THE LYMAN SCHISTS OF NEW HAMPSHIRE 369 



GENERAL DISTRIBUTION OF THE LYMAN SERIES 



No attempt will be made here to mark out the exact distri- 

 bution of this series. It is exposed over broad areas west of the 

 Blueberry Mountain Siluro-Devonian belt and it may be related 

 to schists on the east of this belt. The principal localities (Fig. 1) 

 to which reference will be made in the sequel are Mormon Hill, 

 the valley just northwest of Young's Pond, and Parker Hill. 

 Lyman schists are also exposed on the hill southwest of Young's 

 Pond, on the lower eastern slope of Black Mountain, near Partridge 

 Lake, and elsewhere in the broad valley between Gardner Mountain 

 and the Mormon Hill-Parker Hill range. In all these places the 

 group has a breadth of outcrop of several hundred feet, the rocks 

 are schistose, the strikes are roughly northeast-southwest, and the 

 cleavage and the bedding (where visible) have steep dips. 



FIELD RELATIONS AND MEGASCOPIC DESCRIPTIONS OF THE 

 LYMAN SERIES 



The Young's Pond locality. — Near a small schoolhouse about 

 one-third of a mile northwest of Young's Pond is a large outcrop 

 of a conglomeratic schist which we used to speak of as the " school - 

 house conglomerate" (Fig. 2). It is the rock which Mr. Sayles 

 has recently described as possibly being a tillite. 1 This conglom- 

 erate schist appears to rest unconformably upon a whitish or light- 

 grayish porphyritic sericite schist. The contact, which is very 

 irregular, runs northeast-southwest and may be seen not only near 

 the schoolhouse, but also, a few hundred feet southwest, near the 

 brook that flows into Young's Pond. The conglomerate schist is 

 on the northwest, the porphyry schist on the southeast, of this con- 

 tact. The conglomerate schist is between 300 and 400 feet wide 

 across the strike, and the porphyry schist is between 150 and 250 

 feet wide. This statement should not be understood to imply 

 that these rocks have no variation across their outcrop belts. 

 There is evidence that the porphyry is interrupted at least at one 

 horizon by a bed of fine conglomerate schist. 



West of the "schoolhouse conglomerate" is a series of whitish 

 rocks including fine, non-porphyritic schists, fine porphyritic 



1 R. W. Sayles, "Tillite in New Hampshire," Science, N.S., XLI (1915), 220. 



