Geol.— Vol. II. ] ANDERSON— STRATIGRAPHIC STUDY 1 85 



throughout a distance of twenty miles along their outcrop, 

 where they are almost entirely uncovered, regularly stratified, 

 and quite fossiliferous. Where they rest upon the Monterey 

 Shales, which for the greater part of the distance they do, 

 there is but little appearance of stratigraphic divergence, 

 except an abrupt transition from fine to coarse sediment. In 

 their dip and strike there is considerable uniformity, at most 

 points at least, though there is at some points a sudden 

 change from the hard shales of the Monterey to the soft 

 coarse sands and conglomerates of the Coalinga Beds. As 

 they are followed along their contact, however, as they can 

 be easily for many miles, the Coalinga Beds are not only 

 found resting upon different portions of the Monterey at dif- 

 ferent points, but toward the south they rest in turn upon 

 Monterey Shales, the Eocene, and the Chico. 



The nonconformity therefore of the CoaHnga Beds with 

 all of these older series may be considered equally clear. 



The stratigraphic nonconformity of the Coalinga Beds, 

 on the other hand, with the Etchegoin Beds is also equally 

 clear. 



This is best shown near the northeast corner of the map of 

 the Coalinga field, or about seven miles north of Coalinga. 

 As the basal beds of the Etchegoin are followed westward 

 through the field, they rest upon, and then close out succes- 

 sively lower and lower strata of the CoaHnga Beds until 

 finally the latter disappear from the stratigraphic section 

 entirely, and the Etchegoin Beds are found resting upon the 

 Monterey Shales. A similar occurrence may perhaps also 

 be seen west of CoaHnga, where the Etchegoin Beds are 

 found passing from the CoaHnga Beds to the underlying 

 Chico. 



A faunal study of the CoaHnga Beds shows them more 

 closely related to the Temblor than to any later or living 

 faunas. Notice for example in the basal CoaHnga — that is 

 in the Reef Beds — the occurrence of Agasoma kernianum. 

 Area montereyana, and Pecten discus, besides many other 

 forms closely alHed to those of the Temblor Beds. 



