Mesoproterozoic dykes in the Timmiarmiit area, Southeast Greenland: evidence for a continuous Gardar dyke swarm across Greenland’s North Atlantic Craton
| Autor: | Martin B. Klausen, Mimmi K.M. Nilsson, A. Bartels, Ulf Söderlund |
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| Rok vydání: | 2016 |
| Předmět: |
geography
geography.geographical_feature_category 010504 meteorology & atmospheric sciences Proterozoic Archean Geochemistry Paleontology Geology 010502 geochemistry & geophysics 01 natural sciences Baddeleyite Craton Basement (geology) Geochronology Ice sheet Mafic Geomorphology 0105 earth and related environmental sciences |
| Zdroj: | GFF. 138:255-275 |
| ISSN: | 2000-0863 1103-5897 |
| Popis: | During the Proterozoic, several mafic dykes with variable trends and mineralogies intruded the Archaean basement of Southeast Greenland. Some of the younger ENE-trending dykes are interpreted to represent a prolongation of the Mesoproterozoic Gardar Province, and have been termed Timmiarmiit dykes. Extrapolations of their trends across the inland ice sheet coincide with the northernmost so-called brown dykes (BD’s) which are part of the Gardar Province. Baddeleyite U–Pb ID-TIMS analyses for three ENE-trending Timmiarmiit dykes give ages of 1277 ± 4, 1275 ± 3 and 1268 ± 4 Ma, which are slightly younger than the oldest (BD0 = 1284–1279 ± 3 Ma, Upton 2013) and only dated generation of dykes in the Gardar Province, and thereby indirectly provide a possible age for the two younger dyke generations (BD1 and BD2). The Timmiarmiit–Gardar correlation is strengthened by a rigorous multivariate statistical analysis, on the basis of all major and trace elements. Thus, a coherent ENE-trending trans-Greenlandic... |
| Databáze: | OpenAIRE |
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