Articles | Volume 4, issue 1
https://doi.org/10.5194/gchron-4-311-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/gchron-4-311-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
25 May 2022
Research article |
| 25 May 2022
Reconciling the apparent absence of a Last Glacial Maximum alpine glacial advance, Yukon Territory, Canada, through cosmogenic beryllium-10 and carbon-14 measurements
Department of Earth and Environmental Sciences, Tulane University, New Orleans, LA 70118, USA
Brian Menounos
Geography Earth and Environmental Sciences, University of Northern British Columbia, Prince George, BC, Canada
Gerald Osborn
Department of Geoscience, University of Calgary, Calgary, AB, Canada
Adam Hawkins
Geography Earth and Environmental Sciences, University of Northern British Columbia, Prince George, BC, Canada
Brent Ward
Department of Earth Sciences, Simon Fraser University, Burnaby, BC, Canada
Related authors
Jonathan R. Adams, Joanne S. Johnson, Stephen J. Roberts, Philippa J. Mason, Keir A. Nichols, Ryan A. Venturelli, Klaus Wilcken, Greg Balco, Brent Goehring, Brenda Hall, John Woodward, and Dylan H. Rood
The Cryosphere, 16, 4887–4905, https://doi.org/10.5194/tc-16-4887-2022, https://doi.org/10.5194/tc-16-4887-2022, 2022
Short summary
Short summary
Glaciers in West Antarctica are experiencing significant ice loss. Geological data provide historical context for ongoing ice loss in West Antarctica, including constraints on likely future ice sheet behaviour in response to climatic warming. We present evidence from rare isotopes measured in rocks collected from an outcrop next to Pope Glacier. These data suggest that Pope Glacier thinned faster and sooner after the last ice age than previously thought.
Greg Balco, Nathan Brown, Keir Nichols, Ryan A. Venturelli, Jonathan Adams, Scott Braddock, Seth Campbell, Brent Goehring, Joanne S. Johnson, Dylan H. Rood, Klaus Wilcken, Brenda Hall, and John Woodward
The Cryosphere Discuss., https://doi.org/10.5194/tc-2022-172, https://doi.org/10.5194/tc-2022-172, 2022
Revised manuscript accepted for TC
Short summary
Short summary
Samples of bedrock recovered from below the West Antarctic Ice Sheet show that part of the ice sheet was thinner than it is now several thousand years ago, and subsequently thickened. This is important because of concern that present ice thinning in this region may lead to rapid, irreversible sea level rise. The past episode of thinning at this site, which took place in a similar although not identical climate, was not irreversible. However, reversal required at least 3000 years to complete.
Joanne S. Johnson, Ryan A. Venturelli, Greg Balco, Claire S. Allen, Scott Braddock, Seth Campbell, Brent M. Goehring, Brenda L. Hall, Peter D. Neff, Keir A. Nichols, Dylan H. Rood, Elizabeth R. Thomas, and John Woodward
The Cryosphere, 16, 1543–1562, https://doi.org/10.5194/tc-16-1543-2022, https://doi.org/10.5194/tc-16-1543-2022, 2022
Short summary
Short summary
Recent studies have suggested that some portions of the Antarctic Ice Sheet were less extensive than present in the last few thousand years. We discuss how past ice loss and regrowth during this time would leave its mark on geological and glaciological records and suggest ways in which future studies could detect such changes. Determining timing of ice loss and gain around Antarctica and conditions under which they occurred is critical for preparing for future climate-warming-induced changes.
Trevor R. Hillebrand, John O. Stone, Michelle Koutnik, Courtney King, Howard Conway, Brenda Hall, Keir Nichols, Brent Goehring, and Mette K. Gillespie
The Cryosphere, 15, 3329–3354, https://doi.org/10.5194/tc-15-3329-2021, https://doi.org/10.5194/tc-15-3329-2021, 2021
Short summary
Short summary
We present chronologies from Darwin and Hatherton glaciers to better constrain ice sheet retreat during the last deglaciation in the Ross Sector of Antarctica. We use a glacier flowband model and an ensemble of 3D ice sheet model simulations to show that (i) the whole glacier system likely thinned steadily from about 9–3 ka, and (ii) the grounding line likely reached the Darwin–Hatherton Glacier System at about 3 ka, which is ≥3.8 kyr later than was suggested by previous reconstructions.
Perry Spector, John Stone, and Brent Goehring
The Cryosphere, 13, 3061–3075, https://doi.org/10.5194/tc-13-3061-2019, https://doi.org/10.5194/tc-13-3061-2019, 2019
Short summary
Short summary
We describe constraints on the thickness of the interior of the West Antarctic Ice Sheet (WAIS) through the last deglaciation. Our data imply that the ice-sheet divide between the Ross and Weddell sea sectors of the WAIS was thicker than present for a period less than ~ 8 kyr within the past ~ 15 kyr. These results are consistent with the hypothesis that the divide initially thickened due to the deglacial rise in snowfall and subsequently thinned in response to retreat of the ice-sheet margin.
Keir A. Nichols, Brent M. Goehring, Greg Balco, Joanne S. Johnson, Andrew S. Hein, and Claire Todd
The Cryosphere, 13, 2935–2951, https://doi.org/10.5194/tc-13-2935-2019, https://doi.org/10.5194/tc-13-2935-2019, 2019
Short summary
Short summary
We studied the history of ice masses at three locations in the Weddell Sea Embayment, Antarctica. We measured rare isotopes in material sourced from mountains overlooking the Slessor Glacier, Foundation Ice Stream, and smaller glaciers on the Lassiter Coast. We show that ice masses were between 385 and 800 m thicker during the last glacial cycle than they are at present. The ice masses were both hundreds of metres thicker and remained thicker closer to the present than was previously thought.
Keir A. Nichols and Brent M. Goehring
Geochronology, 1, 43–52, https://doi.org/10.5194/gchron-1-43-2019, https://doi.org/10.5194/gchron-1-43-2019, 2019
Short summary
Short summary
We describe observations of anomalously high measurements of C-14 made from geologic material. We undertake a systematic investigation to identify the source of contamination, which we hypothesise is sourced from a commonly used method that is used prior to sample analysis. We find that the method does introduce modern carbon to samples and elevates C-14 measurements. We describe a standard procedure that effectively removes contamination from the aforementioned method.
Jonathan R. Adams, Joanne S. Johnson, Stephen J. Roberts, Philippa J. Mason, Keir A. Nichols, Ryan A. Venturelli, Klaus Wilcken, Greg Balco, Brent Goehring, Brenda Hall, John Woodward, and Dylan H. Rood
The Cryosphere, 16, 4887–4905, https://doi.org/10.5194/tc-16-4887-2022, https://doi.org/10.5194/tc-16-4887-2022, 2022
Short summary
Short summary
Glaciers in West Antarctica are experiencing significant ice loss. Geological data provide historical context for ongoing ice loss in West Antarctica, including constraints on likely future ice sheet behaviour in response to climatic warming. We present evidence from rare isotopes measured in rocks collected from an outcrop next to Pope Glacier. These data suggest that Pope Glacier thinned faster and sooner after the last ice age than previously thought.
Greg Balco, Nathan Brown, Keir Nichols, Ryan A. Venturelli, Jonathan Adams, Scott Braddock, Seth Campbell, Brent Goehring, Joanne S. Johnson, Dylan H. Rood, Klaus Wilcken, Brenda Hall, and John Woodward
The Cryosphere Discuss., https://doi.org/10.5194/tc-2022-172, https://doi.org/10.5194/tc-2022-172, 2022
Revised manuscript accepted for TC
Short summary
Short summary
Samples of bedrock recovered from below the West Antarctic Ice Sheet show that part of the ice sheet was thinner than it is now several thousand years ago, and subsequently thickened. This is important because of concern that present ice thinning in this region may lead to rapid, irreversible sea level rise. The past episode of thinning at this site, which took place in a similar although not identical climate, was not irreversible. However, reversal required at least 3000 years to complete.
Joanne S. Johnson, Ryan A. Venturelli, Greg Balco, Claire S. Allen, Scott Braddock, Seth Campbell, Brent M. Goehring, Brenda L. Hall, Peter D. Neff, Keir A. Nichols, Dylan H. Rood, Elizabeth R. Thomas, and John Woodward
The Cryosphere, 16, 1543–1562, https://doi.org/10.5194/tc-16-1543-2022, https://doi.org/10.5194/tc-16-1543-2022, 2022
Short summary
Short summary
Recent studies have suggested that some portions of the Antarctic Ice Sheet were less extensive than present in the last few thousand years. We discuss how past ice loss and regrowth during this time would leave its mark on geological and glaciological records and suggest ways in which future studies could detect such changes. Determining timing of ice loss and gain around Antarctica and conditions under which they occurred is critical for preparing for future climate-warming-induced changes.
Trevor R. Hillebrand, John O. Stone, Michelle Koutnik, Courtney King, Howard Conway, Brenda Hall, Keir Nichols, Brent Goehring, and Mette K. Gillespie
The Cryosphere, 15, 3329–3354, https://doi.org/10.5194/tc-15-3329-2021, https://doi.org/10.5194/tc-15-3329-2021, 2021
Short summary
Short summary
We present chronologies from Darwin and Hatherton glaciers to better constrain ice sheet retreat during the last deglaciation in the Ross Sector of Antarctica. We use a glacier flowband model and an ensemble of 3D ice sheet model simulations to show that (i) the whole glacier system likely thinned steadily from about 9–3 ka, and (ii) the grounding line likely reached the Darwin–Hatherton Glacier System at about 3 ka, which is ≥3.8 kyr later than was suggested by previous reconstructions.
Perry Spector, John Stone, and Brent Goehring
The Cryosphere, 13, 3061–3075, https://doi.org/10.5194/tc-13-3061-2019, https://doi.org/10.5194/tc-13-3061-2019, 2019
Short summary
Short summary
We describe constraints on the thickness of the interior of the West Antarctic Ice Sheet (WAIS) through the last deglaciation. Our data imply that the ice-sheet divide between the Ross and Weddell sea sectors of the WAIS was thicker than present for a period less than ~ 8 kyr within the past ~ 15 kyr. These results are consistent with the hypothesis that the divide initially thickened due to the deglacial rise in snowfall and subsequently thinned in response to retreat of the ice-sheet margin.
Keir A. Nichols, Brent M. Goehring, Greg Balco, Joanne S. Johnson, Andrew S. Hein, and Claire Todd
The Cryosphere, 13, 2935–2951, https://doi.org/10.5194/tc-13-2935-2019, https://doi.org/10.5194/tc-13-2935-2019, 2019
Short summary
Short summary
We studied the history of ice masses at three locations in the Weddell Sea Embayment, Antarctica. We measured rare isotopes in material sourced from mountains overlooking the Slessor Glacier, Foundation Ice Stream, and smaller glaciers on the Lassiter Coast. We show that ice masses were between 385 and 800 m thicker during the last glacial cycle than they are at present. The ice masses were both hundreds of metres thicker and remained thicker closer to the present than was previously thought.
Keir A. Nichols and Brent M. Goehring
Geochronology, 1, 43–52, https://doi.org/10.5194/gchron-1-43-2019, https://doi.org/10.5194/gchron-1-43-2019, 2019
Short summary
Short summary
We describe observations of anomalously high measurements of C-14 made from geologic material. We undertake a systematic investigation to identify the source of contamination, which we hypothesise is sourced from a commonly used method that is used prior to sample analysis. We find that the method does introduce modern carbon to samples and elevates C-14 measurements. We describe a standard procedure that effectively removes contamination from the aforementioned method.
Ben M. Pelto, Brian Menounos, and Shawn J. Marshall
The Cryosphere, 13, 1709–1727, https://doi.org/10.5194/tc-13-1709-2019, https://doi.org/10.5194/tc-13-1709-2019, 2019
Short summary
Short summary
Changes in glacier mass are the direct response to meteorological conditions during the accumulation and melt seasons. We derived multi-year, seasonal mass balance from airborne laser scanning surveys and compared them to field measurements for six glaciers in the Columbia and Rocky Mountains, Canada. Our method can accurately measure seasonal changes in glacier mass and can be easily adapted to derive seasonal mass change for entire mountain ranges.
M. J. Beedle, B. Menounos, and R. Wheate
The Cryosphere, 9, 65–80, https://doi.org/10.5194/tc-9-65-2015, https://doi.org/10.5194/tc-9-65-2015, 2015
Related subject area
Cosmogenic nuclide dating
Technical note: A software framework for calculating compositionally dependent in situ 14C production rates
10Be age control of glaciation in the Beartooth Mountains, USA, from the latest Pleistocene through the Holocene
Constraining the aggradation mode of Pleistocene river deposits based on cosmogenic radionuclide depth profiling and numerical modelling
Technical note: Evaluating a geographical information system (GIS)-based approach for determining topographic shielding factors in cosmic-ray exposure dating
Combined linear-regression and Monte Carlo approach to modeling exposure age depth profiles
Cosmogenic nuclide weathering biases: corrections and potential for denudation and weathering rate measurements
Cosmogenic nuclide and solute flux data from central Cuban rivers emphasize the importance of both physical and chemical mass loss from tropical landscapes
Technical note: Accelerator mass spectrometry of 10Be and 26Al at low nuclide concentrations
Cosmogenic ages indicate no MIS 2 refugia in the Alexander Archipelago, Alaska
In situ-produced cosmogenic krypton in zircon and its potential for Earth surface applications
Cosmogenic nuclide exposure age scatter records glacial history and processes in McMurdo Sound, Antarctica
Technical Note: Noble gas extraction procedure and performance of the Cologne Helix MC Plus multi-collector noble gas mass spectrometer for cosmogenic neon isotope analysis
Exposure dating of detrital magnetite using 3He enabled by microCT and calibration of the cosmogenic 3He production rate in magnetite
Calibrating a long-term meteoric 10Be delivery rate into eroding western US glacial deposits by comparing meteoric and in situ produced 10Be depth profiles
Delayed and rapid deglaciation of alpine valleys in the Sawatch Range, southern Rocky Mountains, USA
Technical note: A prototype transparent-middle-layer data management and analysis infrastructure for cosmogenic-nuclide exposure dating
Isolation of quartz for cosmogenic in situ 14C analysis
Chlorine-36∕beryllium-10 burial dating of alluvial fan sediments associated with the Mission Creek strand of the San Andreas Fault system, California, USA
Alexandria J. Koester and Nathaniel A. Lifton
Geochronology, 5, 21–33, https://doi.org/10.5194/gchron-5-21-2023, https://doi.org/10.5194/gchron-5-21-2023, 2023
Short summary
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In situ 14C’s short half-life (5.7 kyr) is unique among cosmogenic nuclides, making it sensitive to complex exposure and burial histories since 25 ka. Current extraction methods focus on quartz, but the ability to extract it from other minerals would expand applications. We developed MATLAB® scripts to calculate in situ 14C production rates from a broad range of mineral compositions. Results confirm O, Si, Al, and Mg as key targets but also find significant production from Na for the first time.
Aaron M. Barth, Elizabeth G. Ceperley, Claire Vavrus, Shaun A. Marcott, Jeremy D. Shakun, and Marc W. Caffee
Geochronology, 4, 731–743, https://doi.org/10.5194/gchron-4-731-2022, https://doi.org/10.5194/gchron-4-731-2022, 2022
Short summary
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Deposits left behind by past glacial activity provide insight into the previous size and behavior of glaciers and act as another line of evidence for past climate. Here we present new age control for glacial deposits in the mountains of Montana and Wyoming, United States. While some deposits indicate glacial activity within the last 2000 years, others are shown to be older than previously thought, thus redefining the extent of regional Holocene glaciation.
Nathan Vandermaelen, Koen Beerten, François Clapuyt, Marcus Christl, and Veerle Vanacker
Geochronology, 4, 713–730, https://doi.org/10.5194/gchron-4-713-2022, https://doi.org/10.5194/gchron-4-713-2022, 2022
Short summary
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We constrained deposition phases of fluvial sediments (NE Belgium) over the last 1 Myr with analysis and modelling of rare isotopes accumulation within sediments, occurring as a function of time and inverse function of depth. They allowed the determination of three superposed deposition phases and intercalated non-deposition periods of ~ 40 kyr each. These phases correspond to 20 % of the sediment age, which highlights the importance of considering deposition phase when dating fluvial sediments.
Felix Martin Hofmann
Geochronology, 4, 691–712, https://doi.org/10.5194/gchron-4-691-2022, https://doi.org/10.5194/gchron-4-691-2022, 2022
Short summary
Short summary
If topographical obstructions are present in the surroundings of sampling sites, exposure ages of rock surfaces need to be corrected. A toolbox for the ESRI ArcGIS software allows for quantifying topographic shielding with a digital elevation model, but it has only been validated with few field data. In this study, the output of the toolbox is evaluated with a more extensive dataset. If suitable elevation data are chosen, the toolbox provides a sound approach to determine topographic shielding.
Yiran Wang and Michael E. Oskin
Geochronology, 4, 533–549, https://doi.org/10.5194/gchron-4-533-2022, https://doi.org/10.5194/gchron-4-533-2022, 2022
Short summary
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When first introduced together with the depth profile technique to determine the surface exposure age, the linear inversion approach has suffered with the drawbacks of not incorporating erosion and muons into calculation. In this paper, we increase the accuracy and applicability of the linear inversion approach by fully considering surface erosion, muogenic production, and radioactive decay, while maintaining its advantage of being straightforward to determine an exposure age.
Richard F. Ott, Sean F. Gallen, and Darryl E. Granger
Geochronology, 4, 455–470, https://doi.org/10.5194/gchron-4-455-2022, https://doi.org/10.5194/gchron-4-455-2022, 2022
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Cosmogenic nuclides are a tool to quantify denudation – the total removal of mass from near the Earth's surface. Chemical weathering can introduce biases to cosmogenic-nuclide-based denudation rates measurements. Here, we investigate the effects of weathering on cosmogenic nuclides and develop tools to correct for this influence. Our results highlight which additional measurements are required to determine accurate denudation rates in regions where weathering is not negligible.
Mae Kate Campbell, Paul R. Bierman, Amanda H. Schmidt, Rita Sibello Hernández, Alejandro García-Moya, Lee B. Corbett, Alan J. Hidy, Héctor Cartas Águila, Aniel Guillén Arruebarrena, Greg Balco, David Dethier, and Marc Caffee
Geochronology, 4, 435–453, https://doi.org/10.5194/gchron-4-435-2022, https://doi.org/10.5194/gchron-4-435-2022, 2022
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We used cosmogenic radionuclides in detrital river sediment to measure erosion rates of watersheds in central Cuba; erosion rates are lower than rock dissolution rates in lowland watersheds. Data from two different cosmogenic nuclides suggest that some basins may have a mixed layer deeper than is typically modeled and could have experienced significant burial after or during exposure. We conclude that significant mass loss may occur at depth through chemical weathering processes.
Klaus M. Wilcken, Alexandru T. Codilean, Réka-H. Fülöp, Steven Kotevski, Anna H. Rood, Dylan H. Rood, Alexander J. Seal, and Krista Simon
Geochronology, 4, 339–352, https://doi.org/10.5194/gchron-4-339-2022, https://doi.org/10.5194/gchron-4-339-2022, 2022
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Cosmogenic nuclides are now widely applied in the Earth sciences; however, more recent applications often push the analytical limits of the technique. Our study presents a comprehensive method for analysis of cosmogenic 10Be and 26Al samples down to isotope concentrations of a few thousand atoms per gram of sample, which opens the door to new and more varied applications of cosmogenic nuclide analysis.
Caleb K. Walcott, Jason P. Briner, James F. Baichtal, Alia J. Lesnek, and Joseph M. Licciardi
Geochronology, 4, 191–211, https://doi.org/10.5194/gchron-4-191-2022, https://doi.org/10.5194/gchron-4-191-2022, 2022
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We present a record of ice retreat from the northern Alexander Archipelago, Alaska. During the last ice age (~ 26 000–19 000 years ago), these islands were covered by the Cordilleran Ice Sheet. We tested whether islands were ice-free during the last ice age for human migrants moving from Asia to the Americas. We found that these islands became ice-free between ~ 15 100 years ago and ~ 16 000 years ago, and thus these islands were not suitable for human habitation during the last ice age.
Tibor János Dunai, Steven Andrew Binnie, and Axel Gerdes
Geochronology, 4, 65–85, https://doi.org/10.5194/gchron-4-65-2022, https://doi.org/10.5194/gchron-4-65-2022, 2022
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We develop in situ-produced terrestrial cosmogenic krypton as a new tool to date and quantify Earth surface processes, the motivation being the availability of six stable isotopes and one radioactive isotope (81Kr, half-life 229 kyr) and of an extremely weathering-resistant target mineral (zircon). We provide proof of principle that terrestrial Krit can be quantified and used to unravel Earth surface processes.
Andrew J. Christ, Paul R. Bierman, Jennifer L. Lamp, Joerg M. Schaefer, and Gisela Winckler
Geochronology, 3, 505–523, https://doi.org/10.5194/gchron-3-505-2021, https://doi.org/10.5194/gchron-3-505-2021, 2021
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Cosmogenic nuclide surface exposure dating is commonly used to constrain the timing of past glacier extents. However, Antarctic exposure age datasets are often scattered and difficult to interpret. We compile new and existing exposure ages of a glacial deposit with independently known age constraints and identify surface processes that increase or reduce the likelihood of exposure age scatter. Then we present new data for a previously unmapped and undated older deposit from the same region.
Benedikt Ritter, Andreas Vogt, and Tibor J. Dunai
Geochronology, 3, 421–431, https://doi.org/10.5194/gchron-3-421-2021, https://doi.org/10.5194/gchron-3-421-2021, 2021
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We describe the design and performance of a new noble gas mass laboratory dedicated to the development of and application to cosmogenic nuclides at the University of Cologne (Germany). At the core of the laboratory are a state-of-the-art high-mass-resolution multicollector Helix MCPlus (Thermo-Fisher) noble gas mass spectrometer and a novel custom-designed automated extraction line, including a laser-powered extraction furnace. Performance was tested with intercomparison (CREU-1) material.
Florian Hofmann, Emily H. G. Cooperdock, A. Joshua West, Dominic Hildebrandt, Kathrin Strößner, and Kenneth A. Farley
Geochronology, 3, 395–414, https://doi.org/10.5194/gchron-3-395-2021, https://doi.org/10.5194/gchron-3-395-2021, 2021
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We use microCT scanning to improve the quality of 3He exposure ages measured in detrital magnetite. We show that the presence of inclusions can significantly increase the measured amount of 3He and thereby the exposure age. By prescreening magnetite with microCT and analyzing only inclusion-free grains, this problem can be avoided. We also calibrate the cosmogenic 3He production rate in magnetite relative to 10Be in quartz, which can be used for similar studies in the future.
Travis Clow, Jane K. Willenbring, Mirjam Schaller, Joel D. Blum, Marcus Christl, Peter W. Kubik, and Friedhelm von Blanckenburg
Geochronology, 2, 411–423, https://doi.org/10.5194/gchron-2-411-2020, https://doi.org/10.5194/gchron-2-411-2020, 2020
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Meteoric beryllium-10 concentrations in soil profiles have great capacity to quantify Earth surface processes, such as erosion rates and landform ages. However, determining these requires an accurate estimate of the delivery rate of this isotope to local sites. Here, we present a new method to constrain the long-term delivery rate to an eroding western US site, compare it against existing delivery rate estimates (revealing considerable disagreement between methods), and suggest best practices.
Joseph P. Tulenko, William Caffee, Avriel D. Schweinsberg, Jason P. Briner, and Eric M. Leonard
Geochronology, 2, 245–255, https://doi.org/10.5194/gchron-2-245-2020, https://doi.org/10.5194/gchron-2-245-2020, 2020
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We investigate the timing and rate of retreat for three alpine glaciers in the southern Rocky Mountains to test whether they followed the pattern of global climate change or were majorly influenced by regional forcing mechanisms. We find that the latter is most likely for these glaciers. Our conclusions are based on a new 10Be chronology of alpine glacier retreat. We quantify retreat rates for each valley using the BACON program in R, which may be of interest for the audience of Geochronology.
Greg Balco
Geochronology, 2, 169–175, https://doi.org/10.5194/gchron-2-169-2020, https://doi.org/10.5194/gchron-2-169-2020, 2020
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Geologic dating methods generally do not directly measure ages. Instead, interpreting a geochemical measurement as an age requires a middle layer of calculations and supporting data, and the fact that this layer continually improves is an obstacle to synoptic analysis of geochronological data. This paper describes a prototype data management and analysis system that addresses this obstacle by making the middle-layer calculations transparent and dynamic to the user.
Keir A. Nichols and Brent M. Goehring
Geochronology, 1, 43–52, https://doi.org/10.5194/gchron-1-43-2019, https://doi.org/10.5194/gchron-1-43-2019, 2019
Short summary
Short summary
We describe observations of anomalously high measurements of C-14 made from geologic material. We undertake a systematic investigation to identify the source of contamination, which we hypothesise is sourced from a commonly used method that is used prior to sample analysis. We find that the method does introduce modern carbon to samples and elevates C-14 measurements. We describe a standard procedure that effectively removes contamination from the aforementioned method.
Greg Balco, Kimberly Blisniuk, and Alan Hidy
Geochronology, 1, 1–16, https://doi.org/10.5194/gchron-1-1-2019, https://doi.org/10.5194/gchron-1-1-2019, 2019
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This article applies a new geochemical dating method to determine the age of sedimentary deposits useful in reconstructing slip rates on a major fault system.
Cited articles
Applegate, P. J., Urban, N. M., Laabs, B. J. C., Keller, K., and Alley, R. B.:
Modeling the statistical distributions of cosmogenic exposure dates from moraines, Geosci. Model Dev., 3, 293–307, https://doi.org/10.5194/gmd-3-293-2010, 2010.
Applegate, P. J., Urban, N. M., Keller, K., Lowell, T. V., Laabs, B. J. C., Kelly, M. A., and Alley, R. B.:
Improved moraine age interpretations through explicit matching of geomorphic process models to cosmogenic nuclide measurements from single landforms, Quaternary Res., 77, 293–304, https://doi.org/10.1016/j.yqres.2011.12.002, 2012.
Balco, G.: Contributions and unrealized potential contributions of cosmogenic-nuclide exposure dating to glacier chronology, 1990–2010, Quaternary Sci. Rev., 30, 3–27, https://doi.org/10.1016/j.quascirev.2010.11.003, 2011.
Balco, G., Stone, J. O. H., Sliwinski, M. G., and Todd, C.: Features of the glacial history of the Transantarctic Mountains inferred from cosmogenic 26Al, 10Be and 21Ne concentrations in bedrock surfaces, Antarct. Science, 26, 708–723, https://doi.org/10.1017/S0954102014000261, 2014.
Balco, G.:
Production rate calculations for cosmic-ray-muon-produced 10Be and 26Al benchmarked against geological calibration data, Quat. Geochron., 39, 150–173, https://doi.org/10.1016/j.quageo.2017.02.001, 2017.
Borchers, B., Marrero, S., Balco, G., Caffee, M., Goehring, B., Lifton, N., Nishiizumi, K., Phillips, F., Schaefer, J., and Stone, J.:
Geological calibration of spallation production rates in the CRONUS-Earth project, Quat. Geochron., 31, 188–198, https://doi.org/10.1016/j.quageo.2015.01.009, 2016.
Carlson, A. E., Ullman, D. J., Anslow, F. S., He, F., Clark, P. U., Liu, Z., and Otto-Bliesner, B. L.:
Modeling the surface mass-balance response of the Laurentide Ice Sheet to Bølling warming and its contribution to Meltwater Pulse 1A, Earth Planet. Sc. Lett., 315, 24–29, https://doi.org/10.1016/j.epsl.2011.07.008, 2012.
Darvill, C. M., Menounos, B., Goehring, B. M., Lian, O. B., and Caffee, M. W.: Retreat of the Western Cordilleran Ice Sheet Margin During the Last Deglaciation, Geophys. Res. Lett., 45, 9710–9720, https://doi.org/10.1029/2018gl079419, 2018.
Ditchburn, R. G. and Whitehead, N. E.:
The separation of 10Be from silicates, Proceedings of the 3rd workshop of the South Pacific Environmental Radioactivity Association (SPERA) Extended abstracts, Canberra, Australia, 15–17 February 1994, 4–7, 1994.
Fulton, R. J.:
A Conceptual Model for Growth and Decay of the Cordilleran Ice Sheet, Geogr. Phys. Quatern., 45, 281–286, https://doi.org/10.7202/032875ar, 1991.
Goehring, B. M., Muzikar, P., and Lifton, N. A.: An in situ 14C–10Be Bayesian isochron approach for interpreting complex glacial histories, Quat. Geochronol., 15, 61–66, https://doi.org/10.1016/j.quageo.2012.11.007, 2013.
Goehring, B. M., Wilson, J., and Nichols, K. A.:
A Fully Automated System for the Extraction of in situ Cosmogenic Carbon-14 in the Tulane University Cosmogenic Nuclide Laboratory, Nucl. Instrum. Methods, 455, 284–292, 2019.
Heisinger, B., Lal, D., Jull, A. J. T., Kubik, P., Ivy-Ochs, S., Knie, K., and Nolte, E.:
Production of selected cosmogenic radionuclides by muons: 2. Capture of negative muons, Earth Planet. Sc. Lett., 200, 357–369, 2002a.
Heisinger, B., Lal, D., Jull, A. J. T., Kubik, P., Ivy-Ochs, S., Neumaier, S., Knie, K., Lazarev, V., and Nolte, E.:
Production of selected cosmogenic radionuclides by muons: 1. Fast muons, Earth Planet. Sc. Lett., 200, 345–355, 2002b.
Heyman, J., Stroeven, A. P., Harbor, J. M., and Caffee, M. W.:
Too young or too old: evaluating cosmogenic exposure dating based on an analysis of compiled boulder exposure ages, Earth Planet. Sc. Lett., 302, 71–80, 2011.
Hughes, O. L.:
Surficial Geology and Geomorphology, Grey Hunter Peak, Yukon Territory, Geological Survey of Canada, https://doi.org/10.4095/109226, 1983.
Jóhannesson, T., Raymond, C. F., and Waddington, E. D.:
A Simple Method for Determining the Response Time of Glaciers, in: Glacier Fluctuations and Climatic Change, edited by: Oerlemans, J., Dordrecht, 343–352, https://doi.org/10.1007/978-94-015-7823-3_22, 1989.
Jull, A. J. T., Jull, A., Scott, E. M., and Bierman, P.:
The CRONUS-Earth inter-comparison for cosmogenic isotope analysis, Quat. Geochron., 26, 3–10, https://doi.org/10.1016/j.quageo.2013.09.003, 2015.
Lesnek, A. J., Briner, J. P., Lindqvist, C., Baichtal, J. F., and Heaton, T. H.:
Deglaciation of the Pacific coastal corridor directly preceded the human colonization of the Americas, Sci. Adv., 4, eaar5040, https://doi.org/10.1126/sciadv.aar5040, 2018.
Lifton, N.:
Implications of two Holocene time-dependent geomagnetic models for cosmogenic nuclide production rate scaling, Earth Planet. Sc. Lett., 433, 257–268, https://doi.org/10.1016/j.epsl.2015.11.006, 2016.
Lifton, N., Sato, T., and Dunai, T. J.:
Scaling in situ cosmogenic nuclide production rates using analytical approximations to atmospheric cosmic-ray fluxes, Earth Planet. Sc. Lett., 386, 149–160, https://doi.org/10.1016/j.epsl.2013.10.052, 2014.
Liu, Z., Otto-Bliesner, B. L., He, F., Brady, E. C., Tomas, R., Clark, P. U., Carlson, A. E., Lynch-Stieglitz, J., Curry, W., Brook, E., Erickson, D., Jacob, R., Kutzbach, J., and Cheng, J.:
Transient Simulation of Last Deglaciation with a New Mechanism for Bølling-Allerød Warming, Science, 325, 310–314, https://doi.org/10.1126/science.1171041, PMID – 19608916, 2009.
Löfverström, M. and Liakka, J.:
On the limited ice intrusion in Alaska at the LGM, Geophys. Res. Lett., 43, 11030–11038, https://doi.org/10.1002/2016gl071012, 2016.
Mahony, M. E.:
50,000 years of paleoenvironmental change recorded in meteoric waters and coeval paleoecological and cryostratigraphic indicators from the Klondike goldfields, Yukon, Canada, University of Alberta, Edmonton, Alberta, Canada, 2015.
Manabe, S. and Broccoli, A. J.:
The Influence of Continental Ice Sheets on Climate of an Ice Age, J. Geophys. Res., 90, 2167–2190, 1985.
Mann, D. H., Peteet, D. M., Reanier, R. E., and Kunz, M. L.:
Responses of an arctic landscape to Lateglacial and early Holocene climatic changes: the importance of moisture, Quaternary Sci. Rev., 21, 997–1021, https://doi.org/10.1016/s0277-3791(01)00116-0, 2002.
Margold, M., Jansson, K. N., Kleman, J., and Stroeven, A. P.: Lateglacial ice dynamics of the Cordilleran Ice Sheet in northern British Columbia and southern Yukon Territory: retreat pattern of the Liard Lobe reconstructed from the glacial landform record, J. Quaternary Sci., 28, 180–188, https://doi.org/10.1002/jqs.2604, 2013a.
Margold, M., Jansson, K. N., Kleman, J., Stroeven, A. P., and Clague, J. J.:
Retreat pattern of the Cordilleran Ice Sheet in central British Columbia at the end of the last glaciation reconstructed from glacial meltwater landforms, Boreas, 45, 9710–9720, https://doi.org/10.1111/bor.12007, 2013b.
Menounos, B., Goehring, B. M., Osborn, G., Margold, M., Ward, B., Bond, J., Clarke, G. K. C., Clague, J. J., Lakeman, T., Koch, J., Caffee, M. W., Gosse, J., Stroeven, A. P., Seguinot, J., and Heyman, J.:
Cordilleran Ice Sheet mass loss preceded climate reversals near the Pleistocene Termination, Science, 358, 781–784, 2017.
Nichols, K. A. and Goehring, B. M.:
Isolation of quartz for cosmogenic in situ 14C analysis, Geochronology, 1, 43–52, https://doi.org/10.5194/gchron-1-43-2019, 2019.
Nishiizumi, K., Imamura, M., Caffee, M. W., Southon, J. R., Finkel, R. C., and McAninch, J.:
Absolute calibration of 10Be AMS standards, Nucl. Instrum. Methods, 258, 403–413, 2007.
Orr, E. N., Owen, L. A., Saha, S., Hammer, S. J., and Caffee, M. W.:
Rockwall Slope Erosion in the Northwestern Himalaya, J. Geophys. Res.-Earth, 126, e2020JF005619, https://doi.org/10.1029/2020jf005619, 2021.
Scherler, D. and Egholm, D. L.:
Production and Transport of Supraglacial Debris: Insights From Cosmogenic 10Be and Numerical Modeling, Chhota Shigri Glacier, Indian Himalaya, J. Geophys. Res.-Earth, 125, e2020JF005586, https://doi.org/10.1029/2020jf005586, 2020.
Scherler, D., Bookhagen, B., and Strecker, M. R.:
Spatially variable response of Himalayan glaciers to climate change affected by debris cover, Nat. Geosci., 4, 156–159, https://doi.org/10.1038/ngeo1068, 2011.
Stroeven, A. P., Fabel, D., Codilean, A. T., Kleman, J., Clague, J. J., Miguens-Rodriguez, M., and Xu, S.:
Investigating the glacial history of the northern sector of the Cordilleran Ice Sheet with cosmogenic 10Be concentrations in quartz, Quaternary Sci. Rev., 29, 3630–3643, https://doi.org/10.1016/j.quascirev.2010.07.010, 2010.
Stroeven, A. P., Fabel, D., Margold, M., Clague, J. J., and Xu, S.:
Investigating absolute chronologies of glacial advances in the NW sector of the Cordilleran Ice Sheet with terrestrial in situ cosmogenic nuclides, Quaternary Sci. Rev., 92, 429–443, https://doi.org/10.1016/j.quascirev.2013.09.026, 2014.
Tulenko, J. P., Lofverstrom, M., and Briner, J. P.:
Ice sheet influence on atmospheric circulation explains the patterns of Pleistocene alpine glacier records in North America, Earth Planet. Sc. Lett., 534, 116115, https://doi.org/10.1016/j.epsl.2020.116115, 2020.
Ward, B. C. and Jackson, L. E.: Late Wisconsinan glaciation of the Glenlyon Range, Pelly Mountains, Yukon Territory, Canada, Can. J. Earth Sci., 29, 2007–2012, https://doi.org/10.1139/e92-156, 1992.
Ward, D. J. and Anderson, R. S.:
The use of ablation-dominated medial moraines as samplers for 10Be-derived erosion rates of glacier valley walls, Kichatna Mountains, AK, Earth Surf. Proc. Land., 36, 495–512, https://doi.org/10.1002/esp.2068, 2010.
Short summary
We explored surface exposure dating with two nuclides to date two sets of moraines from the Yukon Territory and explain the reasoning for the observed ages. Results suggest multiple processes, including preservation of nuclides from a prior exposure period, and later erosion of the moraines is required to explain the data. Our results only allow for the older moraines to date to Marine Isotope Stage 3 or 4 and the younger moraines to date to the very earliest Holocene.
We explored surface exposure dating with two nuclides to date two sets of moraines from the...
