Articles | Volume 2, issue 1
https://doi.org/10.5194/gchron-2-133-2020
© Author(s) 2020. 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-2-133-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
24 Jun 2020
Research article |
| 24 Jun 2020
| 24 Jun 2020
Seasonal deposition processes and chronology of a varved Holocene lake sediment record from Chatyr Kol lake (Kyrgyz Republic)
Julia Kalanke
CORRESPONDING AUTHOR
GFZ German Research Centre for Geosciences, Climate Dynamics
and Landscape Evolution, Potsdam, Germany
Jens Mingram
GFZ German Research Centre for Geosciences, Climate Dynamics
and Landscape Evolution, Potsdam, Germany
Stefan Lauterbach
University of Kiel, Leibniz Laboratory for Radiometric Dating and
Stable Isotope Research, Kiel, Germany
Ryskul Usubaliev
Central Asian Institute for Applied Geoscience, Bishkek, Kyrgyzstan
Rik Tjallingii
GFZ German Research Centre for Geosciences, Climate Dynamics
and Landscape Evolution, Potsdam, Germany
Achim Brauer
GFZ German Research Centre for Geosciences, Climate Dynamics
and Landscape Evolution, Potsdam, Germany
University of Potsdam, Institute of Geoscience, Potsdam, Germany
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Zarina Saidaliyeva, Maria Shahgedanova, Vadim Yapiyev, Andrew John Wade, Fakhriddin Akbarov, Mukhammed Esenaman uulu, Olga Kalashnikova, Vassiliy Kapitsa, Nikolay Kasatkin, Ilkhomiddin Rakhimov, Rysbek Satylkanov, Daniiar Sayakbaev, Eleonora Semakova, Igor Severskiy, Maxim Petrov, Gulomjon Umirzakov, and Ryskul Usubaliev
Atmos. Chem. Phys., 24, 12203–12224, https://doi.org/10.5194/acp-24-12203-2024, https://doi.org/10.5194/acp-24-12203-2024, 2024
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Ratios of stable isotopes of oxygen and hydrogen in precipitation are used to trace source regions and pathways of atmospheric moisture. A database of these measurements was developed for the mountains of Central Asia and analysed in the context of atmospheric trajectories. Over 50 % of precipitation was formed from moisture re-evaporated from regional terrestrial sources including the irrigated land in the Aral Sea basin, highlighting its support of the water tower function of the mountains.
Tamara Mathys, Muslim Azimshoev, Zhoodarbeshim Bektursunov, Christian Hauck, Christin Hilbich, Murataly Duishonakunov, Abdulhamid Kayumov, Nikolay Kassatkin, Vassily Kapitsa, Leo C. P. Martin, Coline Mollaret, Hofiz Navruzshoev, Eric Pohl, Tomas Saks, Intizor Silmonov, Timur Musaev, Ryskul Usubaliev, and Martin Hoelzle
EGUsphere, https://doi.org/10.5194/egusphere-2024-2795, https://doi.org/10.5194/egusphere-2024-2795, 2024
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This study provides a comprehensive geophysical dataset on permafrost in the data-scarce Tien Shan and Pamir mountain regions of Central Asia. It also introduces a novel modeling method to quantify ground ice content across different landforms. The findings indicate that this approach is well-suited for characterizing ice-rich permafrost, which is crucial for evaluating future water availability and assessing risks associated with thawing permafrost.
Ido Sirota, Rik Tjallingii, Sylvia Pinkerneil, Birgit Schroeder, Marlen Albert, Rebecca Kearney, Oliver Heiri, Simona Breu, and Achim Brauer
Biogeosciences, 21, 4317–4339, https://doi.org/10.5194/bg-21-4317-2024, https://doi.org/10.5194/bg-21-4317-2024, 2024
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Hypoxia has spread in Tiefer See (NE Germany) due to increased human activity. The onset of hypoxia indicated by varve preservation is dated to ~1920 at the lake’s depocenter, which responds faster and more severely to the reduction in oxygen level. The spread of hypoxic conditions is a gradual process that has lasted nearly 100 years, and the chemistry of the sediments shows that the depletion of oxygen in the lake started several decades before the onset of varve preservation.
Horst Machguth, Anja Eichler, Margit Schwikowski, Sabina Brütsch, Enrico Mattea, Stanislav Kutuzov, Martin Heule, Ryskul Usubaliev, Sultan Belekov, Vladimir N. Mikhalenko, Martin Hoelzle, and Marlene Kronenberg
The Cryosphere, 18, 1633–1646, https://doi.org/10.5194/tc-18-1633-2024, https://doi.org/10.5194/tc-18-1633-2024, 2024
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In 2018 we drilled an 18 m ice core on the summit of Grigoriev ice cap, located in the Tien Shan mountains of Kyrgyzstan. The core analysis reveals strong melting since the early 2000s. Regardless of this, we find that the structure and temperature of the ice have changed little since the 1980s. The probable cause of this apparent stability is (i) an increase in snowfall and (ii) the fact that meltwater nowadays leaves the glacier and thereby removes so-called latent heat.
Marcel Ortler, Achim Brauer, Stefano C. Fabbri, Jean Nicolas Haas, Irka Hajdas, Kerstin Kowarik, Jochem Kueck, Hans Reschreiter, and Michael Strasser
Sci. Dril., 33, 1–19, https://doi.org/10.5194/sd-33-1-2024, https://doi.org/10.5194/sd-33-1-2024, 2024
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The lake drilling project at Lake Hallstatt (Austria) successfully cored 51 m of lake sediments. This was achieved through the novel drilling platform Hipercorig. A core-log seismic correlation was created for the first time of an inner Alpine lake of the Eastern Alps. The sediments cover over 12 000 years before present with 10 (up to 5.1 m thick) instantaneous deposits. Lake Hallstatt is located within an UNESCO World Heritage area which has a rich history of human salt mining.
Anna Beckett, Cecile Blanchet, Alexander Brauser, Rebecca Kearney, Celia Martin-Puertas, Ian Matthews, Konstantin Mittelbach, Adrian Palmer, Arne Ramisch, and Achim Brauer
Earth Syst. Sci. Data, 16, 595–604, https://doi.org/10.5194/essd-16-595-2024, https://doi.org/10.5194/essd-16-595-2024, 2024
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This paper focuses on volcanic ash (tephra) in European annually laminated (varve) lake records from the period 25 to 8 ka. Tephra enables the synchronisation of these lake records and their proxy reconstructions to absolute timescales. The data incorporate geochemical data from tephra layers across 19 varve lake records. We highlight the potential for synchronising multiple records using tephra layers across continental scales whilst supporting reproducibility through accessible data.
Paula A. Vignoni, Francisco E. Córdoba, Rik Tjallingii, Carla Santamans, Liliana C. Lupo, and Achim Brauer
Geochronology, 5, 333–344, https://doi.org/10.5194/gchron-5-333-2023, https://doi.org/10.5194/gchron-5-333-2023, 2023
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Radiocarbon dating is a widely used tool to establish chronologies for sediment records. We show that modern aquatic plants in the Laguna del Peinado lake system (Altiplano–Puna Plateau) give overestimated ages due to reservoir effects from the input of old groundwater and volcanic CO2. Our results reveal a spatial variability in the modern reservoir effect within the lake basin, which has implications for radiocarbon-based chronologies in paleoclimate studies in this (and similar) regions.
Markus Czymzik, Rik Tjallingii, Birgit Plessen, Peter Feldens, Martin Theuerkauf, Matthias Moros, Markus J. Schwab, Carla K. M. Nantke, Silvia Pinkerneil, Achim Brauer, and Helge W. Arz
Clim. Past, 19, 233–248, https://doi.org/10.5194/cp-19-233-2023, https://doi.org/10.5194/cp-19-233-2023, 2023
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Productivity increases in Lake Kälksjön sediments during the last 9600 years are likely driven by the progressive millennial-scale winter warming in northwestern Europe, following the increasing Northern Hemisphere winter insolation and decadal to centennial periods of a more positive NAO polarity. Strengthened productivity variability since ∼5450 cal yr BP is hypothesized to reflect a reinforcement of NAO-like atmospheric circulation.
Rick Hennekam, Katharine M. Grant, Eelco J. Rohling, Rik Tjallingii, David Heslop, Andrew P. Roberts, Lucas J. Lourens, and Gert-Jan Reichart
Clim. Past, 18, 2509–2521, https://doi.org/10.5194/cp-18-2509-2022, https://doi.org/10.5194/cp-18-2509-2022, 2022
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The ratio of titanium to aluminum (Ti/Al) is an established way to reconstruct North African climate in eastern Mediterranean Sea sediments. We demonstrate here how to obtain reliable Ti/Al data using an efficient scanning method that allows rapid acquisition of long climate records at low expense. Using this method, we reconstruct a 3-million-year North African climate record. African environmental variability was paced predominantly by low-latitude insolation from 3–1.2 million years ago.
Bernhard Diekmann, Werner Stackebrandt, Roland Weiße, Margot Böse, Udo Rothe, Boris Biskaborn, and Achim Brauer
DEUQUA Spec. Pub., 4, 5–17, https://doi.org/10.5194/deuquasp-4-5-2022, https://doi.org/10.5194/deuquasp-4-5-2022, 2022
Achim Brauer, Ingo Heinrich, Markus J. Schwab, Birgit Plessen, Brian Brademann, Matthias Köppl, Sylvia Pinkerneil, Daniel Balanzategui, Gerhard Helle, and Theresa Blume
DEUQUA Spec. Pub., 4, 41–58, https://doi.org/10.5194/deuquasp-4-41-2022, https://doi.org/10.5194/deuquasp-4-41-2022, 2022
Achim Brauer and Markus J. Schwab
DEUQUA Spec. Pub., 4, 1–3, https://doi.org/10.5194/deuquasp-4-1-2022, https://doi.org/10.5194/deuquasp-4-1-2022, 2022
Yoav Ben Dor, Francesco Marra, Moshe Armon, Yehouda Enzel, Achim Brauer, Markus Julius Schwab, and Efrat Morin
Clim. Past, 17, 2653–2677, https://doi.org/10.5194/cp-17-2653-2021, https://doi.org/10.5194/cp-17-2653-2021, 2021
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Laminated sediments from the deepest part of the Dead Sea unravel the hydrological response of the eastern Mediterranean to past climate changes. This study demonstrates the importance of geological archives in complementing modern hydrological measurements that do not fully capture natural hydroclimatic variability, which is crucial to configure for understanding the impact of climate change on the hydrological cycle in subtropical regions.
Cécile L. Blanchet, Rik Tjallingii, Anja M. Schleicher, Stefan Schouten, Martin Frank, and Achim Brauer
Clim. Past, 17, 1025–1050, https://doi.org/10.5194/cp-17-1025-2021, https://doi.org/10.5194/cp-17-1025-2021, 2021
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The Mediterranean Sea turned repeatedly into an oxygen-deprived basin during the geological past, as evidenced by distinct sediment layers called sapropels. We use here records of the last sapropel S1 retrieved in front of the Nile River to explore the relationships between riverine input and seawater oxygenation. We decipher the seasonal cycle of fluvial input and seawater chemistry as well as the decisive influence of primary productivity on deoxygenation at millennial timescales.
Arne Ramisch, Alexander Brauser, Mario Dorn, Cecile Blanchet, Brian Brademann, Matthias Köppl, Jens Mingram, Ina Neugebauer, Norbert Nowaczyk, Florian Ott, Sylvia Pinkerneil, Birgit Plessen, Markus J. Schwab, Rik Tjallingii, and Achim Brauer
Earth Syst. Sci. Data, 12, 2311–2332, https://doi.org/10.5194/essd-12-2311-2020, https://doi.org/10.5194/essd-12-2311-2020, 2020
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Annually laminated lake sediments (varves) record past climate change at seasonal resolution. The VARved sediments DAtabase (VARDA) is created to utilize the full potential of varves for climate reconstructions. VARDA offers free access to a compilation and synchronization of standardized climate-proxy data, with applications ranging from reconstructing regional patterns of past climate change to validating simulations of climate models. VARDA is freely accessible at https://varve.gfz-potsdam.de
Florian Mekhaldi, Markus Czymzik, Florian Adolphi, Jesper Sjolte, Svante Björck, Ala Aldahan, Achim Brauer, Celia Martin-Puertas, Göran Possnert, and Raimund Muscheler
Clim. Past, 16, 1145–1157, https://doi.org/10.5194/cp-16-1145-2020, https://doi.org/10.5194/cp-16-1145-2020, 2020
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Due to chronology uncertainties within paleoclimate archives, it is unclear how climate oscillations from different records relate to one another. By using radionuclides to synchronize Greenland ice cores and a German lake record over 11 000 years, we show that two oscillations observed in these records were not synchronous but terminated and began with the onset of a grand solar minimum. Both this and changes in ocean circulation could have played a role in the two climate oscillations.
Bettina Strauch, Martin Zimmer, and Rik Tjallingii
Adv. Geosci., 49, 149–154, https://doi.org/10.5194/adgeo-49-149-2019, https://doi.org/10.5194/adgeo-49-149-2019, 2019
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Salt caverns are important as subsurface storage space. Knowledge of geochemical interactions in the transition zone between cavity and salt rock is necessary. Lab-based experiments were performed in hand-sized specimens by creating cm-sized cavities. XRF mapping represents a suitable technique to track spatial mineralogical changes related to rock-fluid interaction in salt rocks and showed a clear separation between Na, Mg and K salt layers. Fluorescent visualize potential fluid pathways.
Achim Brauer, Markus J. Schwab, Brian Brademann, Sylvia Pinkerneil, and Martin Theuerkauf
DEUQUA Spec. Pub., 2, 89–93, https://doi.org/10.5194/deuquasp-2-89-2019, https://doi.org/10.5194/deuquasp-2-89-2019, 2019
Bernhard Aichner, Florian Ott, Michał Słowiński, Agnieszka M. Noryśkiewicz, Achim Brauer, and Dirk Sachse
Clim. Past, 14, 1607–1624, https://doi.org/10.5194/cp-14-1607-2018, https://doi.org/10.5194/cp-14-1607-2018, 2018
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Abundances of plant biomarkers are compared with pollen data in a 3000-year climate archive covering the Late Glacial to Holocene transition in northern Poland. Both parameters synchronously show the rapid onset (12680–12600 yr BP) and termination
(11580–11490 yr BP) of the Younger Dryas cold interval in the study area. This demonstrates the suitability of such proxies to record pronounced changes in vegetation cover without significant delay.
Martina Barandun, Matthias Huss, Ryskul Usubaliev, Erlan Azisov, Etienne Berthier, Andreas Kääb, Tobias Bolch, and Martin Hoelzle
The Cryosphere, 12, 1899–1919, https://doi.org/10.5194/tc-12-1899-2018, https://doi.org/10.5194/tc-12-1899-2018, 2018
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In this study, we used three independent methods (in situ measurements, comparison of digital elevation models and modelling) to reconstruct the mass change from 2000 to 2016 for three glaciers in the Tien Shan and Pamir. Snow lines observed on remote sensing images were used to improve conventional modelling by constraining a mass balance model. As a result, glacier mass changes for unmeasured years and glaciers can be better assessed. Substantial mass loss was confirmed for the three glaciers.
Markus Czymzik, Raimund Muscheler, Florian Adolphi, Florian Mekhaldi, Nadine Dräger, Florian Ott, Michał Słowinski, Mirosław Błaszkiewicz, Ala Aldahan, Göran Possnert, and Achim Brauer
Clim. Past, 14, 687–696, https://doi.org/10.5194/cp-14-687-2018, https://doi.org/10.5194/cp-14-687-2018, 2018
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Our results provide a proof of concept for facilitating 10Be in varved lake sediments as a novel synchronization tool required for investigating leads and lags of proxy responses to climate variability. They also point to some limitations of 10Be in these archives mainly connected to in-lake sediment resuspension processes.
Norel Rimbu, Monica Ionita, Markus Czymzik, Achim Brauer, and Gerrit Lohmann
Clim. Past Discuss., https://doi.org/10.5194/cp-2017-137, https://doi.org/10.5194/cp-2017-137, 2017
Manuscript not accepted for further review
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Multi-decadal to millennial flood frequency variations in the Mid- to Late Holocene in a flood layer record from Lake Ammersee is strongly related to the occurrence of extreme precipitation and temperatures in the northeastern Europe.
Annette Witt, Bruce D. Malamud, Clara Mangili, and Achim Brauer
Hydrol. Earth Syst. Sci., 21, 5547–5581, https://doi.org/10.5194/hess-21-5547-2017, https://doi.org/10.5194/hess-21-5547-2017, 2017
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Here we present a unique 9.5 m palaeo-lacustrine record of 771 palaeofloods which occurred over a period of 10 000 years in the Piànico–Sèllere basin (southern Alps) during an interglacial period in the Pleistocene (sometime between 400 000 and 800 000 years ago). We analyse the palaeoflood series correlation, clustering, and cyclicity properties, finding a long-range cyclicity with a period of about 2030 years superimposed onto a fractional noise.
Martin Hoelzle, Erlan Azisov, Martina Barandun, Matthias Huss, Daniel Farinotti, Abror Gafurov, Wilfried Hagg, Ruslan Kenzhebaev, Marlene Kronenberg, Horst Machguth, Alexandr Merkushkin, Bolot Moldobekov, Maxim Petrov, Tomas Saks, Nadine Salzmann, Tilo Schöne, Yuri Tarasov, Ryskul Usubaliev, Sergiy Vorogushyn, Andrey Yakovlev, and Michael Zemp
Geosci. Instrum. Method. Data Syst., 6, 397–418, https://doi.org/10.5194/gi-6-397-2017, https://doi.org/10.5194/gi-6-397-2017, 2017
Oliver Rach, Ansgar Kahmen, Achim Brauer, and Dirk Sachse
Clim. Past, 13, 741–757, https://doi.org/10.5194/cp-13-741-2017, https://doi.org/10.5194/cp-13-741-2017, 2017
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Currently, reconstructions of past changes in the hydrological cycle are usually qualitative, which is a major drawback for testing the accuracy of models in predicting future responses. Here we present a proof of concept of a novel approach to deriving quantitative paleohydrological data, i.e. changes in relative humidity, from lacustrine sediment archives, employing a combination of organic geochemical methods and plant physiological modeling.
Markus Czymzik, Raimund Muscheler, and Achim Brauer
Clim. Past, 12, 799–805, https://doi.org/10.5194/cp-12-799-2016, https://doi.org/10.5194/cp-12-799-2016, 2016
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Integrating discharge data of the River Ammer back to 1926 and a 5500-year flood layer record from an annually laminated sediment core of the downstream Ammersee allowed investigating changes in the frequency of major floods in Central Europe on interannual to multi-centennial timescales. Significant correlations between flood frequency variations in both archives and changes in the activity of the Sun suggest a solar influence on the frequency of these hydrometeorological extremes.
Norel Rimbu, Markus Czymzik, Monica Ionita, Gerrit Lohmann, and Achim Brauer
Clim. Past, 12, 377–385, https://doi.org/10.5194/cp-12-377-2016, https://doi.org/10.5194/cp-12-377-2016, 2016
Dana Felicitas Christine Riechelmann, Jens Fohlmeister, Rik Tjallingii, Klaus Peter Jochum, Detlev Konrad Richter, Geert-Jan A. Brummer, and Denis Scholz
Clim. Past Discuss., https://doi.org/10.5194/cp-2016-18, https://doi.org/10.5194/cp-2016-18, 2016
Revised manuscript not accepted
I. Neugebauer, M. J. Schwab, N. D. Waldmann, R. Tjallingii, U. Frank, E. Hadzhiivanova, R. Naumann, N. Taha, A. Agnon, Y. Enzel, and A. Brauer
Clim. Past, 12, 75–90, https://doi.org/10.5194/cp-12-75-2016, https://doi.org/10.5194/cp-12-75-2016, 2016
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Micro-facies changes and elemental variations in deep Dead Sea sediments are used to reconstruct relative lake level changes for the early last glacial period. The results indicate a close link of hydroclimatic variability in the Levant to North Atlantic-Mediterranean climates during the time of the build-up of Northern Hemisphere ice shields. First petrographic analyses of gravels in the deep core question the recent hypothesis of a Dead Sea dry-down at the end of the last interglacial.
C. Martin-Puertas, A. Brauer, S. Wulf, F. Ott, S. Lauterbach, and P. Dulski
Clim. Past, 10, 2099–2114, https://doi.org/10.5194/cp-10-2099-2014, https://doi.org/10.5194/cp-10-2099-2014, 2014
B. Merz, J. Aerts, K. Arnbjerg-Nielsen, M. Baldi, A. Becker, A. Bichet, G. Blöschl, L. M. Bouwer, A. Brauer, F. Cioffi, J. M. Delgado, M. Gocht, F. Guzzetti, S. Harrigan, K. Hirschboeck, C. Kilsby, W. Kron, H.-H. Kwon, U. Lall, R. Merz, K. Nissen, P. Salvatti, T. Swierczynski, U. Ulbrich, A. Viglione, P. J. Ward, M. Weiler, B. Wilhelm, and M. Nied
Nat. Hazards Earth Syst. Sci., 14, 1921–1942, https://doi.org/10.5194/nhess-14-1921-2014, https://doi.org/10.5194/nhess-14-1921-2014, 2014
T. Swierczynski, S. Lauterbach, P. Dulski, and A. Brauer
Clim. Past, 9, 1601–1612, https://doi.org/10.5194/cp-9-1601-2013, https://doi.org/10.5194/cp-9-1601-2013, 2013
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Marcel Guillong, Elias Samankassou, Inigo A. Müller, Dawid Szymanowski, Nathan Looser, Lorenzo Tavazzani, Óscar Merino-Tomé, Juan R. Bahamonde, Yannick Buret, and Maria Ovtcharova
Geochronology, 6, 465–474, https://doi.org/10.5194/gchron-6-465-2024, https://doi.org/10.5194/gchron-6-465-2024, 2024
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Nil Irvalı, Ulysses S. Ninnemann, Are Olsen, Neil L. Rose, David J. R. Thornalley, Tor L. Mjell, and François Counillon
Geochronology, 6, 449–463, https://doi.org/10.5194/gchron-6-449-2024, https://doi.org/10.5194/gchron-6-449-2024, 2024
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Geochronology, 6, 429–448, https://doi.org/10.5194/gchron-6-429-2024, https://doi.org/10.5194/gchron-6-429-2024, 2024
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We present a new data analysis workflow for thermochronological data based on plots of radiogenic daughter vs. radioactive parent concentration. The daughter–parent relationship helps to identify the sources of age variation. Our workflow classifies the daughter–parent relationship and provides further suggestions, e.g., if a dataset can be described by a sample age and which type of sample age to report. We also introduce Incaplot, which is software for creating daughter–parent plots.
Pieter Vermeesch
Geochronology, 6, 397–407, https://doi.org/10.5194/gchron-6-397-2024, https://doi.org/10.5194/gchron-6-397-2024, 2024
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The age of some geological materials can be estimated from the ratio of certain radiogenic "daughter" isotopes to their radioactive "parent". However, in many cases, the age estimation process is complicated by the presence of an inherited component of non-radiogenic daughter isotopes. This paper presents an improved algorithm to estimate the radiogenic and non-radiogenic components, either separately or jointly.
André Navin Paul, Anders Lindskog, and Urs Schaltegger
Geochronology, 6, 325–335, https://doi.org/10.5194/gchron-6-325-2024, https://doi.org/10.5194/gchron-6-325-2024, 2024
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The “Likhall” bed helps to constrain the timing of increased meteorite bombardment of the Earth during the Ordovician period. It is important to understand the timing of this meteorite bombardment when attempting to correlate it with biodiversity changes during the Ordovician period. Calibrating a good age for the “Likhall” bed is, however, challenging and benefited in this study from advances in sample preparation.
Jesús Muñoz-Montecinos, Andrea Giuliani, Senan Oesch, Silvia Volante, Bradley Peters, and Whitney Behr
Geochronology Discuss., https://doi.org/10.5194/gchron-2024-16, https://doi.org/10.5194/gchron-2024-16, 2024
Revised manuscript accepted for GChron
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Dating the roots of plate boundaries is essential for understanding geologic processes, but geochemical limitations, particularly in young mafic rocks, make this challenging. Advancements in mass spectrometry now enable high-resolution analysis of micro-domains. We assess these limitations by dating rocks from Syros Island. Multi-phase mineral analysis improve age uncertainty by sixfold. We emphasize the importance of the local geologic context and propose strategies to mitigate uncertainties.
Megan A. Mueller, Alexis Licht, Andreas Möller, Cailey B. Condit, Julie C. Fosdick, Faruk Ocakoğlu, and Clay Campbell
Geochronology, 6, 265–290, https://doi.org/10.5194/gchron-6-265-2024, https://doi.org/10.5194/gchron-6-265-2024, 2024
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Sedimentary provenance refers to the study of the origin of sedimentary rocks, tracing where sediment particles originated. Common sedimentary provenance techniques struggle to track mafic igneous and metamorphic rock sources and rutile forms in these rock types. We use rutile form ancient sedimentary rocks in Türkiye to present new recommendations and workflows for integrating rutile U–Pb ages and chemical composition into an accurate sedimentary provenance reconstruction.
Ruohong Jiao, Shengze Cai, and Jean Braun
Geochronology, 6, 227–245, https://doi.org/10.5194/gchron-6-227-2024, https://doi.org/10.5194/gchron-6-227-2024, 2024
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We demonstrate a machine learning method to estimate the temperature changes in the Earth's crust over time. The method respects physical laws and conditions imposed by users. By using observed rock cooling ages as constraints, the method can be used to estimate the tectonic and landscape evolution of the Earth. We show the applications of the method using a synthetic rock uplift model in 1D and an evolution model of a real mountain range in 3D.
Christoph Glotzbach and Todd A. Ehlers
Geochronology Discuss., https://doi.org/10.5194/gchron-2024-12, https://doi.org/10.5194/gchron-2024-12, 2024
Revised manuscript accepted for GChron
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The (U-Th)/He dating method helps understand rock’s cooling history. Synthetic modeling experiments were conducted to explore factors affecting in-situ vs. whole-grain (U-Th)/He dates. In-situ dates are often 30 % older than whole-grain dates, whereas very rapid cooling makes helium loss negligible, resulting in similar whole-grain and in-situ dates. In addition, in-situ data can reveal cooling histories even from a single grain by measuring helium distributions.
Erin E. Donaghy, Michael P. Eddy, Federico Moreno, and Mauricio Ibañez-Mejia
Geochronology, 6, 89–106, https://doi.org/10.5194/gchron-6-89-2024, https://doi.org/10.5194/gchron-6-89-2024, 2024
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Chemical abrasion (CA) is a technique that reduces or eliminates the effects of Pb loss in zircon U–Pb geochronology. However, CA has yet to be applied to large-n detrital zircon (DZ) analyses. We show that CA does not negatively impact or systematically bias U–Pb dates, improves the resolution of age populations defined by 206Pb/238U dates, and increases the percentage of concordant analyses in age populations defined by 207Pb/206Pb dates.
Steven Denyszyn, Donald W. Davis, and Denis Fougerouse
Geochronology Discuss., https://doi.org/10.5194/gchron-2024-4, https://doi.org/10.5194/gchron-2024-4, 2024
Revised manuscript accepted for GChron
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Decay of U to Pb in the mineral baddeleyite is used for precisely dating mafic rocks, but some daughter Pb atoms can be ejected out of the crystal, resulting in an age that appears too young. Atom Probe Tomography was used to map the distribution of U and Pb atoms in 3 dimensions within a baddeleyite crystal and estimate the average distance that Pb atoms are displaced by decay of U. This allows us to correct the measured age on a baddeleyite crystal knowing its size and shape.
Glenn R. Sharman and Matthew A. Malkowski
Geochronology, 6, 37–51, https://doi.org/10.5194/gchron-6-37-2024, https://doi.org/10.5194/gchron-6-37-2024, 2024
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The mineral zircon is widely used to determine the age of rocks based on the radioactive decay of U to Pb, but the measured U–Pb date can be too young if the zircon loses Pb. We present a method for estimating the distribution of apparent Pb loss by mathematical convolution. Applying this approach to 10 samples illustrates contrasting patterns of apparent Pb loss. This study highlights the importance of quantifying Pb loss to better understand its potential effects on zircon U–Pb dates.
Stijn Glorie, Sarah E. Gilbert, Martin Hand, and Jarred C. Lloyd
Geochronology, 6, 21–36, https://doi.org/10.5194/gchron-6-21-2024, https://doi.org/10.5194/gchron-6-21-2024, 2024
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Radiometric dating methods, involving laser ablation as the sample introduction, require robust calibrations to reference materials with similar ablation properties to the analysed samples. In the case of the rubidium–strontium dating method, calibrations are often conducted to nano powder with different ablation characteristics than the crystalline minerals. We describe the limitations of this approach and recommend an alternative calibration method involving natural minerals.
Alex Lipp and Pieter Vermeesch
Geochronology, 5, 263–270, https://doi.org/10.5194/gchron-5-263-2023, https://doi.org/10.5194/gchron-5-263-2023, 2023
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We propose using the Wasserstein-2 distance (W2) as an alternative to the widely used Kolmogorov–Smirnov (KS) statistic for analysing distributional data in geochronology. W2 measures the horizontal distance between observations, while KS measures vertical differences in cumulative distributions. Using case studies, we find that W2 is preferable in scenarios where the absolute age differences in observations provide important geological information. W2 has been added to the R package IsoplotR.
W. Marijn van der Meij, Arnaud J. A. M. Temme, Steven A. Binnie, and Tony Reimann
Geochronology, 5, 241–261, https://doi.org/10.5194/gchron-5-241-2023, https://doi.org/10.5194/gchron-5-241-2023, 2023
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We present our model ChronoLorica. We coupled the original Lorica model, which simulates soil and landscape evolution, with a geochronological module that traces cosmogenic nuclide inventories and particle ages through simulations. These properties are often measured in the field to determine rates of landscape change. The coupling enables calibration of the model and the study of how soil, landscapes and geochronometers change under complex boundary conditions such as intensive land management.
Michael C. Sitar and Ryan J. Leary
Geochronology, 5, 109–126, https://doi.org/10.5194/gchron-5-109-2023, https://doi.org/10.5194/gchron-5-109-2023, 2023
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We developed code to automatically and semi-automatically measure dimensions of detrital mineral grains in reflected-light images saved at laser ablation–inductively coupled plasma–mass spectrometry facilities that use Chromium targeting software. Our code uses trained deep learning models to segment grain images with greater accuracy than is achievable using other segmentation techniques. We implement our code in Jupyter notebooks which can also be run online via Google Colab.
Peter E. Martin, James R. Metcalf, and Rebecca M. Flowers
Geochronology, 5, 91–107, https://doi.org/10.5194/gchron-5-91-2023, https://doi.org/10.5194/gchron-5-91-2023, 2023
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There is currently no standardized method of performing uncertainty propagation in the (U–Th) / He system, causing data interpretation difficulties. We present two methods of uncertainty propagation and describe free, open-source software (HeCalc) to apply them. Compilation of real data using only analytical uncertainty as well as 2 % and 5 % uncertainties in FT yields respective median relative date uncertainties of 2.9 %, 3.3 %, and 5.0 % for apatites and 1.7 %, 3.3 %, and 5.0 % for zircons.
Stella Birlo, Wojciech Tylmann, and Bernd Zolitschka
Geochronology, 5, 65–90, https://doi.org/10.5194/gchron-5-65-2023, https://doi.org/10.5194/gchron-5-65-2023, 2023
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Sediment cores from the volcanic lake Holzmaar provide a very precise chronology based on tree-ring-like annual laminations or varves. We statistically combine this varve chronology with radiometric dating and tested three different methods to upgrade the age–depth model. However, only one of the three methods tested improved the dating accuracy considerably. With this work, an overview of different age integration methods is discussed and made available for increased future demands.
Peter van der Beek and Taylor F. Schildgen
Geochronology, 5, 35–49, https://doi.org/10.5194/gchron-5-35-2023, https://doi.org/10.5194/gchron-5-35-2023, 2023
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Thermochronometric data can provide unique insights into the patterns of rock exhumation and the driving mechanisms of landscape evolution. Several well-established thermal models allow for a detailed exploration of how cooling rates evolved in a limited area or along a transect, but more regional analyses have been challenging. We present age2exhume, a thermal model that can be used to rapidly provide a synoptic overview of exhumation rates from large regional thermochronologic datasets.
Marianna Corre, Arnaud Agranier, Martine Lanson, Cécile Gautheron, Fabrice Brunet, and Stéphane Schwartz
Geochronology, 4, 665–681, https://doi.org/10.5194/gchron-4-665-2022, https://doi.org/10.5194/gchron-4-665-2022, 2022
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This study is focused on the accurate measurement of U and Th by wet chemistry and laser ablation methods to improve (U–Th)/He dating of magnetite and spinel. The low U–Th content and the lack of specific U–Th standards significantly limit the accuracy of (U–Th)/He dating. Obtained U–Th results on natural and synthetic magnetite and aluminous spinel samples analyzed by wet chemistry methods and LA-ICP-MS sampling have important implications for the (U–Th)/He method and dates interpretation.
Aratz Beranoaguirre, Iuliana Vasiliev, and Axel Gerdes
Geochronology, 4, 601–616, https://doi.org/10.5194/gchron-4-601-2022, https://doi.org/10.5194/gchron-4-601-2022, 2022
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U–Pb dating by the in situ laser ablation mass spectrometry (LA-ICPMS) technique requires reference materials of the same nature as the samples to be analysed. Here, we have explored the suitability of using carbonate materials as a reference for sulfates, since there is no sulfate reference material. The results we obtained are satisfactory, and thus, from now on, the sulfates can also be analysed.
Pieter Vermeesch
Geochronology, 4, 561–576, https://doi.org/10.5194/gchron-4-561-2022, https://doi.org/10.5194/gchron-4-561-2022, 2022
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Secondary ion mass spectrometry (SIMS) is the oldest and most sensitive analytical technique for in situ U–Pb geochronology. This paper introduces a new algorithm for SIMS data reduction that treats data as
compositional data, which means that the relative abundances of 204Pb, 206Pb, 207Pb, and 238Pb are processed within a tetrahedral data space or
simplex. The new method is implemented in an eponymous computer programme that is compatible with the two dominant types of SIMS instruments.
Emily H. G. Cooperdock, Florian Hofmann, Ryley M. C. Tibbetts, Anahi Carrera, Aya Takase, and Aaron J. Celestian
Geochronology, 4, 501–515, https://doi.org/10.5194/gchron-4-501-2022, https://doi.org/10.5194/gchron-4-501-2022, 2022
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Apatite and zircon are the most widely used minerals for dating rocks, but they can be difficult to identify in some crushed rock samples. Incorrect mineral identification results in wasted analytical resources and inaccurate data. We show how X-ray computed tomography can be used to efficiently and accurately distinguish apatite from zircon based on density variations, and provide non-destructive 3D grain-specific size, shape, and inclusion information for improved data quality.
Dale R. Issler, Kalin T. McDannell, Paul B. O'Sullivan, and Larry S. Lane
Geochronology, 4, 373–397, https://doi.org/10.5194/gchron-4-373-2022, https://doi.org/10.5194/gchron-4-373-2022, 2022
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Phanerozoic sedimentary rocks of northern Canada have compositionally heterogeneous detrital apatite with high age dispersion caused by differential thermal annealing. Discrete apatite fission track kinetic populations with variable annealing temperatures are defined using elemental data but are poorly resolved using conventional parameters. Inverse thermal modelling of samples from northern Yukon reveals a record of multiple heating–cooling cycles consistent with geological constraints.
Michael Dietze, Sebastian Kreutzer, Margret C. Fuchs, and Sascha Meszner
Geochronology, 4, 323–338, https://doi.org/10.5194/gchron-4-323-2022, https://doi.org/10.5194/gchron-4-323-2022, 2022
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The R package sandbox is a collection of functions that allow the creation, sampling and analysis of fully virtual sediment sections, like having a virtual twin of real-world deposits. This article introduces the concept, features, and workflows required to use sandbox. It shows how a real-world sediment section can be mapped into the model and subsequently addresses a series of theoretical and practical questions, exploiting the flexibility of the model framework.
Gregor Pfalz, Bernhard Diekmann, Johann-Christoph Freytag, Liudmila Syrykh, Dmitry A. Subetto, and Boris K. Biskaborn
Geochronology, 4, 269–295, https://doi.org/10.5194/gchron-4-269-2022, https://doi.org/10.5194/gchron-4-269-2022, 2022
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We use age–depth modeling systems to understand the relationship between age and depth in lake sediment cores. However, depending on which modeling system we use, the model results may vary. We provide a tool to link different modeling systems in an interactive computational environment and make their results comparable. We demonstrate the power of our tool by highlighting three case studies in which we test our application for single-sediment cores and a collection of multiple sediment cores.
Andrea Madella, Christoph Glotzbach, and Todd A. Ehlers
Geochronology, 4, 177–190, https://doi.org/10.5194/gchron-4-177-2022, https://doi.org/10.5194/gchron-4-177-2022, 2022
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Cooling ages date the time at which minerals cross a certain isotherm on the way up to Earth's surface. Such ages can be measured from bedrock material and river sand. If spatial variations in bedrock ages are known in a river catchment, the spatial distribution of erosion can be inferred from the distribution of the ages measured from the river sand grains. Here we develop a new tool to help such analyses, with particular emphasis on quantifying uncertainties due to sample size.
Yang Li and Pieter Vermeesch
Geochronology, 3, 415–420, https://doi.org/10.5194/gchron-3-415-2021, https://doi.org/10.5194/gchron-3-415-2021, 2021
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A conventional isochron is a straight-line fit to two sets of isotopic ratios, D/d and P/d, where P is the radioactive parent, D is the radiogenic daughter, and d is a second isotope of the daughter element. The slope of this line is proportional to the age of the system. An inverse isochron is a linear fit through d/D and P/D. The horizontal intercept of this line is inversely proportional to the age. The latter approach is preferred when d<D, which is the case in Re–Os and K–Ca geochronology.
Cécile Gautheron, Rosella Pinna-Jamme, Alexis Derycke, Floriane Ahadi, Caroline Sanchez, Frédéric Haurine, Gael Monvoisin, Damien Barbosa, Guillaume Delpech, Joseph Maltese, Philippe Sarda, and Laurent Tassan-Got
Geochronology, 3, 351–370, https://doi.org/10.5194/gchron-3-351-2021, https://doi.org/10.5194/gchron-3-351-2021, 2021
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Apatite and zircon (U–Th) / He thermochronology is now a mainstream tool to reconstruct Earth's evolution through the history of cooling and exhumation over the first dozen kilometers. The geological implications of these data rely on the precision of measurements of He, U, Th, and Sm contents in crystals. This technical note documents the methods for He thermochronology developed at the GEOPS laboratory, Paris-Saclay University, that allow (U–Th) / He data to be obtained with precision.
Kalin T. McDannell and Dale R. Issler
Geochronology, 3, 321–335, https://doi.org/10.5194/gchron-3-321-2021, https://doi.org/10.5194/gchron-3-321-2021, 2021
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We generated a synthetic dataset applying published kinetic models and distinct annealing kinetics for the apatite fission track and (U–Th)/He methods using a predetermined thermal history. We then tested how well the true thermal history could be recovered under different data interpretation schemes and geologic constraint assumptions using the Bayesian QTQt software. Our results demonstrate that multikinetic data increase time–temperature resolution and can constrain complex thermal histories.
Birk Härtel, Raymond Jonckheere, Bastian Wauschkuhn, and Lothar Ratschbacher
Geochronology, 3, 259–272, https://doi.org/10.5194/gchron-3-259-2021, https://doi.org/10.5194/gchron-3-259-2021, 2021
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We carried out thermal annealing experiments between 500 and 1000 °C to determine the closure temperature of radiation-damage annealing in zircon (ZrSiO4). Our results show that the different Raman bands of zircon respond differently to annealing. The repair is highest for the external rotation Raman band near 356.6 cm−1. The closure temperature estimates range from 250 to 370 °C for different bands. The differences in closure temperatures offer the prospect of multi-T zircon Raman dating.
Pieter Vermeesch
Geochronology, 3, 247–257, https://doi.org/10.5194/gchron-3-247-2021, https://doi.org/10.5194/gchron-3-247-2021, 2021
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This paper shows that the current practice of filtering discordant U–Pb data based on the relative difference between the 206Pb/238U and 207Pb/206Pb ages is just one of several possible approaches to the problem and demonstrably not the best one. An alternative approach is to define discordance in terms of isotopic composition, as a log ratio distance between the measurement and the concordia line. Application to real data indicates that this reduces the positive bias of filtered age spectra.
Blair Schoene, Michael P. Eddy, C. Brenhin Keller, and Kyle M. Samperton
Geochronology, 3, 181–198, https://doi.org/10.5194/gchron-3-181-2021, https://doi.org/10.5194/gchron-3-181-2021, 2021
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We compare two published U–Pb and 40Ar / 39Ar geochronologic datasets to produce eruption rate models for the Deccan Traps large igneous province. Applying the same approach to each dataset, the resulting models agree well, but the higher-precision U–Pb dataset results in a more detailed eruption model than the lower-precision 40Ar / 39Ar data. We explore sources of geologic uncertainty and reiterate the importance of systematic uncertainties in comparing U–Pb and 40Ar / 39Ar datasets.
Nicholas P. McKay, Julien Emile-Geay, and Deborah Khider
Geochronology, 3, 149–169, https://doi.org/10.5194/gchron-3-149-2021, https://doi.org/10.5194/gchron-3-149-2021, 2021
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This paper describes geoChronR, an R package that streamlines the process of quantifying age uncertainties, propagating uncertainties through several common analyses, and visualizing the results. In addition to describing the structure and underlying theory of the package, we present five real-world use cases that illustrate common workflows in geoChronR. geoChronR is built on the Linked PaleoData framework, is open and extensible, and we welcome feedback and contributions from the community.
Leonie Peti, Kathryn E. Fitzsimmons, Jenni L. Hopkins, Andreas Nilsson, Toshiyuki Fujioka, David Fink, Charles Mifsud, Marcus Christl, Raimund Muscheler, and Paul C. Augustinus
Geochronology, 2, 367–410, https://doi.org/10.5194/gchron-2-367-2020, https://doi.org/10.5194/gchron-2-367-2020, 2020
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Orakei Basin – a former maar lake in Auckland, New Zealand – provides an outstanding sediment record over the last ca. 130 000 years, but an age model is required to allow the reconstruction of climate change and volcanic eruptions contained in the sequence. To construct a relationship between depth in the sediment core and age of deposition, we combined tephrochronology, radiocarbon dating, luminescence dating, and the relative intensity of the paleomagnetic field in a Bayesian age–depth model.
Roger Powell, Eleanor C. R. Green, Estephany Marillo Sialer, and Jon Woodhead
Geochronology, 2, 325–342, https://doi.org/10.5194/gchron-2-325-2020, https://doi.org/10.5194/gchron-2-325-2020, 2020
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The standard approach to isochron calculation assumes that the distribution of uncertainties on the data arising from isotopic analysis is strictly Gaussian. This excludes datasets that have more scatter, even though many appear to have age significance. Our new approach requires only that the central part of the uncertainty distribution of the data defines a "spine" in the trend of the data. A robust statistics approach is used to locate the spine, and an implementation in Python is given.
Simon J. E. Large, Jörn-Frederik Wotzlaw, Marcel Guillong, Albrecht von Quadt, and Christoph A. Heinrich
Geochronology, 2, 209–230, https://doi.org/10.5194/gchron-2-209-2020, https://doi.org/10.5194/gchron-2-209-2020, 2020
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The integration of zircon geochemistry and U–Pb geochronology (petrochronology) allows us to improve our understanding of magmatic processes. Here we could reconstruct the ~300 kyr evolution of the magma reservoir that sourced the magmas, fluids and metals to form the Batu Hijau porphyry Cu–Au deposit. The application of in situ LA-ICP-MS and high-precision CA–ID–TIMS geochronology to the same zircons further allowed an assessment of the strengths and limitations of the different techniques.
Pieter Vermeesch
Geochronology, 2, 119–131, https://doi.org/10.5194/gchron-2-119-2020, https://doi.org/10.5194/gchron-2-119-2020, 2020
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The U–Pb method is one of the most powerful and versatile methods in the geochronological toolbox. With two isotopes of uranium decaying to two different isotopes of lead, the U–Pb method offers an internal quality control that is absent from most other geochronological techniques. U-bearing minerals often contain significant amounts of Th, which decays to a third Pb isotope. This paper presents an algorithm to jointly process all three chronometers at once.
Jon Woodhead and Joseph Petrus
Geochronology, 1, 69–84, https://doi.org/10.5194/gchron-1-69-2019, https://doi.org/10.5194/gchron-1-69-2019, 2019
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Recently developed methods for in situ U–Pb age determination in carbonates have found widespread application, but the benefits and limitations of the method over bulk analysis approaches have yet to be fully explored. Here we use speleothems – cave carbonates such as stalagmites and flowstones – to investigate the utility of these in situ dating methodologies for challenging matrices with low U and Pb contents and predominantly late Cenozoic ages.
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Short summary
Our study presents the first seasonally laminated (varved) sediment record covering almost the entire Holocene in high mountainous arid Central Asia. The established floating varve chronology is confirmed by two terrestrial radiocarbon dates, whereby aquatic radiocarbon dates reveal decreasing reservoir ages up core. Changes in seasonal deposition characteristics are attributed to changes in runoff and precipitation and/or to evaporative summer conditions.
Our study presents the first seasonally laminated (varved) sediment record covering almost the...
