Structure and petrology of the Raglan Range
Gee, Dennis (1962) Structure and petrology of the Raglan Range. Honours thesis, University of Tasmania.
Raglan Range consists dominantly of pelitic schists,
quartzites, and ortho-amphibolites generally of garnet
grade. This is the Franklin Group, and overlies Mary
Group phyllites of chlorite grade. All are Precambrian.
Precambrian structures show a regional and systematic
departure from homoaxiality due to a rotation 'about an
axis trending 326 degrees (true), and plunging 24 degrees This is the
expression of Tabberabberan folding. Unrolling about this
axis reveals a uniformly gently dipping alternation of
schist and quartzite over most of the area.
Two Precambrian deformations are recognisable, here
termed SI and S2. Associated with SI is the regional
metamorphism producing chlorite, biotite, a amandine ,
kyanite in a zonal arrangement. The biotite isograd
is taken as the upper limit of the Mary Group. S2 is
accompanied by retrograde metamorphism and large scale
recumbent folding, during which metamorphic zones were
inverted, and the Franklin Group was transported over
the Mary Group, possibly in a south-west direction.
The Governor River Phyllite, herein defined, is a wide zone
of dispersed movement associated with S2. Albite of metasomatic
origin crystallised in the interval between SI and S2.
Quartzites show R-tectonite micro-fabric. The quartz
fabric is homogeneous, irrespective of tectonic position,
hut the mica fabric is unrollable. Lineation in quartzite
is due to the intersection of SI surfaces with an older
surface, probably bedding. Lineation in schist is the
intersection of the SI surfaces and axial surfaces related
to the S2 folds.
Approximately coaxial relationships between SI, S2 and
the Tabberabberan folding permits a construction of a
tectonic profile of the Raglan Range by axial projection.
Lamprophyre dykes, probably Tabberabberan in age intrude
|Item Type:||Thesis (Honours)|
|Additional Information:||Copyright 1962 the Author.
The University is continuing to endeavour to trace the copyright owner(s) and in the meantime this item has been reproduced here in good faith. We would be pleased to hear from the copyright owner(s).|
|Deposited By:||Ms Sue Li|
|Deposited On:||18 Aug 2011 15:27|
|Last Modified:||17 Sep 2012 11:39|
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