Timing and origin of magmatism in the Sverdrup Basin, Northern Canada-Implications for lithospheric evolution in the High Arctic Large Igneous Province (HALIP)

Six new U-Pb and four 40Ar/ 39Ar ages of mafic lavas and intrusive sheets range from 120.9 +/- 0.9 Ma to 78.4 +/- 0.1 Ma, which is within the published timespan of the HALIP. The U-Pb ages are the first analyzed from the mafic intrusions of Axel Heiberg and Ellesmere Islands. The new geochronology, combined with all recently (post-2000) published ages, detail a > 50 Myr duration of magmatism (128 to 77 Ma) with three main pulses. Tholeiites dominate the first 25 Myr while the latter 25 Myr consisted of coeval emplacement of alkali and tholeiitic basalts. Six new U-Pb and four 40Ar/ 39Ar ages of mafic lavas and intrusive sheets range from 120.9 +/- 0.9 Ma to 78.4 +/- 0.1 Ma, which is within the published timespan of the HALIP. The U-Pb ages are the first analyzed from the mafic intrusions of Axel Heiberg and Ellesmere Islands. The new geochronology, combined with all recently (post-2000) published ages, detail a > 50 Myr duration of magmatism (128 to 77 Ma) with three main pulses. Tholeiites dominate the first 25 Myr while the latter 25 Myr consisted of coeval emplacement of alkali and tholeiitic basalts. Six new U-Pb and four 40Ar/ 39Ar ages of mafic lavas and intrusive sheets range from 120.9 +/- 0.9 Ma to 78.4 +/- 0.1 Ma, which is within the published timespan of the HALIP. The U-Pb ages are the first analyzed from the mafic intrusions of Axel Heiberg and Ellesmere Islands. The new geochronology, combined with all recently (post-2000) published ages, detail a > 50 Myr duration of magmatism (128 to 77 Ma) with three main pulses. Tholeiites dominate the first 25 Myr while the latter 25 Myr consisted of coeval emplacement of alkali and tholeiitic basalts. Six new U-Pb and four 40Ar/ 39Ar ages of mafic lavas and intrusive sheets range from 120.9 +/- 0.9 Ma to 78.4 +/- 0.1 Ma, which is within the published timespan of the HALIP. The U-Pb ages are the first analyzed from the mafic intrusions of Axel Heiberg and Ellesmere Islands. The new geochronology, combined with all recently (post-2000) published ages, detail a > 50 Myr duration of magmatism (128 to 77 Ma) with three main pulses. Tholeiites dominate the first 25 Myr while the latter 25 Myr consisted of coeval emplacement of alkali and tholeiitic basalts.