LITTLE STRAY HOUSE SYNCLINE. 497 



Porphyry and the Lickscuindidrix (P-68) bore-hole, in the middle of the 

 basin, has gone through 400 feet without reaching its base. 



Eastern rim East of the above shafts the El Paso (P-G5) and Little 

 Miami (P-58), at depths of 470 feet and 390 feet, respectively, were still in 

 White Porphyry, after having passed through Gray Porphyry, and through 

 varying thicknesses of Weber Shales both at the contact of the two porphy- 

 ries and within the lower body. The Kennebec (P-55), Cullen (P-57), and 

 Aztec (P-54) have reached the limestone after passing through the two por- 

 phyries, the former finding a second sheet of White Porphyry within the lime- 

 stone. The same sheet is found in the Cordelia Edmondson (P-41), which 

 is sunk in a large body of vein material, directly below the Wash. Several 

 other shafts have struck the very considerable body of vein material which 

 replaces the Blue Limestone on this rim of the basin, but as yet no impor- 

 tant ore bodies have been found. 



The most extensive workings are in the Chieftain and Scooper mines. 

 The former is opened by a tunnel (P-43), which runs southeast through 

 vein material, and then through limestone, compressed into gentle folds but 

 apparently with a slight dip west, and, at a distance of 360 feet from the 

 mouth, strikes granite which forms the foot-wall of the Iron fault. A 

 decomposed porphyry, resembling White Porphyry, is found adjoining the 

 fault. The limestone near the end of the tunnel is quite light colored; it 

 may be the White Limestone, but the structure was not sufficiently shown 

 to make this certain. The Scooper (P-44) shaft was sunk through 60 feet 

 of Wash, 20 feet of Gray Porphyry, and f> feet of White Porphyry, to 

 iron and limestone. The contact with the porphyry is here very steep and 

 runs in a direction a little east of south, being cut by several drifts ; it was 

 supposed to be the line of a fault. It is probably, however, simply an 

 unusual steepening of the dip on this edge of the basin, as the Indiana 

 (P-64) shaft, about 400 feet west of it, was still in Gray Porphyry at a 

 depth of 330 feet. The limestone and vein material are crushed and folded 

 even more than in the Chieftain, and probably from the same cause, viz, 

 compression against the Iron fault. Considerable very silicious, hard car- 

 bonate ore, rich in chloride of silver, has been taken from this mine, but 

 for some unexplained reason the developments have been very irregular 

 and without system. 



MON xir 32 



