Title | Nd-Hf isotope geochemistry and lithogeochemistry of the Rambler Rhyolite, Ming VMS deposit, Baie Verte Peninsula, Newfoundland: evidence for slab melting and implications for VMS localization |
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Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
Author | Piercey, S J ;
Pilote, J -L |
Source | Targeted Geoscience Initiative 5: grant program final reports (2018-2020); by Targeted Geoscience Initiative Coordination Office; Geological Survey of Canada, Open File 8755, 2021 p. 201-215, https://doi.org/10.4095/328988 Open Access |
Year | 2021 |
Publisher | Natural Resources Canada |
Document | open file |
Lang. | English |
Media | on-line; digital |
Related | This publication is contained in Targeted Geoscience
Initiative 5: grant program final reports (2018-2020) |
File format | pdf |
Province | Newfoundland and Labrador |
NTS | 12H/16 |
Area | Island of Newfoundland; Baie Verte Peninsula |
Lat/Long WENS | -56.1358 -56.0397 49.9461 49.8733 |
Subjects | economic geology; geochemistry; stratigraphy; Science and Technology; Nature and Environment; mineral exploration; mineral deposits; volcanogenic deposits; sulphide deposits; gold; ore mineral genesis;
mineralization; ore controls; isotopic studies; neodymium; hafnium; lithogeochemistry; bedrock geology; lithology; igneous rocks; volcanic rocks; felsic volcanic rocks; volcaniclastics; trace element geochemistry; tectonic history; magmatism;
subduction; downgoing slab; mantle; metasomatism; models; tectonostratigraphic zones; Rambler Rhyolite; Ming Deposit; Snooks Arm Group; Appalachian Province; Baie Verte Oceanic Tract; Pacquet Complex; Phanerozoic; Paleozoic; Ordovician;
Cambrian |
Illustrations | location maps; geoscientific sketch maps; stratigraphic columns; plots; histograms |
Program | Targeted Geoscience Initiative (TGI-5) Knowledge Management Coordination |
Released | 2021 10 27 |
Abstract | New high precision lithogeochemistry and Nd and Hf isotopic data were collected on felsic rocks of the Rambler Rhyolite formation from the Ming volcanogenic massive sulphide (VMS) deposit, Baie Verte
Peninsula, Newfoundland. The Rambler Rhyolite formation consists of intermediate to felsic volcanic and volcaniclastic rocks with U-shaped primitive mantle normalized trace element patterns with negative Nb anomalies, light rare earth
element-enrichment (high La/Sm), and distinctively positive Zr and Hf anomalies relative to surrounding middle rare earth elements (high Zr-Hf/Sm). The Rambler Rhyolite samples have epsilon-Ndt = -2.5 to -1.1 and epsilon-Hft = +3.6 to +6.6; depleted
mantle model ages are TDM(Nd) = 1.3-1.5 Ga and TDM(Hf) = 0.9-1.1Ga. The decoupling of the Nd and Hf isotopic data is reflected in epsilon-Hft isotopic data that lies above the mantle array in epsilon-Ndt -epsilon-Hft space with positive ?epsilon-Hft
values (+2.3 to +6.2). These Hf-Nd isotopic attributes, and high Zr-Hf/Sm and U-shaped trace element patterns, are consistent with these rocks having formed as slab melts, consistent with previous studies. The association of these slab melt rocks
with Au-bearing VMS mineralization, and their FI-FII trace element signatures that are similar to rhyolites in Au-rich VMS deposits in other belts (e.g., Abitibi), suggests that assuming that FI-FII felsic rocks are less prospective is invalid and
highlights the importance of having an integrated, full understanding of the tectono-magmatic history of a given belt before assigning whether or not it is prospective for VMS mineralization. |
Summary | (Plain Language Summary, not published) The Targeted Geoscience Initiative (TGI) is a collaborative federal geoscience program that provides industry with the next generation of geoscience
knowledge and innovative techniques, which will result in more effective targeting of buried mineral deposits. This compendium is the result of the TGI Grant Recipients 2018-2020. |
GEOSCAN ID | 328988 |
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