Abstract
Continental transform faults commonly do not obey the kinematic rules of plate tectonics, because at their ends lithosphere is rarely created or destroyed. Earthquakes along them reach depths of some 20 km maximum, except in rare shortening segments, where deeper hypocenters have been detected. They are rarely confined to simple faults, but form broad zones of extensive fracturing containing commonly more than one major strike-slip fault, thus forming major keirogens. Transform faults connecting two divergent plate boundaries in oceans (ridge-ridge type) maintain their lengths, whereas in continents they become shorter or longer depending on whether the extensional zones at their ends migrate toward each other or away from each other, respectively. If the extensional zones migrate toward each other, the separating transform fault eventually disappears and begins growing with an opposite sense of motion. In oceans, a transform fault connecting two subduction zones (trench-trench type) facing each other becomes shorter and eventually disappears only to grow in the opposite direction with a reversed sense of motion. An oceanic transform fault connecting two subduction zones with the same facing does not change its length. If, however, a continental transform fault connects two areas of shortening it becomes shorter with time, provided the loci of shortening do not migrate from one another faster than the shortening itself. Continental transform faults leave behind “tail zones.” Such “tail zones” are not similar to oceanic fracture zones, but have fundamentally different tectonic characteristics. Where continental transform faults are involved in triple junctions, they commonly lead to the formation of “continental holes” resulting in the formation of “incompatibility basins.” All such deviations from the behavior of their oceanic cousins, the continental transform faults owe to the low shear resistance of the continental crust and the floatability of the continental lithosphere.
Original language | English |
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Title of host publication | Transform Plate Boundaries and Fracture Zones |
Publisher | Elsevier |
Pages | 169-247 |
Number of pages | 79 |
ISBN (Electronic) | 9780128120644 |
ISBN (Print) | 9780128122464 |
DOIs | |
Publication status | Published - 1 Jan 2018 |
Bibliographical note
Publisher Copyright:© 2019 Elsevier Inc. All rights reserved.
Keywords
- Continental transform faults
- Keirogens
- Lithosphere
- Orogens
- Strike-slip deformation
- Taphrogens
- Tectonism