394 University of California Publications in Geology [Vol. 13 



Northeast of the limestone the underlying Arrastre quartzite is 

 isolated by a large mass of granite and only in one place, northeast 

 of Horsethief Flat, does it come in contact with the limestone. Here 

 its concordance with the dip and strike of the latter shows that in 

 reality it is part of the same syncline. At Round Valley the Furnace 

 limestone swings around and continues southward as small masses 

 sunken into the granite and isolated from the Saragassa quartzite ; still 

 its distribution is in agreement with the general synclinal structure. 



The southwestern limb of the syncline cannot be clearly recognized 

 so far along its strike as the northeastern. At Gold Mountain the 

 Saragossa quartzite dips 8° to the northeast and south of Baldwin 

 Lake it is nearly flat. The Furnace limestone is found west of Gold 

 Mountain, but is separated from the Saragossa quartzite by a small 

 mass of granite. It was probably faulted up to its present position, 

 as the dip of the quartzite is too flat to account for the limestone out- 

 cropping from beneath it so near the axis of the syncline. 



North of Sugarloaf Mountain the limestone forms a small east- 

 west anticline, the south limb of which passes beneath the Saragossa 

 quartzite. The north limb is covered over with fanglomerate. The 

 relations of the limestone to the Saragossa quartzite on the east are 

 rather obscure, but in consideration of its stratigraphic position it is 

 believed to pass beneath. 



On the west side of Holcomb Valley there is a small mass of Sara- 

 gossa quartzite which appears to dip beneath the limestone, but the 

 rocks are so broken by faulting and the intruding granite that the 

 significance of this observation is uncertain. It may represent a 

 portion of an overturned anticline, a thrust fault, or the block of 

 quartzite may merely have been dropped down into the limestone. 

 North of Holcomb Valley between Wild Rose Canon and Crystal Creek 

 the general attitude of the limestone is horizontal with numerous minor 

 folds whose limbs have local dips of more than 45°. Several dikes of 

 granite traverse the limestone and west of Delemar Mountain, Green- 

 lead Camp, and Crystal Creek granite is the predominating rock. 



On the south side of the hill two miles north of Saddlerock Spring 

 the older heterogeneous granite is clearly seen to form the roof of a 

 younger mass of grey granite. A few small apophyses of the latter 

 have followed along cracks between blocks of the former. Ridges of 

 the older rock strike across the plateau N 50° E and in one of the 

 small gullies an angular block of this roof rock was seen hanging down 

 into the younger. It therefore seems probable that these parallel ridges 



