Annual report . W. J, Milkr, photo Dikes of basic rock (norite) cutting hornblende syenite. Onemile north-northwest of Northville and at the edge of the river. GEOLOGY OF THE BROADALBIN QUADRANGLE 25 sthene; 15 per cent hornblende; 5 per cent biotke; and 5 per centmagnetite. This rock is a non-metamorphosed, medium grainedhypersthene gabbro or norite which, in every way, greatly resemblesthe dike gabbros of the North Creek sheet now being studied bythe writer and which, in that region, seem to be older than thefine grained diabases. A slide from the basic dike rock one mile north-northwest ofN
Annual report . W. J, Milkr, photo Dikes of basic rock (norite) cutting hornblende syenite. Onemile north-northwest of Northville and at the edge of the river. GEOLOGY OF THE BROADALBIN QUADRANGLE 25 sthene; 15 per cent hornblende; 5 per cent biotke; and 5 per centmagnetite. This rock is a non-metamorphosed, medium grainedhypersthene gabbro or norite which, in every way, greatly resemblesthe dike gabbros of the North Creek sheet now being studied bythe writer and which, in that region, seem to be older than thefine grained diabases. A slide from the basic dike rock one mile north-northwest ofNorthville contains: 35 per cent plagioclase (labradorite with someandesine) ; 15 per cent orthoclase (some with albite twinning) ; 20per cent hypersthene (pale green to reddish brown pleochroism) ;25 per cent hornblende; 5 per cent magnetite; and a little pyriteand zircon. The rock shows a fine grained granitoid texturewhich, because of its unusual composition, should be called a horn-blende-orthoclase-hypersthe
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectscience, bookyear1902
