Rb/Sr whole rock age determinations on metavolcanic rocks from the Narssarssuaq region, South Greenland

In the area of Julianehåb granite along the south-west coast of Greeniand remnants of volcanic rocks are widespread. Well banded, intermediate tuffs occur on Mato and adjacent islands to the west of Julianehåb (Nesbitt, 1961; Allaart, 1967). Intermediate plagioclase-porphyritic rocks occur associated with aplitic gneiss north of Bredefjord. Two other important occurrences of vo1canic rocks may be found in the high mountains north of Narssarssuaq dose to the ice cap (Allaart, 1971). All four occurrences of volcanic rocks are surrounded by late Ketilidian granites. These in turn are flanked to the north-west and south-east by older, early Ketilidian granite.