Deep- versus shallow-marine sandstone provenance in the mid-Carboniferous Clare Basin, western Ireland

Abstract

In a ‘source to sink’ sedimentary system, multiple processes have the potential to modify the sediment composition during sediment generation at the source, through transport, deposition and burial. To investigate these issues, a multi-proxy provenance study of deep-water and shallow-marine sandstones from the mid-Carboniferous Clare Basin was undertaken, utilising zircon and apatite U-Pb geochronology, heavy mineral analysis (including apatite trace element data) and petrography. Data from the deep-water submarine fans show a similar provenance signal to the shallow marine sandstones. Data, from across the Clare Basin stratigraphy indicate sands were likely and consistently derived from the south and SW, with a portion of the detritus being recycled from Old Red Sandstone basins to the south. The provenance signal, however, shows spatial and temporal variations across the basin that are explained by fluctuations in the amount of recycled sediments and are linked with the evolving Variscan Orogenic Belt. Heavy mineral data from both shallow marine and deep-water sandstones suggest a basin configuration with a delta system feeding directly into the deep basin.Supplementary material:https://doi.org/10.6084/m9.figshare.c.5446739

Wildfires and Monsoons: Cryptic Drivers for Highly Variable Provenance Signals within a Carboniferous Fluvial System

“…Carbonate production became widespread across much of northwestern Europe during the Mississippian, with terrigenous sediment deposition limited to localised drainage systems. Large-scale drainage systems, such as that feeding the Pennine Basin in Britain [53], and the smaller-scale systems supplying the Shannon Basin in Ireland [54,55] evolved subsequently in the Pennsylvanian.…”

“…Apatite trace element data were acquired simultaneously with the U-Pb isotope data and followed the same procedure. Trace element masses measured were: 55 Mn, 88 Sr, 89 Y, 90 Zr, 139 La, 140 Ce, 141 Pr, 146 Nd, 147 Sm, 153 Eu, 157 Gd, 159 Tb, 163 Dy, 165 Ho, 166 Er, 169 Tm, 172 Yb, 175 Lu, 232 Th and 238 U. NIST612 was the primary reference material employed during trace element data reduction, and an aliquot of Durango apatite was the secondary reference material [100]. Apatite trace elements were reduced using the Iolite Trace Element DRS, employing the internal elemental standardisation approach of Woodhead et al [101] using 43 Ca, set to the stoichiometric content of apatite (40 wt%).…”