|
|
|
|||||||||||||||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
1 Department of Geological Sciences, University of North Carolina, Chapel Hill, North Carolina 27599-3315, USA
2 Department of Geological Sciences and Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado 80309, USA
Recent seismic experiments across the southern Sierra Nevada, California, show that the range lacks a thick crustal root. Xenolith studies indicate that delamination and loss of much of the lower crust may have occurred between 10 and 3 Ma. We estimate that delamination occurred ca. 3.5 Ma on the basis of a sudden pulse of mafic potassic magmatism within and just east of the Sierra Nevada from 4 to 3 Ma. This pulse interrupted the low level of volcanism that had prevailed regionally since 13 Ma. Delamination could have promoted magmatism via decompression melting, heating of the shallow lithosphere by upwelling asthenosphere, and foundering of crustal rocks into the mantle, and could have provided dynamic support to the range. Foundering of the lower crust may have occurred spontaneously, owing to negative buoyancy, or may have been triggered by extension between the Sierra Nevada and Death Valley.
Key Words: tectonics magmatism uplift lithosphere potassic composition
This article has been cited by other articles:
![]() |
G. Pe-Piper, D. J.W. Piper, I. Koukouvelas, L. M. Dolansky, and S. Kokkalas Postorogenic shoshonitic rocks and their origin by melting underplated basalts: The Miocene of Limnos, Greece Geological Society of America Bulletin, January 1, 2009; 121(1-2): 39 - 54. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Cousens, J. Prytulak, C. Henry, A. Alcazar, and T. Brownrigg Geology, geochronology, and geochemistry of the Miocene-Pliocene Ancestral Cascades arc, northern Sierra Nevada, California and Nevada: The roles of the upper mantle, subducting slab, and the Sierra Nevada lithosphere Geosphere, October 1, 2008; 4(5): 829 - 853. [Abstract] [Full Text] [PDF] |
||||
![]() |
C.J. Busby, S.B. DeOreo, I. Skilling, P.B. Gans, and J.C. Hagan Carson Pass-Kirkwood paleocanyon system: Paleogeography of the ancestral Cascades arc and implications for landscape evolution of the Sierra Nevada (California) Geological Society of America Bulletin, March 1, 2008; 120(3-4): 274 - 299. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. M. Phillips Geological and hydrological history of the paleo-Owens River drainage since the late Miocene Geological Society of America Special Papers, January 1, 2008; 439(0): 115 - 150. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. D. Walker, T. D. Bowers, R. A. Black, A. F. Glazner, G. Lang Farmer, and R. W. Carlson A geochemical database for western North American volcanic and intrusive rocks (NAVDAT) Geological Society of America Special Papers, January 1, 2006; 397(0): 61 - 71. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. H. Jones, G. L. Farmer, and J. Unruh Tectonics of Pliocene removal of lithosphere of the Sierra Nevada, California Geological Society of America Bulletin, November 1, 2004; 116(11-12): 1408 - 1422. [Abstract] [Full Text] [PDF] |
||||
![]() |
O. S. Boyd, C. H. Jones, and A. F. Sheehan Foundering Lithosphere Imaged Beneath the Southern Sierra Nevada, California, USA Science, July 30, 2004; 305(5684): 660 - 662. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. M. Stock, R. S. Anderson, and R. C. Finkel Pace of landscape evolution in the Sierra Nevada, California, revealed by cosmogenic dating of cave sediments Geology, March 1, 2004; 32(3): 193 - 196. [Abstract] [Full Text] [PDF] |
||||
![]() |
W.G. Ernst, D. S. Coleman, and C.M. Van de Ven Petrochemistry of granitic rocks in the Mount Barcroft area--Implications for arc evolution, central White Mountains, easternmost California Geological Society of America Bulletin, April 1, 2003; 115(4): 499 - 512. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. L. Farmer, A. F. Glazner, and C. R. Manley Did lithospheric delamination trigger late Cenozoic potassic volcanism in the southern Sierra Nevada, California? Geological Society of America Bulletin, June 1, 2002; 114(6): 754 - 768. [Abstract] [Full Text] [PDF] |
||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |