| Abstract: | Rb and Sr concentrations and Sr-isotopic compositions were measured in 41 whole-rock samples and 12 mineral separates from units of the Samail ophiolite, including peridotite, gabbro, plagiogranite, diabase dykes, and gabbro and websterite dykes within the metamorphic peridotite. Ten samples of cumulate gabbro from the Wadir Kadir section and nine samples from the Wadi Khafifah section have 87Sr/86Sr ratios of 0.70314 + or - 0.00030 and 0.70306 + or - 0.00034, respectively. The dispersion in Sr- isotopic composition may reflect real heterogeneities in the magma source region. The average Sr-isotopic composition of cumulate gabbro falls in the range of isotopic compositions of modern MORB. The 87Sr/86Sr ratios of noncumulate gabbro, plagiogranite, and diabase dykes range 0.7034-0.7047, 0.7038-0.7046 and 0.7037- 0.7061, respectively. These higher 87Sr/86Sr ratios are due to alteration of initial magmatic compositions by hydrothermal exchange with sea-water. Mineral separates from dykes that cut harzburgite tectonite have Sr-isotopic compositions which agree with that of cumulate gabbro. These data indicate that the cumulate gabbro and the different dykes were derived from partial melting of source regions that had similar long-term histories and chemical compositions.-T.R. |
| Genre: | Article |
| ProdID: | 70011691 |
| Citation Author: | Lanphere, M. A.; Coleman, R. G.; Hopson, C. A. |
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| Citation End Page: | 2720 |
| Citation Issue: | B4 |
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| Citation Language: | English |
| Citation Larger Work Title: | Journal of Geophysical Research |
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| Citation Number Of Pages: | 12 |
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| Citation Search Results Text: | Sr isotopic tracer study of the Samail ophiolite, Oman.; 1981; Article; Journal; Journal of Geophysical Research; Lanphere, M. A.; Coleman, R. G.; Hopson, C. A. |
| Citation Start Page: | 2709 |
| Citation Volume: | 86 |
| Citation Year: | 1981 |
| Type: | citation/reference |
| Text: | Sr isotopic tracer study of the Samail ophiolite, Oman.; 1981; Article; Journal; Journal of Geophysical Research; Lanphere, M. A.; Coleman, R. G.; Hopson, C. A. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Thu, 1 Jan 1981 00:00 -0600 |
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