Paper No. 198-3
Presentation Time: 2:00 PM
PANNOTIA: EVIDENCE FOR ITS EXISTENCE AND THERMAL LEGACY (Invited Presentation)
MURPHY, J. Brendan1, NANCE, R. Damian2, CAWOOD, Peter A.3, COLLINS, William J.4, DAN, Wei5, DOUCET, Luc S.6, HERON, Philip J.7, LI, Zheng-Xiang6, MITCHELL, Ross8, PISAREVSKY, Sergei6, PUFAHL, Peir K.9, QUESADA, Cecilio10, SPENCER, Christopher J.11, STRACHAN, Rob A.12 and WU, Lei13, (1)Department of Earth Sciences, St. Francis Xavier University, Box 1623, Nova Scotia, Antigonish, NS B2G 2W5, Canada, (2)Department of Geological Sciences, Ohio University, Athens, OH 45701, (3)Department of Earth Atmosphere and Environment, Monash University, Australia, Clayton, VIC 3000, Australia, (4)Earth Dynamics Research Group,, The Institute for Geoscience Research (TIGeR),, School of Earth and Planetary Sciences,, Perth, WA WA 6845, Australia, (5)State Key Laboratory of Isotope Geochemistry (SKLaBIG), Guangzhou Institute of Geochemistry (GIG), Chinese Academy of Sciences (CAS), Kehua Road, Tianhe District, Guangzhou, 510640, China, (6)Earth Dynamics Research Group, The Institute for Geoscience Research (TIGeR), School of Earth and Planetary Sciences, Perth, WA WA 6845, Australia, (7)Department of Earth Sciences, Durham University, Durham, DH1 3LE, United Kingdom, (8)State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China, (9)Geological Sciences and Geological Engineering, Queen's University, 36 Union St, Miller Hall, Kingston, ON K7L3N6, Canada, (10)Instituto Geológico y Minero de España, and Facultad de Geológicas; Universidad Complutense de Madrid, 23 Rios Rosas, Madrid, 28003, Spain, (11)Department. of Geological Sciences & Geological Engineering, Queen's University, 36 Union St, Miller Hall, Kingston, ON K7L 3N6, Canada, (12)School of Earth and Environmental Sciences, University of Portsmouth, Burnaby Building, Burnaby Road, Portsmouth, PO1 3QL, United Kingdom, (13)Department of Earth and Planetary Sciences, McGill University, 3450 Rue University, Montréal, QC H3A 0E8, Canada
The status of Pannotia as an Ediacaran supercontinent, or even its mere existence as a coherent large landmass, is controversial. The effect of its hypothesized amalgamation is generally ignored in mantle convection models claiming the transition from Rodinia to Pangaea represents a single supercontinent cycle. We apply three geodynamic scenarios to Pannotia amalgamation that are tested using regional geology. Scenarios involving quasi-stationary mantle convection patterns are not supported by the geological record. A scenario involving feedback between the supercontinent cycle and global mantle convection patterns predicts upwellings beneath the Gondwanan portion of Pannotia and the arrival of plumes along the entire Gondwanan (but not Laurentian) margin beginning at c. 0.6 Ga. Such a scenario is compatible with regional geology, but the candidates for plume magmatism we propose require testing by detailed geochemical and isotopic studies. If verified, this scenario could provide geodynamic explanations for the origins of the late Neoproterozoic and Early Paleozoic Iapetus and Rheic oceans and the terranes that were repeatedly detached from their margins.
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