3.8.3 Lineament Zone (Lineamentsone)
3.8.3.1 A lineament zone consists of several, geometrically closely associated lineaments occurring within a long, narrow geographical area. The lineaments in the zone may be genetically associated with one another, but this is not a prerequisite.
3.8.3.2 A lineament zone is a linear unit ranking next above a lineament.
3.8.3.3 The breadth of a lineament zone is defined by the outermost lineaments in the zone. No other limitations are placed on the extent of a lineament zone.
3.8.3.4 The zone is mappable with the help of geomorphological, geological and/or geophysical methods. The degree of detail in the cartographical presentation of a lineament zone will depend upon the map scale and the information available.
3.8.3.5 A lineament zone can consist of several segments of different origin or geometry. The segments may form part of a continuous or discontinuous lineament zone (Fig. 15).
3.8.3.6 Lineament zones are given informal or formal names in accordance with the "general rules for naming and defining geological units" (Chap. 2) and the provisions of Section 3.8.1. The information that enables the lineament zone to be recognized can be indicated by a descriptive term such as "photolineament zone", and "gravimetric lineament zone". A lineament zone can be redefined when the geological origin of the structure is shown to be, for example, surface traces of a fracture zone, joint zone or fault zone. When a formal lineament zone is redefined, the proper name originally given to the zone can be retained (Section 2.5.1).
3.8.3.7 Lineament zone corresponds to features which El-Etr (1976) called "linear set" and "linear master set", and should be used in preference to those terms.
3.8.3.8 Examples: Hobbs (1904, 1911) referred to Kjerulf's (1876, 1879) linear structural elements in South Norway as lineaments, e.g. "Christiania lineament". Gabrielsen & Ramberg (1979) called this "the Oslo--Trondheim intensity zone", but here it is renamed the Oslo--Trondheim lineament zone. Other examples based on Gabrielsen & Ramberg (1979) are the Møre--Trøndelag lineament zone and the Agder lineament zone.
3.8.3.9 Key reference: Hobbs (1904) described lineament zones, but did not use the term himself.
