Airborne radioactivity surveys for phosphate in Florida

Geologic features of areas of abnormal radioactivity south of Ocala, Marion County, Florida

“…12). The average background radioactivity here, presumably over Ocala limestone, was about 1 /*r per hour (microroentgen per hour) at 500 feet above the ground; the highest anomalies recorded reached a maximum of 11/j.r per hour.1 Moxham (1954) points out that the anomalies seem to conform more or less to outliers of the Hawthorn formation, shown on the state geologic map by Cooke (1945). Several small areas of high radioactivity found during the geologic investigation are shown on plate 12; these evidently lie between the flight lines of the aerial survey.…”

“…B. Cathcart for airborne radioactivity survey. The aerial survey was made with scintillationdetection equipment by flying parallel traverse lines, a quarter of a mile apart, at about 500 feet above the ground (Moxham, 1954). Irregular areas of abnormal radioactivity were found between Ocala and Summerfield, which is about 13 miles southeast of Ocala (pi.…”

“…These anomalies had been discovered by the Geological Survey in 1953 in the course of aerial reconnaissance for uraniferous phosphate deposits (Moxham, 1954). One of the anomalous areas was examined at that time, and several other anomalies were later explored by means of a jeep-mounted power auger (Cathcart, 1954).…”

Geology of phosphate deposits of northern peninsular Florida

“…Ketner in 1952-53, by a program of core drilling for geologic infonnation in the area between the landpebble phosphate and hard-rock phosphate fields in 1953 (Ketner and McGreevy, 1959), and by airborne radioactivity surveys of several areas in 1953 (Moxham, 1954). G. H. Espenshade was given the responsibility of continuing these studies in 1954.…”

“…Sylvia de Q. Mattoso, participant from Brazil in the Geological Survey's program under auspices of the International Cooperation Administration, worked with the field party for 7 weeks in 1956. An area of strong radioactivity anomalies south of Ocala, Marion County, which was discovered by the airborne survey (Moxham, 1954), was studied early in the program by means of 10 auger-drill holes and by surface examination. A brief report was written on the results of that phase of the study (Espenshade, 1958); information from that report is summarized in the present paper.…”