84 NEW YORK STATE MUSEUM 



Nearly 5 miles north of the large area of the Grenville, and across 

 a complicated mass of eruptive rocks is another exposure in the 

 valley of Stacy brook. Limestones, black, hornblendic schists and 

 thin gneisses make up a series of outcrops extending across the 

 valley. The structure is a monocline, with intrusives, north and 

 south. 



One of the most extraordinary of all the exposures is a very 

 narrow belt in Split Rock mountain, north of Westport. It lies 

 along the old road that led into the quarry worked many years 

 ago in the anorthosite. The belt appears but one or two hundred 

 yards in width and has anorthosite all around it, but it~ contains 

 typical, coarse, white marble, and associated schistose gneisses. 



Again to the north, and in the edge of this quadrangle, the Gren- 

 ville appears, not, it is true, with limestones but with characteristic 

 gneisses. The limestones are present, however, on Split Rock point 

 and island, in the Willsboro quadrangle, next north and these -two 

 constitute one connected area. 



Immediately west of Westport station an area of basic, thinly 

 schistose gneisses begins and extends a mile or more to the south- 

 west. They have undoubted gabbro on the southeast and equally 

 well defined anorthosite on the northwest. No limestones have ap- 

 peared in them, and their characters are not altogether demonstrated 

 as sedimentary, but it is the writer's conclusion that they can be 

 best placed here. 



The remaining exposures are nearly all near Elizabethtown vil- 

 lage and are small in amount. A mile southeast of Elizabethtown 

 there is an exposure of limestone with a little magnetite associated 

 with it. It seems to be caught in a mass of anorthosite. It is 

 called the Steele ore bed and is illustrated under the iron ores, 

 later on [fig. 30]. 



Again a mile and a half north of Elizabethtown in the western 

 foot of Woods hill is another small ledge, heavily charged with 

 silicates and with anorthosites just above in the hill. Still more 

 interesting are the exposures 3 to 4 miles northwest of Elizabeth- 

 town in the southern portion of Limekiln mountain, whose chief 

 mass lies in the Ausable quadrangle. In the Westcott quarry where 

 the rock has been taken out for lime there is a ledge with 25-30 

 feet of limestone, only moderately charged with silicates, among 

 which is wollastonite. Gneisses presumably sedimentary succeed 

 on the west up the hill, still farther westward and across a high 

 ridge consisting of a phase of the anorthosite ; in the next gulch, 

 a little limestone appears but again to the west a fine exposure was 



