T19 New Insights into Controls on the Behavior of Orogenic Systems and their Associated Basins

Sunday, 15 October 2023
8:00 AM - 12:00 PM
326

COORDINATED DISPLACEMENT ON ADJACENT FAULTS USING GROWTH STRATA AT 104-5 YEAR TIMESCALES; CATALAN COASTAL RANGE, SPAIN

Paper number: T19-15
Program: Technical Sessions
Time: 11:30 AM – 11:45 AM

Authors

Abstract

Samples from the Catalan Coastal Ranges, NE Spain, in the wedge-top Mora basin and in the eastern Ebro foreland basin, allow for high-resolution dating of mountain belt formation. Bulk low field magnetic susceptibility data and magnetic polarity stratigraphy, correlated to the GPTS, provide the stratigraphic ages and the rates of accumulation in the synorogenic stratigraphy. The growth strata are part of the proximal Horta-Gandesa alluvial system of late Eocene-Oligocene age. The synorogenic stratigraphy is exposed along the abandoned Pinell de Bray railroad grade, providing near continuous exposures near the towns of Bot and Horta de Sant Joan, Spain. The growth strata were shed by coarse, transverse, braided streams as alluvial fans coincident with thrust belt formation. The recovered magnetic susceptibility data were tuned to orbital mechanics, which are known to result in long term environmental varibilty in Earth’s climate. The magnetic susceptibility data are used to correlate time between the interpreted magnetic polarity chrons on adjacent structures and to provide insights into deformation mechanics and the feedbacks between deformation, landscape evolution, and synorogenic sedimentation. The recovered astrochronology records significant (with respect to robust red noise models) vertical aggregational cycles at 11-15m, 65-85m, and ~270m. The multihierarchical growth strata ages are used to deduce coordinated fault activity and are interpreted to result from Paleogene precessional, obliquity and eccentricity cyclicity forcing.

Geological Society of America Abstracts with Programs. Vol. 55, No. 6

doi: 10.1130/abs/2023AM-393338

© Copyright 2023 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.