@article {grimley_updated_2024,
	title = {Updated chronology for Peoria Silt (loess) accumulation in Illinois and western Indiana from radiocarbon dating of terrestrial gastropod shells},
	journal = {Quaternary Research},
	year = {2024},
	month = {05/2024},
	pages = {1{\textendash}19},
	abstract = {Based on calibrated radiocarbon ages of terrestrial gastropod shells (Succineidae, Discus, Stenotrema, Webbhelix), the chronology of Peoria Silt (loess) deposition in the Central Lowlands is updated. These taxa provide reliable ages (within \textasciitilde0.2 ka), based on historical shell dating, shell-organic age comparisons, and stratigraphic consistency. A compilation of 53 new and 36 published Peoria Silt shell ages (calibrated), from 12 localities, date from 30.0 to 17.4 ka. Proximal (fossiliferous) loess from 10 sections had mean loess accumulation rates of 0.6{\textendash}2.2 mm/yr. Study sites along the upper Mississippi, Illinois, to mid-Mississippi, and Ohio-Wabash Valleys suggest Peoria loess accumulated from \textasciitilde27 to 15 ka, \textasciitilde29 to 18 ka, and \textasciitilde30 to 18 ka, respectively. The cessation age for Peoria Silt, based on surface extrapolations, is \textasciitilde1{\textendash}6 ka earlier than some prior Illinois estimates, even assuming slower loess accumulation in the modern solum. Younger loess in northwestern Illinois likely reflects, in part, Superior and Des Moines Lobe glacial-meltwater sediment, and Iowan Erosion Surface inputs to the upper Mississippi Valley, after the Lake Michigan Lobe receded. Furthermore, stronger winds, drier conditions, and reduced vegetation cover in valley deflation areas may have favored higher accumulation rates and later loess deposition in northwestern relative to southeastern areas.},
	keywords = {chronology, Illinois, Indiana, Kentucky, Last Glacial, Loess, Peoria Silt, radiocarbon, Succineidae, Wisconsin Episode},
	issn = {0033-5894, 1096-0287},
	doi = {10.1017/qua.2024.15},
	url = {https://www.cambridge.org/core/journals/quaternary-research/article/updated-chronology-for-peoria-silt-loess-accumulation-in-illinois-and-western-indiana-from-radiocarbon-dating-of-terrestrial-gastropod-shells/67CEEB07C31701FF4C2095346BD07F99},
	author = {Grimley, David A. and Loope, Henry M. and Jacobs, Peter M. and Nash, T. Andrew and Dendy, Sarah N. and Conroy, Jessica L. and Curry, B. Brandon}
}
@article {2995,
	title = {ERRONEOUSLY OLD RADIOCARBON AGES FROM TERRESTRIAL POLLEN CONCENTRATES IN YELLOWSTONE LAKE, WYOMING, USA},
	journal = {Radiocarbon},
	volume = {63},
	year = {2021},
	month = {02/2021},
	pages = {321 - 342},
	abstract = {Accelerator mass spectrometry (AMS) dating of pollen concentrates is often used in lake sediment records where large, terrestrial plant remains are unavailable. Ages produced from chemically concentrated pollen as well as manually picked Pinaceae grains in Yellowstone Lake (Wyoming) sediments were consistently 1700{\textendash}4300 cal years older than ages established by terrestrial plant remains, tephrochronology, and the age of the sediment-water interface. Previous studies have successfully utilized the same laboratory space and methods, suggesting the source of old-carbon contamination is specific to these samples. Manually picking pollen grains precludes admixture of non-pollen materials. Furthermore, no clear source of old pollen grains occurs on the deglaciated landscape, making reworking of old pollen grains unlikely. High volumes of CO2 are degassed in the Yellowstone Caldera, potentially introducing old carbon to pollen. While uptake of old CO2 through photosynthesis is minor (F14C approximately 0.99), old-carbon contamination may still take place in the water column or in surficial lake sediments. It remains unclear, however, what mechanism allows for the erroneous ages of highly refractory pollen grains while terrestrial plant remains were unaffected. In the absence of a satisfactory explanation for erroneously old radiocarbon ages from pollen concentrates, we propose steps for further study.},
	keywords = {AMS dating, chronology, contamination, paleoecology, pine},
	isbn = {0033-8222, 1945-5755},
	doi = {10.1017/RDC.2020.118},
	url = {https://www.cambridge.org/core/journals/radiocarbon/article/erroneously-old-radiocarbon-ages-from-terrestrial-pollen-concentrates-in-yellowstone-lake-wyoming-usa/1DAC6B6CCD52443755E7F725B84CFB3F},
	author = {Schiller, Christopher M. and Whitlock, Cathy and Elder, Kathryn L. and Iverson, Nels A. and Abbott, Mark B.}
}
@article {2822,
	title = {Sediment accumulation and sedimentation rates in playas on the High Plains of western Kansas, USA},
	journal = {Geomorphology},
	volume = {342},
	year = {2019},
	month = {Jan-10-2019},
	pages = {117 - 126},
	abstract = {Grassland ecosystems are some of the most modified ecosystems in the world, largely due to conversion to cropland, and the High Plains of the central United States is no exception. Playa wetlands are ubiquitous features of the High Plains and have experienced increased sediment accumulation, which is the primary cause of reduced playa ecosystem function. Seven playas on the High Plains of western Kansas, five with cropland-dominated watersheds and two with grassland-dominated watersheds, were examined to quantify the amount of recent (past ~100{\textendash}175 yr) sediment accumulated within playas and to establish chronologies of playa filling. Thicknesses of recent sediment were determined in the field, and soil cores were extracted from study playas. Four playa cores were analyzed for 210Pb to establish the chronology of recent sediment accumulation and sedimentation rates. Chronologies of pre-agricultural sediments and sedimentation rates were calculated by 14C dating of buried soils preserved within playa cores. Radiocarbon ages indicate playa stratigraphic records span the Holocene and that these playas have persisted on the landscape since at least the Late Pleistocene. Long-term, natural sedimentation rates were highest during the Pleistocene-Holocene transition and early Holocene, at ~2{\textendash}4 cm/century. During the middle and late Holocene, sedimentation rates averaged ~1 cm/century. Cropland playas accumulated ~10{\textendash}15 cm of recent sediment at average rates of ~6.5{\textendash}10 cm/century, while grassland playas accumulated only ~2 cm of recent sediment. Conversion of watersheds to cropland has greatly accelerated sediment accumulation within playas, which is generally resulting in a decline in critical playa ecosystem functions.},
	keywords = {210Pb, Agricultural, chronology, Holocene, Radiocarbon dating, sedimentation},
	issn = {0169555X},
	doi = {10.1016/j.geomorph.2019.06.014},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0169555X19302612},
	author = {Bowen, Mark W. and Johnson, William C.}
}
@article {2209,
	title = {Deglaciation of the northwestern White Mountains, New Hampshire},
	journal = {Geographie Physique Et Quaternaire},
	volume = {53},
	year = {1999},
	note = {218kbTimes Cited:18
Cited References Count:56
},
	month = {1999},
	pages = {59-77},
	abstract = {The mode of deglaciation in the northwestern White Mountains of New Hampshire has been controversial since the mid 1800{\textquoteright}s. Early workers believed that active ice deposited the Bethlehem Moraine complex in the Ammonoosuc River basin during recession of the last ice sheet. In the 1930{\textquoteright}s this deglaciation model was replaced by the concept of widespread simultaneous stagnation and downwastage of Late Wisconsinan ice. The present authors reexamined the Bethlehem Moraine complex and support the original interpretation of a series of moraines deposited by active ice. We found other moraine clusters of similar age to the northeast in the Johns River and lsrael River basins. lce-marginal deposits that probably correlate with the Bethlehem Moraine also occur west of Littleton. The Bethlehem Moraine complex and equivalent deposits in adjacent areas were formed by readvance and oscillatory retreat of the Connecticut Valley lobe of the Laurentide Ice Sheet. This event is called the Littleton-Bethlehem Readvance. Throughout the study area, sequences of glaciolacustrine deposits and meltwater drainage channels indicate progressive northward recession of the glacier margin. Radiocarbon dates from nearby New England and Quebec suggest that the ice sheet withdrew from this part of the White Mountains between about 12,500 and 12,000 (14)C yr BP. We attribute the Littleton-Bethlehem Readvance to a brief climatic cooling during Older Dyas time, close to 12,000 BP.},
	keywords = {canada, chronology, climate, last termination, new-england, record, tills},
	isbn = {0705-7199},
	author = {Thompson, W. B. and Fowler, B. K. and Dorion, C. C.}
}
