nue
(Fig 11) within the wall of Central Park; decaying granite was
uncovered in the excavations for the cellar of the American Museum of
Natural History, and capital examples of the white kaolin surrounding
the unaltered orthoclase were found at 4th Avenue and 77th Street, also
at 43d Street and 1st Avenue. Also found at 56 feet below surface at 14
,West 32d Street. (A. S. Coffin.)
The
granite where it occurs in large developments, as at 48th to 55th
Streets and 10th Avenue, has an industrial value for foundations, but
more generally it is a vein stone of no consequence, a mere geological
incident.
Granite beds or sheets, coarse, pegmatitic, are found along a section on 58th and 59th Streets from 9th to 10th Avenues.
In
the Pennsylvania Railroad excavation (Figs. 12 and 13) from 32d to 33d
Streets, between 7th and 9th Avenues, with an extension towards 6th
Avenue and another westward from 9th to 10th Avenue, granite was
plentifully uncovered, appearing as a coarse rock (pegmatitic) on 32d
Street towards 7th Avenue, and much softened and decomposed, abundantly
in veins in the crumpled and folded gneiss between 7th and 8th Avenues
on 32d Street, developed into a hill (from the level of the excavation)
under 8th Avenue, and somewhat finegrained, and extended west of 8th
Avenue towards 9th on 33d Street, and again seen on 9th Avenue and 32d
Street.
In
the excavations of the Pennsylvania Railroad terminal, west of 9th
Avenue, the granite inclusions seemed less relevant and simple, more
confused, sporadic and involved, though the straight granite walls
between the schists were not absent. About fifty feet east of 10th
Avenue on the south side of the pit there appeared a broad sigmoid of
twisted granite (finegrained) vein, and the rock about was much
crumpled, filled with strips and lenses of granitic material, rolled up
and contorted, with their continuity severed or ruptured by squeezing.
The material of some veins resembled a granite gneiss. Again, faces of
the rock on the same side (south), and some four hundred feet east of
10th Avenue, were streaming with small
