Abstract
Two alkaline igneous complexes and three lines of diatreme breccias were emplaced in the East Arm of Great Slave Lake during the lower Proterozoic. Field relationships suggest that those rocks are broadly cogenetic and were emplaced about 2.1 Ga ago.One of the intrusions, the Easter Island dyke, was rotated subsequent to emplacement such that both top and bottom are now exposed. Field and petrographic data are indicative of progressive differentiation along (i.e., up) the dyke and are substantiated by chemical data. The differentiation history of the early gabbros of the Blachford Lake complex is similar. Late differentiates of both complexes closely resemble the igneous matrices of the breccias and petrographic and chemical data support the proposal of cogenesis and contemporaneity.The field data show that there was a period of significant faulting and concomitant alkaline igneous activity in the East Arm area in the lower Proterozoic.
Publisher
Canadian Science Publishing
Subject
General Earth and Planetary Sciences
Cited by
5 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
1. The petrology and geochemistry of intrusive alkaline rocks of Elchuru, Prakasam District, Andhra Pradesh, India;Geological Journal;2007-04-30
2. Archaean orogenic ultrapotassic magmatism: an example from the southern Abitibi greenstone belt;Precambrian Research;1991-07
3. Lower Proterozoic red beds, evaporites and secondary sedimentary uranium deposits from the East Arm, Great Slave Lake, Canada;Journal of the Geological Society;1984-03
4. Rb–Sr isochron ages, magmatic 87Sr/86Sr initial ratios, and oxygen isotope geochemistry of the Proterozoic lava flows and intrusions of the East Arm of Great Slave Lake, Northwest Territories, Canada;Canadian Journal of Earth Sciences;1982-02-01
5. Petrochemistry of late Aphebian (~ 1.8 Ga) calc-alkaline diorites from the East Arm of Great Slave Lake, N.W.T., Canada;Canadian Journal of Earth Sciences;1981-06-01