Displacement and segment linkage in fracture zones
- Univ. of Southampton (United Kingdom). Dept. of Geology
Fault zones and vein arrays are composed of overstepping and linked segments, so knowledge of segment evolution is crucial in understanding the development of zones. Displacement-distance profiles of faults and veins are used to study the development of segments and zones. Detailed mapping of normal and strike-slip faults allows comparison of the displacement-distance characteristics of faults both normal and parallel to the displacement vector, i.e. modes III and II propagation respectively. Similarly, vein width variations can be used to study mode I propagation. Displacement varies with distance along fractures, with zero displacement at fracture tips. Steep displacement gradients can occur where faults and extension fractures overstep because of displacement transfer between the segments. This displacement transfer is accommodated by relay and bridge structures. Overstepping fractures may link to form a single fracture with an irregular displacement-distance profile. A linkage point is often marked by a bend with a displacement minimum, where relay/bridge structures are preserved as normal drag. Displacement variations are also caused by fault bends, conjugate relationships and by lithological variations. As interaction between fractures increases, r/d[sub MAX] ratios tend to decrease (where r = the distance between the tip and the point of maximum displacement, and d[sub MAX] = maximum displacement). As a result of the interaction of fracture segments, fracture zones tend to have complex displacement-distance profiles.
- OSTI ID:
- 5879773
- Report Number(s):
- CONF-921058--
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Journal Name: Geological Society of America, Abstracts with Programs; (United States) Vol. 24:7; ISSN GAAPBC; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
Similar Records
Fault relay structures and their impact on production behavior
Fault relay structures and their impact on production behavior