New York State Museum bulletin . is a big ledge of syeniticto almost gabbroic looking gneiss with streaks, blotches and bandsof dark, biotite-garnet and gray, biotite-quartz gneisses arrangedparallel to the foliation. The southern portion of this ledge is pinkgranite which merges (as a result of fusion) into a biotite-quartzite. of the sharp point projecting into the lake less than one-quarter of a mile southwest of the locality last described is a solidledge of mixed gneisses which looks as though Grenville stratahad been thoroughly cut up, and more or less fused, by the syenitemagma
New York State Museum bulletin . is a big ledge of syeniticto almost gabbroic looking gneiss with streaks, blotches and bandsof dark, biotite-garnet and gray, biotite-quartz gneisses arrangedparallel to the foliation. The southern portion of this ledge is pinkgranite which merges (as a result of fusion) into a biotite-quartzite. of the sharp point projecting into the lake less than one-quarter of a mile southwest of the locality last described is a solidledge of mixed gneisses which looks as though Grenville stratahad been thoroughly cut up, and more or less fused, by the syenitemagma so that both Grenville and syenite often do not show theirtypical features. In certain other ledges on the lake shores there is good evidencefor some fusion of Grenville strata, and frequently bands ofamphibolite up to 20 or 30 feet wide occur parallel to the foliationof the syenitic or granitic gneisses. Other areas. In the bed of Rock river nearly i mile below theoutlet of Rock lake, large exposures show green pyroxene, white. ^ > ^O S o^ o Plate 10
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Keywords: ., bookauthorne, bookcentury1900, bookdecade1910, booksubjectscience
