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Provenance of Pennsylvanian–Permian sedimentary rocks associated with the Ancestral Rocky Mountains orogeny in southwestern Laurentia: Implications for continental-scale Laurentian sediment transport systems

“…Paleotectonic reconstructions (Dickinson and Lawton, 2001), recent late Paleozoic global plate models (Domeier and Torsvik, 2014), and kinematic analysis of the ARM deformation suggest that this margin evolved from oblique convergence to subduction during late Paleozoic time (Leary et al, 2017;Lawton et al, 2017). The tectonic driver(s) of Ancestral Rocky Mountain basement deformation remain a topic of debate, and proposed models include collision along the Ouachita-Marathon belt (Kluth and Coney, 1981), left-lateral shear along major transcontinental faults (Budnik, 1986), flat-slab subduction along the southwestern continental margin (Ye et al, 1996), reactivation of pre-existing rift structures (Marshak et al, 2000), wrenching associated with the zippering closure of the Iapetus Ocean (Dickinson and Lawton, 2003), dynamic uplift/subsidence due to stress-field interaction with underplated Proterozoic mafic rocks (Soreghan et al, 2012), and oblique convergence along the southwestern Laurentian margin (Leary et al, 2017;Lawton et al, 2017). A complete discussion of the strengths and limitations of these models is beyond the scope of this paper; however, we emphasize several salient aspects of this system that are relevant to the current study:…”

“…1; Ye et al, 1996), with preserved kinematic data suggesting northeast-southwest-oriented shortening (Brewer et al, 1983;Granath, 1989;Shumaker, 1992;Hoy and Ridgway, 2002;Cather et al, 2006;Cox, 2009). Uplift and basin orientations in several cases follow the trends of Proterozoic rifts (Karlstrom and Humphreys, 1998;Marshak et al, 2000), and multiple tectonic models have proposed that associated faults controlled the localization of ARM deformation (Marshak and Paulsen, 1996;Marshak et al, 2000;Soreghan et al, 2012;Leary et al, 2017). (4) ARM deformation did not substantially affect Archean crust of the Wyoming Craton (Karlstrom and Humphreys, 1998), although whether that can be attributed to crustal rheology or distance from active continental margins remains unknown.…”

Lithospheric records of orogeny within the continental U.S.

“…The Ouachita Marathon Orogeny, which formed the ARM, occurred during the late Paleozoic and involved the collision of Africa and South America with the southern United States [Kluth and Coney, 1981;Kluth, 1986]. The collision continues to have a strong impact on upper crustal structure across the central United States (Figure 2a) with ARM uplifts appearing as prominent high-velocity features and basins as low-velocity features when not disrupted by more recent processes [Kluth and Coney, 1981;Kluth, 1986;Soreghan et al, 2012]. This becomes less clear in the midcrust (Figure 2b), but there is some correlation between high velocities and structural highs and vice versa, showing the impact of this orogeny throughout the crustal column.…”

Tectonic Analysis of the Pennsylvanian Ely‐Bird Spring Basin: Late Paleozoic Tectonism on the Southwestern Laurentia Margin and the Distal Limit of the Ancestral Rocky Mountains

“…Several competing and incompatible hypotheses have been proposed to explain the tectonics of Ancestral Rocky Mountains. These include formation with processes similar to Himalayan escape tectonics (Kluth, 1986;Kluth & Coney, 1981;Thomas, 1983), Laramide-style thick-skinned tectonics (Ye et al, 1996), reactivation of Proterozoic structures (Budnik, 1986;Johnson et al, 1992;Marshak et al, 2000;Stevenson & Baars, 1986), a result of sequential closing of the complex Ouachita-Marathon margin (Dickinson & Lawton, 2003), and a result of response to crustal density changes (Soreghan et al, 2012). These competing hypotheses exist due to the poorly exposed basin-bounding structures and overprinting by later tectonism.…”