New Mexico Geological Society Annual Spring Meeting — Abstracts

In this study, we examine the variation of heat flow with depth a16ng several profiles in southeast New Mexico. We divide heat-flow data into two groups: shallow heat flows and deep heat flows. The shallow heat flows show areas of surface ground-water recharge and discharge. Shallow heat flows are also affected by deep vertical ground-water movement. This effect is especially pronounced in the area of
the Pecos river, where there is a significant component of recharge to the san Andres formation from deeper formations, and thus deep vertical ground-water movement. Deep heat flows generally mirror shallow heat flows, and indicate areas of deep upward ground-water movement.

We found that upward ground-water flow from deep depths generally raised the shallow temperatures, therefore increasing the shallow temperature gradients and consequently shallow heat flows. Because of the elevated shallow temperatures, the deep gradients, and hence deep heat flows, were lowered. We also found that, east of the Pecos river, downward ground-water flow from shallow depths decreased the shallow temperatures, therefore decreasirig shallow temperature gradients and shallow heat flows. Because the shallow temperatures were lowered and the deep temperatures remained the same, the deep gradients were increased, as well as the deep heat flows. Preliminary numerical modeling results fit well with our conclusions concerning upward and downward vertical ground-water flow.