GEOLOGY OF THE LAKE PLACID QUADRANGLE I9 



of this rock it is important to note that extreme degrees of crushing 

 may often be observed in single outcrops of ordinary dimensions. 

 A striking example of such phenomena is in the big ledge on the 

 shore of Lake Placid at the southwestern end of Moose island 

 where coarse-grained, nongneissoid anorthosite, with labradorite 

 crystals up to 4 inches across, has in it a zone of much finer grained 

 and moderately gneissoid anorthosite, the one grading into the other. 

 Another illustration is in the road metal quarry near the road i^ 



Fig. I Sketch of a large crystal of labradorite from the anorthosite 

 quarry i^ miles northeast of Upper Jay. Natural size. Note the large 

 amount of granulated feldspar irregularly distributed through the crystal. 

 Due to deformation during the process of granulation, the twinning bands 

 are distinctly curved in the middle right portion and sharply shifted in 

 position in the lower portion. Dark patches are pyroxene. Dotted rim on 

 left is granulated garnet. 



