Petrochemical work on the Precambrian lavas, Eriksfjord Formation, South Greenland

Abstract

The lavas of the Ilímaussaq Volcanic Member of the sandstone-volcanic Eriksfjord Formation (Stewart, 1964; Poulsen, 1964) can be subdivided into an upper Porphyry Division (> 600 m) consisting mainly of trachytic rocks and a lower Basalt Division (230-700 m). To the south-west of the Ilimaussaq alkaline intrusion, the Basalt Division is markedly thinner (Stewart, 1964). During field work in 1970 samples of the volcanics were collected for petrochemical analysis. This report summarises the state of the subsequent laboratory work. Forty-two major and trace element analyses have been made of the lavas. For norm calculation the Fe₂O₃/FeO ratios were corrected to 0.15. There are no signs of fenitisation in the examined rocks except in those collected from dose to the Ilímaussaq intrusion.