Research Paper GEOSPHERE Mesozoic–Paleogene structural evolution of the southern U.S. Cordillera as revealed in the Little and Big Hatchet Mountains, GEOSPHERE; v. 14, no. 1 southwest New Mexico, USA doi:10.1130/GES01539.1 Christopher A. Clinkscales1 and Timothy F. Lawton2 1 12 figures; 1 table; 1 supplemental file Department of Geosciences, University of Arizona, 1040 4th Street, Tucson, Arizona 85721, USA 2Centro de Geociencias, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Campus Juriquilla, Juriquilla, QRO 76230, México CORRESPONDENCE: clinkscales@ email .arizona .edu ABSTRACT Upper Eocene–Oligocene ignimbrites and volcaniclastic rocks of the Boot Heel volcanic field of southwestern New Mexico unconformably overlie Lara- CITATION: Clinkscales, C.A., and Lawton, T.F., 2018, Mesozoic–Paleogene structural evolution A Mesozoic to Paleogene polyphase tectonic model presented here for mide syntectonic strata and bury eroded Laramide structures. The distribution of the southern U.S. Cordillera as revealed in the the southern United States (U.S.) Cordillera provides new insight into style of the Paleogene volcanic rocks in the Little Hatchet and Big Hatchet Moun- Little and Big Hatchet Mountains, southwest New and timing of Mesozoic–Paleogene deformation and basin formation in the tains is in part controlled by synmagmatic east-west and northwest-south- Mexico, USA: Geosphere, v. 14, no. 1, p. 162–186, doi:10.1130/GES01539.1. region south of the Colorado Plateau and Mogollon-Datil volcanic field. The east normal faults active from ca. 34 to 27 Ma, the age range of rhyolite dikes model proposes reverse reactivation of Jurassic normal faults during Late intruded along the faults. Two generations of intrusive rocks occupy these Science Editor: Shanaka de Silva Cretaceous Laramide shortening. It also recognizes late Paleogene east-west– normal faults in the Little Hatchet Mountains: (1) older (ca. 34 Ma) phaneritic Associate Editor: Michael L. Williams and northwest-southeast–trending normal faults formed during a north-south stocks and dikes in the central and southern parts of the range, and (2) younger extensional event that postdated Laramide shortening and preceded Neogene (31–27 Ma) aphanitic latite and rhyolite dikes. East-west–trending faults and Received 3 April 2017 Basin and Range extension. dikes are cut by north-south faults formed during Basin and Range extension. Revision received 23 August 2017 Late Jurassic to Early Cretaceous extension generated northwest-south- The late Eocene–early Oligocene north-south extension provides an important Accepted 20 October 2017 Published online 20 December 2017 east normal faults that formed part of the Border rift system that extended minimum age limit for Laramide shortening, which ended prior to ca. 34 Ma. from southern California to the northwestern Gulf of Mexico. The normal faults cut Mesoproterozoic basement rocks, and localized subsequent uplift of basement rocks during Late Cretaceous fault reactivation that formed north- INTRODUCTION west-southeast–trending Laramide uplifts of southwest New Mexico and southeastern Arizona. The Hidalgo uplift, reconstructed here from structural A comprehensive synthesis of tectonic mechanisms for the Mesozoic– relations in the Little Hatchet and Big Hatchet Mountains of southwestern Ceno zoic evolution of the western United States (U.S.) Cordillera requires New Mexico, is bound by bivergent reverse faults that resulted from tec- consideration of the southern U.S. Cordillera. The southern U.S. Cordillera is tonic inversion of a Jurassic–Early Cretaceous graben. The Hidalgo uplift is defined here to encompass the region north of Mexico and south of the Colo- flanked to the north by the Campanian to earliest Maastrichtian Ringbone ba- rado Plateau and Mogollon-Datil volcanic field, a geographic realm now occu- sin, which accumulated synorogenic continental strata and basaltic andesite pied by the Basin and Range province of southeastern Arizona and southern OLD G flows from ca. 75 to 70 Ma. The Ringbone basin was converted from a subsid- New Mexico (Figs. 1 and 2). Prevailing models for the Late Cretaceous–Paleo- ing basin in the Little Hatchet Mountains to a volcanic center by ca. 69 Ma, the gene tectonic framework of North America commonly focus on the central emplacement age of an assemblage of shallow, subvolcanic intrusions termed Rocky Mountains of Colorado, Utah, Wyoming, and Montana, the Great Basin the Sylvanite plutonic complex. The basement-involved structural style and of Nevada and Utah (e.g., Dickinson, 2006), and the metamorphic core com- OPEN ACCESS yoked intermontane basin resemble other Laramide uplifts and basins in the plexes of Arizona (e.g., Davis, 1980; Dickinson, 1991). Studies have extensively Rocky Mountain Cordillera and refute alternative Laramide models of strike- addressed various geologic aspects of the southern U.S. Cordillera and Rio slip faulting or regionally extensive horizontal thrust faults in southwestern Grande rift area, from Mesozoic deformation, magmatism, and sedimentation New Mexico, the latter of which fail to account for basement-cored uplifts. A (e.g., Seager et al., 1986; Mack et al., 1986; Lawton and McMillan, 1999; Lucas significant difference with the Rocky Mountain Laramide province is the size and Lawton, 2000; Seager, 2004; Amato et al., 2017) to Paleogene magma- of the uplifts and basins and the close association of southern U.S. Cordilleran tism and deformation (e.g., McIntosh and Bryan, 2000; Copeland et al., 2011); This paper is published under the terms of the structures to nearby Late Cretaceous magmatic centers, which contributed to however, the Mesozoic to Paleogene kinematic history of southwestern New CC‑BY‑NC license. interstratified volcanic and volcaniclastic rocks in the basin fill. Mexico lacks a comprehensive geodynamic synthesis. © 2017 The Authors GEOSPHERE | Volume 14 | Number 1 Clinkscales and Lawton | Mesozoic–Paleogene structural evolution of the southern U.S. Cordillera Downloaded from https://pubs.geoscienceworld.org/gsa/geosphere/article-pdf/14/1/162/4035211/162.pdf 162 by guest on 26 June 2019 Research Paper 120° W1115° W 10° W105° W flat slab corridor Montana 45° N 45° N Idaho Figure 1. Late Jurassic (J) to Cretaceous Wyoming (K) tectonic element map. Select tec- tonic elements of the western USA Cor- Nevada dillera consist of the following Meso- zoic features: (1) approximate location 40° N Laramide 40° N of the Laurentian-Farallon trench plate Forearc Uplifts boundary from Jurassic to Cretaceous; Nevadaplano (2) regional extent of the Mesozoic Cretaceous Subduction Zone Cordilleran magmatic arc and associ- Sevier Orogen ated forearc region (Dickinson, 2006); Thrust Front (3) strike of the Sevier orogenic front Utah Colorado (Dickinson, 2006); (4) location and ex- tent of the Late Jurassic to earliest Arizona New Mexico Late Cretaceous Mogollon Highlands and associated Border rift, with names Colorado slab corridor of main rift basins (Lawton, 2004); and Mogollon Highland flat 35° N Plateau 35° N (5) orientation and location of major basement-cored Late Cretaceous Lara- Fig. 3 mide uplifts (Cross, 1986; Saleeby, 2003; s Seager, 2004). The boundaries of the McCoy Basin flat slab corridor are modified from the flat slab margin interpreted extent of Laramide flat slab Mesozoic to very low-angle subduction of Weil NE-SW Rift Shoulder and Yonkee (2012). The Late Cretaceous Cordilleran Texas Tarahumara arc is noted with italicized Bisbee Basin text. Extent of the Colorado Plateau in Magmatic Arc Chihuahua green. The location of the subregional 30° N Ta L 30° N study area is marked by the red rec- rahumaraate K Late J - K tangle (Fig. 3) and occupies the area F Trough Legend arallon Plat referred to in text as the southern U.S. Arc Border Rift Sevier Orogen Cordillera. Thrust Front Sonora e Laramide Orogen Chihuahua Uplift-bounding faults Sabina s Basi Laramide Orogen n Monocline Sinaloa Coahuila 25° N Trajectory Durango Migration Direction of Mesozoic Magmatic Arc of Farallon Plate 500 km Zacatecas 120° W1115° W 10° W 105° W GEOSPHERE | Volume 14 | Number 1 Clinkscales and Lawton | Mesozoic–Paleogene structural evolution of the southern U.S. Cordillera Downloaded from https://pubs.geoscienceworld.org/gsa/geosphere/article-pdf/14/1/162/4035211/162.pdf 163 by guest on 26 June 2019 Research Paper 120° W1115° W 10° W 105° W Metamorphic Core Complex t 50 Ma Montana 45° N olcanic Fron 45° N Migrating V Idaho 45 Ma Wyoming Nevada 40 Ma 40° N Laramide 40° N Figure 2. Paleogene tectonic element map. Uplifts Orange dashed lines denote the strike of 35 Ma the Paleogene magmatic arc and associ- ated ages; arrows point in the direction 30 Ma of arc migration (Dickinson, 2002, 2006). 25 Ma San Juan Volcanic Field The Juan de Fuca and Guadalupe plates 20 Ma were formerly contiguous and constituted Utah Colorado the Farallon plate. By the Paleogene, flat Juan de Fuca Neogene slab and normal subduction transitioned Arizona New Mexico Plate amagmatic corridor to a period of slab rollback, which initi- Colorado ated the west-southwest migration of arc magmatism. The subregional map 35° N Mendocino 35° N Mendocino Fracture Zo Plateau (Fig. 3) occupies the area between the late ne Triple Junction Rio Grande Rift (ca. 25 Ma) migrating north Mogollon-Datil Eocene– Oligocene Mogollon-Datil and Fig. 3 Axis Boot Heel volcanic fields (McIntosh et al., Volcanic Field 1992). Black circular to elliptical domains indicate the locations of Cenozoic (ex- Pacific Plate Rivera