GeoTrivia: Classical Shear FoldingFinding geology in unexpected places, this classical era Greek col

GeoTrivia: Classical Shear FoldingFinding geology in unexpected places, this classical era Greek column sitting along the beachfront at Achilleo, Greece (yes, named after the hero Achilles) exposes an amazing view of “similar folds.” These are folds that form in relatively hot rocks undergoing metamorphism by means of a mechanism which is, well, like poking your finger into a deck of cards, and “shearing” the cards along their surfaces. The resulting pattern includes layers that are thinner along fold limbs (where more shearing occurs) and thicker at fold noses (places where less movement is facilitated). In the region where this column is found, there are abundant supplies of plain old white marble in the hillsides. Why the ancient column maker used this spectacular rock in construction is unknown: possibly he thought it was pretty? Or – could he have been an incipient structural geologist?Annie R.My photo: column ~60 cm in diameterReading to get started on folds:http://www.glossary.oilfield.slb.com/Display.cfm?Term=similar+foldhttp://www.geo.wvu.edu/~jtoro/structure/ppt342/16folds-342.pdfhttp://www.jstor.org/discover/10.2307/30062467?uid=4&sid=21101508915407 -- source link

More pics about