Adamsfjord og Ul'lugai'sa. Beskrivelse til de berggrunngeologiske kart 2135 I og 2135 II - M 1:50 000 (med fargetrykt kart).

Abstract

Descriptions are presented of the different rock-types occurring in either autochthonous or allochthonous position within the confines of these two map-sheets. Five principal geological or tectonostratigraphical elements are recognized in the area, from south to north: (1) Precambrian crystalline basement, (2) the autochthonous Dividal Group, (3) the Gaissa Nappe, (4) the Laksefjord Nappe Complex, and (5) the Kalak Nappe Complex. Unit 1, the Precambrian crystalline basement, comprises three distinctive complexes of rocks with metamorphic ages ranging from c. 2500 to c. 1900 Ma; (i) garnetiferous granulite-facies gneisses, (ii) banded gneisses, and (iii) a complex consisting of quartzdiorite and granodiorite. The second unit, the Dividal Group, consists in this area of max. 50 m of Vendian conglomerates, sandstones, siltstones and shales lying unconformably upon a slightly northward-sloping peneplain of the deeply eroded Precambrian crystallines, and truncated at its top by the Gaissa Thrust. The Gaissa Nappe comprises the stratigraphies of the Tanafjord and Vestertana Groups, ranging in age from latest Riphean to lowermost Cambrian. Lithologies are varied; mostly quartzitic sandstones, siltstones and shales in the Tanafjord, and diamictites, sandstones and subordinate shales in the Vestertana.