Geological Results of Four Expeditions to Ubekendt Ejland, West Greenland

Résumé

Outlines petrological discoveries made in 1938, 1939, 1950 and 1957 by British expeditions to this island in the Umanak Fjord region: an abundance of magnesia-and lime-rich intrusions and lavas; a central intrusive complex in the south where acid and basic magmas co-exist; and a suite of dykes, lavas, and pyroclastic rocks on the west coast. Status of research on problems raised by these findings is reported. Discussion is included of author's investigations in 1957 of the olivine-rich rocks in the lower group of lavas and the minor intrusions cutting them. Detailed information on variations in the intrusions and on their relationship with the lavas is presented.