21 Frontiers in Geochronology: Advances and Applications in the Geosciences
This session highlights cutting-edge geochronologic advances and applications that illuminate Earth’s dynamic history. We welcome contributions spanning new analytical techniques, integrative studies, and innovative case examples demonstrating the essential role of time in geosciences.
Tuesday, 10 March 2026
10:00 AM - 12:00 PM
RCC, 104
Modeling cosmogenic 26Al/10Be burial isochrons with Pysochron
Paper number: 21-0
Program: Technical Sessions
Time: 10:00 AM – 10:15 AM
Authors
Abstract
Isochron burial dating provides a reliable means to model cosmogenic 26Al//10Be burial ages by addressing issues that often complicate traditional burial dating techniques, such as reworking and postburial production of cosmogenic nuclides. By measuring the concentrations of 26Al and 10Be in a suite of clasts from the same depth within a deposit, users can identify shared 26Al/10Be signatures of burial and identify clasts that experienced previous burial, which would yield artificially old ages if included in burial age modeling. Similarly, multiple measurements of 26Al and 10Be from the same depth can be used to calculate common postburial production of cosmogenic nuclides that can confound traditional calculations based solely on radioactive decay and cause deposits to appear artificially young. As such, isochron burial dating proves particularly useful for dating shallowly buried fluvial and alluvial sediments, which often include reworked materials and are poorly shielded against cosmic radiation following deposition.
Accurately performing the calculations necessary for isochron burial dating requires careful treatment of cosmogenic nuclide systematics, which generally necessitates Monte Carlo simulations and outlier identification. Pysochron (https://code.usgs.gov/recon/pysochron) is an open-source, Python-based burial isochron program that permits these calculations on virtually any machine. Its graphical user interface facilitates modification of decay and production parameters, internal and external uncertainty calculations, and visual outputs of isochron diagrams. Running the code on a set of samples yields a comprehensive report that includes isochron burial modeling, MSWD, minimum burial ages of individual samples, outlier identification, and an automated commentary on isochron quality. It has been validated using 40 published 26Al/10Be isochrons from around the world, with burial ages ranging from 4.9-0.2 Ma. Users of 26Al/10Be isochron burial dating are invited to explore Pysochron’s capabilities and provide feedback to be incorporated into future versions of the software.
Geological Society of America Abstracts with Programs. Vol. 58, No. 1
doi: 10.1130/abs/2026SE-411602
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