We hopped on the bus after spending the evening before soaking in Turkish culture in the form of Turkish baths and natural hot spring water at our hotel and headed out to go to the Travertines in Pamukkale.
Pamukkale means “cotton castle” in Turkish and it’s not hard to see why. Stretching over a mile and a half, the dazzling white travertines and hot springs of calcium carbonate look incredibly out of place against the very green Turkish countryside. To say that Pamukkale stands out would be a huge understatement.
The highlight for many would have to be the terraces at the very top. You were unable to swim in these pools as they are formed naturally, while the lower ones were man-made and so the terraces themselves were much more pristine, the difference in colours caused by different minerals in the water. Water is regularly diverted from one side of the valley to the other in order to give the calcium carbonate a chance to harden and form travertines.
After we finished up with the Travertines we got the choice to break off into two groups, one that wanted to explore the very untouched ruins and one that wanted to swim with the ruins. After about an hour an a half we headed back to the bus but not before grabbing some ice cream that came with a show. On our way to our next stay for the night we got to go to multiple geological sites that Professor Oz thought represented the geological landscape of Turkey. Professor Oz taught us about some of the geological loves in his life and what he had been studying, including Foliations and shear strike-slip zones.
Foliation is the alignment and regrowth of minerals when a rock is in the prescence of pressure. The pressure can come from deep burial, or the lateral squeezing caused by plate collisions and subduction. Mineral crystals change their shape and orientation in response to pressure by elongating at right angles to the direction of pressure. Molecules in crystals migrate from the pressurized surface of a mineral to a zone of less pressure within the same mineral. Crystals reform into flattened shapes. The reoriented flattened and elongated minerals are now aligned in planar arrangements with each other, parallel along their long axes. This alignment can impart a layered or banded appearance to the rock, always on the microscopic and often on the visual scale. This is not sedimentary bedding, which is typically destroyed during this metamorphism. The thin layering is called ‘foliation’ from the Latin term folium, a leaf.
In general strike slip is a common mode of deformation in both continental and oceanic crust and occurs at a wide range of scales. Strike slip systems are relatively narrow and sub-vertical wrench zones along which two adjacent blocks move sideways, horizontally, parallel to the strike of the fault zone. However, when it is a shear strike slip zone, the same thing occurs except there is little to no effect on the crustal surface of the tectonic zone.
After a few stops to better learn the geology of turkey we made our last stop before returning to Istanbul for our last day.
