Detrital zircon record of Mesozoic volcanic arcs in the Lower Cretaceous Mural Limestone, northwestern Mexico

Abstract

The northwestern part of Mexico, southern Arizona, and southern California witnessed extensive arc magmatism during Late Triassic to Early Cretaceous. Here, we present results from petrography, whole‐rock geochemistry (major and trace including rare‐earth elements), and detrital zircon geochronological studies that were carried out on sandstones and shales of the Mural Limestone exposed in the Rancho Bufalo area. Based on the petrography, sandstones are classified as sublitharenite, litharenite, feldspathic litharenite, and lithic arkose. The sandstones contain higher proportion of monocrystalline quartz than polycrystalline quartz. Sandstones and shales from the various members of the Mural Limestone show large variations in major and trace elements concentrations. The average concentrations of ΣREE (total ΣREE) are lower in sandstones than in shales. The chondrite‐normalized REE patterns of the sandstones and shales are moderately fractionated with light REE (LREE) enrichment relative to heavy REE (HREE) and with flat to slightly depleted HREE patterns. The chemical index of alteration values and A–CN–K relationships of sandstones indicate low to moderate intensity of weathering in the source region; however, shale samples suggesting the source rocks were subjected to moderate intensity of chemical weathering. The chondrite‐normalized REE patterns, Al2O3/TiO2 ratio, elemental ratios like Cr/V, Y/Ni, and Eu‐anomaly (Eu/Eu*), and bivariate plots suggest that the sandstones and shales were derived mainly from felsic source rocks. Detrital zircon U–Pb geochronology of sandstones from Fronteras, Rancho Bufalo, and Cerro La Ceja members of the Mural Limestone show five main groups of detrital zircon age populations: (a) Proterozoic, (b) Palaeozoic, (c) Triassic, (d) Jurassic, and (e) Early Cretaceous. Our study suggests that continental volcanic arcs in northwestern Mexico, southern Arizona, and southern California served as the provenance for the Late Triassic‐Jurassic detritus, whereas the Early Cretaceous zircon grains were derived mainly from the active Alisitos volcanic arc along the northwestern coast of Mexico.

Detrital zircon U–Pb geochronology and geochemistry of the Riachuelos and Palma Sola beach sediments, Veracruz State, Gulf of Mexico: a new insight on palaeoenvironment

“…Zircon is a common accessory mineral in clastic sediments, which retains U-Pb isotopic signatures during erosion, recycling, and transport; differences in zircon age populations in sediments are linked to the nature and age of source terranes (Ji et al 2019;Joy et al 2019;Liu et al 2019;Chaudhuri et al 2020). Hence, detrital zircon U-Pb age geochronology is reliable to infer provenance, as well as helpful to discriminate sediments derived from various source terranes and to understand their sediment-transport pathways (An et al 2016;Madhavaraju et al 2018;Wang et al 2018a). Although U-Pb ages of detrital zircons have been used widely in different studies to investigate sediment provenance, few studies recommended that the combination of zircon age data and trace element data is more reliable to better understand the depositional history of a complex depositional basin (Wang et al 2017;Li et al 2019).…”

Geochemistry of siltstones in the North Qilian Zhongbao–Mayinggou formations (Late Ordovician–Early Silurian): implications for paleoclimate, paleoweathering, and tectonic setting

“…The geochemical value of the clastic sediments is dominantly used to ascertain the source area and structural setting (Cullers, 1995;McLennan, 1993;Armstrong-Altrin et al, 2004;Armstrong-Altrin et al, 2012;Armstrong-Altrin, 2015;Zaid, 2012;Zaid, 2015;Madhavaraju et al, 2017;Madhavaraju et al, 2019;Madhavaraju et al, 2021). The sandstones from Zhongbao and Mayinggou formations were plotted in the intermediate and felsic field (Figure 8) from the SiO 2 vs. Al 2 O 3 /TiO 2 diagram (Le Bas et al, 1986).…”