120 EEPOET UNITED STATES GEOLOGICAL SUEVEY. 



diminished as it recedes from the central mass. Northward the dip is 

 least, about 10° to 15°, causing the Potsdam strata to disappear under 

 the younger beds. East of the peak, the quartzites first incline steeply, 

 but soon lose their high angle, and are reduced to an inclination of 15° 

 to 18°. Gray, white, and red quartzites and some sandstones compose 

 the series. A good section may be obtained at the southern base of 

 Eawlings Peak. There the thickness of the beds appears to be some- 

 what over COO feet. 



Calciferous Group. 



Above the quartzites and sandstones a thin series of calcareous and 

 dolomitic, partly arenaceous beds may be found. I am hi doubt whether 

 they should be referred to this group. No fossils were found in them, 

 and their position cannot be regarded as established. In lithological 

 character they agree with the members of the Calciferous Group else- 

 where, but they may represent portions of the Subcarboniferous. Be- 

 neath these limestones and dolomites a highly interesting deposit of 

 " red paint " occurs. It is composed of red hematite, exceedingly homo- 

 geneous in texture, and free from impurities. Some of it is fibrous, and 

 is usually regarded as nearly chemically pure. A large quarry has been 

 opened, and the hematite has been obtained from it for commercial pur- 

 poses. Judging from surface indications, its extent is considerable, but 

 the overlying beds rendered it impossible to form any accurate estimate. 



CAEBONIEEK.OTTS. 



Subcarboniferous Group. 



A series of yellow and gray, partly arenaceous, magnesian limestones 

 may be referred to this group. They overlie the dolomites which have 

 been regarded as doubtfully Calciferous. An exposure of these strata 

 may be seen on the narrow ridge leading from the "red-paint mine" to 

 the southeast. Here they show a dip of about 30° eastward, veering 

 gradually to northeast. Enormous masses of drift material, which 

 cover all the depressions and many of the ridges in this region, ob- 

 scures the continuation and vertical development of the strata very 

 much. To the west the same conditions are found to be repeated. Dip- 

 ping at an angle of 30° to 35° westward, the strata rapidly disappear 

 from sight. Northward the dip is more gentle. An estimate of their 

 thickness, which is rendered more or less inaccurate by the superposi- 

 tion of drift, places the thickness of this group at about 200 to 300 feet. 

 No fossils were found except some indistinct corals. 



Carboniferous Group. 



After passing the Subcarboniferous strata east of Eawlings Peak, we 

 ■ cross a fiat valley about 2 mdes in width. Ascending a gently sloping 

 : ridge on the eastern side of this depression, we find outcrops of Car- 

 boniferous limestones. We have here reached the upper members of 

 the group. Along this line no other exposure is found in the valley. 

 From what we can learn from the occurrences west and north, we are 

 • enabled to say that the Carboniferous limestones dip to the eastward 

 throughout, beginning with an angle of about 20°, which decreases to 

 >8° on the ridge mentioned. West of the peak the exposures are more 

 i satisfactory, as also north of it. We there meet with the characteristic 

 iblue limestones, highly siliceous and massively bedded. Much of the 



