650 LEWIS G. WESTGATE 
fail to show evidence of such a movement in the distortion and 
crushing of their individual mineral particles, but such is not 
the case. Anda rock subjected, while still incompletely solidi- 
fied, to such an extensive movement as is indicated in the present 
instance by the form of the schlieren, would naturally have the 
elements which had already crystallized out, in this case biotite 
and, locally, individual grains and aggregates of feldspar, 
arranged in a more or less parallel manner. 
4. Granulite.—For a mile along its western border, and fora 
somewhat greater distance about its southern end, the granite- 
gneiss shows a granulitic facies towards the contact. At other 
points both the ‘‘augen’’-gneiss and the ordinary granite-gneiss 
may occur unchanged in immediate contact with the schist. 
The width of this granulite border is not constant ; it varies from 
two or three feet to many yards. Where typically developed, it 
is a fine-grained, light gray or brownish rock, sometimes pure 
white and lacking all traces of dark minerals. This pure 
white granulite is present only at a few places and imme- 
diately at the contact. Small garnets are usually present. 
The rock has asugary texture, and when somewhat weath- 
ered often crumbles under the pressure of the fingers. Micro- 
scopically it is a fine-grained aggregate of orthoclase, an 
acid plagioclase, microclineand quartz. The structure is the 
so-called granulitic of M. Levy' and the panidiomorphic of 
Rosenbusch.? 
The quartz and feldspar form an aggregate of variously 
oriented rounded grains of uniform size, which are not, however, 
bounded by crystal planes. With the scarcity of biotite, the 
foliation becomes indistinct or wanting. In one case garnet 
grains form fine lines on the broken edge of the rock. No evi- 
dence of crushing exists. 
*M Lévy: Classification des Roches Eruptives, Pp. 30. 
? ROSENBUSCH: Massige Gesteine, p. 461. In this connection see TURNER: 
Geology of the Sierra Nevada, Sixteenth Ann. Report U.S. Geol. Surv., Pt. I, p. 737. 
Granulite (M. Lévy) is synonymous with aplite (Rosenbusch). Rosenbusch regards 
aplites as typically dike rocks, yet recognizes their occurrence as acid border phases of 
granite intrusions. /ézd., p. 65. 
