29 February 2024 l Overberg Geoscientists Group talk by Gerrie van Aswegen Structural geology lessons from South Africa’s mines - shear, fractures, faults and bumps
Hi Gerrie, great talk and great hearing it from a "miner". @ 28:30 you refer to two generations of extension fractures and mentioned you have recorded striation🙂... I assume your record indicates that E1 is right lateral slip and E2 is left lateral slip where E1 has rotated about 40degrees (+-5) relative to E2 if we use the same plane as reference 😅...
Hi, sorry, I do not know how to address you. Note that the primary striations on the E1, E2 and E3 fractures are fractographic, not kinematic. Subsequent to their dynamic formation, because of the advance of the mining face, the direction of load on the fractures do change and some slip is possible, leading to slickensides superimposed on fractographic striae.
