Potential for accurate and precise radiocarbon ages in deglacial-age lacustrine carbonates

Zimmerman, Susan; Steponaitis, Elena; Hemming, S. R.; Zermeño, Paula

doi:10.1016/j.quageo.2012.07.003

Cited by 17 publications

(10 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One sample (1037-2) did not graphitize properly, and is not discussed further. Samples of less than ~300 micrograms of carbon require a background correction scaled to the sample size (Zimmerman et al 2012) and so the analytical uncertainties were larger than desired, between±40 and±170 yr, 1-sigma (Table 1). Unfortunately, the combination of large analytical uncertainty and the shape of the calibration curve in this interval led to large uncertainties in the calibrated ages.…”

Section: Resultsmentioning

confidence: 99%

Testing Pollen Sorted by Flow Cytometry as the Basis for High-Resolution Lacustrine Chronologies

et al. 2018

View full text Add to dashboard Cite

Documenting leads and lags in terrestrial records of past climate change is critical to understanding the behavior of Earth’s natural climate system and making reliable predictions of future climate conditions. However, uncertainties of several hundred years in age models make it difficult to distinguish synchronicity and feedbacks in paleo archives. In lakes this is often due to the lack of terrestrial macrofossils in climate-sensitive locations, such as high alpine or dryland settings. The potential of radiocarbon (14C) dating of pollen has long been recognized, but the difficulty of cleanly separating pollen from other kinds of organic carbon has limited its usefulness. Here we report 14C ages on pollen separated by flow cytometry, from a set of closely spaced samples from Mono Lake, California. The accuracy of the pollen ages is tested using well-dated bracketing tephras, the South Mono and North Mono-Inyo tephras. In spite of the purity of the sorted samples, the pollen dates are older than the bounding tephras by ~400 yr, similar to some other pollen-dating studies. While improvements in sample preparation protocols are planned, understanding the geological processes involved in the production, preservation, and deposition of pollen at each site will be critical to developing robust high-resolution age models.

show abstract

Section: Resultsmentioning

confidence: 99%

Testing Pollen Sorted by Flow Cytometry as the Basis for High-Resolution Lacustrine Chronologies

et al. 2018

View full text Add to dashboard Cite

show abstract

“…In certain cases, when the shell material was still encrusted in sediment or showed signs of surface alteration, the sample was soaked in dilute (0.1 M) HCl to etch the surfaces clean. Despite this treatment, the older samples in particular may have been contaminated by young carbon (Zimmerman et al, 2012), yielding ages that are systematically too young. We subtracted 140 years from all ages, including those of the aquatic gastropod and ostracodes, to adjust for estimated content of old carbon as determined by Miller et al (2010) on paired dates from Anodonta shells and charcoal from Holocene deposits in the nearby Cronese basins (Fig.…”

Section: Methodsmentioning

confidence: 99%

“…(1) Several ages for the older units N38 ka are near the practical limit of radiocarbon dating and have relatively large error bars, and a smaller number of ages constrain these units than are available for the younger units. Further, it is possible that the older 14 C ages may be minimum values due to contamination or replacement by minute amounts of younger carbonate (Zimmerman et al, 2012), despite analytical efforts to remove surface carbonate using HCl. Thus, the duration and age of the oldest lake cycles (particularly P1,~44-42 ka, P2,~40-38.5 ka, and P3,~37-35.5 ka) are less certain than for younger lake cycles.…”

Section: Construction Of Lake-level Curve and Potential Errorsmentioning

confidence: 99%

Directly dated MIS 3 Lake-Level Record from Lake Manix, Mojave Desert, California, USA

et al. 2015

View full text Add to dashboard Cite

An outcrop-based lake-level curve, constrained by ~ 70 calibrated 14C ages on Anodonta shells, indicates at least 8 highstands between 45 and 25 cal ka BP within 10 m of the 543-m upper threshold of Lake Manix in the Mojave Desert of southern California. Correlations of Manix highstands with ice, marine, and speleothem records suggest that at least the youngest three highstands coincide with Dansgaard–Oeschger (D–O) stadials and Heinrich events 3 and 4. The lake-level record is consistent with results from speleothem studies in the Southwest that indicate cool wet conditions during D–O stadials. Notably, highstands between 43 and 25 ka apparently occurred at times of generally low levels of pluvial lakes farther north as interpreted from core-based proxies. Mojave lakes may have been supported by tropical moisture sources during oxygen-isotope stage 3, perhaps controlled by southerly deflection of Pacific storm tracks due to weakening of the sea-surface temperature gradient in response to North Atlantic climate perturbations.

show abstract

“…The 14 C-based chronology of Benson et al (1990) delimits the timing of Wilson Creek sedimentation to the interval between 12 and 36 ka. However, multiple studies (e.g., Hajdas et al, 2004;Kent et al, 2002;Zimmerman et al, 2011Zimmerman et al, , 2012 have demonstrated with leaching experiments that Wilson Creek ostracodes at different stratigraphic levels have been open systems, and their bulk 14 C ages are thus minimum depositional ages (Benson et al, 1990). Additionally, the recognition of Ash 18 and Ash 20 as probable Mammoth Mountain-derived tephras (Marcaida et al, 2014) places a minimum depositional age constraint of~50 ka, that is, the youngest Mammoth Mountain dome eruption (Hildreth et al, 2014), for the base of the Wilson Creek formation.…”

Section: Tephras and The Controversial Excursion In The Wilson Creek mentioning

confidence: 99%

Constraining the Early Eruptive History of the Mono Craters Rhyolites, California, Based on ²³⁸U‐²³⁰Th Isochron Dating of Their Explosive and Effusive Products

Marcaida

Stelten

Miller

2019

Geochem Geophys Geosyst

View full text Add to dashboard Cite

The Mono Craters are an overlapping chain of at least 28 domes and coulees located south of Mono Lake, east central California, and represent the most recent eruptions of high‐silica rhyolite magma in the Mono Lake‐Long Valley volcanic region. Regionally widespread tephra fall deposits from the Mono Craters serve as important chronostratigraphic markers for correlations of late Quaternary terrestrial archives in the western United States. A well‐resolved eruption chronology for the Mono Craters is thus not only critical for volcanic hazard considerations but also for paleoclimatic and paleomagnetic studies. Here we constrain the timing of early Mono Craters volcanism using ion microprobe 238U‐230Th dating of unpolished crystal faces of autocrystic zircon and allanite microphenocrysts, which samples the final stage of crystallization prior to eruption. The stratigraphically oldest domes (biotite‐bearing rhyolites) yield 238U‐230Th isochron dates between ca. 42 and ca. 19 ka and are unambiguously linked to dated tephras in the Wilson Creek formation of ancestral Mono Lake via coupled 238U‐230Th geochronology and titanomagnetite geochemistry. The second oldest set of domes (orthopyroxene‐bearing rhyolites) have overlapping 238U‐230Th isochron dates that are within uncertainty of published K/Ar and 40Ar/39Ar dates for the fayalite‐bearing rhyolite domes, suggesting a period of intense effusive activity for the Mono Craters near the Pleistocene‐Holocene boundary. Our new and previously published 238U‐230Th dates for tephras in the Wilson Creek formation provide robust geochronologic constraints for the controversial geomagnetic excursion recorded in the Wilson Creek formation.

show abstract

Potential for accurate and precise radiocarbon ages in deglacial-age lacustrine carbonates

Cited by 17 publications

References 22 publications

Testing Pollen Sorted by Flow Cytometry as the Basis for High-Resolution Lacustrine Chronologies

Testing Pollen Sorted by Flow Cytometry as the Basis for High-Resolution Lacustrine Chronologies

Directly dated MIS 3 Lake-Level Record from Lake Manix, Mojave Desert, California, USA

Constraining the Early Eruptive History of the Mono Craters Rhyolites, California, Based on ²³⁸U‐²³⁰Th Isochron Dating of Their Explosive and Effusive Products

Contact Info

Product

Resources

About

Potential for accurate and precise radiocarbon ages in deglacial-age lacustrine carbonates

Cited by 17 publications

References 22 publications

Testing Pollen Sorted by Flow Cytometry as the Basis for High-Resolution Lacustrine Chronologies

Testing Pollen Sorted by Flow Cytometry as the Basis for High-Resolution Lacustrine Chronologies

Directly dated MIS 3 Lake-Level Record from Lake Manix, Mojave Desert, California, USA

Constraining the Early Eruptive History of the Mono Craters Rhyolites, California, Based on 238U‐230Th Isochron Dating of Their Explosive and Effusive Products

Contact Info

Product

Resources

About

Constraining the Early Eruptive History of the Mono Craters Rhyolites, California, Based on ²³⁸U‐²³⁰Th Isochron Dating of Their Explosive and Effusive Products