@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 {2944,
	title = {A FRAMEWORK FOR TRANSDISCIPLINARY RADIOCARBON RESEARCH: USE OF NATURAL-LEVEL AND ELEVATED-LEVEL -14- C IN ANTARCTIC FIELD RESEARCHABSTRACT},
	journal = {Radiocarbon},
	volume = {63},
	year = {2021},
	month = {Jan-10-2021},
	pages = {1555 - 1568},
	abstract = {Radiocarbon (C-14) is an isotopic tracer used to address a wide range of scientific research questions. However, contamination by elevated levels of C-14 is deleterious to natural-level laboratory workspaces and accelerator mass spectrometer facilities designed to precisely measure small amounts of C-14. The risk of contaminating materials and facilities intended for natural-level C-14 with elevated-level C-14-labeled materials has dictated near complete separation of research groups practicing profoundly different measurements. Such separation can hinder transdisciplinary research initiatives, especially in remote and isolated field locations where both natural-level and elevated-level radiocarbon applications may be useful. This paper outlines the successful collaboration between researchers making natural-level C-14 measurements and researchers using C-14-labeled materials during a subglacial drilling project in West Antarctica (SALSA 2018-2019). Our strict operating protocol allowed us to successfully carry out C-14 labeling experiments within close quarters at our remote field camp without contaminating samples of sediment and water intended for natural level C-14 measurements. Here we present our collaborative protocol for maintaining natural level C-14 cleanliness as a framework for future transdisciplinary radiocarbon collaborations.},
	keywords = {AMS, contamination, LEUCINE, radiocarbon},
	issn = {0033-8222},
	doi = {10.1017/RDC.2021.55},
	url = {https://www.cambridge.org/core/product/identifier/S0033822221000552/type/journal_articlehttps://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033822221000552},
	author = {Venturelli, Ryan A and Vick-Majors, Trista J and Collins, Billy and Gagnon, Alan and Kasic, Kathy and Kurz, Mark D and Li, Wei and Priscu, John and Roberts, Mark and Rosenheim, Brad E}
}
