Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published January 2022 | Accepted Version + Published + Supplemental Material
Journal Article Open

Microcontinent Breakup and Links to Possible Plate Boundary Reorganization in the Northern Gulf of California, México

Abstract

Faults on microcontinents record the dynamic evolution of plate boundaries. However, most microcontinents are submarine and difficult to study. Here, we show that the southern part of the Isla Ángel de la Guarda (IAG) microcontinent, in the northern Gulf of California rift, is densely faulted by a late Quaternary-active normal fault zone. To characterize the onshore kinematics of this Almeja fault zone, we integrated remote fault mapping using high-resolution satellite- and drone-based topography with neotectonic field-mapping. We produced 13 luminescence ages from sediment deposits offset or impounded by faults to constrain the timing of fault offsets. We found that north-striking normal faults in the Almeja fault zone continue offshore to the south and likely into the nascent North Salsipuedes basin southwest of IAG. Late Pleistocene and Holocene luminescence ages indicate that the most recent onshore fault activity occurred in the last ∼50 kyr. These observations suggest that the North Salsipuedes basin is kinematically linked with and continues onshore as the active Almeja fault zone. We suggest that fragmentation of the evolving IAG microcontinent may not yet be complete and that the Pacific-North America plate boundary is either not fully localized onto the Ballenas transform fault and Lower Delfin pull-apart basin or is in the initial stage of a plate boundary reorganization.

Additional Information

© 2022. American Geophysical Union. Issue Online: 24 January 2022; Version of Record online: 24 January 2022; Accepted manuscript online: 13 January 2022; Manuscript accepted: 15 December 2021; Manuscript revised: 22 October 2021; Manuscript received: 04 June 2021. We thank the Secretaría de Gobernación and SEMARNAT for permits, J. Lin and M. Say for fieldwork, R. Arce, M. Camacho, and I. Covarrubias Rodreguez for boat transportation, C. Athanassas, M. Darin, M. Diggles, M. Oskin, K. Scharer, one anonymous reviewer, and editors L. Giambiagi and M. Rusmore for thorough reviews, and X. Ding, H. Kirkpatrick, C. Kitamikado, B. Kuhasubpasin, S. Saha, and K. Shao for discussion. Support provided by NSF EAR-1728145 to Moon and EAR-1728690 to Stock, CONACYT 2014242561 to Martín-Barajas, National Aeronautics and Space Administration contract 80NM0018D0004 to Sabbeth at Jet Propulsion Laboratory, California Institute of Technology, and the U.S. Geological Survey's National Cooperative Geologic Mapping Program to Bennett. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Data Availability Statement: Topography and luminescence data produced here are available at the UCLA Dataverse repository (https://dataverse.ucla.edu/dataverse/iag1_project/).

Attached Files

Published - 2021TC006933.pdf

Accepted Version - 2021TC006933-acc.pdf

Supplemental Material - 2021tc006933-t-sup-0001-supporting_information_si-s01.pdf

Files

2021TC006933.pdf
Files (16.3 MB)
Name Size Download all
md5:8c18baece4784a37d97dcce833ab37b4
9.3 MB Preview Download
md5:697f26b8f543a0e42a0d66cba1f0511d
3.1 MB Preview Download
md5:dde9724d4b0c9df13b859fae478f2a82
3.9 MB Preview Download

Additional details

Created:
October 9, 2023
Modified:
October 24, 2023