Print this pageTexas Heat Flow Patterns
Petru T. Negraru, David D. Blackwell, and Maria Richards
Geology, Southern Methodist University, Dallas, TX
New heat flow data are combined with BHT data in Texas and surrounding areas to more accurately define the thermal field. The results are interpreted in terms of local and regional geology and tectonics. The variation in heat flow across Texas can be explained by a combination of three factors: changes in basement radiogenic heat production, heat generation within sedimentary rocks, and the local effect of possible groundwater flow. In south and east Texas, in spite of the moderate heat flow values, temperatures are quite high in the sedimentary section and thus there is significant geothermal potential.
The thermal pattern in north-central Texas defines the Ouachita tectonic front as an important thermal boundary. Heat flow values increase eastward from 48 mW/m2 in the Fort Worth Basin to 61 mW/m2 in the Ouachita tectonic front. It drops to 55 mW/m2 in the interior zone to the east before increasing again to the interior of the Ouachita belt in Louisiana, probably due to a high radioactivity in the accreted basement rocks. In addition, a zone of heat flow values below 44 mW/m2 extends from approximately 30 km north of Dallas towards Oklahoma, and is linked to the low heat flow values recorded in the deep Anadarko Basin and in the frontal part of the Wichita Uplift.
Heat flow data derived from high-resolution temperature logs are compared to the values obtained from conventional BHT. The BHT derived heat flow values suggest that the low heat flow in the Fort Worth basin and north of Dallas are isolated features and that they are not linked to the similarly low heat flow in Midland and Delaware basins. We interpret the 51 mW/m2 values for the Palo Duro basin as a transition zone between low heat flow in the Midland Basin, and higher heat flow immediately north of the Amarillo uplift north into Kansas.
AAPG Search and Discover Article #90078©2008 AAPG Annual Convention, San Antonio, Texas