Ca isotope fractionation on the moonCa has been measured in a lunar soil in order to establish the presence of isotopically mass-fractionated components. Ca was extracted by a series of water leaches after the soils were 'activated' by brief exposures to fluorine gas. The O2 obtained by this fluorination is found to have delta (O-18) of +21 per mil and to be, therefore, significantly mass-fractionated. Ca obtained in the leaches was analyzed using the double-spike technique. Very small Ca isotope fractionation is found in the leaches of this soil of up to 1 per mil per mass unit difference. The small Ca effects are in marked contrast to the measured delta (O-18) for the same sample and to large effects observed in many soils for oxygen, silicon, sulfur, and potassium. The data on Ca provide stringent constraints on models which attempt to explain the isotope mass-fractionation effects in lunar soils.
Document ID
19780057859
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Russell, W. A. (California Inst. of Tech. Pasadena, CA, United States)
Papanastassiou, D. A. (California Inst. of Tech. Pasadena, CA, United States)
Tombrello, T. A. (California Inst. of Tech. Pasadena, CA, United States)
Epstein, S. (California Institute of Technology Pasadena, Calif., United States)