29 Cenozoic Tectonics in Asia and North America: Linking Processes Across Scales

This session invites research integrating geologic, geomorphic, and paleoclimate data to advance understanding on orogenesis, seismic hazards, and global change.

Tuesday, 19 May 2026
1:30 PM - 4:30 PM
Alvarado A

Late Oligocene Reactivation of the Mongolian Altai Constrained by Structural, Sedimentological, and Detrital Provenance Data

Paper number: 29-1
Program: Technical Sessions
Time: 1:50 PM – 2:10 PM

Authors

Abstract

Episodes of intracontinental deformation can be difficult to detect using low-temperature thermochronological approaches, particularly in regions characterized by limited erosion and exhumation. The Cenozoic intracontinental reactivation of the Mongolian Altai has exerted a first-order control on regional topography and climate in central Asia; however, the timing and surface expression of this episode of deformation remain poorly constrained. Here, we present new structural, sedimentological, and detrital geochronological data to constrain the onset of Cenozoic reactivation of the Mongolian Altai. Our results show that the upper Oligocene Beger Formation preserves the earliest stratigraphic record of synorogenic sedimentation, characterized by the development of basin-margin folds and related growth strata and syntectonic unconformities. Integrated fluvial architecture element analysis and detrital zircon U–Pb data support that late Oligocene reactivation was expressed in the development of structurally compartmentalized, internally drained, and locally sourced sedimentary basins in which deformation localized along basin margins. This resulted in the development of alluvial fan systems sourced from local uplifted ranges. Our study demonstrates that synorogenic strata provide a sensitive record of deformation along the margins of Mongolian Altai basins, and that sediment dispersal systems can serve as robust proxies for constraining the timing of intracontinental reactivation.

Geological Society of America Abstracts with Programs. Vol. 58, No. 4

doi: 10.1130/abs/2026RM-410484

© Copyright 2026 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.