3.8 Linear structural units
3.8.1 General properties and rules
Linear structural units include all large and small structures which have properties resembling a line. It is not relevant to give small lineations in a rock (e.g. parallel-oriented mineral grains, slickensides and fold axes) a proper name, and these will not be dealt with here. Linear structural units also include major, straight or curved structures which stand out because of special features in the bedrock and landscape, and which can be clearly seen on satellite photographs, aerial photographs or maps. Such linear elements may originate from surface traces of various planar- or linear-shaped structures and crustal features (Figs. 14, 15). When they are recorded, their origin may often be unknown, uncertain, only partially clarified, or mixed. These types of structure are recorded by one or more remote sensing (fjernanalyse) methods and are grouped under the term "lineaments" (lineamenter). Increasing use of remote-sensing techniques in recent years has created a need for a uniform terminology for lineaments. The units in this category are lineaments and lineament zones.
Nomenclature
Names are applied in accordance with the "general rules for naming and defining geological units" (Chap. 2). It is recommended that only the most prominent lineaments and lineament zones are defined formally and given formal proper names. The proper name component of the formal name should consist of either one geographical name or two geographical names joined by a dash. These two names should be chosen from places situated close to the extremities of the structure (see Section 2.2.3). On the continental shelf, other names than geographical ones may be used (Section 2.2.4). The lineament structure can be redefined when its mode of formation has been clarified (Section 2.5.1).
