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Whitman Cross

Publications and source records attributed to Whitman Cross.

16 recordsLinked to original sources
USGS1915

Contributions to the stratigraphy of southwestern Colorado

In the course of field work of the United States Geological Survey in the San Juan region of Colorado observations have been made in the last three seasons that considerably extend our knowledge of the great stratigraphic break below the La Plata sandstone, which is currently assumed to be of Jurassic age. The new data pertain partly to the relations existing in the Gunnison Valley, north of the San Juan Mountains, where the unconformity marking this break was already known at certain places, and partly to the conditions in the Piedra Valley, on the south side of the mountains, where the unconformity had not before been noted. The Piedra Valley is of special interest, and it seems well to call attention to the relations observed even though they were examined only in a reconnaissance. The first part of this paper is devoted to the evidence of the overlap of the La Plata sandstone; the second to the stratigraphic relations in the Piedra Valley. The section of sedimentary formations in Piedra Canyon is of much interest because none of the pre-La Plata formations are known east of this locality on the south side of the San Juan Mountains. Most of these formations exhibit a notably different facies where they reappear from beneath the overlying beds at their nearest exposures in New Mexico, southeast of the Piedra Valley. It is believed that the character of the formations in the Piedra section should be recorded for the benefit of geologists who may be studying the Paleozoic and Mesozoic rocks of New Mexico, and accordingly the second part of the paper presents details of the structure and the stratigraphic section of Piedra Valley.

Colorado↗
USGS1912

Potash-bearing rocks of the Leucite Hills, Sweetwater County, Wyoming

The purpose of the present paper is to give a brief description of the rocks in the Leucite Hills, Wyo., with an estimate of the amount of leucite-bearing rock available and of the approximate amount of potash that these rocks may yield as soon as a process is discovered by which the potash may be dissociated from the rock cheaply enough for commercial use.

Wyoming↗
USGS1907

Ouray folio, Colorado

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Folios of the Geologic Atlas↗
USGS1905

Silverton folio, Colorado

The term San Juan region, or simply "the San Juan," used with variable meaning by early explorers, and naturally with indefinite limitation during the period of settlement, is now quite generally applied to a large tract of mountainous country in southwestern Colorado, together with an undefined zone of lower country bordering it on the north, west, and south. The Continental Divide traverses this area in a great bow. The principal part of the district is a deeply scored volcanic plateau, more than 3000 square miles in extent, drained on the north by the tributaties of the Gunnison River, on the west by those of the Dolores and San Miguel rivers, on the south by numerous branches of the San Juan, and on the east by the Rio Grande. ALl but the latter drainage finds its way to the Gulf of California through the Colorado River.

Colorado↗
USGS1905

Rico folio, Colorado

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Folios of the Geologic Atlas↗