralogical Association of Canada, Ottawa, ON, Canada, Volume 37, Part 6, p.1385-1403 (1999)

ISBN:

0008-4476

Keywords:

amphibole group, breccia, Canada, chain silicates, Chlorine, clastic rocks, copper ores, crystal chemistry, crystallization, eastern canada, halogens, host rocks, indicators, metal ores, mineral deposits, genesis, nickel ores, Ontario, Paleoproterozoic, Precambrian, proterozoic, Sedimentary rocks, silicates, Sudbury District Ontario, Sudbury structure, upper Precambrian, Whitewater Group

Abstract:

Three chemically distinct populations of Cl-bearing amphibole occur in association with contact Ni-Cu ore deposits in footwall breccia at the Fraser mine. The first consists of halogen-poor (Cl < 0.05 wt.%) actinolite and magnesiohornblende and is generally overgrown by amphibole of the other two populations: a) an Fe-rich, halogen-poor deep green rim of ferro-actinolite to ferrohornblende and b) an Fe-rich, Cl-rich (Cl < or = 4 wt.%) ferrotschermakite to hastingsite to potassic-chlorohastingsite with a characteristic deep blue-green pleochroism. Major element data for these amphiboles indicate a linear negative correlation of mg vs Cl [not positive as stated] and a positive one for K vs Cl, with a logarithmic, positive one for (super [4]) Al vs Cl. The Cl is homogeneously distributed and structurally bound. Calculated Fe (super 3+) /Fe (super 2+) values suggest crystallization at relatively low f (sub O) (sub 2) . The paragenesis is discussed.

Notes:

GeoRef, Copyright 2018, American Geological Institute.<br/>2000-050456<br/>Fraser Mine