Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Sharp, W. D. Articles by Renne, P. R. Search for Related Content GeoRef GeoRef Citation

Development of Cretaceous transpressional cleavage synchronous with batholith emplacement, central Sierra Nevada, California

¹ Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, California 94709, USA
² Earth Sciences Department, University of California, Santa Cruz, California 95064, USA

Metamorphosed strata of the Ritter Range pendant record structures formed during the emplacement of granitic plutons at upper crustal levels (<8 km) in the Late Cretaceous Sierra Nevada magmatic arc. Paleozoic to Middle Jurassic strata of the pendant have been penetratively shortened 30%–50%, forming slates, phyllites, and schists with bedding-inclined cleavage and associated linear structures. The cleavage, secondary cleavages, and folds associated with these cleavages have orientations and geometries consistent with dextral transpression between the Farallon and North American plates. Microstructural relations show that cleavage development accompanied greenschist to amphibolite facies metamorphism. Metamorphic hornblende, muscovite, and biotite in the wall rocks show weak to strong preferred orientation and have ⁴⁰Ar/³⁹Ar plateau ages ranging from about 85 to 80 Ma. Hornblende, and possibly muscovite, are expected to retain ⁴⁰Ar at or near estimated peak metamorphic temperatures of 500 °C, thus their ⁴⁰Ar/³⁹Ar ages closely correspond to the time of cleavage formation. Granitic plutons adjacent to the Ritter Range pendant have yielded U-Pb and other ages that cluster from 91 to 82 Ma. We conclude that bedding-inclined cleavage and metamorphism in the Ritter Range wall rocks developed in a dextral transpressive strain regime penecontemporaneously with emplacement of adjacent granitic plutons.

Key Words: emplacement • geochronology • granite • Sierra Nevada batholith • structures • transpression

This article has been cited by other articles:

				E. Horsman, B. Tikoff, and D. Czeck Rheological implications of heterogeneous deformation at multiple scales in the Late Cretaceous Sierra Nevada, California Geological Society of America Bulletin, January 1, 2008; 120(1-2): 238 - 255. [Abstract] [Full Text] [PDF]

				A. R.C. Kylander-Clark, D. S. Coleman, A. F. Glazner, and J. M. Bartley Evidence for 65 km of dextral slip across Owens Valley, California, since 83 Ma Geological Society of America Bulletin, July 1, 2005; 117(7-8): 962 - 968. [Abstract] [Full Text] [PDF]

				O. T. Tobisch, O. T. Tobisch, R. S. Fiske, J. B. Saleeby, E. Holt, and S. S. Sorensen Steep tilting of metavolcanic rocks by multiple mechanisms, central Sierra Nevada, California Geological Society of America Bulletin, July 1, 2000; 112(7): 1043 - 1058. [Abstract] [Full Text] [PDF]