1916] Merriam: Mammalian Remains from the Tejon Hills 113 



garita," considered as Upper Miocene; and (3) an alluvial or fresh- 

 water formation described as the "Chanac" by Dr. Buwalda. An 

 unconformity is reported to occur between "Temblor" and "Santa 

 Margarita." The Chanac formation is later than the "Santa Mar- 

 garita" and is presumed to be unconformable upon it, but the evi- 

 dence is not complete on this point. 



The 1915 party found remains only in beds of the uppermost or 

 Chanac formation, though they occurred at localities in close prox- 

 imity to marine beds. 



Following are the statements as to geologic sequence and occur- 

 rence of mammalian fauna by Dr. Buwalda and Dr. Clark : 



Note on the Geology of the Tejon Hills, Furnished by J. P. Buwalda 



The Tejon Hills occupy an area about seven miles long in a north- 

 south direction and about three miles wide, on the eastern side of the 

 southern end of the San Joaquin Valley. They rise to heights of 

 six hundred to eight hundred feet above the floor of the valley, and 

 present a subdued topography. 



The section in the Tejon Hills contains three Tertiary formations. 

 The lowermost is a series of sandstones and conglomerates considered 

 by Dr. B. L. Clark to be of Monterey age (Vaqueros or Temblor, 

 marine Lower Miocene). Overlying these strata unconformably is 

 a formation considered by Dr. Clark to be the equivalent of the ' ' Santa 

 Margarita" (marine Upper Miocene). The uppermost formation is a 

 terrane which is apparently of terrestrial origin. 



The Monterey is exposed over an area about two and one-half 

 miles in length between Comanche Creek and the escarpment of old 

 crystalline rocks of the Sierra Nevada. It lies on an eroded surface of 

 the crystalline rocks and is not faulted against them. The formation 

 consists of dark gray and yellow sandstones. It is often conglomer- 

 atic, and is usually rather coarse and massive. Conglomerate beds 

 occur especially in the upper and lower parts of the formation. The 

 pebbles and boulders are usually quartz and are well waterworn. The 

 thickness is estimated at about three hundred feet. The formation dips 

 gently toward the west and away from the crystalline rocks. It con- 

 tains a marine fauna determined by Dr. B. L. Clark as Lower Miocene. 



In the northern end of the Tejon Hills, strata of distinctly differ- 

 ent character overlie the Monterey just described and extend up on 

 the crystalline rocks. They are exposed over an irregular area about 

 two miles in diameter around the lower portion of Comanche Creek. 

 These beds consist of strikingly white and cream-colored quartzose 



