Field work on marble and calc-silicate rocks in the Nordre Strømfjord region

Abstract

As a member of the group working in the Agto-Nordre Strømfjord area (see Bondesen, this report) the writer studied and collected from the extensive outcrops of marble and associated calc-silicate rocks which occur in the region, especially around Nordre Strømfjord. Ramberg (1949) divided the Nagssugtoqidian fold belt in this region into the Isortoq Complex and the Egedesminde Complex, the first characterised by granulite facies metamorphism and the latter by amphibolite facies. K. Sørensen (personal communication) has indicated that a metamorphic gradient exists in the Isortoq Complex from the north to the south in the western part of the Agto sheet area, as seen by the increasing amount of orthopyroxene in the basic rocks. The field data obtained on the calcareous rocks can be correlated with this scheme although a detailed study is necessary.