Open AccessNd and Sr isotope compositions from the Gardiner Complex, East Greenland Tertiary igneous province
Author(s) -
Thorkild Nielsen,
Paul Martin Holm
Publication year - 1993
Publication title -
bulletin of the geological society of denmark
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.674
H-Index - 28
eISSN - 2245-7070
pISSN - 0011-6297
DOI - 10.37570/bgsd-1993-40-17
Subject(s) - geology , magmatism , basalt , geochemistry , igneous rock , mantle (geology) , carbonatite , plume , archean , precambrian , rift , paleontology , structural basin , physics , tectonics , thermodynamics
The Gardiner Complex formed during the early Tertiary opening of the North Atlantic. The complex is strongly alkaline and referred to a zone of alkaline flank magmatism 100 km west of the melting anomaly in the initial rift of the North Atlantic. Earlier investigations have documented that most rocks of the complex can be referred to three suites which are all suggested to have been formed from a single parental melanephelinitic liquid. The Nd and Sr isotope compositions presented here support this conclusion. Minor deviations are believed to be due to interaction with Archaean basement. The isotopic characteristics suggest that the alkaline magmatism originated in a source similar to that of the contemporaneous picritic and basaltic tholeiites. The isotopic composition of the source is Jess depleted than pervalent mantle (PREMA) and sets an upper enrichment limit to the composition of the Icelandic plume component 50 Ma ago.