Zur Geologie von Süd-west-Hinks Land (Ostgrönland 71°30’N)

Abstract

In Hinks Land the large Caledonian migmatite complex of the inner Nordvestfjord is covered, in the western part, by a conformably folded series of mesometamorphic sediments (up to 1500 m thick). This pelitic series consists mainly of garnet mica-schists, underlying, in the North, a horizon of mica quartzites and having a basal band of white marbles associated with amphibolites.

In the westernmost part, along a thrust plane, the whole comes to overlay an epimetamorphic series which contains marbles, phyllites, quartzites and probably sediments of glacial origin (varves); this series is mixed up with ophiolitic rocks inciuding spilite and tuff (Grüngestein-Marmor Serie).

The epimetamorphic series corresponds, as presumed by WENK (1961), to the parautochthonous ‘marble chlorite-phyllite series’ in Gaaseland (south-western part of Scoresby Sund) which covers, together with irregularly distributed basal tillite deposits, the ‘Archaean’ basement representing thus the lowest horizon of the Groenlandian. The same series is shown to be in all probability also an equivalent to the marble amphibolite band at the base of the series which covers the migmatite; together with the garnet mica-schists and the mica quartzites it forms a sequence characteristic for the lowest Groenlandian in Gaaseland and in the type section of the Petermanns Bjerg.

Based on these stratigraphic relations, the Caledonian migmatites of Hinks Land evidently represent rejuvenated and reworked ‘Archaean’ basement rock.