| Title | Preliminary geochemical results on mantle metal mobility |
| Download | Download (whole publication) |
| |
| Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
| Author | Lawley, C J M ;
Kjarsgaard, B A; Zagorevski, A; Pearson, G; Waterton, P; Savard, D; Jackson, S E; Yang, Z; Zhang, S; Tschirhart, V |
| Source | Targeted Geoscience Initiative: 2017 report of activities, volume 1; by Rogers, N (ed.); Geological Survey of Canada, Open File 8358, 2018 p. 127-131, https://doi.org/10.4095/306445  Open Access |
| Year | 2018 |
| Publisher | Natural Resources Canada |
| Document | open file |
| Lang. | English |
| Media | on-line; digital |
| Related | This publication is contained in Targeted Geoscience
Initiative: 2017 report of activities, volume 1 |
| File format | pdf |
| Province | British Columbia; Ontario |
| NTS | 32D; 32E; 104J; 104K; 104N; 104O |
| Area | Atlin; Kirkland Lake |
| Lat/Long WENS | -134.0000 -130.0000 60.0000 58.0000 |
| Lat/Long WENS | -80.0000 -80.0000 48.5000 48.0000 |
| Subjects | economic geology; igneous and metamorphic petrology; geochemistry; mineralogy; mineral deposits; mineral potential; mineral exploration; ore controls; ore mineral genesis; gold; nickel; copper; base
metals; mantle; ophiolites; kimberlites; inclusions; host rocks; source rocks; isotopic studies; lead isotope ratios; clinopyroxene; olivine; electron probe analyses; mass spectrometer analysis; scanning electron microscope analyses; spectroscopic
analyses; bedrock geology; lithology; igneous rocks; intrusive rocks; granites; tonalites; ultramafic rocks; Canadian Cordillera; Cache Creek Terrane; Canadian Shield; Superior Province; Abitibi Subprovince; Kirkland Lake Kimberlite Field; Blake
River Group; Tisdale Group; Kidd-munro Assemblage; Phanerozoic; Mesozoic; Precambrian; Proterozoic |
| Illustrations | location maps; geoscientific sketch maps; photographs; photomicrographs |
| Program | Targeted Geoscience Initiative (TGI-5) Knowledge Management Coordination |
| Program | Targeted Geoscience Initiative (TGI-5) Gold systems |
| Released | 2018 01 19 |
| Abstract | Processes operating within mantle source regions likely impact the fertility of ore-bearing melts, although the precise link between mantle conditioning and ore genesis remain poorly understood. New
fieldwork and isotopic (Re-Os and Pb-Pb) results for ultramafic samples from young (Mesozoic), ophiolitic mantle near Atlin British Columbia, document ancient (i.e. Paleoproterozoic and younger), refractory mantle domains hosted within variably
depleted harzburgite. The metal endowment of these distinct mantle segments and the microscale distribution of gold, platinum group elements and base metals are the focus of on-going study.
Field-based research at Atlin complements chemical
analysis of kimberlite-hosted mantle olivine and clinopyroxene xenocrysts. These mantle fragments provide a snapshot of the ancient, sub-continental lithospheric mantle beneath the Neoarchean Abitibi sub-province (Kirkland Lake kimberlite field).
Geochemical depth profiles, based on preliminary in situ geochemical results of the least-altered xenocrysts, suggest that high temperature olivine is a significant silicate mineral host for some of the so-called chalcophile elements at depth (e.g.
Cu and Zn). Other metals, including a rare subset of xenocrysts that yield concentrations for gold and platinum at or above the analytical detection limit (1-5 ppb), occur as micro-inclusions. The distribution of metal-bearing mineral phases within
the mantle and, the micro-scale setting of metals within those phases (e.g. mineral inclusions versus lattice substitution), may control the variable metallic endowment of mantle-derived melts in ancient and modern settings. |
| Summary | (Plain Language Summary, not published)
The Targeted Geoscience Initiative (TGI) is directed towards providing next generation knowledge and methods to facilitate more effective targeting of
buried mineral deposits. The program aims to enhance the effectiveness of exploration for Canada¿s major mineral systems by resolving foundational geoscience problems that constrain the geological processes responsible for the liberation metals from
their source region, transportation of these ore metals and control their eventual deposition. TGI supports projects on gold, Ni-Cr-PGE, porphyry-style mineralization, uranium and volcanic- and sedimentary-hosted base metal mineralization ore
systems, with each project divided into subprojects focused on resolving specific knowledge gaps by integrating data and studies from multiple sites across Canada. Herein, we present interim results and interpretations from a selection of the
research activities currently being conducted under the auspices of TGI. |
| GEOSCAN ID | 306445 |
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