Small, endorheic (closed), dune-dammed basins along the southern margins of the northwestern Negev desert dunefield are hypothesized to preserve high-resolution depositional archives of climate-driven sediment dynamics. This study examines two 7.5m deep cores from a dune-dammed playa (0.047km2) of a ~2km2 basin within Eocene chalk, and a core of the damming dune, mainly by grain-size analysis and imaging, XRF geochemistry, high-resolution portable-OSL profiling, and OSL dating.

The cores' sedimentology and stratigraphy reflect transitions between fluvial and aeolian-dominated environments. Basal silt loam from early MIS-3 indicate enhanced erosion of primary up-basin loess, apparently evolving into hyper-concentrated flows. Following a significant MIS-3 - Younger Dryas hiatus, Younger Dryas to early Holocene dune incursion blocked the studied drainage basin leading to seasonal ponding, fine-grained sedimentation and playa formation. Throughout the Holocene, the playa trapped sediments reflecting varying fluvial erosion rates, including anthropogenically-induced mobilized sand during the Roman-Byzantine periods. Thin units with diluted sand content suggest rapid pulses of up-basin loess delivery during high-intensity, rain events with ~1:1,000-year recurrence.

Loess-sized sediment accumulation rates reveal a fluctuating erosion trajectory from a MIS-3 "loess-loaded" landscape to a modern "loess-starved" basin. Notably, late Holocene average accumulation rates are three-fold higher than early Holocene ones. This change suggests that despite depleting up-basin loess availability, higher erosion rates were probably driven by increased high-intensity rainfall that may correspond with increased late Holocene aridity. Ultimately, small dunefield fringe basins provide a vital, underrecognized archive for resolving the timing and magnitude of aeolian, fluvial and erosive processes.