U–Pb detrital zircon evidence of transcontinental sediment dispersal: provenance of Late Mississippian Wedington Sandstone member, NW Arkansas

ABSTRACT

U–Pb ages of detrital zircons from the Wedington Sandstone member in northwest Arkansas provide evidence for Late Mississippian westward transcontinental sediment transport from the Appalachian foreland. The Late Mississippian Wedington Sandstone member of the Fayetteville Shale is a fine- to medium-grained quartzarenite. It separates the Fayetteville Shale into informal lower and upper intervals, and was deposited as a small constructive delta complex that prograded towards the south and southeast during the Late Mississippian. As a major influx of clastic sediments, the Wedington Sandstone member records the sediment source and dispersal in the mid-continent during the Late Mississippian. A total of 559 detrital zircon grains from six Wedington samples were recovered for U–Pb detrital zircon geochronological analysis. Results show that age distributions can be subdivided into six groups: ~350–500, ~900–1350, ~1360–1500, ~1600–1800, ~1800–2300, and > ~2500 Ma, and are characterized by a prominent peak for the age group of ~900–1350 Ma, a major peak at ~1600–1800 Ma, and a few other minor age clusters. Regional correlation and geological evidence from surrounding areas suggest that the transcontinental sediment dispersal started as early as the Late Mississippian. U–Pb detrital zircon age distribution suggests that the Wedington Sandstone member was likely derived from the Appalachian foreland with contributions from the Nemaha Ridge to the west where the Yavapai–Mazatzal sources were exposed during the Late Mississippian. Sediment was likely transported westward through or around the Illinois Basin, merged with mid-continent sediment, and then entered into its current location in northwest Arkansas. Transportation of this sediment from mixed sources continued along its course to the south, forming a delta on the Northern Arkansas Structural Platform.

KEYWORDS:

• Wedington Sandstone member
• Late Mississippian
• U–Pb detrital zircon
• sediment dispersal
• North American mid-continent
• Nemaha Ridge

Acknowledgements

The authors thank Dr Doy L. Zachry, Department of Geosciences, University of Arkansas, and Dr Jeff Vervoort, School of Earth and Environmental Sciences, Washington State University, for discussion regarding field sites, sample preparation, analysis, and data processing. Special thanks to Dr Arthur Busbey for all edits and proofreading. This research was partially supported by the Research and Creative Scholarship (2015) from Texas Christian University and research funding from the Fulbright College of Art and Science (2012), University of Arkansas, Fayetteville. Thanks to Editor Dr Robert Stern, Dr Gary Michelfelder, and an anonymous reviewer provided constructive reviews that significantly improved the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

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Additional information

Funding

This work was supported by the Research and Creative Scholarship (2015) from Texas Christian University and research Funding from the Fulbright College of Art and Science, University of Arkansas, Fayetteville [2012];.