3 photos in 2 sub-albums
Vitreous matrix fault rocks formed by partial fusion from friction of the lips of a seismic fault. As time passes the rock devitrifies and resembles a cataclasite.
3 photos in 2 sub-albums
Vitreous matrix fault rocks formed by partial fusion from friction of the lips of a seismic fault. As time passes the rock devitrifies and resembles a cataclasite.
25 photos in 15 sub-albums
Fissures and filonnets are clogged fractures indicating a gap between the walls of the affected material. The slots have a spindle shape and a large length/width ratio compared to the filonnets.
The gashes are sometimes organized in echelons where they materialize a zone of shear. They may then have a sigmoidal shape showing us the sense of the shearing movement.
Stylolites are structures made from dissolution under stress along globally planar surfaces (stylolitic joints) but very irregular in details (stylolite peaks).
53 photos in 20 sub-albums
These "fault rocks" were born from the more or less intense fragmentation of the rocks in the fault zones. Different types of fault rocks are distinguished according to the size of the elements, the cohesive character or name of the matrix, and the proportion of matrix relative to the elements. The cataclasites have a cohesive matrix whereas the breccias and gouges have an incoherent matrix.