New Mexico Geological Society Annual Spring Meeting — Abstracts

Soda Dam is an active travertine mound located in the Jemez Mountains, Sandoval County, New Mexico. Associated with it are several thermal springs and a number of other travertine deposits of various ages and sizes. Although the thermal springs at Soda Dam have received considerable attention in the past, the travertine deposits have only now been mapped in detail.

In the Soda Dam area, Precambrian gneiss is overlain by Paleozoic sedimentary rocks and Quaternary travertine. From oldest to youngest, the sedimentary strata include the Mississippian Arroyo Peñasco and Log Springs Formations, and the Pennsylvanian Osha Canyon, Sandia, and Madera Formations. A northeast-striking, high-angle normal fault intersects the western end of Soda Dam. Herein designated as the Soda Dam fault, it is exposed for only about 40 m where it separates clastic sediments of the Sandia Formation from Precambrian gneiss. The Soda Dam fault is the primary conduit for the thermal waters that have formed and continue to form the travertine deposits. The thermal waters migrating along the fault are further dispersed by two dominant fracture sets having trends of N20-41^o E and N43-56^o W. Soda Dam, which has formed along a northwest-trending fracture, is one of the larger and currently the most active of the travertine deposits, a consequence of being connected directly to the Soda Dam fault.