skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Implications of U-Pb zircon ages for the tectonic settings of the Smartville and Slate Creek complexes, northern Sierra Nevada, California

Abstract

U-Pb zircon ages combined with stratigraphic and structural data indicate that ca. 160 Ma arc rocks of the Smartville Complex were constructed across ca. 200 Ma arc rocks of the Slate Creek Complex, which were already juxtaposed against more easterly units in the northern Sierra Nevada. The Slate Creek Complex, an ophiolitic thrust sheet east of the Smartville Complex, is 200-210 Ma, which precludes previous correlations with ca. 160 Ma rocks of the Smartville Complex. The Slate Creek Complex tectonically overlies chert-rich Paleozoic-early Mesozoic units along a low-angle fault that is cut by 163-168 Ma and 158-161 Ma plutons. Seven new ages of 160-163 Ma for plutonic rocks in the Smartville Complex agree with previous ages from Smartville volcanic rocks, sheeted dikes, and other plutons. In addition, one tonalite is 198 Ma and is cut by a 163 Ma dike, thus providing the first evidence of the basement of the ca. 160 Ma rocks. The 198 Ma tonalitic basement is probably correlative with the Slate Creek Complex, which contains the only other ca. 200 Ma tonalite in the northern Sierra Nevada. Thrust emplacement of the Slate Creek Complex between 200 and 163 Ma was followed by locally extensional arc magmatismmore » in the Smartville Complex at about 160 Ma, then by Nevadan contractional deformation, a sequence of Jurassic deformation similar to that in the Klamath Mountains. Nevadan deformation could be part of a noncollisional deformation or a long-lived arc (Slate Creek Complex) collision.« less

Authors:
;  [1];  [2]
  1. Univ. of California, Davis (USA)
  2. Univ. of Kansas, Lawrence (USA)
Publication Date:
OSTI Identifier:
6314784
Resource Type:
Journal Article
Journal Name:
Geology; (USA)
Additional Journal Information:
Journal Volume: 17:11; Journal ID: ISSN 0091-7613
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES; CALIFORNIA; GEOLOGIC DEPOSITS; TECTONICS; BASEMENT ROCK; CHERT; DEFORMATION; GEOLOGIC HISTORY; GEOLOGIC STRUCTURES; GEOLOGY; ISOTOPE RATIO; LEAD ISOTOPES; MAGMATISM; MESOZOIC ERA; MOUNTAINS; PALEOZOIC ERA; STRATIGRAPHY; URANIUM ISOTOPES; ZIRCON; ACTINIDE ISOTOPES; FEDERAL REGION IX; GEOLOGIC AGES; ISOTOPES; MINERALS; NORTH AMERICA; OXYGEN COMPOUNDS; ROCKS; SEDIMENTARY ROCKS; SILICATE MINERALS; SILICATES; SILICON COMPOUNDS; TRANSITION ELEMENT COMPOUNDS; USA; ZIRCONIUM COMPOUNDS; ZIRCONIUM SILICATES; 580000* - Geosciences

Citation Formats

Day, H W, Edelman, S H, and Bickford, M E. Implications of U-Pb zircon ages for the tectonic settings of the Smartville and Slate Creek complexes, northern Sierra Nevada, California. United States: N. p., 1989. Web.
Day, H W, Edelman, S H, & Bickford, M E. Implications of U-Pb zircon ages for the tectonic settings of the Smartville and Slate Creek complexes, northern Sierra Nevada, California. United States.
Day, H W, Edelman, S H, and Bickford, M E. 1989. "Implications of U-Pb zircon ages for the tectonic settings of the Smartville and Slate Creek complexes, northern Sierra Nevada, California". United States.
@article{osti_6314784,
title = {Implications of U-Pb zircon ages for the tectonic settings of the Smartville and Slate Creek complexes, northern Sierra Nevada, California},
author = {Day, H W and Edelman, S H and Bickford, M E},
abstractNote = {U-Pb zircon ages combined with stratigraphic and structural data indicate that ca. 160 Ma arc rocks of the Smartville Complex were constructed across ca. 200 Ma arc rocks of the Slate Creek Complex, which were already juxtaposed against more easterly units in the northern Sierra Nevada. The Slate Creek Complex, an ophiolitic thrust sheet east of the Smartville Complex, is 200-210 Ma, which precludes previous correlations with ca. 160 Ma rocks of the Smartville Complex. The Slate Creek Complex tectonically overlies chert-rich Paleozoic-early Mesozoic units along a low-angle fault that is cut by 163-168 Ma and 158-161 Ma plutons. Seven new ages of 160-163 Ma for plutonic rocks in the Smartville Complex agree with previous ages from Smartville volcanic rocks, sheeted dikes, and other plutons. In addition, one tonalite is 198 Ma and is cut by a 163 Ma dike, thus providing the first evidence of the basement of the ca. 160 Ma rocks. The 198 Ma tonalitic basement is probably correlative with the Slate Creek Complex, which contains the only other ca. 200 Ma tonalite in the northern Sierra Nevada. Thrust emplacement of the Slate Creek Complex between 200 and 163 Ma was followed by locally extensional arc magmatism in the Smartville Complex at about 160 Ma, then by Nevadan contractional deformation, a sequence of Jurassic deformation similar to that in the Klamath Mountains. Nevadan deformation could be part of a noncollisional deformation or a long-lived arc (Slate Creek Complex) collision.},
doi = {},
url = {https://www.osti.gov/biblio/6314784}, journal = {Geology; (USA)},
issn = {0091-7613},
number = ,
volume = 17:11,
place = {United States},
year = {Wed Nov 01 00:00:00 EST 1989},
month = {Wed Nov 01 00:00:00 EST 1989}
}