3.7.7 Horst (Horst)
3.7.7.1 A horst is an elongate, relatively uplifted, fault block bounded by parallel or nearly parallel faults along its flanks. It is a structural form element which need not necessarily be, or have existed as, a landform (Figs. 9, 10).
3.7.7.2 Horst is a genetical term for a positive structural form element. Every horst is a structural high.
3.7.7.3 No limitations are placed on the dimensions of a horst.
3.7.7.4 Horsts are mappable with the help of geomorphological, geological and/or geophysical methods.
3.7.7.5 A horst may be an isolated, independent form element, but may also constitute part of a larger geomorphological and/or structural feature. Horsts may frequently be divided into smaller form elements.
3.7.7.6 A horst can be formally or informally named in accordance with the "general rules for naming and defining geological units" (Chap. 2) and the rules for naming geological form units (Section 3.7.1). In formal compound names, a proper name (Section 2.2.2) is placed between the words "the ... Horst".
3.7.7.7 The term horst is to be preferred to ridge when it is established that the structural feature is bounded by faults along its flanks.
3.7.7.8 Examples: The Halibut Horst (Kent 1975) is a buried horst in the North Sea. Solbergåsen in Hedmark county (Skjeseth 1963) is a horst of basement rocks brought to the surface by erosion, separated by parallel faults from Cambro-Silurian rocks. Nesodden in Oslofjord forms a long, narrow, triangular fault block of basement, elevated in relation to surrounding rocks. The Nesodden Block can be looked upon as an eroded horst whose flanking faults are not completely parallel.
3.7.7.9 Key reference: Bates & Jackson (1980).
