376 University of California Publications in Geology [Vol. 13 



these species are presumed to change relatively rapidly." \ r aughan 22 

 has recently made a rather exhaustive study of the Carrizo Creek 

 locality and concludes that the beds "are not older than Lower Plio- 

 cene." 



The fauna from the Lion sandstone is of great importance, since 

 it is the most definite evidence afforded in the whole region for the 

 age of the sediments along the south front and for the age of uplift 

 of the mountain mass; and in considering these questions it will be 

 referred to again. It is also important to note that the fauna belongs 

 to the Gulf of California rather than to the Southern California coast. 

 Hence the Gulf of California probably extended into the region of 

 the present San Gorgonio Pass at the time of the deposition of the 

 Lion sandstone. 



Fig. 6. Section west of San Gorgonio Eiver. Gr, Granite; Seh, Schist; 

 Hsh, Hathaway shale; Hs, Hathaway sandstone; Cf, Cabezon fanglomerate; 

 Hf, Heights fanglomerate. 



Hathaway formation. — A light grey shale, containing hard cal- 

 careous streaks, outcrops with a dip of 15° to the north near the 

 mouth of the canon west of San Gorgonio River. Farther up in the 

 canon the dip becomes greater and about two hundred yards from 

 the mouth of the canon this shale is conformably overlain by a grey 

 sandstone, both having a dip of 45°. The sandstone is light grey in 

 color and contains many streaks of angular pebbles derived from the 

 igneous and metamorphic rocks to the north. The admixture of coarse 

 and fine material and the general poor definition of the beds suggest 

 very strongly that the deposit was land-laid. The shale below is 

 identical with the material found in the playas in the desert north 

 of the mountain range. Near the sandstone-shale contact the shale 

 contains strata of sandstone similar to that overlying it, thus showing 

 a gradation of one into the other. Near the head of the canon the 

 sandstone projects through the flat-lying fanglomerate with a strike 

 of S 60° W and a dip of 45° NW (fig. 6). On the west side of San 

 Gorgonio Canon, at its mouth, the sandstone outcrops with the same 

 dip and strike. 



-- Vaughan, T. W., The reef-coral fauna of Carrizo Creek, Imperial County, 

 California, and its significance, IT. S. G. S., Professional paper 98-T. 



