Post #2330544

I was surprised to learn after watching the new Netflix film Apex, that gniess (the rock the Troll Wall in Norway is comprised of) despite being a high-grade metamorphic rock formed from rock like granite at temperatures above 500°C makes for unstable climbing, compared to sandstone such as the Blue Mountains where parts of the film were shot is actually pretty good for climbing as I though it would be weak (although some can be weakened after rain). But when you think about the process it kinda makes sense; intense pressure forces minerals into parallel alignment i.e. foliation, which makes them weak along that plane, even if gneiss is very dense and has low porosity. #geology