Provenance of Upper Devonian-Lower Carboniferous Miogeoclinal Strata, Southeastern Canadian Cordillera: Link Between Tectonics and Sedimentation

Abstract

Upper Devonian-Lower Mississippian siliciclastic miogeoclinal strata in the southern Canadian Rocky Mountains provide a partial record of the geographic and tectonic setting of the Paleozoic western margin. Although these marine strata (Exshaw and lower Banff formations) contain extensive shale and mudstone, and some quartzofeldspathic sandstone and siltstone, as well as volcanic ash layers, the provenance of these clastic units has, thus far, remained poorly or incompletely understood. The integration of sandstone petrofacies analysis with neodymium isotopic and trace-element (rare earth element, Th, and Sc) analyses of mudrock facies was undertaken in this study to constrain better the sedimentary provenance.Coarse siltstones and sandstones in the Exshaw and Banff formations are chiefly subfeldspathic and feldspathic (quartzose-arkosic) arenites, with a complex sedimentary history involving derivation, at least in part, from an uplifted plutonic and volcanic source, such as possible western ''Antler'' orogenic highlands. The presence of monocrystalline quartz (inclusionless and with unit extinction) and sanidine in Exshaw sandstones at some sections suggests at least a partial acidic volcanic or shallow intrusive source component. The Exshaw and Banff petrofacies reflect the possible combined effects of regional tectonic complexity (different and/or mixed source terranes), sediment transport and recycling, complex sediment dispersal paths, and weathering and diagenesis. Mudrock elemental and isotope geochemistry also support a provenance involving potentially multiple sources (mixed provenance). Chondrite-normalized REE distribution patterns and La-Th-Sc ratios for Exshaw and Banff mudrocks resemble patterns for sediments derived from old continental crust (e.g., passive margins, etc.) as well as some arc settings. Nd isotopic compositions of the Exshaw and Banff formations do not support a specific provenance, but they are consistent with addition of material younger than Archean in age.

Facies control on sandstone composition (and influence of statistical methods on interpretations) in the John Henry Member, Straight Cliffs Formation, Southern Utah, USA

“…Black stars represent measured section localities for this study. Grey stars represent partial and Thomson, 2000;Ramm, 2000) or incorporated petrofacies into analyses of tectonic history (e.g., Currie, 1998;Savoy et al, 2000;Mora et al, 2006). Relatively few studies assess the influence of depositional systems on detrital modes, specifically evaluating linked compositional and facies changes through space and time (Garzanti, 1986;Marenssi et al, 2002).…”

Provenance, depositional setting, and crustal evolution of the Cathaysia Block, South China: Insights from detrital zircon U–Pb geochronology and geochemistry of clastic rocks

“…This discrepancy of using trace elements in this study may reflect inherited signatures of the clastic sediments from old provenance terranes (e.g., ancient basement of active continental margins) rather than its depositional environment (e.g., Bai, Zhou, Wang, Zhang, & Ma, ; Concepcion et al, ; Savoy, Stevenson, & Mountjoy, ). The U–Pb detrital zircon dating of the sandstone samples is dominated in Neoproterozoic to Mesoarchean, much older than their depositional age (Sinian–Cambrian) confirms this hypothesis.…”

Provenance and depositional setting of Lower Silurian siliciclastic rocks on Hainan Island, South China: Implications for a passive margin environment of South China in Gondwana

“…This discrepancy most likely results from an inherited signature, which in turn indicates a continental, passive margin derivation from potentially multiple sources (i.e. mixed provenance), as suggested by Savoy et al (2000) and Concepcion et al (2012).…”