Pleistocene history in an Arkansas Cave, Part 2: Cave deposits, glacial cycles, & river incision

Sediment deposits and calcite formations in Arkansas' Fitton Cave hold clues to interpreting the broader Ice Age history of cave development, climate cycles, and river incision in the Ozarks. This is Part 2 of a series on Fitton Cave, within the Buffalo National River. Here we explore how a 2025 study obtained dates for cave sediment deposits and speleothems (stalagmites, flowstones, etc.) within Arkansas' longest cave, and used the results to draw connections with broader Ice Age conditions over the last two million years. The results point to fascinating potential correlations between periods of glacial advance (well to the north), timing of cave development and periods of internal sediment deposition, and periods of river incision and terrace development along the Buffalo River. This video is our own independent interpretation of the published study, and was not developed in collaboration with the authors. Comments and feedback welcome! Like this video? Consider leaving us a tip via the Thanks button below this video, or through Ko-Fi (no account required): https://ko-fi.com/ozarkoutsider Learn more about us online at: https://ozarkoutsider.com 00:00 Introduction 02:14 Setting: Geography and cave features 04:05 Premise: Relative age of cave deposits 06:24 Methods: Intro 06:54 Methods: Cosmogenic nuclide burial dating 08:17 Methods: Optically stimulated luminescence dating 08:51 Methods: Uranium-series disequilibrium dating 09:27 Methods: Paleomagnetism 11:00 Results: Sediment deposit dating 14:19 Results: Speleothem dating 16:25 Results: Summary of cave history 18:48 Discussion: Correlation with glacial cycles 20:59 Discussion: Correlation with Buffalo River terraces 26:47 Wrapup and further questions Links: Hudson et al. (2025) Two million years of climate-driven cave-sediment aggradation and valley incision in the southern Ozark Plateau from Fitton Cave, northern Arkansas, USA: https://doi.org/10.1017/qua.2025.14 Paces et al. (2023) Isotope analyses and U-series disequilibrium ages for speleothem, water, and rock samples associated with Fitton Cave, Buffalo National River, Arkansas, USA: https://www.usgs.gov/data/isotope-ana... Buffalo National River: https://www.nps.gov/buff/index.htm