136 University of California Publications in Geology ["Vol. 7 



longer axis, produced by a greater amount of differential uplift 

 on both sides of the localities of Red Rock Canon and Last Chance 

 Gulch, which might have given sites to courses of consequent 

 drainage. The evidence thus points strongly to an antecedent 

 origin for the lower courses of Red Rock Canon and Last Chance 

 Gulch. 



Among the most remarkable features noted by the writer in 

 the southern Great Basin must be included those probable ante- 

 cedent drainage courses which have been developed athwart the 

 courses of the lately uplifted ranges in a region where the present 

 rainfall is so scanty. Even if one assumes that precipitation was 

 greater in former times than now, these antecedent drainage 

 courses bear an eloquent testimony to the slowness of the moun- 

 tain uplifts. And yet these mountains have probably been up- 

 lifted since the close of the Tertiary. 



Recent Faulting. — Hess 8 has recently described rift features 

 caused by the faulting along the southern base of the eastern 

 El Paso Range north of Garlock station, where these features are 

 so striking as to have been noted by the present author from the 

 railway train. There are some suggestions of recent faulting 

 along the south base of the range between the mouths of Red 

 Rock Canon and Last Chance Gulch, in the nature of truncated 

 shoulders separated by shallow depressions from low hummocks 

 with their courses parallel to the range's south base. One of 

 these low hummocks can be seen at the base of the escarpment 

 in the middle distance in plate 8, figure 1. It is quite possible 

 that there has been a small uplift of the range recently, which has 

 been responsible for the recent trenching of the alluvium at the 

 mouths of Red Rock Canon and Last Chance Gulch and for the 

 formation of the alluvial terraces higher up in these drainage 

 basins. This view must be regarded as a mere suggestion, how- 

 ever, which is worthy of more extensive investigation. 



s Gold mining in the Bandsburg Quadrangle, California, U. S. Geol. Surv., 

 Bull. no. 430, pp. 23-47, 1910. 



