Circular 205—Laboratory data for calcic soils in central New Mexico—Background information for mapping Quaternary deposits in the Albuquerque Basin

By M. N. Machette, T. Long, G. O. Bachman, and N. R. Timbel, 1997, 63 pp., 2 tables, 3 figs., 1 appendix.

The descriptive and laboratory data are reported in tabular form in the appendix. Supersedes the U.S. Geological Survey's Open-file Report 96-722. The U.S. Geological Survey conducted geologic mapping in the central part of the Rio Grande rift in New Mexico during the middle to late 1970s. As part of this effort, the authors described, sampled, and analyzed more than 50 soils on Quaternary deposits in order to establish criteria for mapping different ages of deposits and for using calcic soils as a relative-age tool. These data were used in two papers summarizing regional aspects of calcic soils as part of detailed 1:24,000-scale mapping of the San Acacia 7½-min quadrangle in the southern part of the Albuquerque basin and regional 1:250,000-scale mapping of the Socorro 1º x 2º quadrangle. In addition, detailed soil analyses were made for dating movement on specific Quaternary faults and as a tool for deciphering timing of faulting on a regional basis. Although the soil data was fundamental to each of these studies, it was never archived nor released as a public document.

With the renewed interest in the Quaternary geologic and tectonic history of the middle Rio Grande drainage basin (current USGS cooperative project between Water Resources and Geologic Divisions and the New Mexico Bureau of Mines and Mineral Resources) it seems appropriate to publish this data as reference material for future stratigraphic work. This report includes basic geologic and geographic information as well as laboratory and chemical data used to calculate the amount of secondary (pedogenic) calcium carbonate in 52 soil profiles from central New Mexico. The descriptive and laboratory data are reported in tabular form in the appendix. Circular 205 supersedes the U.S. Geological Survey's Open-file Report 96-722.