Chowdhury, Ali H.1, Cindy Ridgeway1, Robert E. Mace1
(1) Texas Water Development Board, Austin, TX
ABSTRACT: Source Areas of the San Solomon Spring System, West Texas: Chemical and Isotopic Evidence
The San Solomon Spring system includes Phantom Lake, Giffin, Saragosa, San Solomon,
West Sandia and East Sandia springs. They are located along the valley floor between the
Davis Mountains and the Toyah basin. These springs historically provided a considerable
amount of irrigation water for this semi-arid area. Two rare endangered species, the
Comanche spring pupfish and the Pecos gambusia, are also endemic to these springs.
Two sources of waters were identified for the springs – one derived from the Davis Mountains and the other from west of the Apache and the Delaware Mountains. Discharge from the Davis Mountains fails to reach the springs except during intense local rainfall events. Groundwater from the Davis Mountains is dominated by Ca-Na-HCO3 facies. The spring waters and the groundwater west of the Apache and the Delaware Mountains are dominated by Na-Cl-SO4 facies. Groundwater composition and 34S values from west of the Apache and the Delaware Mountains indicate their derivation from dissolution of halite and gypsum. Groundwater from the Davis Mountains is fresh containing low total dissolved solids. Groundwater from the Davis Mountains has high 3H, 14C pmC, and lighter 13C values suggesting contribution from modern to sub-modern waters. Most of the spring waters and groundwater from west of the Apache and the Delaware Mountains have low 3H, low 14C pmC and heavier 13C values suggesting their derivation from an older groundwater system. NETPATH simulations suggest that a substantial amount of the spring waters could be derived from west of the Apache and the Delaware Mountains.
AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.