AEEA NORTH OF BEEECE FAULT. 243 



^ulcli, passed through over four hundred and eighty feet of the upper 

 sheet of White Porphyr}^ before reaching Blue Limestone. 



Adelaide fault. — The Adelaide cross-fault follows nearly the bed of Stray 

 Horse gulch from the Iron fault up as far as the Adelaide smelter, from 

 which point it bends southward, passing to the south of the Laura Lynn 

 shaft. In this portion, however, it is impossible to determine its location 

 with any approach to accuracy, as but few shafts are sunk and at its east- 

 ern end White Porphj^ry occurs on either side of it. Its displacement is 

 slight, its upthrow being on the northeast, and probably reaching a maxi- 

 mum at its eastern end. It might be considered as a branch of the Mike 

 fault, that fault having split into two at its northern extremity. 



It must be admitted that the triangular piece of ground in Adelaide 

 Park between the Mike feult and the Adelaide cross-fault, in which the few 

 deep shafts that have been sunk are mainly in different varieties of porphyry 

 which the miners do not distinguish apart, shows a complication of struct- 

 ure of which the explanation afforded by the map and sections may not 

 prove entirely accurate when more extended explorations are made. There 

 seems little doubt, however, that the irregular body of Adelaide or Gray 

 Porphyry has been forced up directly from below somewhere in this I'e- 

 gion; that it crosses the strata, and by thus interrupting the currents has 

 been influential in determining the deposition of metallic minerals in this 

 neighborhood, which are not only very abundant, but very irregularly dis- 

 tributed. 



Southwest slope. — On the southwest slope of Yankee Hill the succession 

 of outcrops indicated by the shafts is as follows : The Shenango (P-16) 

 and Logan No. 2 shafts are in White Porphyry, below the Wash, while the 

 Woodruff and Red-Headed Mary (P-22) have penetrated this body and 

 reached the White Limestone beneath it. The shaft P-25 finds White 

 Limestone below the Wash; the Hard Cash (P-31) and the Moonstone 

 (P-32) shafts are in Lower Quartzite, and the Hard Cash (P-35), Logan 

 No. 1 (P-27), and Silver Basin shafts have penetrated the Lower Quartz- 

 ite to the underlying Archean. The Double-Decker shafts (P-47 and 

 P-48) have been working on a body of gold ore in the Lower Quartzite, 

 near the junction of the Adelaide and Iron faults. 



