Late Paleozoic Tectonic Assembly of the Sierra Nevada Prebatholithic
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The Geological Society of America Special Paper 540 Late Paleozoic tectonic assembly of the Sierra Nevada prebatholithic framework and western Laurentian provenance links based on synthesized detrital zircon geochronology Snir Attia Scott R. Paterson Department of Earth Sciences, University of Southern California, Los Angeles, California 90098, USA Wenrong Cao Department of Geological Sciences and Engineering, University of Nevada, Reno, Nevada 89557, USA Alan D. Chapman Geology Department, Macalester College, St. Paul, Minnesota 55105, USA Jason Saleeby Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA George C. Dunne Department of Geological Sciences, California State University, Northridge, California 91330, USA Calvin H. Stevens Department of Geology, San Jose State University, San Jose, California 95192, USA Valbone Memeti Department of Geological Sciences, California State University, Fullerton, California 92831, USA ABSTRACT The Sierra Nevada batholith of California represents the intrusive footprint of composite Mesozoic Cordilleran arcs built through pre-Mesozoic strata exposed in isolated pendants. Neoproterozoic to Permian strata, which formed the prebatholithic framework of the Sierran arc, were emplaced against the tectonically reorganized SW Laurentian continental margin in the late Paleozoic, culminating with fi nal collapse of the fringing McCloud arc against SW Laurentia. Synthesis of 22 new and 135 existing detrital zircon U/Pb geochronology sample analyses clarifi es the provenance, affi nity, and history of Sierra Nevada framework rocks. Framework strata comprise terranes with distinct postdepositional histo- ries and detrital zircon provenance that form three broad groups: allochthonous Attia, S., Paterson, S.R., Cao, W., Chapman, A.D., Saleeby, J., Dunne, G.C., Stevens, C.H., and Memeti, V., 2018, Late Paleozoic tectonic assembly of the Sierra Nevada prebatholithic framework and western Laurentian provenance links based on synthesized detrital zircon geochronology, in Ingersoll, R.V., Lawton, T.F., and Graham, S.A., eds., Tectonics, Sedimentary Basins, and Provenance: A Celebration of William R. Dickinson’s Career: Geological Society of America Special Paper 540, p. 267–295, https://doi.org/10.1130/2018.2540(12). © 2018 The Geological Society of America. All rights reserved. For permission to copy, contact [email protected]. 267 Downloaded from https://pubs.geoscienceworld.org/books/chapter-pdf/4539580/spe540-12.pdf by University of Southern California user on 08 November 2018 268 Attia et al. Neoproterozoic to lower Paleozoic strata with interpreted sediment sources from Idaho to northern British Columbia; Neoproterozoic to Permian strata parautoch- thonous to SW Laurentia; and middle to upper Paleozoic deposits related to the fring- ing McCloud arc. Only three sedimentary packages potentially contain detritus from rocks exotic to western Laurentia: the Sierra City mélange, chert-argillite unit, and Twin Lakes assemblage. We reject previous correlations of eastern Sierra Nevada strata with the Roberts Mountains and Golconda allochthons and fi nd no evidence that these allochthons ever extended westward across Owens Valley. Snow Lake ter- rane detrital ages are consistent with interpreted provenance over a wide range from the Mojave Desert to central Idaho. The composite detrital zircon population of all analyses from pre-Mesozoic Sier- ran framework rocks is indistinguishable from that of the Neoproterozoic to Permian SW Laurentian margin, providing a strong link, in aggregate, between these strata and western Laurentia. These fi ndings support interpretations that the Sierran arc was built into thick sediments underpinned by transitional to continental western Laurentian lithosphere. Thus, the Mesozoic Sierra Nevada arc is native to the SW Cordilleran margin, with the Sierran framework emplaced along SW Laurentia prior to Permian–Triassic initiation of Cordilleran arc activity. INTRODUCTION SW Laurentian Continental Margin The Mesozoic Sierra Nevada arc of eastern California was Autochthonous strata are those with current exposures that built into the truncated and tectonically reorganized margin of preserve their original paleogeographic relationships and posi- SW Laurentia, with pre-Mesozoic strata related to the western tions relative to their locus of deposition along the western Lau- Laurentian margin making up the prebatholithic metamorphic rentian margin. Allochthonous strata are those western Laurentian framework of the arc (Fig. 1; Davis et al., 1978; Bateman, 1992). continental margin deposits with western Laurentian sedimentary Deformed and metamorphosed prebatholithic framework rocks provenance that have been signifi cantly displaced relative to the are preserved as structural slivers or infolded with younger arc margin segment where they originated. This subtly contrasts with deposits in isolated host-rock pendants, obscuring the prov- parautochthonous rocks, which are fault-bounded but not sig- enance and pre-Mesozoic tectonic history of the Sierran frame- nifi cantly displaced relative to their original locus of deposition. work (Bateman, 1992; Saleeby and Busby, 1993). New U/Pb Herein, we apply the terms autochthonous, parautochthonous, detrital zircon geochronology analyses of 23 samples from dis- and allochthonous in reference to SW Laurentia, except where rupted pre-Mesozoic strata across the Sierra Nevada and east- explicitly stated otherwise. We apply the term “exotic” to those ern California provide new constraints on the nature of Sierran rocks, strata, arcs, or terranes that were not formed or deposited framework rocks and the tectonic evolution of the SW Lauren- within, along, or outboard of the western Laurentian margin. The tian margin prior to Cordilleran arc magmatism. To link Sierran fringing arc, partially built on exotic rocks, is defi ned as that arc framework rocks to continental margin assemblages, for which that was active outboard of, and translated parallel to, the western relationships to the western Laurentian margin are better docu- Laurentian margin prior to accretion. mented, we compiled published detrital zircon data from 135 The Neoproterozoic to Paleozoic history of the western mar- samples of Mesoproterozoic to Permian strata of the SW Lau- gin of North America can be divided into fi ve distinct phases: rentian continental margin spanning eastern California, Nevada, (1) The western margin of the North American craton was Utah, and Arizona. In this study, we sought to determine the created by the breakup of Rodinia that began ca. 750 Ma (Burch- following: (1) provenance and age of Sierran framework rocks; fi el and Davis, 1972). The initial breakup of Rodinia may have (2) affi nity of isolated framework rock exposures to larger been marked by deposition of the upper Pahrump Group in east- “framework terranes”; and (3) the postdepositional, prebatho- ern California and other intracratonic basin deposits along the lithic histories of these terranes. length of western Laurentia (Wrucke et al., 2007; Dehler et al., Next, we provide an overview of the SW Laurentian con- 2010; Yonkee et al., 2014). Detrital zircon geochronology studies tinental margin and Sierra Nevada prebatholithic framework, show that Neoproterozoic strata of SW Laurentia record a signifi - present geochronology and comparisons of methods and results, cant provenance shift compared to the underlying, locally sourced and then discuss implications of this work for Sierran framework Mesoproterozoic strata (Yonkee et al., 2014). Strata autochtho- rock provenance, evolution of the SW Laurentian continental nous to SW Laurentia were derived from local, central Lauren- margin, and assembly of the Sierran framework terranes. tian, and Grenville basement rocks, as well as from recycling of Downloaded from https://pubs.geoscienceworld.org/books/chapter-pdf/4539580/spe540-12.pdf by University of Southern California user on 08 November 2018 Detrital zircon geochronology of the Sierra Nevada prebatholithic framework 269 SNB Nevada-Utah EK A M shelf facies R p a l Northern n r o e h v Sierra t o h c r e terrane o e l l n l t i a n l a A e d g n n o i c Twin l h o Lakes G Inyo F SLT Wasatch SAF o o facies t h i ll s s S. Inyo u t u Mtns. r e Grand Death Valley Fairview Canyon pendant GF facies 35°N Mojave facies Kern Plateau Arch 120°W Transcontinental S inner Death Valley facies / NV-UT shelf / S r shelf Mojave facies / Snow Lake terrane (SLT) r i > i < outer shelf- 0 Inyo facies / Morrison block 0 slope . 7 . 7 slope-rise Shoo Fly complex (SFC) / 0 0 Kernville terrane 6 6 rise- Roberts Mountain allochthon (RMA) / abyssal Golconda allochthon / El Paso terrane U.S. abyssal Paleozoic oceanic assemblages Mex. chert-argillite unit / Twin Lakes assemblage Caborca 30°N Paleozoic faults block Trace of late Pz truncation Approx. location of detrital zircon samples Sri = 0.706 isopleth 100 km 115°W Figure 1. Schematic overview of the geologic and geographic relationships of pre-Mesozoic strata of the SW Cordilleran mar- gin. Extent of Mesozoic Sierra Nevada batholith (SNB) outlined in medium gray. EK—Eastern Klamath Mountains, SAF—San Andreas fault, GF—Garlock fault, NV—Nevada, UT—Utah, Pz—Paleozoic. Figure is modifi ed from Kistler and Ross (1990), Stevens et al. (2005), Crafford (2008), Dickinson (2008), Alsleben et al. (2012), and Chapman et al. (2015). Downloaded from https://pubs.geoscienceworld.org/books/chapter-pdf/4539580/spe540-12.pdf by University