From Rodinia to Pangea: The Lithotectonic Record of the Appalachian Region
Depositional and tectonic setting of the Neoproterozoic–early Paleozoic rocks of the Virgilina sequence and Albemarle Group, North Carolina
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Published:September 01, 2010
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Jeffrey C. Pollock, James P. Hibbard, Paul J. Sylvester, 2010. "Depositional and tectonic setting of the Neoproterozoic–early Paleozoic rocks of the Virgilina sequence and Albemarle Group, North Carolina", From Rodinia to Pangea: The Lithotectonic Record of the Appalachian Region, Richard P. Tollo, Mervin J. Bartholomew, James P. Hibbard, Paul M. Karabinos
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Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) U-Pb ages of more than 400 detrital zircons from the Neoproterozoic–early Paleozoic clastic sequences of Carolinia range from ca. 530 Ma (Early Cambrian) to ca. 2600 (Archean). The majority of analyzed zircon grains are late Neoproterozoic (Ediacaran), with minor amounts of Mesoproterozoic–Paleozoic and accessory Archean grains. The overall distribution of age populations of detrital zircons is consistent with sediment derivation from the Amazonian craton and its peripheral orogenic belts on the margin of west Gondwana. On the basis of the age of the youngest detrital zircon populations (ca. 550 Ma), the Uwharrie, Tillery, Cid, and Yadkin formations are no older than Ediacaran. The minimum depositional ages of the Uwharrie and Cid formations are constrained by ages of contemporaneous volcanism (551 ± 8 and 547 ± 2 Ma, respectively). Thus, all units of the Albemarle sequence were deposited between ca. 550 and 532 Ma. The dominance of Ediacaran and early Paleozoic zircons in the Albemarle Group suggests an underlying local protosource for the sediments. Mesoproterozoic and older detrital grains constitute a minor component and have an age signature that suggests derivation from the underlying continental crust basement. Dated samples from the Albemarle Group yield similar detrital zircon U-Pb age popu lations consistent with a common provenance. The results of this study illustrate that sedimentation in the Albemarle sequence of Carolinia is a manifestation of active tectonics and occurred broadly coeval with felsic magmatism. These relationships suggest that magmatism, tectonism, and deposition were broadly coeval and important regional-scale mechanisms consistent with formation in a late Neoproterozoic–early Paleozoic arc rift to backarc basin tectonic setting.
- absolute age
- Amazonian Craton
- back-arc basins
- basins
- Cambrian
- Carolina Terrane
- dates
- depositional environment
- Ediacaran
- Gondwana
- ICP mass spectra
- laser ablation
- laser methods
- Lower Cambrian
- lower Paleozoic
- magmatism
- mass spectra
- Neoproterozoic
- nesosilicates
- North Carolina
- orthosilicates
- Paleozoic
- Precambrian
- Proterozoic
- provenance
- sedimentation
- silicates
- South America
- spectra
- tectonics
- U/Pb
- United States
- upper Precambrian
- Vendian
- volcanism
- zircon
- zircon group
- Aaron Formation
- Cid Formation
- Tillery Formation
- Uwharrie Formation
- Albemarle Group
- Virgilina Sequence
- Yadkin Formation
- Carolinia
- Roanoke Rapids Terrane