An age-depth model and revised stratigraphy of vertebrate-bearing units in Natural Trap Cave, Wyoming

Excavations at Natural Trap Cave (NTC) began in the mid-1970's and quickly yielded evidence of a diverse steppe fauna that existed during Last Glacial Maximum (MIS 2) along western slope Bighorn Mountains north central Wyoming. NTC is karst pit cave with 24.5 m vertical drop into roughly 43 wide bell-shaped ‘Main Chamber’ course early excavations plugged entrance to fossil-bearing ‘Lower was discovered. Stratigraphic relationships below Main Chamber were originally studied mid-1970's, but never formally published. Although stratigraphy, taphonomy, depositional circumstances briefly discussed over following years, little has been done correlate numerous stratigraphic schemes used by various authors. In this study, four sections measured analyzed establish an easily modifiable lithostratigraphic system nomenclature. We provide first correlations all nomenclature throughout facilitate comparisons current previous collections publications. By leveraging more than 100 radioisotopic dates we developed age-depth model chronostratigraphic framework further interrogate spatiotemporal between strata, paleoenvironmental proxies, fossil assemblages. Deposition shown be discontinuous; sediment accumulation study area restricted buildup through peak penultimate maxima. More recent (<10 ka) Holocene deposits unconformably cover eroded surface underlying Pleistocene strata. There active reworking sediments transport deposition reactivated material within Lower Chamber. note two hiatuses coincide interglacial periods may reflect changing such as extended non-deposition, erosion, or bypass (possibly leading Chamber). Contrary reports, demonstrate it unlikely prominent snow cone contributed pattern distribution area, furthermore, do not observe continuous Pleistocene-Holocene transition area. Further work will needed better understand interrelationship chamber evolution NTC.