Collection: Books and Periodicals

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Title: The Tertiary Gravels of the Sierra Nevada of California by Waldemar Lindgren (1911) Collection Type: Books and Periodicals Source(s): Google Books # of Pages: 301 Download PDF: User Login Required Download OCR Text: User Login Required

Date Scanned: 2024-07-14 06:26:22 Item Sourced From: PDF First Created: 2025-03-17 05:53:20 Last Updated: 2025-03-17 05:53:20

Original Held At: Searls Historical Library Location: 161 Nevada City Hwy, Nevada City, CA 95959

Page: of 301  

CHAPTER 3. FOSSILS OF THE TERTIARY AURIFEROUS GRAVELS. INTRODUCTION. The fossils found in the Tertiary gravels of the Sierra Nevada comprise mammal remains, including doubtful human bones, associated with which objects of human handiwork are said to have been found; fossil leaves, which in places are very abundant and well preserved; and diatoms, which occur in abundance in several of the so-called ‘‘infusorial earths” in association with rhyolitic tuffs. As will be shown in the following pages, the testimony on which dependence can be placed is confined almost exclusively to the fossil plants and the paleontologic determination of age must therefore be furnished by paleobotany. MAMMAL REMAINS. Whitney, in his volume on the auriferous gravels, gives a list of all the mammal remains which have been found and determined and divides this list into two parts, the first comprising localities in which the bones were found in known and undisturbed Tertiary deposits and the second and larger part including those occurrences in which the geologic formation was less satisfactorily determined. The number of species of clearly prevolcanic occurrence is not large. The most important localities are Douglas Flat and Chili Gulch, in Calaveras County, and the Tuolumne Table Mountain, not far to the south, in Tuolumne County. In the Calaveras County localities bones and teeth of a species of rhinoceros, described by Leidy’ under the name R. hesperius, have been discovered. At Douglas Flat was also found a tooth of the pachyderm Elotherium, which belongs to the Eocene or Qligocene (White River group of the Rocky Mountain region). The material in which this fossil was found is not described. These few occurrences complete the list of fossils which Whitney considered authentic and beyond doubt derived from the Tertiary gravels. Among the less certain occurrences are those of Kincaid Flat, near Sonora, where molars of Bos latifrons are stated to have been found at a depth of 18 feet in the auriferous detritus of that locality. At a number of places in the vicinity of Sonora and Columbia, along a belt of limestone, fossil bones have been found in the clay filling crevices or spaces of dissolution. These fossils belong principally to the well-known species Mastodon americanus. One other species of this genus (MM. obscurus) has been discovered at Dry Creek, in Stanislaus County. At Gold Spring, near the locality mentioned above, a few miles from Sonora, a great quantity of bones were heaped together. A tooth of M. americanus was also found at a depth of 48 feet at Douglas Flat. This tooth, however, did not appear as thoroughly fossilized as the rhinoceros jaw found in the same locality, said to have come from a great depth in the gravel, which in places is probably over 200 feet thick. A number of elephant remains, consisting principally of molar teeth, have been discovered in the Sierra Nevada; among the localities is a place near Murphy, in Calaveras County, where they were found at a depth of about 30 feet in the auriferous detritus overlying the limestone. An excellent specimen, more complete than usual, was found, according to Whitney, near Fresno River, 3 miles above the crossing of the stage road from Hornitos to Visalia. The remains were covered by only 3 or 4 feet of sandy alluvium. All these remains are believed to belong to Elephas americanus or to its variety, E. columh. Leidy has identified remains of Equus ezcelsus Leidy or E. occidentalis Leidy, from 20 feet below the surface at Columbia, Tuolumne County; also at Matlock Gulch, in the same county. Equus caballus is reported from Texas Flat, Kincaid Flat, and Columbia, Tuolumne County; also at Brandy City, Sierra County. The skull found at Brandy City was labeled “from 1 Leidy, Joseph, Contributions to the extinct vertebrate fauna of the western Territories. U. S. Geol. Survey Terr., vol, 1, 1873. 51