LITTLE STRAY HORSE SYNCLINE. 255 



Wash; and the Highland Mary (P-52) and Snowstorm (P-50), after pass- 

 ing through White Porphyry, reach the lower sheet of Blue Limestone be- 

 neath it. 



Center of basin. — Towards the Center of the basin a number of shafts have 

 been sunk to a considerable depth in the overlying Gray Porphyry, and 

 generally find sandstones or black carbonaceous shales at its contact with 

 the overlying White Porphyry, but none have as yet reached the Blue 

 Limestone. The greatest depths obtained have been in the Little Miami 

 (P-58), which went through 269 feet of Gray Porphyry and 30 feet of 

 White Porphyry, having a total deptli of 396 feet; the Indiana (P-64) 

 shaft, 230 feet of Gray Porphyry in a total depth of 330 feet; the El Paso, 

 325 feet of Gray Porphyry, having a total depth of 470 feet, and the 

 Lickscumdidrix bore-hole (P-68), which went through 400 feet of Gray 

 Porphyry without reaching the White Porphyry. The deepest portion of 

 the basin is probably somewhere near the latter. 



Western rim. — On the westem rim of the basin contact has been reached 

 in the shafts of the Denver City, Tip-top, and Little Sliver mines, in whicli 

 a varying thickness of black shale and sandstone, belonging to the Weber 

 Shale group, has been found at the contact of Gray and White Porphyry. 

 The Bangkok (P-77) has penetrated the Gray Porphyiy to the underlying 

 White Porphyry, while the Forepaugh (P-76), Cora Bell (P-78), and 

 Union Emma (P-79) are still in Gray Porphyry. The Hunkidori shaft, 

 in Little Stray Horse gulch, at the southern end of the basin, has already 

 reached White Porphyry under the Gray. The Denver City (P-82), 

 Wright (P-74), and Shamus O'Brien (P-73) shafts found Gray Porphyry 

 under 180, 157, and 165 feet of Wash, and reached the Blue Limestone 

 horizon at 234, 320, and 362 feet, respectively, each disclosing about ten 

 feet of sandstone and shale, which carried as high as 22 ounces of silver, 

 between Gray and White Porphyries. 



FRYER HILL. 



As the structure of Fryer Hill will be given in detail in a later chapter, 

 it is only necessary here to give a brief outline of its structure as bearing 

 on that of the sui-rounding regions. 



