22 



Report of the State Geologist. 



1. Gneissic series; 2. Limestone series; 3. Gabbro series ; 4. Palaeozoic 

 series : (a) Potsdam sandstone, (/>) Calciferous sandrock, (c) Chazy lime- 

 stone, (V/) Black River limestone, (e) Trenton limestone, (/) Utica slate; 

 5. Dike series ; 6. Pleistocene deposits. 



Then follow important chapters on the metamorphism of the Pre- 

 Cambrian Rocks and on Post-Champlain (Lower Silurian) Disturbances. 



The latter half of the paper is devoted to the discussion of the areal 

 geology by townships, in the following order : 



Clinton, Mooers, Ellenburg, Dannemora, Saranac, Black Brook, Ausable, 

 Peru, Schuyler Falls, Plattsburg, Beekmantown, Altona, Chazy, Champlain. 



Preliminary Report on the Geology of Essex County. 



By J. F. Kemp. 



This report is a continuation of the author's geologic investigations, 

 published in the report of the State Geologist for 1893. Townships not 

 previously described are taken up for special consideration and descrip- 

 tion, and the areal geology of each is given, so far as determined. Special 

 notice is taken of economic products, mainly of iron ores. 



In the town of Chesterfield, so far as explored, the gneisses are extensively 

 developed, but no new facts in regard to other series of rocks have been 

 obtained since the last report. 



In Jay, the gneisses constitute the northeastern corner; the crystalline 

 limestones occur in upper Jay, and constitute the northerly continuation of 

 the area of similar rocks occurring in Keene ; rocks of the gabbro family 

 cover the main portion of the town, while no palaeozoic sediments or dikes 

 of irruptive rocks have been observed. 



In Wilmington, the gneisses and gneissoid rocks with crystalline lime- 

 stones are believed to be absent. The entire eastern portion of the town is 

 covered \\ ith gabbros and anorthosites, while no sedimentary rocks are found 

 in the tow n. A single trap dike is observed at the high falls of the West 

 Branch of the Ansable. 



St. Annand. The gneisses are well represented, but the crystalline lime- 

 stones and their associated rocks are not met with in the town. The area of 

 gabbros, represented on the ma}) largely from inference, appears to be con- 

 siderable. No palaeozoic or irruptive rocks have been noted. 



