Contributions to the geology and paleontology of San Juan County, New Mexico: 1. Stratigraphy of a part of the Chaco River valley

This preliminary paper is an attempt to set forth the principal features of the stratigraphy in a part of the San Juan Basin-to describe the succession of strata irrespective of possible correlations and thereby to establish a type section for the formations exposed and to bring out their relations to the strata immediately above and below. The paper presents only a part of the data collected by a field party of the United States Geological Survey in the season of 1915, in charge of the writer, and does not describe the economic resources of the area, such as coal, nor the general geologic problems.