UNIVERSITY OF CALIFORNIA PUBLICATIONS 



BULLETIN OF THE DEPARTMENT OF 



GEOLOGY 



Vol. 10, No. 14, pp. 191-254, 2 text-figs., pis. 6-12 Issued April 19, 1917 



BULLETIN OF THE DEPARTMENT OF 



GEOLOGY 



THE ETCHEGOIN PLIOCENE OF MIDDLE 

 CALIFORNIA 



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JOEGEN O. NOMLAND Ify MAY 4" '1917 # 



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CONTENTS ' ^ 



PAGE 



Introduction , - 192 



Previous work — - 193 



Eelation of the Jacalitos to the Etehegoin 195 



Etehegoin group of Middle California 197 



Areal distribution 197 



Eelation to adjoining formations 200 



Eelation to the Santa Margarita ( ? ) 200 



Eelation to the Tulare 202 



Thickness 203 



Structure - 205 



Lithology of the Etehegoin 206 



Sandstone, clay, and conglomerate 206 



Coal and carbonaceous deposits 207 



Ehyolitic tuffs 208 



Gypsum 209 



Limestone 210 



Invertebrate fauna 210 



Invertebrate zones 210 



Etehegoin fauna west of the Diablo Eange 214 



Fauna of lacustrine( ?) beds 215 



Eange of temperature and depth 216 



Serpula(?) reef 216 



Comparative table showing stratigraphic relationship of faunal zones 



south of Coalinga 216 



Vertebrate fauna 217 



Faunal list of the Etehegoin of the Coalinga district 218 



Age and correlation of the Etehegoin 223 



History of correlation 223 



Age determination ! 225 



Correlation with other Pliocene formations 226 



