NJG87-1/2-14
2007
Diagenesis and weathering of quartzite at the palaeic surface on the Varanger Peninsula, northern Norway
87
1, 2
pp. 239-251
978-82-92-39437-3

The palaeic surface of the Varanger Peninsula has been studied to evaluate formational processes and glacial remoulding. The peninsula largely consists of a plateau (the palaeic surface) where quartzite heights resembling lithostructurally controlled inselbergs, protrude above a broadly undulating surface largely developed on sandstones. The lowest parts of the palaeic landscape are mainly developed on less resistant rocks like shales, and are often in the form of broad valleys. Along lithostructurally controlled escarpments depressions often occur and pediment-like forms are seldom found. An abundance of weathered zones, probably of pre-Quaternary age, occur in the quartzites, and autochthonous blockfields up to more than 3 meters thick are extensive on quartzites and sandstones. Weathering mantles are extensive also outside the blockfields. It is suggested that differential etching and etchplanation has played an important role for the formation of the palaeic surface, but surface levels also indicate cyclic processes related to former sea levels. Large parts of the plateau show no or only limited signs of glacial erosion. The incision of V-shaped valleys reflects the changing climatic-geomorphic conditions in the late Cenozoic, the increased relief created by selective glacial erosion, and uplift. The late Cenozoic uplift is estimated to be at the most 200 meters for the Varanger Peninsula, but may be significantly less.

Jakob Fjellanger & Johan Petter Nystuen, Department of Geosciences, University of Oslo, P.O Bok 1047 Blindern, 0316 Oslo, Norway.
E-mail: jakob. This email address is being protected from spambots. You need JavaScript enabled to view it.

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