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Evolution of granitoids in the Catalina metamorphic core complex, southeastern Arizona: U-Pb, Nd, and Hf isotopic constraints
- Source :
- Contributions to Mineralogy and Petrology. June 1, 2013, Vol. 165 Issue 6, p1295, 16 p.
- Publication Year :
- 2013
-
Abstract
- The Santa Catalina Mountains, SE Arizona, was one of the first metamorphic core complexes to be described. Despite its status as a type example, relatively little is known about precise ages and origins of the intrusive rocks that make up most of the crystalline core. U-Pb and Hf isotopic data by laser ablation-inductively coupled plasma-mass spectrometry from zircons and Nd isotopic results from whole rocks were obtained for 12 granitoids ranging from 1,440 to 26 Ma. Results confirm that the 1.44-Ga Oracle Granite extends through the Catalina Range as variably mylonitic granite and banded gneiss. Laramide intrusions (67-73 Ma) display initial [ζ.sub.Nd] values -5to -8 and [ζ.sub.Hf] from -7.5 to -9. Magmatic ages for the prominent white granite sills of the Wilderness suite are 46-57 Ma, in agreement with Terrien (2012), and these granites have initial [ζ.sub.Nd] values -8 to -10 and [ζ.sub.Hf] from -7 to -14. Lastly, the undeformed Catalina Granite has an age of 26 Ma, with an initial [ζ.sub.Nd] and [ζ.sub.Hf] of -6 and -8, respectively. Our Nd results agree with limited results from Farmer and DePaolo (89:10141-10160, 1984). Although the Catalina Granite seems to have a significant juvenile component based on Nd and Hf, most of the Laramide and Wilderness intrusions contain Nd and Hf compositions lying close to the evolution of 1.44-Ga Oracle Granites, a fact that is confirmed by the U-Pb data, which show both 1.7- and 1.4-Ga zircon cores in these samples, with 1.4 Ga as the dominant core age. In order to become the dominant source of most of the 72-45-Ma magmas, the Oracle pluton must not only extend across the whole Catalina region, but also have abundant deep-seated equivalents to provide magma sources. Keywords Santa Catalina metamorphic core complex * Granite origins * U-Pb ages * Hafnium isotopes * Neodymium isotopes<br />Introduction The Santa Catalina metamorphic core complex (Fig. 1), part of a chain of NW-trending metamorphic core complexes stretching across Arizona (Banks 1980; Davis 1980), is among the first occurrence [...]
- Subjects :
- Granite
Toy industry
Earth sciences
Subjects
Details
- Language :
- English
- ISSN :
- 00107999
- Volume :
- 165
- Issue :
- 6
- Database :
- Gale General OneFile
- Journal :
- Contributions to Mineralogy and Petrology
- Publication Type :
- Academic Journal
- Accession number :
- edsgcl.336941321
- Full Text :
- https://doi.org/10.1007/s00410-013-0859-4