<p> Amphibolites and gneisses of the "Grenville province" and
granitic rocks of the Chief Lake batholith near Sudbury show the effects
of several phases of deformation. </p> <p> The first phase of deformation affected previously metamorphosed rocks of the "Grenville province" together with enclosed
pegmatite sills, and formed congruous parasitic S- and Z-folds. The
rocks were then subjected to faulting and local refolding. About
1, 750 m. y. ago, the Chief Lake batholith was intruded and truncated
the previous folds. Finally, all the rocks were subjected to a simultaneous
regional metamorphism and strong deformation. </p> <p> During this final deformation, all the previous linear
structures were rotated to parallel the strongly-developed regional
mineral lineations. The high-grade rocks of high amphibolite facies
to the S. E. of the cataclastic zone flowed upwards from a greater
depth than the rocks of greenschist facies to the N. E. of the cataclastic
zone. The sharp increase in metamorphic grade occurs
within the cataclastic zone which is about one mile wide. </p> <p> The final progressive deformation of the rocks is compared
with the constant-volume deformation ellipsoid as initiated from the
uniaxial prolate type through the constriction type to the plane- strain
type; wherein the direction of maximum elongation plunges moderately
to the S. S. E. and parallels the regional mineral lineations, the passive
fold axes, the elongations of conical folds, and the original flow directions (shown by deformed mineral lineations) of slip folds; while the
direction of maximum shortening generally plunges to the N. W. and is
normal to the penetrative foliations and the active axial planes of slip
folds. </p> / Thesis / Master of Science (MSc)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/20143 |
| Date | 07 1900 |
| Creators | Hsu, Mao-Yang |
| Contributors | Clifford, P. M., Geology |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
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