Articles | Volume 5, issue 2
https://doi.org/10.5194/gchron-5-433-2023
© Author(s) 2023. 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-5-433-2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
01 Dec 2023
Research article |
| 01 Dec 2023
| 01 Dec 2023
Late Neogene terrestrial climate reconstruction of the central Namib Desert derived by the combination of U–Pb silcrete and terrestrial cosmogenic nuclide exposure dating
Benedikt Ritter
CORRESPONDING AUTHOR
Institute of Geology & Mineralogy, University of Cologne, Cologne, Germany
Richard Albert
CORRESPONDING AUTHOR
Frankfurt Isotope and Element Research Center (FIERCE), Goethe University Frankfurt, Frankfurt, Germany
Institute of Geosciences, Goethe University Frankfurt, Frankfurt, Germany
Aleksandr Rakipov
Frankfurt Isotope and Element Research Center (FIERCE), Goethe University Frankfurt, Frankfurt, Germany
Institute of Geosciences, Goethe University Frankfurt, Frankfurt, Germany
Frederik M. Van der Wateren
Philosophical Practice, Cas Oorthuyskade 23, 1087 DP Amsterdam, the Netherlands
Tibor J. Dunai
Institute of Geology & Mineralogy, University of Cologne, Cologne, Germany
Axel Gerdes
Frankfurt Isotope and Element Research Center (FIERCE), Goethe University Frankfurt, Frankfurt, Germany
Institute of Geosciences, Goethe University Frankfurt, Frankfurt, Germany
Related authors
Volker Wennrich, Julia Diederich-Leicher, Bárbara Nataly Blanco-Arrué, Christoph Büttner, Stefan Buske, Eduardo Campos Sepulveda, Tibor Dunai, Jacob Feller, Emma Galego, Ascelina Hasberg, Niklas Leicher, Damián Alejandro López, Jorge Maldonado, Alicia Medialdea, Lukas Ninnemann, Russell Perryman, Juan Cristóbal Ríos-Contesse, Benedikt Ritter, Stephanie Scheidt, Barbara Vargas-Machuca, Pritam Yogeshwar, and Martin Melles
Sci. Dril., 34, 1–20, https://doi.org/10.5194/sd-34-1-2025, https://doi.org/10.5194/sd-34-1-2025, 2025
Short summary
Short summary
We present the results of comprehensive pre-site surveys and deep drillings in two clay pans in the central Atacama Desert of northern Chile, one of the driest deserts on Earth. The results of the site surveys as well as lithological and downhole-logging data of the deep-drilling operations highlight the potential of the sediment records from the PAG (Playa Adamito Grande) and Paranal clay pans to provide unprecedented information on the Neogene precipitation history of the hyperarid core of the Atacama Desert.
Aline Zinelabedin, Joel Mohren, Maria Wierzbicka-Wieczorek, Tibor Janos Dunai, Stefan Heinze, and Benedikt Ritter
Earth Surf. Dynam., 13, 257–276, https://doi.org/10.5194/esurf-13-257-2025, https://doi.org/10.5194/esurf-13-257-2025, 2025
Short summary
Short summary
In order to interpret the formation processes of subsurface salt wedges and polygonal patterned grounds from the northern Atacama Desert, we present a multi-methodological approach. Due to the high salt content of the wedges, we suggest that their formation is dominated by subsurface salt dynamics requiring moisture. We assume that the climatic conditions during the wedge growth were slightly wetter than today, offering the potential to use the wedges as palaeoclimate archives.
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
Short summary
Short summary
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.
Jesse B. Walters, Joshua M. Garber, Aratz Beranoaguirre, Leo J. Millonig, Axel Gerdes, Tobias Grützner, and Horst R. Marschall
Geochronology, 7, 309–333, https://doi.org/10.5194/gchron-7-309-2025, https://doi.org/10.5194/gchron-7-309-2025, 2025
Short summary
Short summary
Garnet U–Pb dating is useful for dating geologic events. However, contamination by U-rich minerals included in garnet is a risk. Inclusions are often spotted by high-U spikes or large errors in the age. We dated garnets in metamorphic rocks and calculated ages 10–15 Myr older than expected, reflecting contamination by the mineral zircon. We provide recommendations for identifying contamination and suggest that the bulk dating of zircon inclusions in garnet may also provide valuable information.
Volker Wennrich, Julia Diederich-Leicher, Bárbara Nataly Blanco-Arrué, Christoph Büttner, Stefan Buske, Eduardo Campos Sepulveda, Tibor Dunai, Jacob Feller, Emma Galego, Ascelina Hasberg, Niklas Leicher, Damián Alejandro López, Jorge Maldonado, Alicia Medialdea, Lukas Ninnemann, Russell Perryman, Juan Cristóbal Ríos-Contesse, Benedikt Ritter, Stephanie Scheidt, Barbara Vargas-Machuca, Pritam Yogeshwar, and Martin Melles
Sci. Dril., 34, 1–20, https://doi.org/10.5194/sd-34-1-2025, https://doi.org/10.5194/sd-34-1-2025, 2025
Short summary
Short summary
We present the results of comprehensive pre-site surveys and deep drillings in two clay pans in the central Atacama Desert of northern Chile, one of the driest deserts on Earth. The results of the site surveys as well as lithological and downhole-logging data of the deep-drilling operations highlight the potential of the sediment records from the PAG (Playa Adamito Grande) and Paranal clay pans to provide unprecedented information on the Neogene precipitation history of the hyperarid core of the Atacama Desert.
Aline Zinelabedin, Joel Mohren, Maria Wierzbicka-Wieczorek, Tibor Janos Dunai, Stefan Heinze, and Benedikt Ritter
Earth Surf. Dynam., 13, 257–276, https://doi.org/10.5194/esurf-13-257-2025, https://doi.org/10.5194/esurf-13-257-2025, 2025
Short summary
Short summary
In order to interpret the formation processes of subsurface salt wedges and polygonal patterned grounds from the northern Atacama Desert, we present a multi-methodological approach. Due to the high salt content of the wedges, we suggest that their formation is dominated by subsurface salt dynamics requiring moisture. We assume that the climatic conditions during the wedge growth were slightly wetter than today, offering the potential to use the wedges as palaeoclimate archives.
Joel Mohren, Hendrik Wiesel, Wulf Amelung, L. Keith Fifield, Alexandra Sandhage-Hofmann, Erik Strub, Steven A. Binnie, Stefan Heinze, Elmarie Kotze, Chris Du Preez, Stephen G. Tims, and Tibor J. Dunai
Biogeosciences, 22, 1077–1094, https://doi.org/10.5194/bg-22-1077-2025, https://doi.org/10.5194/bg-22-1077-2025, 2025
Short summary
Short summary
We measured concentrations of nuclear fallout in soil samples taken from arable land in South Africa. We find that during the second half of the 20th century, the data strongly correlate with the organic matter content of the soils. The finding implies that wind erosion strongly influenced the loss of organic matter in the soils we investigated. Furthermore, the exponential decline of fallout concentrations and organic matter content over time peaks shortly after native grassland is ploughed.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
Joel Mohren, Steven A. Binnie, Gregor M. Rink, Katharina Knödgen, Carlos Miranda, Nora Tilly, and Tibor J. Dunai
Earth Surf. Dynam., 8, 995–1020, https://doi.org/10.5194/esurf-8-995-2020, https://doi.org/10.5194/esurf-8-995-2020, 2020
Short summary
Short summary
In this study, we comprehensively test a method to derive soil densities under fieldwork conditions. The method is mainly based on images taken from consumer-grade cameras. The obtained soil/sediment densities reflect
truevalues by generally > 95 %, even if a smartphone is used for imaging. All computing steps can be conducted using freeware programs. Soil density is an important variable in the analysis of terrestrial cosmogenic nuclides, for example to infer long-term soil production rates.
Eric Salomon, Atle Rotevatn, Thomas Berg Kristensen, Sten-Andreas Grundvåg, Gijs Allard Henstra, Anna Nele Meckler, Richard Albert, and Axel Gerdes
Solid Earth, 11, 1987–2013, https://doi.org/10.5194/se-11-1987-2020, https://doi.org/10.5194/se-11-1987-2020, 2020
Short summary
Short summary
This study focuses on the impact of major rift border faults on fluid circulation and hanging wall sediment diagenesis by investigating a well-exposed example in NE Greenland using field observations, U–Pb calcite dating, clumped isotope, and minor element analyses. We show that fault-proximal sediments became calcite cemented quickly after deposition to form a near-impermeable barrier along the fault, which has important implications for border fault zone evolution and reservoir assessments.
Related subject area
SIMS, LA-ICP-MS
Zircon micro-inclusions as an obstacle for in situ garnet U–Pb geochronology: an example from the As Sifah eclogite locality, Oman
A comparison between in situ monazite Lu–Hf and U–Pb geochronology
U–Pb dating on calcite paleosol nodules: first absolute age constraints on the Miocene continental succession of the Paris Basin
Effect of chemical abrasion of zircon on SIMS U–Pb, δ18O, trace element, and LA-ICPMS trace element and Lu–Hf isotopic analyses
On the viability of detrital biotite Rb–Sr geochronology
Examination of the accuracy of SHRIMP U–Pb geochronology based on samples dated by both SHRIMP and CA-TIMS
In situ U–Pb dating of 4 billion-year-old carbonates in the martian meteorite Allan Hills 84001
Constraining the geothermal parameters of in situ Rb–Sr dating on Proterozoic shales and their subsequent applications
Short communication: On the potential use of materials with heterogeneously distributed parent and daughter isotopes as primary standards for non-U–Pb geochronological applications of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS)
In situ Lu–Hf geochronology of calcite
Calcite U–Pb dating of altered ancient oceanic crust in the North Pamir, Central Asia
Towards in situ U–Pb dating of dolomite
Uranium incorporation in fluorite and exploration of U–Pb dating
U − Pb geochronology of epidote by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) as a tool for dating hydrothermal-vein formation
Tools for uranium characterization in carbonate samples: case studies of natural U–Pb geochronology reference materials
Direct U–Pb dating of carbonates from micron-scale femtosecond laser ablation inductively coupled plasma mass spectrometry images using robust regression
Technical note: LA–ICP-MS U–Pb dating of unetched and etched apatites
The use of ASH-15 flowstone as a matrix-matched reference material for laser-ablation U − Pb geochronology of calcite
Expanding the limits of laser-ablation U–Pb calcite geochronology
Resolving multiple geological events using in situ Rb–Sr geochronology: implications for metallogenesis at Tropicana, Western Australia
LA-ICPMS U–Pb geochronology of detrital zircon grains from the Coconino, Moenkopi, and Chinle formations in the Petrified Forest National Park (Arizona)
Evaluating the reliability of U–Pb laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) carbonate geochronology: matrix issues and a potential calcite validation reference material
Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) U–Pb carbonate geochronology: strategies, progress, and limitations
Jesse B. Walters, Joshua M. Garber, Aratz Beranoaguirre, Leo J. Millonig, Axel Gerdes, Tobias Grützner, and Horst R. Marschall
Geochronology, 7, 309–333, https://doi.org/10.5194/gchron-7-309-2025, https://doi.org/10.5194/gchron-7-309-2025, 2025
Short summary
Short summary
Garnet U–Pb dating is useful for dating geologic events. However, contamination by U-rich minerals included in garnet is a risk. Inclusions are often spotted by high-U spikes or large errors in the age. We dated garnets in metamorphic rocks and calculated ages 10–15 Myr older than expected, reflecting contamination by the mineral zircon. We provide recommendations for identifying contamination and suggest that the bulk dating of zircon inclusions in garnet may also provide valuable information.
Alexander T. De Vries Van Leeuwen, Stijn Glorie, Martin Hand, Jacob Mulder, and Sarah E. Gilbert
Geochronology, 7, 199–211, https://doi.org/10.5194/gchron-7-199-2025, https://doi.org/10.5194/gchron-7-199-2025, 2025
Short summary
Short summary
In this contribution, we demonstrate in situ monazite lutetium–hafnium dating and compare results with uranium–lead dating. We present data from monazite reference materials and complex samples to demonstrate the viability of this method. We show that in situ lutetium–hafnium dating of monazite can resolve multiple age populations and may find use in scenarios where the uranium–lead system has been compromised.
Vincent Monchal, Rémi Rateau, Kerstin Drost, Cyril Gagnaison, Bastien Mennecart, Renaud Toullec, Koen Torremans, and David Chew
Geochronology, 7, 139–156, https://doi.org/10.5194/gchron-7-139-2025, https://doi.org/10.5194/gchron-7-139-2025, 2025
Short summary
Short summary
Sedimentary rocks are typically dated indirectly, by comparing the fossil content of basins with the geological timescale. In this study, we employed an absolute dating approach to date 19\,Myr old sediments in the Paris Basin, using uranium–lead dating of calcite nodules associated with soil formation. The precision of our new ages enable more accurate comparisons (independent of their fossil contents) between the Paris Basin and other basins of similar age.
Cate Kooymans, Charles W. Magee Jr., Kathryn Waltenberg, Noreen J. Evans, Simon Bodorkos, Yuri Amelin, Sandra L. Kamo, and Trevor Ireland
Geochronology, 6, 337–363, https://doi.org/10.5194/gchron-6-337-2024, https://doi.org/10.5194/gchron-6-337-2024, 2024
Short summary
Short summary
Zircon is a mineral where uranium decays to lead. Some radiation damage lets lead escape. A method called chemical abrasion (CA) dissolves out the damaged portions of zircon so that remaining zircon retains lead. We compare ion beam analyses of untreated and chemically abraded zircons. The ion beam ages for untreated zircons match the reference values for untreated zircon. The ion beam ages for CA zircon match CA reference ages. Other elements are unaffected by the chemical abrasion process.
Kyle P. Larson, Brendan Dyck, Sudip Shrestha, Mark Button, and Yani Najman
Geochronology, 6, 303–312, https://doi.org/10.5194/gchron-6-303-2024, https://doi.org/10.5194/gchron-6-303-2024, 2024
Short summary
Short summary
This study demonstrates the utility of laser-ablation-based detrital biotite Rb–Sr geochronology to investigate the rates of exhumation and burial in active mountain-building systems. It is further demonstrated that additional chemical data collected during spot analyses can be used to determine temperatures recorded in biotite. The method used has advantages over traditional methods in speed, ease of acquisition, and the ability to collect additional chemical information.
Charles W. Magee Jr., Simon Bodorkos, Christopher J. Lewis, James L. Crowley, Corey J. Wall, and Richard M. Friedman
Geochronology, 5, 1–19, https://doi.org/10.5194/gchron-5-1-2023, https://doi.org/10.5194/gchron-5-1-2023, 2023
Short summary
Short summary
SHRIMP (Sensitive High Resolution Ion MicroProbe) is an instrument that for decades has used the radioactive decay of uranium into lead to measure geologic time. The accuracy and precision of this instrument has not been seriously reviewed in almost 20 years. This paper compares several dozen SHRIMP ages in our database with more accurate and precise methods to assess SHRIMP accuracy and precision. Analytical and geological complications are addressed to try to improve the method.
Romain Tartèse and Ian C. Lyon
Geochronology, 4, 683–690, https://doi.org/10.5194/gchron-4-683-2022, https://doi.org/10.5194/gchron-4-683-2022, 2022
Short summary
Short summary
Absolute chronological constraints are crucial in Earth and planetary sciences. In recent years, U–Pb dating of carbonates has provided information on the timing of, for example, diagenesis, faulting, or hydrothermalism. These studies have targeted relatively young terrestrial carbonates up to 300 million years old. By dating 3.9 billion-year-old martian carbonates in situ using the U–Pb chronometer, we show that this system is robust in ancient samples that have had a relatively simple history.
Darwinaji Subarkah, Angus L. Nixon, Monica Jimenez, Alan S. Collins, Morgan L. Blades, Juraj Farkaš, Sarah E. Gilbert, Simon Holford, and Amber Jarrett
Geochronology, 4, 577–600, https://doi.org/10.5194/gchron-4-577-2022, https://doi.org/10.5194/gchron-4-577-2022, 2022
Short summary
Short summary
Advancements in technology have introduced new techniques to more quickly and cheaply date rocks with little sample preparation. A unique use of this method is to date shales and constrain when these rocks were first deposited. This approach can also time when such sequences were subsequently affected by heat or fluids after they were deposited. This is useful, as the formation of precious-metal-bearing systems or petroleum source rocks is commonly associated with such processes.
Daniil V. Popov
Geochronology, 4, 399–407, https://doi.org/10.5194/gchron-4-399-2022, https://doi.org/10.5194/gchron-4-399-2022, 2022
Short summary
Short summary
This work provides equations allowing the use of minerals with variable concentrations of parent and daughter isotopes as primary standards to correct for elemental fractionation during the analysis by laser ablation inductively coupled plasma mass spectrometry.
Alexander Simpson, Stijn Glorie, Martin Hand, Carl Spandler, Sarah Gilbert, and Brad Cave
Geochronology, 4, 353–372, https://doi.org/10.5194/gchron-4-353-2022, https://doi.org/10.5194/gchron-4-353-2022, 2022
Short summary
Short summary
The article demonstrates a new technique that can be used to determine the age of calcite crystallisation using the decay of 176Lu to 176Hf. The technique is novel because (a) Lu–Hf radiometric dating is rarely applied to calcite and (b) this is the first instance where analysis has been conducted by ablating the sample with a laser beam rather than bulk dissolution. By using laser ablation the original context of the sample is preserved.
Johannes Rembe, Renjie Zhou, Edward R. Sobel, Jonas Kley, Jie Chen, Jian-Xin Zhao, Yuexing Feng, and Daryl L. Howard
Geochronology, 4, 227–250, https://doi.org/10.5194/gchron-4-227-2022, https://doi.org/10.5194/gchron-4-227-2022, 2022
Short summary
Short summary
Calcite is frequently formed during alteration processes in the basaltic, uppermost layer of juvenile oceanic crust. Weathered oceanic basalts are hard to date with conventional radiometric methods. We show in a case study from the North Pamir, Central Asia, that calcite U–Pb age data, supported by geochemistry and petrological microscopy, have potential to date sufficiently old oceanic basalts, if the time span between basalt extrusion and latest calcite precipitation (~ 25 Myr) is considered.
Bar Elisha, Perach Nuriel, Andrew Kylander-Clark, and Ram Weinberger
Geochronology, 3, 337–349, https://doi.org/10.5194/gchron-3-337-2021, https://doi.org/10.5194/gchron-3-337-2021, 2021
Short summary
Short summary
Distinguishing between different dolomitization processes is challenging yet critical for resolving some of the issues and ambiguities related to the formation of dolomitic rocks. Accurate U–Pb absolute dating of dolomite by LA-ICP-MS could contribute to a better understanding of the dolomitization process by placing syngenetic, early diagenetic, and/or epigenetic events in the proper geological context.
Louise Lenoir, Thomas Blaise, Andréa Somogyi, Benjamin Brigaud, Jocelyn Barbarand, Claire Boukari, Julius Nouet, Aurore Brézard-Oudot, and Maurice Pagel
Geochronology, 3, 199–227, https://doi.org/10.5194/gchron-3-199-2021, https://doi.org/10.5194/gchron-3-199-2021, 2021
Short summary
Short summary
To explore the U–Pb geochronometer in fluorite, the spatial distribution of uranium and other substituted elements in natural crystals is investigated using induced fission-track and synchrotron radiation X-ray fluorescence mapping. LA-ICP-MS U–Pb dating on four crystals, which preserve micrometer-scale variations in U concentrations, yields identical ages within analytical uncertainty. Our results show that fluorite U–Pb geochronology has potential for dating distinct crystal growth stages.
Veronica Peverelli, Tanya Ewing, Daniela Rubatto, Martin Wille, Alfons Berger, Igor Maria Villa, Pierre Lanari, Thomas Pettke, and Marco Herwegh
Geochronology, 3, 123–147, https://doi.org/10.5194/gchron-3-123-2021, https://doi.org/10.5194/gchron-3-123-2021, 2021
Short summary
Short summary
This work presents LA-ICP-MS U–Pb geochronology of epidote in hydrothermal veins. The challenges of epidote dating are addressed, and a protocol is proposed allowing us to obtain epidote U–Pb ages with a precision as good as 5 % in addition to the initial Pb isotopic composition of the epidote-forming fluid. Epidote demonstrates its potential to be used as a U–Pb geochronometer and as a fluid tracer, allowing us to reconstruct the timing of hydrothermal activity and the origin of the fluid(s).
E. Troy Rasbury, Theodore M. Present, Paul Northrup, Ryan V. Tappero, Antonio Lanzirotti, Jennifer M. Cole, Kathleen M. Wooton, and Kevin Hatton
Geochronology, 3, 103–122, https://doi.org/10.5194/gchron-3-103-2021, https://doi.org/10.5194/gchron-3-103-2021, 2021
Short summary
Short summary
We characterize three natural carbonate samples with elevated uranium/lead (U/Pb) ratios to demonstrate techniques improving the understanding of U incorporation in carbonates for U/Pb dating. With the rapidly accelerating application of laser ablation analyses, there is a great need for well-characterized reference materials that can serve multiple functions. Strontium (Sr) isotope analyses and U XANES demonstrate that these samples could be used as reference materials.
Guilhem Hoareau, Fanny Claverie, Christophe Pecheyran, Christian Paroissin, Pierre-Alexandre Grignard, Geoffrey Motte, Olivier Chailan, and Jean-Pierre Girard
Geochronology, 3, 67–87, https://doi.org/10.5194/gchron-3-67-2021, https://doi.org/10.5194/gchron-3-67-2021, 2021
Short summary
Short summary
A new methodology for the micron-scale uranium–lead dating of carbonate minerals is proposed. It is based on the extraction of ages directly from pixel images (< 1 mm2) obtained by laser ablation coupled to a mass spectrometer. The ages are calculated with a robust linear regression through the pixel values. This methodology is compared to existing approaches.
Fanis Abdullin, Luigi A. Solari, Jesús Solé, and Carlos Ortega-Obregón
Geochronology, 3, 59–65, https://doi.org/10.5194/gchron-3-59-2021, https://doi.org/10.5194/gchron-3-59-2021, 2021
Short summary
Short summary
Unetched and etched apatite grains from five samples were dated by U–Pb method using laser ablation inductively coupled plasma mass spectrometry. Our experiment indicates that etching needed for apatite fission track dating has insignificant effects on obtaining accurate U–Pb ages; thus, the laser ablation-based technique may be used for apatite fission track and U–Pb double dating.
Perach Nuriel, Jörn-Frederik Wotzlaw, Maria Ovtcharova, Anton Vaks, Ciprian Stremtan, Martin Šala, Nick M. W. Roberts, and Andrew R. C. Kylander-Clark
Geochronology, 3, 35–47, https://doi.org/10.5194/gchron-3-35-2021, https://doi.org/10.5194/gchron-3-35-2021, 2021
Short summary
Short summary
This contribution presents a new reference material, ASH-15 flowstone with an age of 2.965 ± 0.011 Ma (95 % CI), to be used for in situ U–Pb dating of carbonate material. The new age analyses include the use of the EARTHTIME isotopic tracers and a large number of sub-samples (n = 37) with small aliquots (1–7 mg) each that are more representative of laser-ablation spot analysis. The new results could improve the propagated uncertainties on the final age with a minimal value of 0.4 %.
Andrew R. C. Kylander-Clark
Geochronology, 2, 343–354, https://doi.org/10.5194/gchron-2-343-2020, https://doi.org/10.5194/gchron-2-343-2020, 2020
Short summary
Short summary
This paper serves as a guide to those interested in dating calcite by laser ablation. Within it are theoretical and practical limits of U and Pb concentrations (and U / Pb ratios), which would allow viable extraction of ages from calcite (and other minerals with moderate U / Pb ratios), and which type of instrumentation would be appropriate for any given sample. The method described uses a new detector array, allowing for lower detection limits and thereby expanding the range of viable samples.
Hugo K. H. Olierook, Kai Rankenburg, Stanislav Ulrich, Christopher L. Kirkland, Noreen J. Evans, Stephen Brown, Brent I. A. McInnes, Alexander Prent, Jack Gillespie, Bradley McDonald, and Miles Darragh
Geochronology, 2, 283–303, https://doi.org/10.5194/gchron-2-283-2020, https://doi.org/10.5194/gchron-2-283-2020, 2020
Short summary
Short summary
Using a relatively new dating technique, in situ Rb–Sr geochronology, we constrain the ages of two generations of mineral assemblages from the Tropicana Zone, Western Australia. The first, dated at ca. 2535 Ma, is associated with exhumation of an Archean craton margin and gold mineralization. The second, dated at ca. 1210 Ma, has not been previously documented in the Tropicana Zone. It is probably associated with Stage II of the Albany–Fraser Orogeny and additional gold mineralization.
George Gehrels, Dominique Giesler, Paul Olsen, Dennis Kent, Adam Marsh, William Parker, Cornelia Rasmussen, Roland Mundil, Randall Irmis, John Geissman, and Christopher Lepre
Geochronology, 2, 257–282, https://doi.org/10.5194/gchron-2-257-2020, https://doi.org/10.5194/gchron-2-257-2020, 2020
Short summary
Short summary
U–Pb ages of zircon crystals are used to determine the provenance and depositional age of strata of the Triassic Chinle and Moenkopi formations and the Permian Coconino Sandstone of northern Arizona. Primary source regions include the Ouachita orogen, local Precambrian basement rocks, and Permian–Triassic magmatic arcs to the south and west. Ages from fine-grained strata provide reliable depositional ages, whereas ages from sandstones are compromised by zircon grains recycled from older strata.
Marcel Guillong, Jörn-Frederik Wotzlaw, Nathan Looser, and Oscar Laurent
Geochronology, 2, 155–167, https://doi.org/10.5194/gchron-2-155-2020, https://doi.org/10.5194/gchron-2-155-2020, 2020
Short summary
Short summary
The dating of carbonates by laser ablation inductively coupled plasma mass spectrometry is improved by an additional, newly characterised reference material and adapted data evaluation protocols: the shape (diameter to depth) of the ablation crater has to be as similar as possible in the reference material used and the unknown samples to avoid an offset. Different carbonates have different ablation rates per laser pulse. With robust uncertainty propagation, precision can be as good as 2–3 %.
Nick M. W. Roberts, Kerstin Drost, Matthew S. A. Horstwood, Daniel J. Condon, David Chew, Henrik Drake, Antoni E. Milodowski, Noah M. McLean, Andrew J. Smye, Richard J. Walker, Richard Haslam, Keith Hodson, Jonathan Imber, Nicolas Beaudoin, and Jack K. Lee
Geochronology, 2, 33–61, https://doi.org/10.5194/gchron-2-33-2020, https://doi.org/10.5194/gchron-2-33-2020, 2020
Short summary
Short summary
Here we review current progress in LA-ICP-MS U–Pb carbonate geochronology and present strategies for acquisition and interpretation of carbonate U–Pb dates. We cover topics from imaging techniques and U and Pb incorporation into calcite to potential limitations of the method – disequilibrium and isotope mobility. We demonstrate the incorporation of imaging and compositional data to help refine and interpret U–Pb dates. We expect this paper to become a
go-toreference paper for years to come.
Cited articles
Allen, J.: Richards K. (ed.) 1987. River Channels, Environment and Process, vi 393 pp. Oxford, New York: Basil Blackwell, Price 39.50 (hard covers), ISBN 0 631 14577 X, Geological Magazine, 126, 313–314, https://doi.org/10.1017/S0016756800022536, 1989.
Alonso-Zarza, A. M.: Palaeoenvironmental significance of palustrine carbonates and calcretes in the geological record, Earth-Sci. Rev., 60, 261–298, 2003.
Alonso-Zarza, A. M. and Wright, V.: Calcretes, Developments in Sedimentology, 61, 225–267, 2010.
Balco, G., Stone, J. O., Lifton, N. A., and Dunai, T. J.: A complete and easily accessible means of calculating surface exposure ages or erosion rates from 10Be and 26Al measurements, Quat. Geochronol., 3, 174–195, https://doi.org/10.1016/j.quageo.2007.12.001, 2008.
Bierman, P. R. and Caffee, M.: Slow rates of rock surface erosion and sediment production across the Namib Desert and escarpment, southern Africa, Am. J. Sci., 301, 326–358, 2001.
Bonnet, S. and Crave, A.: Landscape response to climate change: Insights from experimental modeling and implications for tectonic versus climatic uplift of topography, Geology, 31, 123–126, 2003.
Branca, M., Masi, U., and Voltaggio, M.: An unsuccessful attempt at
Butt, C., Horwitz, R., and Mann, A.: Uranium occurences in calcrete and associated sediments in Western Australia, Commonwealth Scientific and Industrial Research Organization, Report Number CSIRO-FP–16, 1977.
Candy, I. and Black, S.: The timing of Quaternary calcrete development in semi-arid southeast Spain: investigating the role of climate on calcrete genesis, Sediment. Geol., 218, 6–15, 2009.
Candy, I., Black, S., and Sellwood, B. W.: Quantifying time scales of pedogenic calcrete formation using U-series disequilibria, Sediment. Geol., 170, 177–187, https://doi.org/10.1016/j.sedgeo.2004.07.003, 2004.
Cooper, F. J., Adams, B., Blundy, J., Farley, K., McKeon, R., and Ruggiero, A.: Aridity-induced Miocene canyon incision in the Central Andes, Geology, 44, 675–678, 2016.
Dupont, L. M.: Late Pliocene vegetation and climate in Namibia (southern Africa) derived from palynology of ODP site 1082, Geochem. Geophys. Geosyst., 7, Q05007, https://doi.org/10.1029/2005GC001208, 2006.
Dupont, L. M., Donner, B., Vidal, L., Pérez, E. M., and Wefer, G.: Linking desert evolution and coastal upwelling: Pliocene climate change in Namibia, Geology, 33, 461–464, 2005.
Dupont, L. M., Rommerskirchen, F., Mollenhauer, G., and Schefuß, E.: Miocene to Pliocene changes in South African hydrology and vegetation in relation to the expansion of C4 plants, Earth Planet. Sc. Lett., 375, 408–417, 2013.
Etourneau, J., Martinez, P., Blanz, T., and Schneider, R.: Pliocene–Pleistocene variability of upwelling activity, productivity, and nutrient cycling in the Benguela region, Geology, 37, 871–874, 2009.
Geological Survey of Namibia: Geological map 2314 Kuiseb 1:250 000 ESRI Shapefile, Geological Survey of Namibia, Windhoek, Geological Series, Geological Survey of Namibia, 2016.
Gerdes, A. and Zeh, A.: Combined U-Pb and Hf isotope LA-(MC-) ICP-MS analyses of detrital zircons: comparison with SHRIMP and new constraints for the provenance and age of an Armorican metasediment in Central Germany, Earth Planet. Sc. Lett., 249, 47–61, 2006.
Gerdes, A. and Zeh, A.: Zircon formation versus zircon alteration – new insights from combined U-Pb and Lu–Hf in-situ LA-ICP-MS analyses, and consequences for the interpretation of Archean zircon from the Central Zone of the Limpopo Belt, Chem. Geol., 261, 230–243, 2009.
Geyh, M. A. and Eitel, B.: Radiometric dating of young and old calcrete, Radiocarbon, 40, 795–802, 1997.
Goudie, A.: Duricrusts in tropical and subtropical landscapes, Duricrusts in Tropical and Subtropical Landscapes, ISBN-10 0198232128, ISBN-13 978-0198232124, 1973.
Goudie, A.: Calcrete, Chemical Sediments and Geomorphology: precipitates and residua in the near-surface environment, 1983.
Goudie, A.: Organic agency in calcrete development, J. Arid Environ., 32, 103–110, 1996.
Goudie, A.: Duricrusts and landforms, in: Geomorphology and soils, Routledge, 37–57, 2020.
Goudie, A. and Viles, H.: Landscapes and landforms of Namibia, Springer, ISBN 109402400311, ISBN 13978-9402400311, 2014.
Goudie, A., Viles, H., Goudie, A., and Viles, H.: Calcretes: The Kamberg Calcrete Formation and the Karpencliff Conglomerate, Landscapes and Landforms of Namibia, 111–114, 2015.
Hansen, J., Sato, M., Russell, G., and Kharecha, P.: Climate sensitivity, sea level and atmospheric carbon dioxide, Philosophical Transactions of the Royal Society A: Mathematical, Phys. Eng. Sci., 371, 20120294, https://doi.org/10.1098/rsta.2012.0294, 2013.
Herman, F. and Champagnac, J. D.: Plio-Pleistocene increase of erosion rates in mountain belts in response to climate change, Terra Nova, 28, 2–10, 2016.
Herman, F., Seward, D., Valla, P. G., Carter, A., Kohn, B., Willett, S. D., and Ehlers, T. A.: Worldwide acceleration of mountain erosion under a cooling climate, Nature, 504, 423–426, 2013.
Hoetzel, S., Dupont, L. M., and Wefer, G.: Miocene–Pliocene vegetation change in south-western Africa (ODP Site 1081, offshore Namibia), Palaeogeography, Palaeoclimatology, Palaeoecology, 423, 102–108, 2015.
Hoetzel, S., Dupont, L. M., Marret, F., Jung, G., and Wefer, G.: Steps in the intensification of Benguela upwelling over the Walvis Ridge during Miocene and Pliocene, Int. J. Earth Sci., 106, 171–183, 2017.
Horstwood, M. S., Košler, J., Gehrels, G., Jackson, S. E., McLean, N. M., Paton, C., Pearson, N. J., Sircombe, K., Sylvester, P., and Vermeesch, P.: Community-derived standards for LA-ICP-MS U-(Th-) Pb geochronology–Uncertainty propagation, age interpretation and data reporting, Geostand. Geoanal. Res., 40, 311–332, 2016.
Houben, G. J., Kaufhold, S., Miller, R. M., Lohe, C., Hinderer, M., Noll, M., Hornung, J., Joseph, R., Gerdes, A., and Sitnikova, M.: Stacked megafans of the Kalahari Basin as archives of paleogeography, river capture, and Cenozoic paleoclimate of southwestern Africa, J. Sediment. Res., 90, 980–1010, 2020.
Jacobson, P. J., Jacobson, K. M., and Seely, M. K.: Ephemeral rivers and their catchments: Sustaining people and developement in Namibia, Desert Research Foundation of Namibia, Windhoek, 160 pp., 1995.
Kelly, M., Black, S., and Rowan, J.: A calcrete-based
King, L.: The geomorphology of the Eastern and Southern districs of Southern Rhodesia, S. Afr. J. Geol., 54, 33–64, 1951.
King, L. C.: Pediplanation and isostasy: an example from South Africa, Quart. J. Geol. Soc.,, 111, 353–359, 1955.
Korn, H. and Martin, H.: The Pleistocene in South West Africa, Proceedings of the 3rd Pan-African Congress on Prehistory, 14–22, 1957.
Lancaster, N.: Paleoenvironments in the Tsondab valley, Central Namib desert, in: Palaeoecology of Africa and of the Surrounding Islands and Antarctica, edited by: Coetzee, J. A. and van Zinderen Bakker, E. M., Balkema, Cape Town, 411–419, 1984.
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.
Ludwig, K. R.: User's Manual for Isoplot 3.75, Berkeley GeochronologicalCenter Special Publication No. 5., 2012.
Mack, G. H. and James, W.: Paleoclimate and the global distribution of paleosols, J. Geol., 102, 360–366, 1994.
Maher, K., Wooden, J., Paces, J., and Miller, D.: 230Th-U dating of surficial deposits using the ion microprobe (SHRIMP-RG): A microstratigraphic perspective, Quat. Int., 166, 15–28, 2007.
Mann, A. and Horwitz, R.: Groundwater calcrete deposits in Australia some observations from Western Australia, J. Geol. Soc. Austr., 26, 293–303, 1979.
Marlow, J. R., Lange, C. B., Wefer, G., and Rosell-Melé, A.: Upwelling intensification as part of the Pliocene-Pleistocene climate transition, Science, 290, 2288–2291, 2000.
McBride, E. F.: Quartz cement in sandstones: a review, Earth-Sci. Rev., 26, 69–112, 1989.
Miller, R.: The Geology of Namibia, Ministry of Mines and Energy – Geological Survey Namibia, 3, 25–21, 2008.
Miller, R. M., Pickford, M., and Senut, B.: The geology, palaeontology and evolution of the Etosha Pan, Namibia: Implications for terminal Kalahari deposition, S. Afr. J. Geol., 113, 307–334, 2010.
Miller, R. M., Krapf, C., Hoey, T., Fitchett, J., Nguno, A.-K., Muyambas, R., Ndeutepo, A., Medialdea, A., Whitehead, A., and Stengel, I.: A sedimentological record of fluvial-aeolian interactions and climate variability in the hyperarid northern Namib Desert, Namibia, S. Afr. J. Geol., 124, 575–610, 2021.
Milnes, A. and Thiry, M.: Silcretes, in: Developments in earth surface processes, Elsevier, 349–377, 1992.
Milnes, A., Wright, M., and Thiry, M.: Silica accumulations in saprolites and soils in South Australia, Occurrence, characteristics, and genesis of carbonate, gypsum, and silica accumulations in soils, Soil Sci. Soc. Am., 26, 121–149, 1991.
Molnar, P.: Climate change, flooding in arid environments, and erosion rates, Geology, 29, 1071–1074, 2001.
Nash, D. J. and Shaw, P. A.: Silica and carbonate relationships in silcrete-calcrete intergrade duricrusts from the Kalahari of Botswana and Namibia, J. Afr. Earth Sci., 27, 11–25, 1998.
Nash, D. J. and Smith, R. F.: Multiple calcrete profiles in the Tabernas Basin, southeast Spain: their origins and geomorphic implications, Earth Surf. Proc. Land., 23, 1009–1029, 1998.
Netterberg, F.: The interpretation of some basic calcrete types, S. Afr. Archaeol. Bull., 24, 117–122, 1969.
Neymark, L.: Potential effects of alpha-recoil on uranium-series dating of calcrete, Chem. Geol., 282, 98–112, 2011.
Neymark, L.: Uranium–Lead Dating, Opal, edited by: Rink, W., Thompson, J., Encyclopedia of Scientific Dating Methods, Springer, Dordrecht, https://doi.org/10.1007/978-94-007-6326-5_263-1, 2014.
Ollier, C.: Outline geological and geomorphic history of the central Namib Desert, Madoqua, 1977, 207–212, 1977.
Oster, J. L., Kitajima, K., Valley, J. W., Rogers, B., and Maher, K.: An evaluation of paired δ18O and (234U
Partridge, T. and Maud, R.: Geomorphic evolution of southern Africa since the Mesozoic, S. Afr. J. Geol., 90, 179–208, 1987.
Pickford, M. and Senut, B.: Geology and Palaeobiology of the Central and Southern Namib Desert, Southwestern Africa: Geology and History of Study, Geological Survey, 1–155, 2000.
Pickford, M., Senut, B., and Dauphin, Y.: Biostratigraphyof the Tsondab sandstone (Namibia) based on gigantic avian eggshells, Geobios, 28, 85–98, 1995.
Pickford, M., Senut, B., Gommery, D., Andrews, P., and Banham, P.: Sexual dimorphism in Morotopithecus bishopi, an early Middle Miocene hominoid from Uganda, Late Cenozoic environments and hominid evolution: a tribute to Bill Bishop, 27–38, 1999.
Rasbury, E. T. and Cole, J. M.: Directly dating geologic events: U-Pb dating of carbonates, Rev. Geophys., 47, RG3001, https://doi.org/10.1029/2007RG000246, 2009.
Repka, J. L., Anderson, R. S., and Finkel, R. C.: Cosmogenic dating of fluvial terraces, Fremont River, Utah, Earth Planet. Sc. Lett., 152, 59–73, https://doi.org/10.1016/S0012-821X(97)00149-0, 1997.
Retallack, G. J.: The environmental factor approach to the interpretation of paleosols, Factors of soil formation: A fiftieth anniversary retrospective, Soil Science Society of America Special Publications, 33, 31–64, 1994.
Ritter, B., Vogt, A., and Dunai, T. J.: 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, Geochronology, 3, 421–431, https://doi.org/10.5194/gchron-3-421-2021, 2021.
Rosell-Melé, A., Martínez-Garcia, A., and McClymont, E. L.: Persistent warmth across the Benguela upwelling system during the Pliocene epoch, Earth Planet. Sc. Lett., 386, 10–20, 2014.
Ruggieri, E., Herbert, T., Lawrence, K. T., and Lawrence, C. E.: Change point method for detecting regime shifts in paleoclimatic time series: application to δ18O time series of the Plio-Pleistocene, Paleoceanography, 24, 2009.
Rutter, E.: Pressure solution in nature, theory and experiment, J. Geol. Soc., 140, 725–740, 1983.
Scardia, G., Parenti, F., Miggins, D. P., Gerdes, A., Araujo, A. G., and Neves, W. A.: Chronologic constraints on hominin dispersal outside Africa since 2.48 Ma from the Zarqa Valley, Jordan, Quat. Sci. Rev., 219, 1–19, 2019.
Senut, B.: Fossil ratite eggshells: a useful tool for Cainozoic biostratigraphy in Namibia, Communications of the geological Survey of Namibia, 12, 367–373, 2000.
Sorby, H. C.: The Bakerian Lecture: On the Direct Correlation of Mechanical and Chemical Forces, P. R. Soc. London, 12, 538–550, 1863.
Stacey, J. T. and Kramers, J.: Approximation of terrestrial lead isotope evolution by a two-stage model, Earth Planet. Sc. Lett., 26, 207–221, 1975.
Stokes, M., Nash, D. J., and Harvey, A. M.: Calcrete “fossilisation” of alluvial fans in SE Spain: The roles of groundwater, pedogenic processes and fan dynamics in calcrete development, Geomorphology, 85, 63–84, 2007.
Stollhofen, H., Stanistreet, I. G., von Hagke, C., and Nguno, A.: Pliocene–Pleistocene climate change, sea level and uplift history recorded by the Horingbaai fan-delta, NW Namibia, Sediment. Geol., 309, 15–32, 2014.
Stone, A.: Age and dynamics of the Namib Sand Sea: A review of chronological evidence and possible landscape development models, J. Afr. Earth Sci., 82, 70–87, 2013.
Summerfield, M.: Silcrete as a palaeoclimatic indicator: evidence from southern Africa, Palaeogeogr. Palaeocl., 41, 65–79, 1983a.
Summerfield, M. A.: Petrography and diagenesis of silcrete from the Kalahari Basin and Cape coastal zone, Southern Africa, J. Sediment. Res., 53, 895–909, 1983b.
Taylor, G. and Eggleton, R.: Silcrete: an Australian perspective, Australian Journal of Earth Sciences, 64, 987–1016, 2017.
Tera, F. and Wasserburg, G.: U-Th-Pb systematics in lunar highland samples from the Luna 20 and Apollo 16 missions, Earth Planet. Sc. Lett., 17, 36–51, 1972.
Van der Wateren, F. M. and Dunai, T. J.: Late Neogene passive margin denudation history – cosmogenic isotope measurements from the central Namib desert, Global Planet. Change, 30, 271–307, https://doi.org/10.1016/s0921-8181(01)00104-7, 2001.
Vermeesch, P., Fenton, C., Kober, F., Wiggs, G., Bristow, C. S., and Xu, S.: Sand residence times of one million years in the Namib Sand Sea from cosmogenic nuclides, Nat. Geosci., 3, 862–865, 2010.
Vermeesch, P., Balco, G., Blard, P. H., Dunai, T. J., Kober, F., Niedermann, S., Shuster, D. L., Strasky, S., Stuart, F. M., Wieler, R., and Zimmermann, L.: Interlaboratory comparison of cosmogenic 21Ne in quartz, Quat. Geochronol., 26, 20–28, https://doi.org/10.1016/j.quageo.2012.11.009, 2015.
Ward, J. and Corbett, I.: Towards an age for the Namib, Namib Ecol., 25, 17–26, 1990.
Ward, J. D.: The Cenozoic succession in the Kuiseb valley, central Namib desert, Geological Survey of Namibia Memoir, Windhoek, 124 p., 1987.
Ward, J. D., Seely, M. K., and Lancaster, N.: On the antiquity of the Namib, S. Afr. J. Sci., 79, 175–183, 1983.
Weissel, J. K. and Seidl, M. A.: Inland propagation of erosional escarpments and river profile evolution across the southeast Australian passive continental margin, Geophysical Monograph-American Geophysical Union, 107, 189–206, 1998.
Wendt, I. and Carl, C.: U
Westerhold, T., Marwan, N., Drury, A. J., Liebrand, D., Agnini, C., Anagnostou, E., Barnet, J. S., Bohaty, S. M., De Vleeschouwer, D., and Florindo, F.: An astronomically dated record of Earth's climate and its predictability over the last 66 million years, Science, 369, 1383–1387, 2020.
Whipple, K. X. and Tucker, G. E.: Dynamics of the stream-power river incision model: Implications for height limits of mountain ranges, landscape response timescales, and research needs, J. Geophys. Res.-Sol. Ea., 104, 17661–17674, 1999.
Wilson, M. J.: Dissolution and formation of quartz in soil environments: A review, Soil Sci. Annu., 71, 3–14, 2020.
Yaalon, D. H. and Ward, J. D.: Observations on calcrete and recent calcic horizons in relation to landforms, central Namib desert, in: Palaeoecology of Africa and of the Surrounding Islands and Antarctica, edited by: Coetzee, J. A. and van Zinderen Bakker, E. M., Balkema, Cape Town, 183–186, 1982.
Short summary
Chronological information on the evolution of the Namib Desert is scarce. We used U–Pb dating of silcretes formed by pressure solution during calcrete formation to track paleoclimate variability since the Late Miocene. Calcrete formation took place during the Pliocene with an abrupt cessation at 2.9 Ma. The end took place due to deep canyon incision which we dated using TCN exposure dating. With our data we correct and contribute to the Neogene history of the Namib Desert and its evolution.
Chronological information on the evolution of the Namib Desert is scarce. We used U–Pb dating of...
