CaltechAUTHORS
  A Caltech Library Service

Oxygen isotope studies of minerals in stony meteorites

Taylor, Hugh P., Jr. and Duke, Michael B. and Silver, Leon T. and Epstein, Samuel (1965) Oxygen isotope studies of minerals in stony meteorites. Geochimica et Cosmochimica Acta, 29 (5). pp. 489-512. ISSN 0016-7037. http://resolver.caltech.edu/CaltechAUTHORS:20151021-100249965

Full text is not posted in this repository. Consult Related URLs below.

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20151021-100249965

Abstract

Oxygen isotope analyses demonstrate the following sequence (as in terrestrial igneous rocks) of increasing O^(18) content for coexisting minerals of stony meteorites: olivine, pyroxene, plagioclase, free silica. Except for the carbonaceous chondrites, the O^(18)/O^(16) ratio of a given mineral is quite uniform in each meteorite class. Differences exist between classes of meteorites, however, as well as between certain meteorites and terrestrial igneous rocks. For example, the O^(18)/O^(16) ratios of meteoritic pyroxenes vary from δ = −0.5 per mil to δ = + 8.6 per mil (relative to SMOW), whereas pyroxenes in 8 terrestrial igneous rocks have δ-values which range only from + 5.5 to +6.6. The oxygen isotope data suggest a separation of the stony meteorites into three groups, as follows: 1. I. Basaltic achondrites, hypersthene achondrites, and mesosiderites—with pyroxene δ-values of 3.7 to 4.4. 2. II. Hypersthene-olivine chondrites, bronzite-olivine chondrites, enstatite chondrites, enstatite achondrites, and nakhlites—with pyroxene δ-values of 5.3 to 6.3. 3. III. Types I, II and III carbonaceous chondrites, and ureilites—with highly variable olivine and pyroxene δ-values. It is suggested that the meteorites within each of these three groups are genetically related to one another, but that the three groups may themselves be only distantly related or unrelated. The chondrites have O^(18)/O^(16) ratios similar to their terrestrial analogs, the ultramafic rocks. However, whereas terrestrial basaltic rocks are 1 to 2 per mil richer in O^(18) than ultramafic rocks, the basaltic meteorites are 0.5 to 1.5 per mil lower than chondrites; thus there are serious restrictions placed on any postulated derivation of the basaltic meteorites from chondrites. In addition, the carbonaceous chondrites cannot be simply normal chondrites which have suffered a low-temperature alteration. The olivine in carbonaceous meteorites is lower in O^(18)/O^(16) and isotopically much more variable than chondrite olivine, implying that it is derived from a distinctly different source material.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1016/0016-7037(65)90043-8DOIArticle
http://www.sciencedirect.com/science/article/pii/0016703765900438PublisherArticle
Additional Information:© 1965 Pergamon Press Ltd. Received 28 August 1964. The authors are indebted to the following persons who kindly provided samples of meteorites for analysis: H. S. BROWN, R. E. FOLINSBEE, G. GOLES, E. P. HENDERSON, I. KAPLAN, J. F. LOVERING, B. MASON, C. B. MOORE, V. R. MURTHY, B. ROY, R. SCHMITT, H. SUESS, H. C. UREY, W. VON ENGELHARDT and J. ZÄHRINGER. Financial support for this research was provided by the National Science Foundation (Grant no. G23992), and by the Atomic Energy Commission Contract AT(04-3)-427, CALT-427-1.
Funders:
Funding AgencyGrant Number
NSFG23992
Atomic Energy CommissionAT(04-3)-427
Record Number:CaltechAUTHORS:20151021-100249965
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20151021-100249965
Official Citation:Hugh P Taylor, Michael B Duke, Leon T Silver, Samuel Epstein, Oxygen isotope studies of minerals in stony meteorites, Geochimica et Cosmochimica Acta, Volume 29, Issue 5, 1965, Pages 489-512, ISSN 0016-7037, http://dx.doi.org/10.1016/0016-7037(65)90043-8. (http://www.sciencedirect.com/science/article/pii/0016703765900438)
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:61365
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:21 Oct 2015 19:08
Last Modified:21 Oct 2015 19:08

Repository Staff Only: item control page