CORRELATION AND CHRONOLOGY OF ORE DEPOSITS AND VOLCANIC ROCKS. Annual Progress Report No. 2

Technical Report · Fri Jul 01 04:00:00 EDT 1960

OSTI ID:4133143

Damon, P E; Green, W D; Halva, C J; Sabels, B E

The construction of the 60/sup o/ 6-in. first-order singlefocusing mass spectrometer was completed. The design and operation of the trochoidal mass spectrometer, consisting of a CEC Diatron 20 modified for degassing it up to 4OO/ sup o/C, are described. The research effort on ore deposits was concentrated on two major problems which must be solved before precise and accurate dates may be obtained by the helium method using magnetite as the geochronometer. It was necessary (1) to define the location of uranium and thorium in magnetite and (2) to accurately determine the uranium/thorium ratio as well as the total rate of alpha emission. Acid-leaching experiments and radio-autography were used to determine the location of uranium and thorium in magnetite. Fluorimetric analysis and gamma -ray spectroscopy were employed to determine the uranium/ thorium ratio. Various techniques for correlating volcanic rocks were investigated. These include chemical and radiometric as well as petrographic and field techniques. The Plio-Pleistocene basalts of southeastern Arizona and the San Francisco volcanic field and adjacent areas were investigated. (W.L.H.)

• Research Organization: Arizona. Univ., Tucson. Geochronology Labs.
• NSA Number: NSA-15-001590
• OSTI ID: 4133143
• Report Number(s): TID-6482
• Country of Publication: United States
• Language: English

Related Subjects

AGE ESTIMATION
ALPHA DETECTION
BASALT
DEGASSING
DEPOSITS
ELECTRODYNAMICS
GAMMA SPECTROMETERS
GEOLOGY
GEOLOGY, MINERALOGY, AND METEOROLOGY
HELIUM
IRON OXIDES
LUMINESCENT DETECTORS
MAGNETITE
MASS SPECTROMETERS
ORES
QUALITATIVE ANALYSIS
QUANTUM MECHANICS
RADIATION DETECTORS
RADIOAUTOGRAPHY
ROCKS
SCINTILLATION COUNTERS
SPINELS
THORIUM ORES
URANIUM ORES