3.7.4 Ridge (rygg)
3.7.4.1 A ridge is a long, narrow, positive geomorphological and/or structural feature delimited from the surrounding terrain by steep sides which may be defined by faults (Figs. 10, 11).
3.7.4.2 Every ridge is a high.
3.7.4.3 No limitations are placed on the dimensions of a ridge.
3.7.4.4 The structure is mappable with the help of geomorphological, geological and/or geophysical methods.
3.7.4.5 A ridge can form an isolated, independent feature, but may also be part of a larger geomorphological and/or structural feature. It will often be possible to divide a ridge into smaller form elements.
3.7.4.6 A ridge can be given a formal or an informal name 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 the compound name, the proper name (Section 2.2.2) is placed between the words "the ... Ridge" (formal). If the ridge is known to be a geomorphological ridge, the nature of this may be indicated by a descriptive word, such as "volcanic ridge", "mid-oceanic ridge", etc. (see Section 3.7.4.7).
3.7.4.7.a A ridge that is known to be a structural ridge (strukturell rygg), but which is not delimited by faults, may be an anticline, antiform or arch.
3.7.4.7.b An ice-marginal ridge (israndrygg) is a general term in Quaternary geomorphology for a ridge formed along the margin of a glacier, irrespective of the inner construction and composition of the ridge. Ice-marginal ridges include ridge-shaped ice-contact deltas, moraine ridges and ridges of mixed origin. ("Ra" in ¥stfold and Vestfold counties is the local name for the main ice-marginal ridge of Younger Dryas age there.)
3.7.4.7.c A moraine ridge (morenerygg) is, in Quaternary geomorphology, any ridge-shaped deposit consisting largely of the superficial deposit, moraine. Such ridges may be deposited as terminal moraines and lateral moraines on land and in water, as crevasse fillings and by the pressing together of morainic material beneath glaciers.
3.7.4.7.d Esker (esker) is a morphological and/or genetical term for a ridge-shaped deposit formed in a meltwater channel in a tunnel in or at the base of a glacier, or in a crevasse in a glacier.
3.7.4.7.e A beach ridge (voll, strandvoll) is a low, often long, narrow ridge consisting of sand, gravel or shingle heaped up by waves along a shore. Beach ridges often mark former positions of relative sea level (strandlines).
3.7.4.7.f Form elements b-e can be given formal or informal names. Some examples of such features may have traditional, old-established proper names. Form elements b-e can provide a basis for morphostratigraphical classification (see Section 3.10).
3.7.4.8 Example: The Senja Ridge (Sundvor 1971) is one of several structural ridges on the Norwegian continental shelf.
3.7.4.9 Key references: Gjessing (1978), Bates & Jackson (1980).
