July 20, 1900.] 



SCIENCE. 



91 



and Lake George several small beds in 

 Putnam and Dresden townships. In White- 

 hall and Fort Ann, however, the exposures 

 become more serious and give greater prom- 

 ise of stratigraphical results. At White- 

 hall an attempt has been made by me to 

 work them out, and in a report, that will 

 shortly appear from the ofiBce of the State 

 Geologist in Albany, a detailed map with 

 cross- sections will be given which indicate 

 a marked anticlinal character for them 

 and the associated gneisses. Quartzose 

 gneisses are also present that afford strong 

 evidence of being metamorphosed sedi- 

 ments. 



If now we return to the latitude of Crown 

 point and Ticonderoga and pass westward 

 into Schroon, we find a belt along a some- 

 what marked depression, ranging from west- 

 ern Crown Point, through the valley of 

 Paradox lake to and along Schroon lake. 

 There are likewise scattered outliers in the 

 adjoining hills. Still further westward in 

 Minerva and again to the north in New- 

 comb, right in the heart of the mountains 

 and west of the highest peaks, very ex- 

 tended outcrops occur, as usual with the 

 associated gneisses. They scarcely cross the 

 line from Essex into Hamilton county to the 

 west, but they run south through Warren 

 county and appear in small and scattered 

 areas in Johnsburgh, Chester, and Thurman. 

 In eastern Hamilton county, two or three 

 have been discovered in Wells and Lake 

 Pleasant townships. But then they seem 

 to end so far as our present information 

 goes, and from these townships southward 

 along the western border line of Hamilton 

 county and in a sweep around to the west- 

 ward along the southern rim of the crystal- 

 lines, so far as known they fail. To the 

 eastward in Warren county, we have loca- 

 ted a number of small and scattered out- 

 crops, amid the gneisses of Horicon and 

 Bolton townships, while in Hague are the 

 interesting quartzites already referred to. 



In the several townships that intervene on 

 the south before the mantle of the Paleozoic 

 conceals the crystallines, the limestone is 

 lacking so far as known. 



Resitfme.—ln a brief general survey of 

 these various details, it is evident that the 

 limestones are chiefly found along the north- 

 west and southeast or eastern portion of 

 the great crystalline area. In its northern 

 portion they practically fail, and in the 

 broad band running from northeast to 

 southwest across it, they are unknown. 

 They are likewise absent in the southern 

 and southwestern border. On the north- 

 west they are in extended and compara- 

 tively broad belts, but in the eastern portion 

 they appear in many small and separated 

 exposures, associated with some quartzites 

 and much greater amounts of characteristic 

 gneisses, but greatly broken up by igneous 

 intrusions. 



Broadly considered, it is inconceivable 

 that we should have these numerous, thin 

 exposures of limestones, undoubted sedi- 

 ments, over so wide an area, without cor- 

 responding and very much greater amounts 

 of elastics. The comparatively few recog- 

 nizable quartzites serve to corroborate the 

 inference so far as they go, but it is still an 

 inevitable conclusion that we must have the 

 representatives of very much greater de- 

 posits, that have been shales or some simi- 

 lar materials, and that are represented now 

 by the gneisses, because schists or slates 

 are practically unknown. 



It is also significant that so far as our pres- 

 ent information goes the recognizable, frag- 

 mental sediments are most numerous on the 

 east, where at the same time the limestones 

 are thinnest and most scattered. While it 

 is well appreciated by me, that much fuller 

 knowledge awaits us as Professor Smyth's 

 work progresses, yet the significance of this 

 relation cannot be entirely overlooked, and 

 it seems justifiable to believe that if the 

 limestones on both sides of the mountains 



