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



175 



bituminous appearance in their yellow red, and brown dis- 

 colorations. The stratigraphic position of these white marly 

 beds can be well observed at many points, as on the south 

 side of Sec. 20, T. 19 S., R. 15 E., where a conspicuous 

 reef of sandstone crosses the ravine, with marly beds both 

 above and below. This sandy stratum, on account of its dis- 

 position to protrude here into a sort of wall, and from the 

 fact of its being fossiliferous, was during our field-study 

 termed the J^eef Bed, and it proved a useful name in further 

 exploration. The accompanying sections show the principal 

 stratigraphic features of the Coalinga Beds at two or more 



points: 



ft. 



Yellow sands, etc 1300 



Tamiosoma Bed with oysters, pectens, etc... 20 



Yellow sands 550 



White shale (marly) 20 



Dark sands 50 



Reef Bed 40 



White shale with oysters 20 



Basal sands, etc 180 



Coalinga Beds ten miles 

 north of Coalinara 



Coalinga Beds twenty 

 miles northwest of - 

 Coalinga 



Coalinga Beds three 

 miles west of Coal- 

 inga 



Yellow sands 1000 



Sands with oysters 6 



Sandy white shales 80 



Tamiosoma Bed with oysters, pectens, etc... 15 



Yellowish sands, gravels, etc 320 



Reef Bed (sandy) 15 



Basal sands and conglomerate 120 



Blue sands, gravels, etc 2400 



Pecten beds 40 



Sands, gravels, etc 700 



Sands and yellow gravels 1000 



Dark sands with Diplodonta harfordi. 50 



Reef Bed (sand stone) 50 



Gray sands, unconsolidated 200 



1 Basal gravels 50 



It will be seen by an inspection of these sections that there 

 is throughout the field but little continuity to any of the litho- 

 logic features that seem locally to be significant, as gravels 

 give place to sands, and both become locally calcareous, or 

 the reverse. 



A somewhat more satisfactory means of correlating or 

 identifying strata is found in the faunal contents as illustrated 



