A "Residual Temperature Map" of Arizona

Abstract

I made a "Residual Temperature Map" of Arizona using geothermal gradient measurements. To eliminate problems inherent in thermal gradients the following corrections were made: highly disturbed gradients were eliminated; a straight line was fitted to slightly disturbed gradients and the extrapolated temperature was used; temperatures were taken from the 100 m depth interval and the man annual temperature was subtracted; measurements in sedimentary rocks were normalized to those in crystalline rocks to eliminate thermal conductivity difference. On the resulting map, residual temperature zones cross cut major physiographic province boundaries, but show a strong correlation with features on the historical seismicity and major lineament maps of Arizona. Positive anomalies on the residual temperature map are shown on the Geothermal Gradient Map of the Conterminous United States, but negative anomalies generally are not. More confidence can be placed in this map than in a gradient map, although correcting data can be time consuming.