is one of the significant effect of ductile deformation in this period and propagated mylonitic foliation with the NW-SE general trend.
This transitional rheological context, which was contemporary to gold deposition, is supported by field evidence including brittle-ductile auriferous faults (with low-T mylonitization
) as well as cross-cutting relationships between pure tensile gold-bearing veins and ductile features (folding on various scales and boudinage).
During later mylonitization
, the rims of the plagioclase, quartz, hornblende and biotite grains were recrystallized to matrices of minute grains (20-30 pm).
It may undergo mylonitization
, cataclasis, brecciation, geochemical alteration, and development of clay-rich fault gouge.
The shear zone shows ductile to brittle-ductile deformational pattern  associated with intense brecciation, mylonitization
, and hydrothermal alterations accompanied by development of apatite, magnetite, base metal, rare metals, rare earth, and uranium [14, 19, 21].
The Gawuch Formation has an intrusive contact with the Lowari pluton towards south, however, the contact is now intensely sheared and is occupied by phyllites derived from metavolcanics of the Gawuch Formation through mylonitization
(Tahirkheli et al.,2005).
(1995), 4[degrees]Ar/39Ar dating of various size fractions of muscovite formed and/or deformed during mylonitization
yield ages of ca.
The muscovite in two samples yielded [sup.40]Ar/[sup.39]Ar plateau ages of 364 [+ or -] 2 Ma and 367 [+ or -] 3 Ma, an indication of the age of mylonitization
and a minimum age for the metasedimentary unit (Reynolds et al.
These rocks preserve a remarkably complete record of the microstructural and thermobaric evolution of the GHS and bear directly on the tectonothermal history of rocks incorporated into the MCT zone during mylonitization