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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. ******************************************************************************* SUPRIYO MITRA ----------------- St. JOHN'S COLLEGE CAMBRIDGE email: [log in to unmask] CB2 1TP [log in to unmask] U.K. [log in to unmask] phone: +44-1223-569803 ******************************************************************************* 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 > %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%