Subsurface-temperature observations, made by gas-producing companies in south Louisiana during the course of bottom-hole pressure determinations, were compiled on a magnetic tape by the Federal Power Commission. The measurements were taken long after the wells were completed, and they are therefore more nearly true than those taken during electric-logging operations. Reliable temperature versus depth plots could be made for 132 gas fields. The temperature

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gradients range from 1 to 2°F and most are between 1.2 and 1.3°F per 100 ft of depth. At a depth of 10,000 ft the temperature ranges between 190 and 230°F. The most prominent features of the temperature distribution at 10,000 ft is a belt of high temperature about 30 mi wide close to the present coastline. The location of this "hot belt" is puzzling because it is located approximately where the greatest thickness of Cenozoic sediments is believed to occur. Extrapolating the temperature and pressure downward, it seems possible that conditions necessary for regional metamorphism are present in the lower part of the sedimentary column at depths below 40,000 ft. Possibly the recrystallization of the sediments accounts for the high temperature values.

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