Cretaceous basalts of the High Arctic large igneous province at Axel Heiberg Island (Canada): Volcanic stratigraphy, geodynamic setting, and origin. (17th January 2018)

• Record Type: Journal Article
• Authors: Dostal, Jaroslav; MacRae, Andrew
• Editors: Somerville, I.
• Is Part Of: Geological journal. Volume 53:Number 6(2018)
• Page Start: 2918
• Page End: 2934
• Publication Date: 2018-01-17
• Subjects: Canadian Arctic -- Cretaceous -- flood basalt -- large igneous province -- mantle plume -- subcontinental lithospheric mantle -- Sverdrup Basin; Geology -- Periodicals; 551
• DOI: 10.1002/gj.3132
• Languages: English
• ISSNs: 0072-1050

Abstract

Abstract : The Cretaceous (Cenomanian, ~96 Ma) basaltic rocks of the Strand Fiord Formation of the Sverdrup Basin of the Canadian Arctic Archipelago, Nunavut, Canada, are a part of the High Arctic large igneous province. The basaltic suite reaches a thickness of almost 1, 000 m on Axel Heiberg Island in its depocentre and over 700 m at the studied section. The rocks are variably fractionated tholeiitic basalts, which are geochemically similar to many other continental flood basalts, particularly to low Ti basalts of flood basalt provinces. Geochemical as well as Sr ( 87 Sr/ 86 Srinitial ~ 0.7045 to 0.7067) and Nd (ƐNd(t) ~ +1.3 to +4.3) isotopic signatures of the basalts were inherited during partial melting of spinel peridotite of an ancient subcontinental lithospheric mantle, which was modified around 0.7–0.9 Ga by a metasomatic event. The melting generating the Cretaceous basalts was probably triggered by a mantle plume but was also associated with basin rifting and stretching. There is evidence of plume‐induced doming and uplift of the crust prior to and during the eruption of the basalts as documented by the progression from marine sedimentation to subaerial/lacustrine and then back to marine sedimentation in the Sverdrup Basin centre. The basalts represent parts of the Early Cretaceous igneous province that is dispersed around the Arctic Ocean due to the opening of the Canada Basin, which is inferred to be related to a mantle plume.