| Title | Structural and tectonic controls on Devonian intrusion related mineralisation on the Connaigre Peninsula, Newfoundland |
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| Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
| Author | Ruberti, G; Rogers, N; Kellett, D A ; van Staal, C R; Hanchar, J |
| Source | TGI 4 - Intrusion Related Mineralisation Project: new vectors to buried porphyry-style mineralisation; by Rogers, N (ed.); Geological Survey of Canada, Open File 7843, 2015 p. 559-560, https://doi.org/10.4095/296490  Open Access |
| Links | Canadian Database of Geochemical Surveys, downloadable
files
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| Links | Banque de données de levés géochimiques du Canada,
fichiers téléchargeables
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| Image |  |
| Year | 2015 |
| Publisher | Natural Resources Canada |
| Document | open file |
| Lang. | English |
| Media | on-line; digital |
| Related | This publication is contained in TGI 4 - Intrusion Related
Mineralisation Project: new vectors to buried porphyry-style mineralisation |
| File format | pdf |
| Province | Newfoundland and Labrador |
| NTS | 1M |
| Area | Connaigre Peninsula |
| Lat/Long WENS | -56.5000 -55.0000 48.0000 47.5000 |
| Subjects | economic geology; tectonics; structural geology; porphyry deposits; porphyry copper; mineral exploration; mineralization; alteration; indicator elements; tungsten; molybdenum; tin; bismuth; mineral
deposits; structural interpretations; intrusive rocks; granitic rocks; tectonostratigraphic zones; uranium lead dates; Old Woman Stock; Paleozoic; Devonian; Silurian |
| Illustrations | location maps; plots; photographs |
| Program | Targeted Geoscience Initiative (TGI-4) Intrusion/Porphyry Ore Systems |
| Released | 2015 06 11; 2023 03 17 |
| Abstract | The Canadian Appalachians represent an archetypal ancient, accretionary orogen the study of which has played a substantial role in developing modern geological concepts. From the initial simplistic
models of a mountain belt deriving from the closure of the Iapetus Ocean, our understanding has evolved, recognising a richer, more complex geological history. Current models define multiple collisions between arcs and microcontinents due to the
closures of interposed oceans and seaways. Delineating specific tectonic events provides context to the various periods and styles of mineralisation produced, which in turn can define new exploration models for the next generation of deposits.
One
of the least understood deposit types in the Canadian Appalachians are the Devonian granitoid intrusion-related Sn-W-Mo mineralisation. The Connaigre Peninsula was selected to study such deposits as it contains a variety of supracrustal units plus
(apparently) barren and mineralised intrusives within a relatively constrained and accessible area. The distributions of the main lithotectonic packages indicate three distinct tectonic blocks that were amalgamated by the Middle Devonian, and
subsequently intruded by Upper Devonian granitoids concurrent with clastic sedimentation.
The ca. 376 Ma Old Woman Stock contains several known Mo occurrences. Molybdenite is disseminated and associated with vugs containing dog-tooth quartz, and
intense alteration zones (up to 5 cm wide) are localised along north - south to north-west - south-east trending joints. The distribution of deposits demonstrates a potential linkage between regional structures and the localisation of mineralisation.
At the large scale, the Connaigre Peninsula in the Upper Devonian is interpreted to be in extension associated with far removed non-orthogonal accretion of other peri-Gondwanan elements to composite Laurentia. It is notable however that the
mineralisation does not occur at a major fault, but rather at the intersection of a prominent north- east to south-west lineament and well-developed north - south to north-west - south-east jointing. The implication is that the high-angle
intersection of breaks that are contemporaneous with intrusion but have relatively little motion provide ideal pathways for mineralising fluids. In contrast to the Old Woman Stock, the adjacent, approximately coeval to slightly younger Belleoram
Granite is apparently barren. It remains unclear why the Belleoram Granite contains no known Sn-W-Mo mineralisation. Possible explanations include: i) its hybrid nature makes it compositionally unsuitable; ii) it formed at too shallow a crustal
depth; or iii) it was too dry and did not develop fluid pathways. |
| Summary | (Plain Language Summary, not published)
The Targeted Geoscience Initiative (TGI-4) is a collaborative federal geoscience program that provides industry with the next generation of geoscience
knowledge and innovative techniques to better detect buried mineral deposits, thereby reducing some of the risks of exploration. This volume summarises research activities completed under the TGI 4 Intrusion Related Mineralisation Project that
focused on porphyry-style ore systems related to the Cu- and Cu-Mo deposits of South-Central British Columbia and the Sn-W-Mo-In deposits in New Brunswick, Nova Scotia and Newfoundland. |
| GEOSCAN ID | 296490 |
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