Metamorphic aspects of the magnetite-hematite deposit at Benson mines, New York

Garnet, sillimanite, and plagioclase rim and poikiloblastically enclose some iron-oxide and sulfide grains, and iron-oxide grains similarly enclose sulfides. Late sulfides vein silicates, iron-oxides, and early sulfides. Long axes of ovate ore grains tend to lie within biotite-foliation planes, and to be concentrated in the direction of sillimanite lineations. These relationships show that some opaque minerals were present at the time of metamorphism, and are consistent with introduction during or before metamorphism, or even with theirexistence as original syngenetic constituents of the host rocks.

This record provided courtesy of AGI/GeoRef.