164 University of California Publications in Geology [Vol. 9 



flows antedate the andesites. Basaltic lavas are known to overlie 

 the Esmeralda beds and seem to rest upon an eroded surface cut in 

 the Esmeralda. 



Judging from the amount of movement and erosion in beds above 

 the pre-Esmeralda lavas as compared with that between the lavas and 

 the older series, Buwalda judges that these igneous rocks largely 

 represent lower or middle Miocene time. A postdacustral andesite 

 which has been deformed and much eroded is considered as probably 

 Pliocene. A basalt resting in apparent unconformity upon the post- 

 lacustral andesite at Table Mountain is considered as late Pliocene. 



The Esmeralda formation of the Cedar Mountain region has been 

 subjected to moderate deformation, six or seven low, open folds being 

 noted by Buwalda in crossing Stewart "valley. Since the time of 

 principal deformation the beds have suffered extensive erosion, which 

 has been succeded by a gentle warping presumed to have taken place 

 in Pleistocene time. 



In a sketch of the historical geology of Esmeralda County, Nevada, 

 published in 1902, II. W. Turner 3 refers to lake beds containing 

 abundant fossils four miles west of Black Spring near the line between 

 Esmeralda and Nye counties on the road between Sodaville and Clover- 

 dale. A block containing molluscan and ostracod remains was obtained 

 by Robert Stewart of Sodaville. This specimen was examined by 

 J. C. Merriam who recognized the following molluscan forms: 



Sphaerium, near idahoense Carinifex, sp. a 



Melania?, sp. Carinifex, sp. b 



The Sphaerium and two Carinifex species resembled forms known 

 from the Truckee beds of Fossil Hill in the Kawsoh Mountains of 

 Nevada. Two species of Melania are also known from the Fossil Hill 

 beds. The fauna was considered by Merriam to resemble that of the 

 Truckee, but evidence of similarity to the Esmeralda was not apparent. 



From the block containing the molluscan shells a number of ostra- 

 cods were obtained. These were referred to Dr. R. H. Chapman, who 

 identified the forms as follows : 



Ilyoeypris, sp. nov., near I. gibba Candona, sp. probably new 



but distinct in important points Candona, sp. probably new 



Candona, sp. near C. kingsleyi 



Organic remains representing plants, molluscs, fishes, testudinates. 

 and mammals were obtained in the Cedar Mountain beds by Baker 



3 Turner, H. W., Amer. Geol. vol. 29, p. 268, 1902. 



