A comparison of mineral grain fabrics and finite strain in amphibolites from eastern Finland

Saved in:
Online Access: Get full text
doi: 10.1139/e81-095
Authors:Gapais, Denis; Brun, Jean-Pierre
Author Affiliations:Primary:
Univ. Rennes, Cent. Armoricain Etude Struc. Socles, Rennes, France
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, 18(6), p.995-1003. Publisher: National Research Council of Canada, Ottawa, ON, Canada. ISSN: 0008-4077
Publication Date:1981
Note:In English with French summary. 34 refs.; illus. incl. 2 tables, geol. sketch map
Summary:Fabrics in amphibolites from the Kuopio area are described and compared with results of finite strain analysis. The area consists of mantled gneiss domes, which are deep-seated diapiric structures. The results concern the cover rocks of the domes. Strain ellipsoids range in shape from prolate to oblate and strain intensities vary strongly. Preferred orientations were measured by X-ray texture goniometry and corresponding fabric ellipsoids calculated, using an eigenvalue method. Fabric ellipsoids obtained from biotite are all oblate; those for hornblende range from prolate to oblate; intensities of hornblende fabric are weaker than those of biotite fabric. Local variations of results are induced by grain-scale factors, such as grain size, or original fabrics. No simple correlation was found between intensities of fabric and strain. In general, increasing strains are probably accompanied by an increase of the oblateness of biotite fabric ellipsoids. Hornblende fabrics are found to give a good approximation of the oblateness of the finite strain ellipsoid. The resulting L-S tectonite pattern is consistent with the general strain pattern and with the development of domal structures in the Kuopio area. [P.Br.]
Subjects:Amphibole group; Amphibolites; Biotite; Chain silicates; Clinoamphibole; Deformation; Domes; Fabric; Field studies; Finite strain analysis; Foliation; Hornblende; Indicators; Metamorphic rocks; Mica group; Preferred orientation; Sheet silicates; Silicates; Strain; Structural analysis; Structural geology; Tectonite; Textures; Europe; Finland; Kuopio Finland; Scandinavia; Western Europe; Eastern Finland Province; Mantled gneiss domes
Coordinates:N621000 N630000 E0290000 E0260000
Abstract Numbers:82M/0713
Record ID:1982001847
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!
Be the first to leave a comment!
You must be logged in first