Gravitational observations were made of the pre-Cambrian Coal Creek serpentine mass in Blanco and Gillespie Counties, Texas, the geology of which had been mapped previously. The observed gravitational anomalies indicate roughly the depth of the serpentine mass below which it may possibly grade into its parent peridotitic rock. Probable correlation between the gravitational map and the other geologic features of the area is indicated.

The magnetic iron-ore prospects of the Llano region of central Texas were investigated in a program which combined dip-needle and gravity-meter surveys by the Bureau of Economic Geology of The University of Texas and the U.S. Geological Survey with exploration by the U.S. Bureau of Mines. Magnetic observations were made on the Iron Mountain, the Bader, the Gamble, and the Olive mine prospects. Gravity observations were made over the first three areas, which subsequently were drilled. Approximately 65,000 long tons of ore is indicated for the Iron Mountain deposit.

Steeply dipping shales and interbedded sandstones presumably of the Ouachita facies have been discovered along the Colorado River in Burnet and Travis counties, Texas. Previously the Ouachita facies was known in Texas only from bore-hole samples. The outcropping rocks are not metamorphosed, whereas many of the borehole samples described in the literature are metamorphosed.