4 Sedimentary Systems and Provenance in the Western Cordillera

This session invites contributions on sedimentary processes, depositional environments, stratigraphic frameworks, and provenance evolution across western North America. Topics may include basin analysis, source-to-sink studies, and applications of stratigraphy to energy and environmental questions.

Wednesday, 22 April 2026
8:00 AM - 12:00 PM
LMH, Fiesta Terrace Salon

Characterizing Sediment Sources and Grain-Source Attribution Using Detrital Zircon Petrochronology

Paper number: 4-1
Program: Technical Sessions
Time: 8:05 AM – 8:25 AM

Authors

Abstract

Detrital petrochronology is a powerful multivariate method of characterizing sediment sources. The recently developed Tucker-1 decomposition method holds promise of using detrital petrochronology to identify both sediment-source characteristics and the proportions in which sources are present in sink samples even when sediment sources are unknown or unavailable for sampling. Herein we present a case study of the recently developed Tucker-1 decomposition method to a multivariate geochemical data set from detrital zircons in till samples collected above the Cu-bearing Guichon Creek Batholith (GCB) in southern British Columbia, Canada. Data include a suite of 11 variables from 12 samples from collected at a range of distances in the down ice-flow direction from the GCB.

We demonstrate that endmember modelling using the Tucker-1 decomposition method successfully deconvolves the multivariate data sets into two endmembers in which the geochemical distributions are consistent with derivation from either non-oxidized and relatively anhydrous (i.e., low ore potential, Source 1) or oxidized and hydrous (i.e., potential ore bodies, Source 2) igneous rocks. Comparison of the endmembers to zircons from local bedrock confirms that the method successfully reproduces geochemical distributions in potential sediment sources. The proportions of the Source 2 endmember decrease with increasing distance from the ore bodies, as expected due to downstream zircon mixing and dilution. Finally, we conduct a grain-by-grain attribution of the zircons to either the Source 1 or 2 endmember based on maximization of the likelihood that their measured multivariate geochemistry was drawn from one or the other of the learned multivariate endmembers.

Geological Society of America Abstracts with Programs. Vol. 58, No. 3

doi: 10.1130/abs/2026CD-410941

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