PROVENANCE OF THE CASTLE VALLEY EOLIANITE, PARADOX BASIN, UTAH: A MIX OF NEARBY AND DISTANT DETRITAL SOURCES
The eolian sandstone is compositional subarkose with potassium feldspar, plagioclase and biotite derived from local Uncompahgre sources. These minerals are absent from quartzarenite of the greater White Rim erg, and comparison of detrital zircon populations in the Castle Valley eolianite and locally-derived redbeds of the underlying Cutler Group indicate that only a subordinate fraction of the zircons were locally derived, with the majority of zircon ages similar to those of the greater White Rim erg. Grain ages include late Paleoproterozoic and early Mesoproterozoic grains (~1.80-1.49 Ga) and important populations of Grenville, Neoproterozoic and Paleozoic grains, the latter three groups absent from the subjacent redbeds and therefore not attributable to the Uncompahgre uplift. Grenville and younger grains are generally interpreted as having an eastern Laurentian (Appalachian) source, and the older grains as having a more local source in southwestern Laurentia, although the winds generally blew toward SW Laurentia. We posit that many of the Paleoproterozoic and Mesoproterozoic grains in the eolian sandstone were derived from the Sveconorwegian province of western Baltica by trans-Pangean fluvial systems analogous to those that delivered the eastern Laurentian grains to the western edge of the continent.