GEOLOGY OF THE LAKE PLACID QUADRANGLE 



21 



Table i Thin sections of anorthosite 





d 



c 



a ^ 



3 



-g 



'B 



I fi 



3 J^ 



I 1 

 3 O 



-a 

 a 



3 



a 



c 



c 







60 



1 



c 

 p. 



s 



53 







'S 



II 



















1 



.2 

 > 



c 



1 



5 



"3 

 



<u f 



1 



2 



4 



5 

 35 

 44 



6 



6a 



8 



9 

 13 

 14 

 15 

 17 

 18 

 19 

 20 

 34 



5g3 



6bl 



6bl 



7cl 



7c3 . 



8a3 .. 



Ik2 .. 



Ik2 .. 



6el .. 



4dl . 



ogl 



9f3 



8f4 



8il 



9il 



9gl3 . . 



1L8 



7f7b 



6el . 



99 .... 

 82 .... 

 93 .... 

 95 



"2 



2 



little 

 8 











1 

 2 



little 

 little 



1 



I 









"3 





i 



7 



1 















s-s 







littk 













Sd 





1 

 5 













-*° 



95 



98 

 93 



.. 93 



.. 86 

 90 

 97 



98 .... 



88 .... 



92 .... 



86 .... 

 75 



95 .... 



94 .... 

 50 



1 

 i 



1 







i 



5 



1 

 ....^ 



f 

 2 



little 



little 















« 



little 

 Lttk 



little 





^ 







f 









1 



little 



little 



little 



little 



3 







5 

 6 

 3 

 1 

 1 

 4i 



3 



'2 

 3 



2 

 6 



7 



t 



2.5 



4J 



3 



10 







1 

 2i 





5 

















littU 

 i 



i 



i 









^ 













littlf 

 little 







S 











i 



little 

 little 





i;jJ 









i 





little 









1 















•« 



3 





















-S 









little 

 i 



i 



3 











l.ttle 



1 











.a 









5 













little 



little 

 2 













30 







little 











i 



No, I, five-sixths of a mile east-southeast of Owen pond; no. 2, south- 

 western end of Moose island in Lake Placid; no. 4, same; no. 5, Under- 

 cliff, on Lake Placid; no. 35, three-fifths of a mile north of Underclifl; 

 no. 44, five-sixths of a mile north ol Loch Bonnie; nos. 6 and 6a, river 

 gorge one-half of a mile south of Keene; no. 7, by the river two-thirds 

 of a mile southwest of Copperas pond; no. 8, one-half of a mile northwest 

 of Malcom pond; no. 9, one-half of a mile east of Owen pond; no. 13, one- 

 third of a mile northwest of the summit of Mit Whiteface; no. 14, summit 

 of Mt Whiteface; no. 15, just above bridge at The Flume; no. 17, The 

 Flume; no. 18, between the tongues of granite 1% miles northeast of the 

 summit of Little Whiteface imountain; no. 19, by the road three-fourths 

 of a mile east-northeast of Keene; no. 20, two-thirds of a mile northeast 

 of the summit of Sunrise mountain; no. 34, same locality as no. 7 above. 



yellowish green to deep green. Garnet is quite certainly of second- 

 ary origin, having developed along the contact betw^een feldspar 

 and pyroxene, or as rims around the pyroxene. The other minerals 

 require no special comment. Under the microscope, the granula- 

 tion is often a striking feature. 



Whiteface type of anorthosite. Distribution. Of the defi- 

 nitely known areas of outcrop of anorthosite within the quadrangle, 

 the Whiteface type, where practically free from mixture with 

 other rocks, occupies about 40 square miles. It is, therefore, some- 

 what more extensive than the Marcy anorthosite. There must be 

 added some 2 or 3 square miles of Whiteface anorthosite more or 

 less intimately mixed with other rocks and mapped as such. An 

 unknown, though considerable, amount of this anorthosite also 



