Regional and temporal variability of melts during a Cordilleran magma pulse: Age and chemical evolution of the Jurassic arc, eastern Mojave Desert, California

Abstract

Intrusive rock sequences in the central and east Mojave Desert segment of the Jurassic Cordilleran arc of the western US record regional and temporal variations in magmas generated during the second prominent pulse of Mesozoic continental arc magmatism. U/Pb zircon ages provide temporal control for describing variations in rock and zircon geochemistry that reflect differences in magma source components. These source signatures are discernible through mixing and fractionation processes associated with magma ascent and emplacement. The oldest well-dated Jurassic rocks defining initiation of the Jurassic pulse are a 183 Ma monzodiorite and a 181 Ma ignimbrite.Early to Middle Jurassic intrusive rocks comprising the main stage of magmatism include two high K calc-alkalic groups; to the north, the deformed 183 to 172 Ma Fort

Beveling the Colorado Plateau: Early Mesozoic Rift‐Related Flexure Explains Erosion and Anomalous Deposition in the Southern Cordilleran Foreland Basin

“…Although the topographic relief and geometry of this fluvial surface during the Late Jurassic are unknown, we estimated it using an ideal equilibrium river profile with standard concavity parameters (Hack, 1975;Whipple & Tucker, 1999) and assumed 1 km topographic relief CHAPMAN AND DECELLES 10.1029/2020TC006517 5 of 16 Formation is adopted from Dickinson (2013). Ages of Jurassic arc rocks are from Barth et al (2008Barth et al ( , 2017 and Tosdal and Wooden (2015). Syn-rift deposits in the Bisbee basin are ca.…”

“…CHAPMAN AND DECELLES 10.1029/2020TC006517 6 of 16 (Seedorff et al, 2019) and Cretaceous (K) flare up timing in the Sierra Nevada batholith (SNB) (Kirsch et al, 2016); orange = syntectonic strata associated with the Laramide Orogeny (Clinkscales & Lawton, 2018;Caylor et al, 2021;Dickinson et al, 1989), blue = McCoy Mountains Formation (Barth et al, 2004;Spencer et al, 2011), dark green = Bisbee Group (Dickinson & Lawton, 2001;Kluth, 1982;Olmstead & Young, 2000), light green = Dakota Formation (Cobban & Hook, 1984;Williamson et al, 1993), brown = Cedar Mountain Formation, also includes other lower Cretaceous units (e.g., Burro Canyon Formation) (Ludvigson et al, 2010), purple = Morrison Formation (Kowallis et al, 1998;Maidment & Muxworthy, 2019;Trujillo et al, 2014;Turner & Peterson, 2004), red = Jurassic arc (Barth et al, 2008(Barth et al, , 2017Tosdal & Wooden, 2015). In addition to the magnitude of the vertical load, the two other main variables that control the geometry of flexural profiles are horizontal forces and flexural rigidity.…”

“…Provenance and paleocurrent data from the Morrison Formation indicate that uplift and erosion of the Mogollon Highlands started during the Late Jurassic (e.g., Dickinson & Gehrels, 2008), around the same time that magmatism in the Jurassic arc in southeastern California, southern Arizona, and northwestern Mexico was waning (Barth et al, 2008(Barth et al, , 2017Tosdal & Wooden, 2015) (Figures 4 and 5). Cessation of Jurassic arc magmatism and initiation of the Bisbee rift system have been attributed to slab rollback (Bilodeau, 1982;Dickinson & Lawton, 2001;Lawton & McMillan, 1999).…”

Detrital zircon geochronology and evolution of the Nacimiento block late Mesozoic forearc basin, central California coast

“…Abundant Cretaceous zircon in Nacimiento block strata of Upper Albian-Cenomanian age is accompanied by a signif cant component of Jurassic zircon of 170-157 Ma age, which could have been derived from Middle Jurassic magmatic rocks that are widespread throughout the Cordilleran arcs (e.g., Chen and Moore, 1979;Shaw et al, 2003;Barth et al, 2017). Alternatively, McLean et al (1977) described abundant mafc and ultramaf c clasts in Cenomanian conglomerate of the San Rafael Mountains and argued that they were derived from source terranes composed largely of oceanic crust similar to the Coast Range ophiolite.…”

Geochemical and isotopic study of Mesozoic magmatism in the Sonobari Complex, western Mexico: Implications for the tectonic evolution of southwestern North America

“…Therefore, Triassic rocks in the area are interpreted as the southward continuation of the Permo-Triassic magmatic belt occurring from southwestern USA (e.g., Barth et al, 1990Barth et al, , 1997Barth and Wooden, 2006;Miller et al, 1995), eastern Peninsular Ranges batholith (Kimbrough et al, 2015;Schmidt et al, 2014), northern Sonora (Arvizu et al, 2009;Arvizu and Iriondo, 2015), eastern and southern Mexico (Torres et al, 1999;Weber et al, 2007;Ducea et al, 2004), and perhaps extending to South America (e.g., Cardona et al, 2010;Maksaev et al, 2014). Jurassic rocks also occur along a continental magmatic arc extending from southwestern USA through the Mojave and Sonora Deserts (Busby-Spera et al, 1990;Barth et al, 2017), northern Sonora (Anderson et al, 2005;Haxel et al, 2005), southern Sonora and northern Sinaloa (this work), central Sinaloa (Cuéllar-Cárdenas et al, 2012), and Maria Madre Island (Pompa-Mera et al, 2013). These rocks are also coeval with rocks in El Arco, Baja California, although the rocks from this region have a geochemical signature indicating an island arc setting (Weber and López-Martínez, 2006).…”