Astrogeologic studies, semiannual progress report, February 26, 1961 to August 24, 1961

Abstract

This report is the second semiannual report on a geological program of research conducted by the Geological Survey on behalf of the National Aeronautics and Space Administration. This research is being carried out under the Branch of Astrogeology. The long-range objectives of this program are to determine and map the stratigraphy and structure of the Moon's crust, to develop basic information on processes that have led to the present condition of the Moon's surface, and to work out the sequence of events in the geologic history recorded in the Moon's stratigraphy and structure. The work includes three closely interrelated areas of study: (1) investigation of the chemistry, petrography, and physical properties of extraterrestrial materials that may have been derived from the Moon, such as tektites, certain types of meteorites, and extraterrestrial dust; (2) experimental and field investigations of the mechanics and phenomena of impact of high-speed objects and of cratering; and (3) geologic mapping of the Moon. Immediate objectives for the fiscal year 1961 have included the preparation of geologic maps for the nominal target area for the Ranger Project of the National Aeronautics and Space Administration. Field and laboratory work on craters was directed toward developing data and an adequate theory for the integrated effect of meteoroid bombardment of the lunar surface. Special attention has been given to phase changes and solid state changes produced in rock by meteorite impact. American and Philippine tektites were the principal materials of possible lunar origin to receive detailed petrographic and chemical analysis.