17 Geological Surveys and Resource Mapping/Evaluation Studies

This session highlights studies from state geologic surveys and the U.S. Geological Survey regarding natural resource evaluations. We welcome submissions with relevance to critical minerals, rare earth elements, various energy sectors, and the construction industry.

Tuesday, 10 March 2026
8:30 AM - 10:00 AM
RCC, 103

Detrital zircon and rutile U-Pb geochronology of Cretaceous strata along the eastern Gulf Coastal Plain: Insight to heavy mineral sand accumulations

Paper number: 17-1
Program: Technical Sessions
Time: 8:35 AM – 8:50 AM

Authors

Abstract

Heavy mineral sand deposits are economically important hosts of critical minerals and rare earth elements in the growing non-fuel energy industry. However, to advance our understanding of the spatial-temporal distribution of heavy mineral sands, process-based determinations of associated sedimentary systems are required. We present detrital zircon and rutile U-Pb geochronology to determine the sediment provenance of Upper Cretaceous sand deposits and to reconstruct paleo-geographic drainage networks along the eastern Gulf Coastal Plain and northern Mississippi Embayment. Detrital zircon age spectra are characterized by Appalachian (490-270 Ma) and Grenville (1250-900 Ma) populations alongside minor Granite-Rhyolite (1550-1300 Ma), Yavapai-Mazatzal (1800-1600 Ma), and Wyoming (> 2400 Ma) populations. Detrital rutile age spectra consist almost exclusively of Appalachian and Grenville populations. We interpret samples that are proportionately dominated by Appalachian grains to be sourced directly from the eastern Blue Ridge and Inner Piedmont litho-tectonic terranes of the southern Appalachians; whereas, samples that are proportionately dominated by Grenville grains are sourced from the southern Appalachian western Blue Ridge and or Valley and Ridge provinces, representing multiple generations of sediment recycling. These proportional relationships seem to correlate to heavy mineral abundance in Upper Cretaceous sand deposits; with a first-generation, eastern Blue Ridge and Inner Piedmont source correlating with higher heavy mineral concentrations and a multi-generation, western Blue Ridge and Valley and Ridge source correlating to lower concentrations. This geochronologic relationship presents a first-order assessment of heavy mineral sand accumulations and could be applied to other Mesozoic and Cenozoic strata in the Gulf and Atlantic Coastal Plains.

Geological Society of America Abstracts with Programs. Vol. 58, No. 1

doi: 10.1130/abs/2026SE-411819

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