A survey of Sierra Nevada magmatism using Great Valley detrital zircon trace-element geochemistry: View from the forearc

Abstract

The well-characterized Sierra Nevada magmatic arc offers an unparalleled opportunity to improve our understanding of continental arc magmatism, but present bedrock exposure provides an incomplete record that is dominated by Cretaceous plutons, making it challenging to decipher details of older magmatism and the dynamic interplay between plutonism and volcanism. Moreover, the forearc detrital record includes abundant zircon formed during apparent magmatic lulls, suggesting that understanding the long-term history of arc magmatism requires integrating plutonic, volcanic, and detrital records. We present trace-element geochemistry of detrital zircon grains from the Great Valley forearc basin to survey Sierra Nevadan arc magmatism through Mesozoic time. We analyzed 257 previously dated detrital zircon grains from seven sandstone samples of volcanogenic, arkosic, and mixed compositions deposited ca. 145–80 Ma along the length of the forearc basin. Detrital zircon trace-element geochemistry is largely consistent with continental arc derivation and shows similar geochemical ranges between samples, regardless of location along strike of the forearc basin, depositional age, or sandstone composition. Comparison of zircon trace-element data from the forearc, arc, and retroarc regions revealed geochemical asymmetry across the arc that was persistent through time and demonstrated that forearc and retroarc basins sampled different parts of the arc and therefore recorded different magmatic histories. In addition, we identified a minor group of Jurassic detrital zircon grains with oceanic geochemical signatures that may have provenance in the Coast Range ophiolite. Taken together, these results suggest that the forearc detrital zircon data set reveals information different from that gleaned from the arc itself and that zircon compositions can help to identify and differentiate geochemically distinct parts of continental arc systems. Our results highlight the importance of integrating multiple proxies to fully document arc magmatism, demonstrating that detrital zircon geochemical data can enhance understanding of a well-characterized arc, and these data may prove an effective means by which to survey an arc that is inaccessible and therefore poorly characterized.

Age constraint for the Moreno Hill Formation (Zuni Basin) by CA-TIMS and LA-ICP-MS detrital zircon geochronology

“…Other than the notable Precambrian signatures, all four samples contain distinct Late Jurassic – Cretaceous multi-grain populations with the majority within phases A (160–140 Ma) and B (140–105 Ma) and the most youthful populations falling within Phase C (105–80 Ma) ( DeCelles & Graham, 2015 ). All samples assessed in this study contain multi-grain populations within Phase C, which we link to the westerly lying Cordilleran Arc; more specifically, the southern portion of the Sierra Nevada Batholith, the northern portion of the Peninsular Ranges Batholith, and minor volcanism near the Maria Fold and Thrust Belt ( DeCelles, 2004 ; Dickinson, 2008 ; Busby, Busby & Azor, 2012 ; Hildebrand & Whalen, 2014 ; LaMaskin, 2012 ; Szwarc et al, 2015 ; Pecha et al, 2018 ; Lawton, 2019 ; DeGraaff Surpless et al, 2019 ). Shorter-lived and more-localized volcanic events within Phases B and C that could have been contributors include the (1) Black Rock Arc Terrane (114–103 Ma); (2) Sierra Crest Magmatic Event (98–86 Ma); (3) Santa Rosa Range and the Bloody Run Hills (110–85 Ma); and (4) Soldier and Cathedral peak plutons ( Fig.…”

Detrital zircon provenance and depositional links of Mesozoic Sierra Nevada intra-arc strata

“…Such lower zircon U/Th values (~0.5-1.5) are present in detrital zircon populations from Mojave Desert strata (Fig. 8), bedrock zircons from Sierra Nevada Jurassic arc rocks, and mid-Jurassic plutons of the Mojave Desert (Barth et al, 2017;Surpless et al, 2019). Detrital zircons of earliest to mid-Early Cretaceous age, uncommon in Sierra Nevada intra-arc strata, show U/Th values that overlap with analyses from Great Valley Group fore-arc strata (Fig.…”

“…U/Th values of 80-300 Ma detrital zircons are compared to bedrock zircons from CSN Mesozoic metavolcanic rocks and detrital zircons from intra-and retro-arc strata of the Mojave Desert as well as Great Valley Group fore-arc basin strata (Fig. 8; Barth et al, 2004;Riggs et al, 2013, Stone et al, 2013Paterson et al, 2017;Surpless et al, 2019;Attia et al, 2020). In Sierra Nevada intra-arc strata, Late Triassic detrital zircon U/Th values range from ~1.0-6.0, Early Jurassic detrital zircons show U/Th values of ~0.6-4.0, Middle to Late Jurassic detrital zircons show U/Th values of ~0.5-6.0, Early Cretaceous detrital zircons show U/Th values of ~1.0-5.5, and mid-Cretaceous grains show U/Th values of ~0.7-3.5 (Fig.…”

“…Arc rocks of this age are rarely preserved in the Sierra Nevada (Fig. 3) and Mojave Desert, but geochronology from the westernmost WMB, Tehachapi Mountains, and subsurface drill cores from the eastern Central Valley, as well as the Mount Goddard and Mineral King pendants, indicates that at least some arc activity continued at this time (Saleeby et al, 1989;Saleeby, 2007;Chapman et al, 2012;Kirsch et al, 2016;Surpless et al, 2019). Detrital zircons of mid-Cretaceous age dominate detrital age distributions of mid-Lower to mid-Cretaceous Sierra Nevada strata (Fig.…”

Zircon provenance of Quaternary cover beds using U–Pb dating: Regional differences in the Southwestern USA

“…These started at around 380 Ma, probably not connected with magmatism (non-collisional Antler orogen underlying parts of Nevada, Beranek, Link, & Fanning, 2016). The formation of the Cordilleran magmatic arc system started at around 250 Ma with a distinctive peak in the zircon record some 25 myr later; a second, even larger peak occurred at 165 Ma; finally, the main body of the Sierra Nevada batholith formed (Lackey et al, 2012;DeGraaff Surpless et al, 2019). This latter, most productive phase peaked 85-95 Ma in the centre of the mountain range (Memeti et al, 2010).…”