Coupled Sr-O isotope variations as an indicator of source heterogeneity for the Northern Peninsular Ranges batholith
- Creators
- Hill, R. I.
- Silver, L. T.
- Taylor, H. P., Jr.
Abstract
Primary δ^(18)O values for tonalitic rocks from the San Jacinto Intrusive Complex range from +9.0 to +10.6; initial ^(87)Sr/^(86)Sr for the same samples varies from 0.7058 to 0.7076. Rocks with low δ^(18)O tend to have higher initial ^(87)Sr/^(86)Sr. The majority of samples have a limited range of δ^(18)O values (+10.0–+10.4) that is anticorrelated with colour index; this variation is compatible with crystallization of rocks with varying mineral abundances from an homogeneous (for oxygen) reservoir. More mafic rocks show a large range of δ^(18)O values, reflecting original variations in source material compositions. The combined Sr-O isotope data demonstrate that three or more distinct components were involved in the genesis of these rocks; these three components are also seen in batholithic rocks from the Mojave Block and Sierra Nevada to the north. These data are interpreted as indicating a 0–35% (oxygen atom basis) contribution to the San Jacinto rocks from an old continental lithosphere source.
Additional Information
© 1986 Springer-Verlag. Received January 21, 1985; accepted October 28, 1985. Financial support for field and laboratory work was provided by NSF Grants EAR 76-23153 and EAR 77-23507 to LTS and EAR 78-16874 to HPT; by DOE Contract DE-AC13-76 GJO 1664, Bendix Field Engineering Corp. subcontract No. 79-384-E to LTS; and by a grant from the Atlantic Richfield Corporation to L.T. Silver. Support for RIH was also provided by a Conoco Fellowship and by the Division of Geological and Planetary Sciences, California Institute of Technology. The California Dept. of Parks and Recreation kindly allowed sample collecting within Mt. San Jacinto State Park; the U.S. Forest Service and the Lake Hemet Municipal Water District allowed access to lands normally closed to public entry.Additional details
- Eprint ID
- 42591
- Resolver ID
- CaltechAUTHORS:20131120-102544794
- EAR 76-23153
- NSF
- EAR 77-23507
- NSF
- EAR 78-16874
- NSF
- DE-AC13-76 GJO 1664
- Department of Energy (DOE)
- 79-384-E
- Bendix Field Engineering Corp.
- Atlantic Richfield Corporation
- Conoco Fellowship
- Caltech Division of Geological and Planetary Sciences
- Created
-
2013-11-20Created from EPrint's datestamp field
- Updated
-
2021-11-10Created from EPrint's last_modified field
- Other Numbering System Name
- Caltech Division of Geological and Planetary Sciences
- Other Numbering System Identifier
- 4064