Tertiary Mammals from the Auriferous Gravels near Columbia, California

Abstract

Since their earliest exploitation for gold, the auriferous gravels of the Sierra Nevada have yielded on occasion remains of fossil mammals whose age clearly indicates the presence of deposits belonging to several divisions of the Cenozoic. Extensive hydraulic and placer mining in this region is largely responsible for the fact that many localities where fossil materials have been found in the past are now no longer accessible. In the course of mining operations by the Springfield Development Company, two horse teeth and a fragmentary camel jaw were found in gravels and sands of the Springfield shafts Nos. 2 and 3, located one and one-half miles southwest of Columbia, California. The mammalian remains were obtained by R. W. Chaney from J. S. Cademartori, Superintendent of the Springfield Development Company. Since the stratigraphic occurrence of the material, as determined by Professor George D. Louderback, is definitely established with reference to the Tertiary section exposed in this region, interest attaches to the age and correlation of the deposits as suggested by the relationships of the fossil mammals. Moreover, the presence of fossil plants in the sedimentary series offers, among other features, an opportunity to check the age relationships of the accumulations by the application of paleobotanical evidence.