A cohort is a group of people who share a common characteristic or experience within a defined period (e.g., are currently living, are exposed to a drug or vaccine or pollutant, or undergo a certain medical procedure).
A rift valley is a lowland region formed by the interaction of Earth's tectonic plates. This small rift valley has a typical formationâlong, narrow, and deep. It was formed by the Thingvellir rift, where the North American and Eurasian tectonic plates are tearing, or rifting, apart over a hotspot on the island of Iceland.
Faults. 1  Faults: a fault is a break in the lithosphere along which movement has occurred. 2  The part of the fault above the fault plane is called the hanging wall and the part below is called the footwall. 3  A normal fault occurs when a hanging wall moves down with respect to the footwall.