Research Paper GEOSPHERE Detrital zircons from crystalline rocks along the Southern Oklahoma fault system, Wichita and Arbuckle Mountains, USA GEOSPHERE; v. 12, no. 4 William A. Thomas1,*, George E. Gehrels2, and Mariah C. Romero3 1Geological Survey of Alabama, Tuscaloosa, Alabama 35486, USA doi:10.1130/GES01316.1 2Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA 3Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, Indiana 47907, USA 8 figures; 2 supplemental files ABSTRACT tia and opening of the Iapetus Ocean during final breakup of supercontinent CORRESPONDENCE: geowat@ uky .edu Rodinia (Hogan and Gilbert, 1998; Thomas et al., 2012; Hanson et al., 2013). Detrital zircons with ages of 535 ± 10 Ma in many North American Mid- A thick post-rift, Cambrian–Ordovician, passive-margin carbonate succession CITATION: Thomas, W.A., Gehrels, G.E., and continent sandstones are commonly attributed to sources in Cambrian syn- covered the Cambrian igneous rocks and associated Mesoproterozoic base- Romero, M.C., 2016, Detrital zircons from crystalline rocks along the Southern Oklahoma fault system, rift igneous rocks along the Southern Oklahoma fault system. New analyses ment rocks (Denison, in Johnson et al., 1988). Late Paleozoic basement-rooted Wichita and Arbuckle Mountains, USA: Geosphere, are designed to test the characteristics of proximal detritus from the Wichita uplifts (Wichita and Arbuckle) along the Southern Oklahoma fault system v. 12, no. 4, p. 1224–1234, doi:10.1130/GES01316.1. and Arbuckle uplifts. Detrital zircons from a sandstone (Lower Permian Post incorporated the Cambrian igneous rocks and Precambrian basement rocks Oak Conglomerate) directly above an unconformable contact with the Wichita (Fig. 1). Unroofing of the Wichita and Arbuckle uplifts and Pennsylvanian– Received 21 January 2016 Granite Group in the Wichita Mountains have strongly unimodal U-Pb ages Permian stratigraphic onlap rimmed the Southern Oklahoma fault system with Revision received 19 April 2016 Accepted 17 May 2016 of 540–520 Ma and εHft values of +4.7 to +10.1. In contrast, two sandstone proximal clastic deposits, including the classic “Granite Wash” from the crys- Published online 1 July 2016 samples (Upper Pennsylvanian Vanoss Conglomerate) in the onlapping suc- talline rocks (Johnson et al., 1988). cession above an angular unconformity on Paleozoic strata on the flank of the Gondwanan accreted terranes, which are distributed along the late Paleo- Arbuckle anticline have detrital zircons with U-Pb ages that correspond domi- zoic Appalachian-Ouachita orogenic belt, include Brasiliano–Pan-African and nantly to the Superior (~2700 Ma) and secondarily to the Granite-Rhyolite Pampean components, the ages of which range through 700–530 Ma (Lopez (1480–1320 Ma) and Grenville (1300–970 Ma) provinces of the Laurentian cra- et al., 2001; Mueller et al., 2014). The accreted terranes offer an alternative ton. The Vanoss zircons indicate recycling from quartzose sandstones within source of ~535 Ma zircons, which are not distinguishable from zircons of the the Middle Ordovician platform carbonates in the Arbuckle passive-margin Southern Oklahoma igneous rocks on the basis of age alone. cover succession. A stratigraphically higher sandstone (Permian Wellington In order to characterize the detritus from the Southern Oklahoma prove- Formation) above the onlapping conglomerates has a more diverse detrital- nance, new samples of proximal Pennsylvanian and Permian sandstones along zircon population, indicating that sediment dispersal from external sources the uplifts were analyzed for U-Pb ages and Hf isotopes of detrital zircons. overwhelmed the proximal detritus in the immediate cover of the Wichita and Analyses of detrital zircons from a Permian sandstone stratigraphically above Arbuckle uplifts. The distinctive εHft values of the proximal detritus from the the proximal detritus were conducted to test sediment dispersal in space and Cambrian synrift igneous rocks offer potential discrimination from zircons of time, as well as to document the early evolution of sediment-dispersal systems the same age from Gondwanan accreted terranes, which are represented in around the Southern Oklahoma (Wichita and Arbuckle) uplifts. Ultimately, the Wellington sample. these results may provide a basis for discrimination of the Southern Oklahoma provenance from Gondwanan accreted terranes. INTRODUCTION GEOLOGIC SETTING AND EVOLUTION OF THE Detrital zircons with ages of 535 ± 10 Ma, although generally not abun- SOUTHERN OKLAHOMA FAULT SYSTEM dant, are common in many Paleozoic sandstones across the North American Midcontinent, and almost universally are attributed to a source in the well- Mesoproterozoic Basement Rocks known Cambrian igneous rocks along the Southern Oklahoma fault system (e.g., Riggs et al., 1996; Dickinson and Gehrels, 2003, 2008; Gleason et al., 2007; Basement rocks in the Arbuckle uplift belong to the Southern Granite-Rhyo- Soreghan and Soreghan, 2013). Emplacement of the Cambrian (539–530 Ma) lite province (Fig. 1) (e.g., Ham et al., 1964; Van Schmus et al., 1993). U-Pb synrift magmas accompanied the late stages of rifting of southeastern Lauren- zircon ages for various granites and gneisses in the Arbuckle uplift range from For permission to copy, contact Copyright 1399 ± 95 and 1397 ± 7 Ma to 1364 ± 2 and 1363 ± 8 Ma (Bickford and Lewis, Permissions, GSA, or [email protected]. *Professor Emeritus at University of Kentucky; Visiting Scientist at Geological Survey of Alabama 1979; Thomas et al., 1984; Rohs and Van Schmus, 2007; Thomas et al., 2012). © 2016 Geological Society of America GEOSPHERE | Volume 12 | Number 4 Thomas et al. | Detrital zircons, Southern Oklahoma Wichita-Arbuckle uplifts Downloaded from http://pubs.geoscienceworld.org/gsa/geosphere/article-pdf/12/4/1224/4178158/1224.pdf 1224 by guest on 25 September 2021 Research Paper continental crust (Keller and Stephenson, 2007). The Cambrian igneous rocks 100°W 90°W 80°W are interpreted to be along a system of intracratonic fractures associated with Superior 50°N continental rifting and breakup of supercontinent Rodinia and opening of the 50°N >2400 Ma Iapetus Ocean (Fig. 1) (e.g., Thomas, 2006, 2014). Data from U-Pb analyses of zircons from the igneous rocks give a range of possible ages for detrital zircons available from this provenance. U-Pb ages of zircons from rhyolites in the Wichita Mountains bracket a short time interval Midc. 1100 Ma of 533–530 Ma (Wright et al., 1996; Hogan and Gilbert, 1998; Hanson et al., Trans-Hudson 2000–1800 Ma 2013). A U-Pb zircon age of 552 ± 7 Ma for gabbro (Bowring and Hoppe, 1982) is older than indicated by geologic relationships to other dated rocks and may 45°N have an inherited component (Hogan and Gilbert, 1998; Hanson et al., 2013). Penokean a U-Pb ages of zircons from rhyolites in the Arbuckle Mountains are 539 ± 5 and 1900–1800 Ma MMa 7 536 ± 5 Ma (Thomas et al., 2012). Previously determined U-Pb zircon ages of 997 ––9 525 ± 25 Ma for rhyolite and granite (Tilton et al., 1962) are within error of the Central Plains 00–9 GrenvilleG 00 more recent data. Some components of the igneous suite are older on the 1800–1650 Ma 1300–970 Ma basis of geologic relationships than the geochronologically dated rocks; how- 40°N ever, no data are available to quantify the time span of those rocks. Combining all of the available U-Pb data, zircons with ages of 539–530 Ma and possibly somewhat older are available to the supply of sediment from the Southern Oklahoma synrift igneous rocks. Granite-Rhyolite S.O. 539–530OK Ma 1480–1320 Ma Cambrian–Ordovician Passive-Margin Carbonate Succession 35°N A transgressive passive-margin succession of basal sandstone and over- ) a lying shallow-marine carbonates onlaps the Cambrian igneous rocks along MaM the Southern Oklahoma fault system. Cambrian–Ordovician rocks along the 3 535 Southern Oklahoma fault system are part of a craton-wide passive-margin car- Llano-Grenville 30°N bonate (referred to as the Great American Carbonate Bank, Derby et al., 2012). 1300–1000 Ma 30°N n The age of the sandstone at the base of the transgressive succession is middle 0 500 kmm Late Cambrian; and the overlying carbonate succession extends up through L the Middle Ordovician (Denison, in Johnson et al., 1988). The Middle Ordovi- 100°W Iapetanf L rift95°W margin 90°W 85°W ofo Laurentia (~530 Ma cian part of the carbonate succession includes mature quartzose sandstone. Figure 1. Regional map of Precambrian provinces of interior North America (modified from Van The carbonate succession is exceptionally thick (as much as 2.2 km) along Schmus et al., 1993), Iapetan rift margin and synrift intracratonic faults of Laurentia (from Thomas, the Southern Oklahoma fault system, consistent with large-magnitude synrift 2014), and location of Cambrian igneous rocks (539–530 Ma) along the synrift Southern Oklahoma thermal uplift followed by post-rift cooling and deep subsidence (Thomas and fault system. Black dots in Oklahoma (OK) show locations of samples for analysis of detrital zir- cons. Abbreviations: Midc.—Midcontinent rift system; S.O.—Southern Oklahoma fault system. Astini, 1999). Cambrian Synrift Igneous Rocks Late Paleozoic Uplifts and Clastic Sedimentary Rocks Along the Southern Oklahoma fault system (Arbuckle and Wichita uplifts), A relatively thin, unconformity-punctuated, heterolithic, Upper Ordovician– a Cambrian bimodal suite of plutonic and volcanic rocks includes gabbro, ba-