The secret of the different gold veins ( white quartz and hematite ) so meticulous separated in the ground, is on the clue which says how the mine ( inclined shaft ) is on a terraced terrain.
The fact how on the highest point of those terraces is a mountain wall, shows how there were colaptions ( like melted glacier ) of few layers from the mountain in the cooling of the magma process. I believe the valley was deeper but narrow and the first layer on its fall hits the the other side, cracks, and the cracked fragment at the top flipped on the fallen layer. And after the first fall, followed few other layers colaptions, resulting the image which has today that region.