AERORADIOACTIVITY SURVEY AND RELATED SURFACE GEOLOGY OF PARTS OF THE SAN FRANCISCO REGION, CALIFORNIA (ARMS-I)

摘要

A recent aeroradioactivity survey in the San Francisco region, Calif., shows a moderate range of 0 to 1000 counts per second in the levels of natural radioactivity. The lower levels can be related to unconsolidated sediments with a high water content and the higher levels can be related to igneous rocks or alluvium and soils derived from igneous rocks.nThe survey is approximately 14,000 square miles in area and was made by the U. S. Geological Survey on behalf of the Division of Biology and Medicine, U. S. Atomic Energy Commission. Continuous radioactivity profiles were obtained with scintillation counting equipment at approximately 500 ft above the ground on parallel northeast-southwest flight lines spaced 1 mile apart. A map of aeroradioactivity levels was prepared from the profiles.