true enough , they are the asymmetric folds , but my point is that with
further shearing the folds get transformed into sheath folds which if seen
on a T-section will show as asymmetric fold profile with a reflection
image of it accompanying the fold profile. this indicates that the fold
had been dragged during subsequent shearing and its axes becoming parallel
to the transportation direction.
thanks
supriyo.
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SUPRIYO MITRA
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St. JOHN'S COLLEGE
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On Tue, 7 Nov 2000, Wojciech Czaplinski wrote:
> "S. Mitra" wrote:
>
> > On Tue, 7 Nov 2000, Wojciech Czaplinski wrote:
> >
> > > Hello,
> > > Before I say farewell and unsubscribe from this group, there is one
> > > question I want to ask:
> > > It is commonly believed, that stretching lineation in the shear zones
> > > marks the direction of tectonic transport. So why the hell is it usually
> > > parallel to the folds' axes? Seems in contrary to me...
> >
> > hello,
> > well this ia a thing which is related to subsequent stages of shearing
> > when the cylindrical folds with fold axes perpendicular to the transport
> > direction gets dragged down forming seath folds, with a hair pin bend
> > developed on the fold axis. this might seemingly look as if the fold axes
> > were parallel to the stretching lineation
>
> Well, I've never seen any of those cylindrical folds from the _early_
> stages of shearing... Besides, the folds with axes parallel to the
> lineation are mostly consistently asymmetric...
>
> greetings - Wojtek
>
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