Abstract
The rocks of the Ammassalik area comprise reworked Archaean gneisses and a variety of mainly pelitic to psammitic Proterozoic metasediments. Proterozoic deformation caused thrust intercalation of the rocks and folded them into overturned, southerly directed nappes. Three dioritic centres, collectively named the 'Ammassalik Intrusive Complex' in this paper, were emplaced into a tract occupied by metasediments, causing extensive anatexis. The granitic liquids produced from this resulted in magma mixing with the still liquid diorite; they also formed discrete sheets of augen granite intruding the country rocks. The diorite centres were emplaced as relatively dry bodies, and together with anatexis, they caused the formation of granulite facies assemblages by dehydration reactions in the country rocks. Further away from the contact zone garnet appeared in the surrounding grey gneisses.
Highlights
The central part of the early Proterozoic mobile belt of East Greenland (Bridgwater & Myers, 1979) is dominated by an WNW-trending zone of orthopyroxenebearing intrusive rocks of mid-Proterozoic age (1886 ± 2 Ma, Hansen & Kalsbeek, this volume) flanked by heterogeneous garnet gneisses (Wright et al, 1973)
Collectively named the 'Ammassalik Intrusive Complex' in this paper, were emplaced into a tract occupied by metasediments, causing extensive anatexis
The granitic liquids produced from this resulted in magma mixing with the stillliquid diorite; they forrned discrete sheets of augen granite intruding the country rocks
Summary
The central part of the early Proterozoic mobile belt of East Greenland (Bridgwater & Myers, 1979) is dominated by an WNW-trending zone of orthopyroxenebearing intrusive rocks of mid-Proterozoic age (1886 ± 2 Ma, Hansen & Kalsbeek, this volume) flanked by heterogeneous garnet gneisses (Wright et al, 1973). Together they form an approximately 30 km wide belt which runs from the Inland lce south of Johan Petersen Fjord, east-southeast across the southern part of Angmagssalik ø and on to Kulusuk and the southern part of the islands to the north Studies of these rocks and the adjacent gneiss complex by a team from Birmingham University (Wright et al, 1973) and later by GGU teams (Bridgwater et al, 1978a; Bridgwater & Myers, 1979) were the starting point for the work reported here
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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 callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
