ON THE AGE OF THE ILlMAUSSAQ AND IGALIKO INTRUSIONS IN THE GARDAR PROVINCE OF SOUTHERN GREENLAND

• Main Authors: V. I. Gerassimovsky, N. I. Stupnikova, S. I. Zykov, S. I. On
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Greenland; Ura; Igaliko; Narssaq
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.566.9210; http://2dgf.dk/xpdf/bull19-02-224-226.pdf

A sample of well crystallised zircon from a pegmatite at Nars-sårssuk near Igaliko, South Greenland, has been dated by ura-nium-lead methods. Although the sample has suffered loss of uranium a probable age of 1150 ± 120 m.y. has been calculated. Lead from a galena sample from a hydrothermal vein at Kvane-f jeld near Narssaq is shown to be anomalous due to the polycyclic nature of the rocks of South Greenland. During a visit to South Greenland in 1964 the firstnamed author collected a specimen of well crystallised, euhedral zircon from a pegmatite at Nars-sårssuk near the village of Igaliko, South Greenland. The pegmatite is genetically related to the Igaliko nepheline syenite intrusion of which no age determination has yet been published. An attempt has now been made to determine the age of the zircon by uranium-lead methods. The investigation also includes the measurement of the isotopic composi-tion of lead in a sample of galena from a hydrothermal vein at Kvanefjeld