Pennsylvanian and Early Permian paleogeography of east-central California: Implications for the shape of the continental margin and the timing of continental truncation

Geologic map database of the El Mirage Lake area, San Bernardino and Los Angeles Counties, California

“…The crust in this area formed during the early Proterozoic, and late Proterozoic and Paleozoic strata were laid on this crust as it gradually subsided (Stewart, 1970). Late Paleozoic and early Mesozoic continental-margin tectonics resulted in more complex sedimentation patterns of shallow marine and continental sediments Stone and Stevens, 1988;Martin and Walker, 1992). The area later lay within multiple Mesozoic magmatic arcs, which created a composite batholith of granitoids, most of which range in age from midJurassic to latest Cretaceous.…”

The Triassic/Jurassic boundary and the Jurassic stratigraphy and biostratigraphy of northern Sonora, northwest Mexico

“…A northwest-southeast trending magmatic arc, that was well developed by early Mesozoic time in southwestern North America, was constructed at a high angle to the trend of the late Paleozoic truncated margin of Laurentia (Stone and Stevens, 1988;Walker, 1988;Barth et al, 1990Barth et al, , 1997Busby-Spera, 1988;Busby-Spera et al, 1990;Dickinson and Lawton, 2001;Riggs et al, 2016). The early phase of this magmatism started in Permian time and continued into the Triassic as was recorded by plutonic suites of Sonora and southeastern California.…”

“…The arc magmatic activity ended by Middle-Late Triassic time and resumed again in Early Jurassic. Although southeast-directed tectonic transportation of the Caborca block, from its original position in southern California to its present position in Sonora, is a widely accepted idea, debate remains whether it was transported by sinistral strike-slip faults during the late Paleozoic (Stone and Stevens, 1988;Dickinson, 2000;Lawton et al, 2017) or by the Mojave-Sonora megashear (Anderson and Silver, 2005) in Late Jurassic time. However, an alternative hypothesis considers the Caborca block as autochthonous (Poole et al, 2005).…”

Phanerozoic evolution of sedimentary basins in the Uinta-Piceance Basin region, northwestern Colorado and northeastern Utah

“…The Antler orogenic belt was a highland until the Early Pennsylvanian, but mid-Late Mississippian erosion of this highland and associated filling of the Antler foreland basin is considered postorogenic (Sandberg and others, 1982;Dickinson and others, 1983;Goebel, 1991). Antler shortening in the Great Basin gave way to a complex, heterogeneous (temporally and regionally) tectonic style characterized by local uplift, subsidence, and volcanism (Ketner, 1977;Miller and others, 1984;Stone and Stevens, 1988;Smith and Miller, 1990;Trexler and others, 1991) that is most consistent with a regional strike-slip setting. Ketner (1977) described this late Paleozoic structural style and named the protracted deforaiational event the "Humboldt orogeny," a designation used here.…”