3.9.7 Fault Complex (Forkastningskompleks)
3.9.7.1 A fault complex comprises two or more intersecting or geometrically associated faults or fault sets of different ages or having unknown relative ages. It generally consists of individual faults formed during two or more deformational events (Fig. 17).
3.9.7.2 Fault complex, like fault zone, fault set and fault system ranks next above fault.
3.9.7.3 No limitations are placed on the extent of a fault complex beyond those which are related to the individual component faults.
3.9.7.4 The structure is mappable with the help of geomorphological, geological and/or geophysical methods.
3.9.7.5 A fault complex generally consists of faults having different structural character (see Section 3.9.4.5).
3.9.7.6 A fault complex should preferably be formally defined and named, this being done in accordance with the "general rules for naming and defining geological units" (Chap. 2) and the provisions of Section 3.9.1. The proper name (Section 2.2.2) is placed between the words "the ... Fault Complex" in the compound name.
3.9.7.7 Individual faults in a fault complex may be formed under different physical conditions and when stress fields have different orientations. A fault complex may therefore contain normal, lateral and reverse faults, and also faults having structural elements from all these three main types. Repeated fault movements along older fracture zones may give rise to a fault complex.
3.9.7.8 Examples: Gabrielsen & Robinson (1984) defined the Kristiansund--Bodø Fault Complex on the continental shelf off central Norway. The Ringvassøy--Loppa Fault Complex (Gabrielsen et al. 1984) is located on the continental shelf off Troms and Finnmark. The Trollfjord--Komagelv fault zone is also an example of a complex since the "zone" contains fault segments of different age (Gabrielsen 1984).
3.9.7.9 Key reference: Bates & Jackson (1980), but with the modification that a fault complex does not include fault sets of the same age (see fault system, below).
