Neoproterozoic and Cambrian arc magmatism along the eastern margin of the Victoria Lake Supergroup: A remnant of Ganderian basement in central Newfoundland?

A Review of Proterozoic to Early Paleozoic Lithotectonic Terranes in New Brunswick, Canada and their Tectonic Evolution during Penobscot, Taconic, Salinic and Acadian Orogenesis

“…4). The presence of these quartz-rich sedimentary rocks across the region from Panel A in the southwest to Panel C in the northeast suggests that Neoproterozoic to earliest Cambrian arc activity on Gondwana was followed by a period of magmatic quiescence and deposition of an Early Paleozoic passive-margin sequence (Rogers et al 2006).…”

Lithostratigraphic and structural reconstruction of the Zn-Pb-Cu-Ag-Au Lemarchant volcanogenic massive sulphide (VMS) deposit, Tally Pond group, central Newfoundland, Canada

“…Furthermore, the rocks at the Lemarchant area do not exhibit a continuous 551 spectrum of magmatic products, features common in most "arc" environments (e.g., 552 Tatsumi and Eggins, 1995), but rather are bimodal to trimodal in nature, features 553 commonly observed in rifted arc environments (e.g., Vivallo andClaesson, 1987, Wright 554 et al, 1996), and consistent with regional tectonics models (e.g,. Rogers et al, 2006;555 Zagorevski et al, 2010;Piercey et al, 2014). However, it should be noted that some areas 556 of the Tally Pond group (e.i., West and South Tally Pond zones) exhibit a continuous 557 spectrum of magmatic products fractionation (Pollock 2004).…”

“…The Tally Pond group is underlain by the 563 Ma Sandy Brook group, which 571 consists of rhyolite, andesite and basalt (tholeiitic and calc-alkaline), and minor 572 siliciclastic rocks, including black shale and chert horizons (Rogers et al, 2006). These 573 rocks have evolved Nd isotopic signatures (εNd 563Ma from −5.18 to −0.67) and are 574 interpreted to have formed within a continental arc environment (Rogers et al, 2006;575 Zagorevski et al, 2010).…”

“…These 573 rocks have evolved Nd isotopic signatures (εNd 563Ma from −5.18 to −0.67) and are 574 interpreted to have formed within a continental arc environment (Rogers et al, 2006;575 Zagorevski et al, 2010). Evidence of relatively young, but evolved crust beneath the 576…”

“…However, they argue that the Tally Pond volcanic arc was 589 built on the Ganderian microcontinent (Sandy Brook group -Crippleback Intrusive Suite 590 crust) and not in an oceanic setting as proposed by Dunning et al (1991). Based on Nd 591 isotopes, Rogers et al (2006) proposed that the Tally Pond belt formed from 60% 592 juvenile depleted mantle and 40% recycling of older crust. In contrast, Zagorevski et al 593 (2010) hypothesised that the arc signature of the Tally Pond belt was the result of 594 eastward subduction creating local arc volcanism within a greater extensional back-arc 595 complex in which the magmatic front migrated westward with time due to slab rollback.…”