Search results
Results from the WOW.Com Content Network
Lifted fault-block geology Tilted fault-block formation in the Teton Range. Fault-block mountains often result from rifting, an indicator of extensional tectonics. These can be small or form extensive rift valley systems, such as the East African Rift zone. Death Valley in California is a smaller example.
Fault-block mountain of the tilted type. [16] Sierra Nevada Mountains (formed by delamination) as seen from the International Space Station. When a fault block is raised or tilted, a block mountain can result. [17] Higher blocks are called horsts, and troughs are called grabens. A spreading apart of the surface causes tensional forces.
Tilted block faulting, also called rotational block faulting, is a mode of structural evolution in extensional tectonic events, a result of tectonic plates stretching apart. [ 1 ] [ 2 ] When the upper lithospheric crust experiences extensional pressures, the brittle crust fractures, creating detachment faults . [ 3 ]
Fault scarps are exposed on the horst block and expose the footwall of the normal fault. This is a type of block faulting known as grabens and horsts. This basin and range topography is symmetrical having equal slopes on both sides of the valleys and mountain ranges. Timelapse of tilted block faulting
One block, the Jackson Hole basin, moved down while the other block, containing the westward-tilting eastern part of the Teton Range, moved up; thus creating the youngest mountain range in the Rocky Mountains. [14] Most of the downward movement occurred right next to the fault, resulting in a 15° tilt of the Colter Formation. [13]
The Rwenzori Mountains in the East African Rift are an upthrown fault block, and are the highest non-volcanic, non-orogenic mountains in the world. [13] [14] The Vosges Mountains in France were formed by isostatic uplift in response to the opening of the Rhine Graben, a major extensional basin. [15]
A horst is a section of crust that has been lifted relative to the blocks on either side, which is a result of its bounding faults dipping away from each other. [2] Horsts can form features such as plateaus, mountain ranges or ridges on either side of the valleys.
A fault plane is the plane that represents the fracture surface of a fault. A fault trace or fault line is a place where the fault can be seen or mapped on the surface. A fault trace is also the line commonly plotted on geologic maps to represent a fault. [3] [4] A fault zone is a cluster of parallel faults.