Geothermal Assessment of Dona Ana County, New Mexico

Abstract

Sixty conductive heat flow values for Dona Ana County, New Mexico, were calculated from measured temperature-depth data and estimated thermal conductivities. A histogram of the heat flow values (above the water table) shows a mode of 100-150 mW m-2 and a range exceeding -42 to 672 mW m-2. A bottom hole temperature gradient map show that the geographic distribution of temperature gradients is as follows: 1) a north-northwesterly trend of anomalously high gradients along the Valley fault; 2) abnormally low or negative gradients associated with the large intrabasin groundwater flow of the Mesilla Bolson; 3) a west-northwesterly trend of high gradients bounded by more normal values running parallel to or online with a structural feature know as the Aden Rift; and 4) high gradients associated with known geothermal areas. The elevate temperatures and temperature gradients along the Valley fault and the Aden Rift are thought to be due to ascending warm or hot water up the faults and fractured zones, while the reduced temperatures and temperature gradients in the Mesilla Bolson are due to downward percolation of recharge water and intrabasin groundwater flow.