KELATION OF SYENITE-GRANITE SERIES 433 



face anortliosite whose borders were fused by the enveloping magma. A 

 big ledge of typical syenite, 1% miles west of East Kilns, contains many 

 inclusions of Whiteface anorthosite which are bunches, lenses, or bands 

 from 2 or 3 inches to several yards long. Their borders are not always 

 sharp against the syenite. A small body of Whiteface anorthosite 1 mile 

 north of Middle Kilns is really a distinct inclusion in the granite. The 

 same is true of the small body of Grenville-anorthosite mixed rocks a few 

 rods east of Silver Lake at the map edge. 



In the Long Lake quadrangle the broad tongue of syenite, already 

 referred to as cutting almost through the border f acies of the anorthosite, 

 contains five mappable inclusions of the border facies. From 5 to 7 miles 

 southwest of these the map shows three small masses of Marcy anortho- 

 site, one with sharp contacts against the inclosing syenite, according to 

 Gushing. These are reasonably to be interpreted as inclusions. 



The two small mappable bodies of border anorthosite in the Elizabeth- 

 town quadrangle, already referred to as occurring in the syenite 1 and 2 

 miles, respectively, from the main body of anorthosite, are also quite cer- 

 tainly inclusions. 



AREAS OF SYENITE SURROUNDED BY ANORTHOSITE 



In some places small isolated masses of syenite are completely sur- 

 rounded by anorthosite. Several such are represented on my Lake Placid 

 geologic map — two of them near Keene, one a mile west of Upper Jay, 

 and another 2 miles southwest of East Kilns. The largest area is only 

 one-half of a mile long, and all are surrounded by the Whiteface type of 

 anorthosite. Kemp's Elizabethtown map shows three such areas — one at 

 the top of Giant Mountain, another a mile north of Chapel Pond, and a 

 third, over a mile across, a few miles west of Elizabethtown. These are 

 all surrounded by Marcy anorthosite except the third, whose eastern side 

 comes against basic border anorthosite. Cushing's Long Lake map shows 

 two small masses of syenite (not including the narrow dikes) surrounded 

 by the basic border anorthosite within a mile of its outer margin. Neither 

 my Schroon Lake map nor Doctor Ogilvie's Paradox Lake map shows a 

 single mass of syenite or granite within the anorthosite. 



The few small areas of syenite above mentioned are the only ones rep- 

 resented as completely surrounded by anorthosite on any of the detailed 

 geologic maps. Of these the only ones within Marcy anorthosite are in 

 the Elizabethtown quadrangle. It is therefore a striking fact that such 

 syenite areas are almost entirely absent from the great area of Marcy 

 anorthosite. The significance of this fact is considered beyond, under 

 another caption of this paper. 



