Metamorphism in the Fiskenæsset region

Abstract

This study is based on a collection of 300 rock samples, taken on the basis of a grid consisting of equilateral triangular cells within a region of c. 4000 km2 between Grædefjord and Frederikshåbs Isblink. The localities were visited by helicopter, two samples being taken at each of 150 grid points. To promote unbiased sampling, location of the grid points in the field was left to the pilot. It was attempted to obtain two representative samples at each locality, but due to the inhomogeneity of the rocks the choice of representative samples was generally a matter of personal judgement. The collection ean therefore at best be regarded as representative for the region, but not as a random sample. No samples of the late dolerite dykes of the area were taken, with one exception, even if the sample point (landing place) was on one of these dykes. Thin sections of the 300 samples were studied. The volumetric percentages of the main minerals were visually estimated and the presence of accessory minerals was noterl. In addition, the anorthite content of the plagioclase in a number of samples was measured, the colour of the hornblende was noted and the degree of alteration of the samples was assessed.