Geology Note - PIP please to compare the thickness of another sample with a pocket knife.

1 - The Côa Territory is an excellent record of Earth's geological evolution,
Between 480 and 250 million years ago (in the Paleozoic)
2 - Its landscapes are constituted by SHALES, QUARTZITOS; GRANITOS and GRAUVAQUES.
The sedimentary rocks were formed at the bottom of the sea, they were subjected to very high pressures and temperatures in the wake of the ascent of the granite magma, that not only metamorphosed them as they led to their elevation, emersion and wrinkling (geological folds).