Abstract
The Tartoq Group is located in the Sermiligaarsuk fjord region in South-West Greenland in an area of approximately 20 × 50 km (Fig. 1). The Tartoq Group consists of several discrete, fault-bound blocks of metavolcanic rocks, surrounded by Archaean tonalite-trondhjemite-granodioritetype (TTG) gneisses. A zircon age of 2996.3 ± 5.9 Ma of a TTG intrusion provides a minimum age for the formation of the Tartoq Group (Fig. 2). The metavolcanic rocks probably show the lowest degree of metamorphism found anywhere in the Archaean craton of Greenland. Here we present a new model for the origin of the metavolcanic rocks of the Tartoq Group based on geochemical, metamorphic and structural data. The samples used for this study were collected by the Geological Survey of Denmark and Greenland (GEUS) in 2009 and 2010. The study is part of a joint project between the Greenland Bureau of Minerals and Petroleum and GEUS on the mineral potential of south-western Greenland.
Highlights
Geology of the Tartoq GroupThe Tartoq Group can be divided into five main lithological units: (1) subaqueous, mafic pillow lavas, (2) mafic dykes and sills with semi-ophitic textures, (3) gabbros with relict magmatic textures and tonalite-trondhjemite-granodiorite composition, (4) ultramafic rocks that are mainly serpentinites and (5) felsic schists that commonly show high strain with mylonitic textures
The Tartoq Group is located in the Sermiligaarsuk fjord region in South-West Greenland in an area of approximately 20 × 50 km (Fig. 1)
The Tartoq Group can be divided into five main lithological units: (1) subaqueous, mafic pillow lavas, (2) mafic dykes and sills with semi-ophitic textures, (3) gabbros with relict magmatic textures and tonalite-trondhjemite-granodiorite composition, (4) ultramafic rocks that are mainly serpentinites and (5) felsic schists that commonly show high strain with mylonitic textures
Summary
The Tartoq Group can be divided into five main lithological units: (1) subaqueous, mafic pillow lavas, (2) mafic dykes and sills with semi-ophitic textures, (3) gabbros with relict magmatic textures and tonalite-trondhjemite-granodiorite composition, (4) ultramafic rocks that are mainly serpentinites and (5) felsic schists that commonly show high strain with mylonitic textures. A marble unit occurs in the Nuuluk block; gneiss of quartz dioritic composition lies in a large breccia zone with intrusive tonalite-trondhjemitegranodiorite-type (TTG) gneisses that have been fractured and chloritised; and undifferentiated pegmatites are found in the Bikuben and the Iterlak blocks. The lithologies and their relations were described by Higgins (1968), Berthelsen & Henriksen (1975), Petersen (1992) and van Hinsberg et al (2010). Kilometre-scale nappes, low-angle shear zones, and younger cataclastites formed as a
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
