26 Undergraduate Research Session I (Posters)

Sunday, 19 March 2017
1:30 PM - 5:30 PM
Urban, 17th Floor

THE SAN JUAN FAULT, AN E-W TRENDING LEFT-LATERAL STRIKE SLIP FAULT ZONE INFERRED FROM ANALYSIS OF KINEMATIC INDICATORS; VANCOUVER ISLAND, CANADA

Paper number: 26-24
Program: Theme Sessions
Time: 1:30 PM – 5:30 PM

Authors

Abstract

We present data on the kinematics and geometry of a western segment of the San Juan Fault, which strikes east-west near the southern tip of Vancouver Island, British Columbia, Canada. This fault delineates the boundary between metamorphosed volcanic and plutonic rocks of the Wrangellia terrane to the north from the altered Pandora Peak unit and Leech River Complex of the Pacific Rim terrane to the south, but the kinematic history of this fault remains poorly understood. Detailed geologic mapping of the study area suggests the San Juan Fault is not a discrete fault, but rather a distributed shear zone. Fault kinematic data from six locations, including a total of 203 slickenlines measured and shear-sense indicators from both slickensides and thin sections of fault surfaces, all suggest left-lateral oblique slip with a minor component of oblique thrust motion. Thus, the San Juan fault is an east-west trending, left-lateral high angle strike-slip fault with a minor oblique thrust component, and is as much as 2,400 meters wide.

Geological Society of America Abstracts with Programs. Vol. 49, No. 2

doi: 10.1130/abs/2017NE-291472

© Copyright 2017 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.