Playas are ephemeral upland-embedded wetlands found in semiarid and arid regions worldwide. Lunettes are isolated dunes that form along the downwind margin of playas. The paleoclimatic and geomorphic history of High Plains playa-lunette systems (PLSs) are poorly understood. To address this, we characterize the stratigraphy of four PLSs in southwest Kansas, USA. Methods include: 1) collect soil-sediment cores from playa centers and windward slopes of lunettes; 2) describe cores using USDA techniques; 3) estimate age of stratigraphic units using radiocarbon (14C); and 4) reconstruct paleoenvironmental conditions using stable carbon isotopes (13C) and particle size analysis. Playa stratigraphy is relatively simple and consists of well-developed surface soils underlain by gleyed clays. Calibrated playa 14C ages range from 6,280-23,600 cal yr BP. Lunette stratigraphy is complex; buried soils and thick units of light-dark bands are common. Calibrated 14C ages for buried soils in lunettes range from 19,050-32,300 cal yr BP. Lunette 13C data are highly oscillatory. These data indicate a warm-dry period dominated with C4 plants preceded ~30 ka, and was followed by a cool-moist, C3 plant dominated period before returning to warm-dry conditions throughout much of the Holocene. Playa records extend from marine isotope stage (MIS) 3 (i.e., prior to the Last Glacial Maximum), and lunette records extend into MIS 3. Playa stratigraphy suggests they were dominated by alluvial-lacustrine processes during the late Pleistocene and early Holocene. Alternating light-dark bands in lunettes are hypothesized to represent incipient soils and aeolian sediment resulting from small-scale shifts in climate throughout much of the late Pleistocene and early Holocene, with geomorphic processes alternating between aeolian deposition and pedogenesis. Well-developed surface soils in playas and lunettes suggest stabilization and pedogenesis dominated the mid to late Holocene under a warming and drier climate. Thus, PLS development appears linked to both global-scale and regional climate processes.


Mark Bowen

Committee Member

Phil Larson

Committee Member

Samantha Kaplan

Date of Degree




Document Type



Master of Science (MS)

Degree Program/Certificate





Social and Behavioral Sciences

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Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License
This work is licensed under a Creative Commons Attribution-NonCommercial-Share Alike 4.0 International License.



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