Abstract:
The Jutulrora and Roerkulten tabular granite intrusions in the Maud Terrane, western Sverdrupfjella have ages of ca. 1085 Ma, marginally younger than the 1140 Maarcrelated tonalitic Jutulrora Formation gneiss they intrude. Unlike the tonalitic Jutulrora Gneiss, which has Paleoproterozoic-Archean Nd TDm ages, the Jutulrora and Roerkultengranites have Nd TDm ages, Hf TDm ages and εNd 1080Ma and Sr initial 1080Macharacteristics comparable to the on-craton ca. 1110 Ma Borgmassivet Suite, correlatedwith the Umkondo Large Igneous Province. The Brekkerista Granite has an Archaean age of ca. 2850 Ma and has Archaean Nd TDm and Hf 2 stage TDm zircon ages of ca.3100 and 3300 Ma respectively. These ages and chemistry of these granites, previously assumed to be Mesoproteroic in age and related to the continental arc setting of the Maud Belt, confirm the existence of Archaean age crust underlying the Maud Belt in Sverdrupfjella and additionally suggest that the 1080 Ma granite sheet magmatism inthe Maud Belt may be related to the intracratonic ca. 1105 Ma Umkondo Large Igneous Province, rather than the marginally older ca. 1140 Ma arc accretionary settingpreviously inferred.
On reconstruction of Gondwana, the ca. 2850 age of the BrekkeristaGranite is similar to ages from the Pietersburg block of the northern Kaapvaal Craton. Incontrast the ca. 3100 Ma age of the Annandagstoppane Granite is comparable togranites from the Barberton block of the southeastern Kaapvaal Craton in South Africa.