Reconnaisance of the Tømmerås Anticline.

Abstract

A granitic basement dome, overlain with unconformity by Palaeozoic and perhaps Eocambrian rocks, is described. The flat-lying \"leptites\" and intercalated sediments, which comprise the basement, were little affected by events earlier than the Caledonian orogeny, and formed a gently-domed ridge against which the later sediments were deposited. It is probable that the Caledonian fold-pattern of northeast-trending synclines and anticlines reflects the distribution of the sedimentary basins. The relative displacement of the basement blocks upwards and the throughs downwards has been continued by the later faulting. The three main tectonic units are: 1) the Tømmerås basement anticline and its autochtonous Palaeozoic cover, which are overlain with tectonic unconformity by 2) further Palaeozoic rocks on the eastern flank of the anticline. Units (1) and (2) lie structurally above 3) the Older nappe (cf. Oftedahl, 1956), which is exposed along the median ridge of the grong culmination. After their emplacement they have been folded together into a series of southwestplunging synclines and anticlines.