This a reverse or dip-slip fault.
a reverse fault
Reverse fault
Reverse Fault
Reverse fault
The rocks that are forced up and over the rocks below the fault surface are referred to as "hanging wall" rocks. This occurs in a specific type of fault known as a thrust fault, where compressional forces cause the hanging wall to move upward relative to the footwall, which is the block of rock below the fault surface. This movement can result in significant geological features, such as mountain ranges.
A reverse fault is formed here
In a reverse or thrust fault or a nape.
This geological phenomenon is called overthrusting, where older rocks are pushed up and over younger rocks due to tectonic forces. It results in the older rocks being positioned above the younger ones.
Submersion zone, as described in the theory of plate techtonics.
In a reverse fault, the oldest rocks will be at the bottom of the fault plane, while the youngest rocks will be at the top. This is because reverse faults form when compressional forces cause rocks to be pushed together and up, resulting in older rocks being thrust over younger ones.
A Thrust fault is why, if my memory serves me. The strata is pushed up by a fault and flipped over to expose old rock on top and young on the bottom. Nevada's Red Rock Canyon has a Thrust fault.
The 4 September earthquake was caused by movement along the Greendale fault (a break in the rocks below the earth's surface) near to Christchurch. It happened when the forces within the earth became greater than the friction holding rocks together. As the rocks moved the vibrations caused the ground to shake. The fault had been hidden below the gravels of the Canterbury Plains.