Helium, argon, and carbon in some natural gases
Abstract
Thirty-nine samples of natural gases representing varied chemical compositions and geological occurrences were analyzed for their helium, radiogenic argon, and atmospheric argon contents. The total range in the (He/A)_(rad) ratio was found to be 1.6 to 130 with most samples having values between 6 and 25. This range of values is essentially equal to the production ratio from the uranium, thorium, and potassium in average igneous rocks and a wide variety of sediments. This indicates that all of these natural gases have obtained their radiogenic gases from rather average rock types. This is true in spite of the fact that the gases range in helium content from 37 to 62,000 ppm. A theoretical discussion of the origin of helium and argon in natural gases is given. It can be shown from the ratio of nitrogen to atmospheric argon that most of the nitrogen in these gases cannot come from the entrapment of air. From a consideration of the concentration of atmospheric argon in natural gases it is possible to estimate the proportion of gaseous and aqueous phases assuming diffusive equilibrium. The isotopic composition of the carbon in the methane of these gases was found to be very light. It was shown that for coexisting CH_4-CO_2 pairs the carbon dioxide was always isotopically heavier.
Additional Information
Copyright 1961 by the American Geophysical Union. (Manuscript received April 12, 1960; revised October 11, 1960.) We would like to thank Dr. H. A. Lowenstam for providing us with many of the samples of limestones and shells. The authors are indebted to Mr. Theodore Wen and Mrs. Dorothy Settle for their careful work on the potassium determinations.Attached Files
Published - jgr2272.pdf
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Additional details
- Eprint ID
- 51508
- Resolver ID
- CaltechAUTHORS:20141110-114319192
- NSF
- California Research Corporation
- Atomic Energy Commission
- Created
-
2014-11-10Created from EPrint's datestamp field
- Updated
-
2021-11-10Created from EPrint's last_modified field
- Other Numbering System Name
- Caltech Division of Geological Sciences
- Other Numbering System Identifier
- 978