3.11.5 Nappe Complex (Dekkekompleks)
3.11.5.1 A nappe complex is defined as comprising two or more nappes that are geometrically closely related to one another. The movements along the floor thrusts of the individual nappes originally took place during different deformational phases or orogenies, or are of unknown or uncertain relative ages (Fig. 27).
3.11.5.2 Nappe complex is a tectonostratigraphical unit ranking next above nappe.
3.11.5.3 A nappe complex has a regional extent, but all the individual nappes in a complex need not be present wherever it is found. In areas where the nappe complex thins, it may be represented by only one of its component nappes.
3.11.5.4 A nappe complex is mappable on the surface and traceable in the subsurface with the help of geological and/or geophysical methods.
3.11.5.5 A nappe complex usually contains several individual nappes and thrust sheets that can be distinguished from one another by their content of lithostratigraphical, lithodemic and biostratigraphical units. The nappes may be characterized by earlier and different degrees and types of deformation and metamorphism, but may have experienced one or more later and common metamorphic and deformational event(s).
3.11.5.6 A nappe complex 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 provisions of Section 3.11.1.2. It must not be given the same geographical name as a component nappe, or as any of the lithological units in it. In areas where the nappe complex becomes thin its name is retained even though the complex is only represented by a single nappe. The proper name (Section 2.2.2) is combined with the words "the ... Nappe Complex" in formal names. In informal contexts the geographical name of the nappe complex can be used together with the term "the nappes" (e.g. "the Nordland nappes" -- "Nordlandsdekkene"). Informal names of this kind which are in use may, if desired, be redefined to formal names of nappe complexes.
3.11.5.7 A nappe complex can be redefined as a nappe system when it can be shown that movement along all the thrust faults is of the same age or belongs to the same deformational event (see Section 4.8).
3.11.5.8 Examples: The Kalak Nappe Complex (Roberts 1974) was originally called the Kalak Nappe by Føyn (1967), but was subsequently termed a complex due to its structural complexity and complicated geological history (e.g. Sturt et al. 1975). The Trondheim Nappe as it was defined by Wolff (1979) will, according to this Code, be a nappe complex having the Gula and Støren Nappes as individual nappes.
3.11.5.9 Key reference: this Code.
