Kinematic interpretation of mylonitic rocks in part of the Columbia River fault zone, Shuswap Terrane, British Columbia

Saved in:
Online Access: Get full text
doi: 10.1139/e82-037
Authors:Brown, Richard L.; Murphy, Donald C.
Author Affiliations:Primary:
Carleton Univ., Dep. Geol., Ottawa, ON, Canada
Volume Title:Canadian Journal of Earth Sciences Revue Canadienne des Sciences de la Terre
Source:Canadian Journal of Earth Sciences = Revue Canadienne des Sciences de la Terre, 19(3), p.456-465. Publisher: National Research Council of Canada, Ottawa, ON, Canada. ISSN: 0008-4077
Publication Date:1982
Note:In English with French summary. 21 refs.; illus. incl. sketch maps
Summary:Mylonitic rocks were examined in a 600 m-thick section 20 km N of Revelstoke. At this locality coarse-grained granite with well-preserved igneous texture lies in the hanging wall of the fault zone. Adjacent to the boundary of the mylonite zone the granite is foliated and mineral segregation gives rise to well-defined compositional layering. The foliation (Sf) is defined by orientated mineral grains and flattened porphyroclasts. In areas of intense strain, compositional layering (Sc) is parallel Sf. At the boundary of the mylonite zone, and in weakly deformed areas within it, Sc and Sf are inclined at angles = or <30°. Sf is taken to be a plane of flattening and Sc appears to parallel a plane of shear. After correction for effects of late-stage flexural slip folding, the angular relationship of Sc to Sf may be used to determine sense of shear in the mylonite zone; the hanging wall rocks have been displaced to the E relative to the footwall. Formation of mylonitic fabrics and associated displacement of the Selkirk allochthon eastwards relative to the underlying Monashee complex occurred after the Middle Jurassic peak of regional metamorphism, and before brittle reactivation and uplift in the Tertiary. [P.Br.]
Subjects:Deformation; Effects; Fabric; Fault zones; Faults; Field studies; Foliation; Interpretation; Kinematics; Lineation; Metamorphic rocks; Mylonites; Petrofabrics; Shear; Structural analysis; Structural geology; Textures; British Columbia; Canada; North America; Shuswap Complex; Western Canada; Columbia River Fault
Coordinates:N510000 N512000 W1180000 W1183000
Abstract Numbers:82M/5058
Record ID:1982040115
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom
Tags: Add Tag
No Tags, Be the first to tag this record!