Paul Evins napisał(a):
>
> You're not the only one Wojtek,
> As far as I know, Segupta is working on modelling this. I would like to
> study it as well. Meanwhile, get a piece of clay into a ball. Put it
> between your hands and begin shearing it by moving you hands back and
> forth. What do you get? A cigar-shaped "snake" perpendicular to the
> movement direction.
> Children have known this for years, but it is still not so easy to apply it
> to rocks.
Yeah, that's brings us back to the b-lineation of Bruno Sander. Let's
imagine an orthogneiss with nice winged feldspar porphyroclasts (they
were _rotated_) and stretching lineation on foliation plane. In every
textbook you'll find that asymmetry of those porphyroclasts, observed in
section parallel to the lineation, shows the direction of tectonic
transport. In the same textbook you'll find that asymmetric folds are
another type of shear-sense indicator. These folds are usually parallel
to the lineation. Strange, isn't it?
> We'll miss you Wojtek,
> Paul
I'll miss the group (and geology) too... Unless I'll find some post-doc,
but it seems I was born on the wrong side of the (former) Iron Curtain.
thanks - Wojtek
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