Provenance of the Meguma terrane, Nova Scotia: rifted margin of early Paleozoic Gondwana

2009/01/01 by John W.F. Waldron, Chris E. White, Sandra M. Barr +2 · 11 citations
Earth and Planetary Sciences · Computer Science · #Geological and Geochemical Analysis #Paleontology and Stratigraphy of Fossils #Geochemistry and Geologic Mapping

paper · doi:10.1139/e09-004

Abstract

Detrital zircon ages from the lower part of the Late Proterozoic(?) to Middle Cambrian Goldenville Group in the Meguma terrane of Nova Scotia suggest derivation from local sources in the Avalonian and Pan-African orogens on the margins of Early Cambrian Gondwana. Samples from near the top of the group show a broader distribution, including ages back to Archean. The ε Nd data show a corresponding trend, from slightly positive in the lower Goldenville Group to highly negative in the upper Goldenville Group and overlying Upper Cambrian to Lower Ordovician Halifax Group. The trends are consistent with deposition of the lower part of the Meguma succession in a rift, in which uplifted rift-flanks were the main source of the early basin fill, whereas subsequent thermal subsidence of rift margins allowed for more widespread sediment sourcing in younger units. The rift was possibly located between Gondwana and Avalonia, and may have been the locus for separation of Avalonia from Gondwana to form part of the Rheic Ocean.

Citations

• A Middle Cambrian trilobite faunule from the Meguma Group of Nova Scotia
• The Goldenville–Halifax transition, Mahone Bay, Nova Scotia: relative sea-level rise in the Meguma source terrane
• Southeastern Atlantic Canada, Northwestern Africa, and Continental Drift

Cited by

• Devonian plutons in the eastern Meguma terrane, Nova Scotia, Canada: zircon U–Pb, Lu–Hf, and O isotopic compositions, age, and petrogenetic implications
• The age and origin of the South Mountain Batholith (Nova Scotia, Canada) as constrained by zircon U–Pb geochronology, geochemistry, and O–Hf isotopes
• Probing the composition of unexposed basement, South Portuguese Zone, southern Iberia: implications for the connections between the Appalachian and Variscan orogens
• U–Pb (zircon) ages and provenance of the White Rock Formation of the Rockville Notch Group, Meguma terrane, Nova Scotia, Canada: evidence for the “Sardian gap” and West African origin
• The evolutionary significance of a Lower Cambrian trace-fossil assemblage from the Meguma terrane, Nova Scotia
• New constraints on the timing and nature of metamorphism in the eastern Meguma terrane, Nova Scotia, Canada
• Meguma terrane orocline: U–Pb age and paleomagnetism of the Silurian Mavillette gabbro, Nova Scotia, Canada
• Conjugate shear model for emplacement of mid-crustal plutons during dextral transpression, southern Nova Scotia, Canada: tectonic and petrological consequences
• Derivation of the Early Carboniferous Wedgeport pluton by crystal fractionation of a mafic parental magma: a rare case of an A-type granite within the Meguma terrane (Nova Scotia, Canada)
• Effects of fluid flow, cooling and deformation as recorded by⁴⁰Ar/³⁹Ar, Rb–Sr and zircon fission track ages in very low- to low-grade metamorphic rocks in Avalonian SE Cape Breton Island (Nova Scotia, Canada)
• The Ouarzazate Supergroup and its plutonic keel: the relicts of an Ediacaran silicic large igneous province in North Africa

Related

• U–Pb (zircon) ages and provenance of the White Rock Formation of the Rockville Notch Group, Meguma terrane, Nova Scotia, Canada: evidence for the “Sardian gap” and West African origin
• 440 Ma igneous activity in the Meguma Terrane, Nova Scotia, Canada; part of the Appalachian overstep sequence?
• Orogenesis and Basin Development: U‐Pb Detrital Zircon Age Constraints on Evolution of the Late Paleozoic St. Marys Basin, Central Mainland Nova Scotia
• The Goldenville–Halifax transition, Mahone Bay, Nova Scotia: relative sea-level rise in the Meguma source terrane
• New constraints on the timing and nature of metamorphism in the eastern Meguma terrane, Nova Scotia, Canada