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Provenance of Carboniferous Strata in the Cumberland Plateau, Tennessee: Insights from Detrital Zircon U-Pb Geochronology and Lu-Hf Isotopic Constraints in the Southern Appalachian Basin

Session: Advances and Applications in Geochronology for Interpreting Stratigraphic and Basin Records (Posters)

Presenting Author:

Abigail Morris

Authors:

Morris, Abigail¹, Schelling, Kaci², Belt, Katherine³, Bhattacharya, Gourab⁴

(1) Earth Sciences, Tennessee Tech University, Sparta, Tennessee, USA, (2) Earth Sciences, Tennessee Tech University, Spring Hill, Tennessee, USA, (3) Chemistry, Virginia Tech, Blacksburg, Virginia, USA, (4) Earth Sciences, Tennessee Tech University, Cookeville, Tennessee, USA,

Abstract:

The Appalachian Basin is a composite retroarc foreland basin that developed in response to three major Paleozoic orogenic events: the Taconic, Acadian, and Alleghenian–Ouachita orogenies. This extensive basin system parallels the western margin of the Appalachian fold-thrust belt and preserves a complex record of sedimentation spanning hundreds of millions of years. To investigate sediment provenance in the southern Appalachian Basin, we conducted detrital zircon U–Pb geochronology (n = 2885) on eleven Mississippian–Pennsylvanian sandstone samples from the Cumberland Plateau in Tennessee. The resulting detrital zircon U-Pb age spectra reveal consistent patterns across samples, with prominent age peaks at ~435 Ma, 900–1000 Ma, and ~1650 Ma, and minor peaks at ~2700 Ma. Notably, several samples contain rare but significant Archean zircons (~3200–3600 Ma), representing some of Earth’s earliest continental crust. Cross-correlation and similarity coefficients indicate 50–97% inter-sample similarity, consistent with extensive sediment recycling. Lu–Hf isotopic analyses of 280 detrital zircons further support this interpretation, with predominantly positive ε_Hfvalues suggesting derivation from evolved crustal sources subjected to multiple recycling events. These detrital zircon U–Pb age spectra from the Southern Appalachian Basin closely match those from the Northern and Central Appalachian Basin, indicating basin-wide consistency in sediment sources and recycling processes. Our results highlight the fundamental role of sediment recycling in shaping the stratigraphic architecture of the Appalachian Basin through multiple generations of exhumation, transport, and redeposition during its prolonged tectono-sedimentary evolution.