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Quaternary geology fIeldwork, including till sampling and ice-flow-indicator mapping, was conducted over a portion of the buried Fox River greenstone belt in northeastern Manitoba (NTS 53M15, 16; parts of 53N13, 54C4, 54D1). This follow-up to 2020 fIeldwork included visits to 143 field sites to ground-truth the surficial geology mapping, collect till samples and identify ice-flow indicators. Sixty-five 2 kg till samples were collected for geochemical (<63 um size fraction) and clast-lithology (2-8 mm size fraction) analyses in 2022. At 40 of these sample sites, an additional 11.4 L was collected for heavy mineral analysis (magmatic or metamorphosed massive-sulphide-indicator minerals, kimberlite-indicator minerals and visible gold). Sediment cover in the area varies from 0 m, along some river beds, to at least 60 m, as indicated by drillholes in the study area. The study area is draped by a light-coloured diamict with a sandy-silt or silty-sand matrix. A darker-coloured and finer-textured diamict, with a crumbly or blocky texture, can also be found at surface. At six mapping sites, older buried tills, which are denser than the overlying diamicts, blocky with oxidation rinds on joints, darker-coloured and usually finer-grained, were also identified. Most parts of the study area are covered by a veneer of glaciolacustrine clay or silt (0.1 to ~1.0 m thick), though thicker glaciolacustrine deposits were observed (up to 1.5 m). A proglacial lake washed the existing substrate, commonly to depths of 0.6 m. Consequently, till samples collected for drift exploration purposes must be taken at depth to avoid sampling till that has been washed of fines and/ or leached of water-soluble elements and/or sampling displaced material. Paleo-ice flow was interpreted from both erosional field-based ice-flow indicators (total of seven sites) and till fabrics (total of 13 sites). The till-fabric interpretations suggest young south- to south- southwest-trending ice flow (170-215°), west-trending ice flow (283°) and either a northwest- or southeast-trending ice flow (300-334° or 120-154°). Older ice-flow phases were oriented to the northwest-southeast (bimodal, twice), west (twice), southwest, south-southwest and south. The study area is covered by erosional streamlined landforms, which trend toward the southwest (215-245°) and were formed by the deglacial Hayes Lobe of the Laurentide Ice Sheet. [ABSTRACT FROM AUTHOR]

In 2021, the Manitoba Geological Survey resumed its multiyear bedrock mapping project in the Paleoproterozoic Lynn Lake greenstone belt. The mapping took advantage of outcrops exposed by bush fire east of Ralph Lake to investigate a volcano-sedimentary sequence of the Wasekwan group and overlying sedimentary rocks of the Ralph Lake and Zed Lake groups, the unconformity between them, and pre- to post-Sickle granitoid intrusions. Part of the Wasekwan group supracrustal rocks is well exposed in the burned area and, from the base to top, consists of heterolithic volcanic breccia, tuff breccia, lapillistone, lapilli tuff, tuff and plagioclase-phyric basalt to massive basalt and pillow basalt, as well as associated gabbroic intrusions. This volcanic sequence, cut by pre- and post-Sickle granitoid intrusions, is overturned and unconformably overlain by sediments of the Ralph Lake and Zed Lake groups. These sedimentary rocks are cut by a two-mica granite intrusion of the late intrusive suite. The pre- and post-Sickle intrusions are characterized by high magnetic-susceptibility (MS) values of up to 53.2×10-3 SI, and are typical of volcanic-arc I-type and adakite-like granitoids, respectively. The two-mica granite, displaying the lowest MS value (0.054×10-3 SI) in the area, is S type and was emplaced into a collisional setting. The unconformity between the Ralph Lake and Zed Lake sediments and the Wasekwan supracrustal rocks reflects a tectonic event likely linked to regional extension resulting from orogen relaxation and/or collapse triggered by slab roll-back, which may have created the synorogenic basin(s) that received sediments derived from the surrounding greenstone belt, forming the polymictic conglomerate, greywacke, psammite and siltstone. The greywacke to siltstone is characterized by porphyroblastic hornblende and muscovite (±garnet), together with hornblende-bearing matrix of the polymictic conglomerate, indicating middle amphibolite-facies metamorphism. The pre-Sickle granitoid rocks, post-Sickle adakite-like granitoid rocks and late intrusive granite suites were emplaced into the supracrustal sequences, recording tectonic evolution from volcanic arc through extension induced by slab roll-back to terminal collision. More importantly, ore fluids related to adakite-like magmatism could be important for Au mineralization, so the adakite-like granitoids may serve as an indicator for Au exploration in the belt. Furthermore, the occurrence of late S-type granite cutting the Zed Lake greywacke suggests 1) emplacement in a collisional setting and potential association with rare-metal mineralization (e.g., Li, Cs, Ta), and 2) location of the boundary between the Lynn Lake greenstone belt and Southern Indian domain. [ABSTRACT FROM AUTHOR]

Quaternary geology fieldwork, including till sampling and ice-flow-indicator mapping, was conducted over a portion of the buried Fox River greenstone belt in northeastern Manitoba (NTS 53M15, 16). Field sites were visited to ground-truth the surficial geology mapping, collect till samples and identify ice-flow indicators. Eighty-nine 2 kg till samples were collected for geochemical (<63 µm size-fraction) and clast-lithology (2-8 mm size-fraction) analyses. An additional 59 till samples (11.4 L each) were collected for kimberlite-indicator-mineral analysis. This work was completed during year one of a two-year project. Paleo-ice-flow indicators were documented at 14 sites, from both erosional field-based ice-flow indicators and till fabrics. The till-fabric interpretations suggest young south- to south-southwest-trending ice flow (180-200°) and either a northwest- or southeast-trending ice-flow (300-320° or 120-140°). Older ice-flow phases were oriented to the northwest, northwest-southeast (bimodal, possibly twice), west (twice) and southwest. The study area is covered by erosional streamlined landforms, which trend toward the southwest (~245°) and were formed by the deglacial Hayes Lobe of the Laurentide Ice Sheet. Parts of the study area are covered by a veneer of glaciolacustrine clay or silt (0.1 to ~1.0 m thick), though thicker glaciolacustrine deposits were observed (up to 1.5 m). Till varies in thickness from 0.1 to 14.0 m; thicker quaternary sediment packages are possible. [ABSTRACT FROM AUTHOR]

The article reports on the announcement of the International Mineralogical Association Commission on New Minerals that it has accepted the novel mineral tredouxite which was discovered in the Bon Accord Ni-oxide deposit of the Barberton greenstone belt in South Africa. The tredouxite was reportedly found by Luca Bindi, married couple Federica Zaccarini and Giorgio Garuti, and Ducan Miller. It also offers information on the Bon Accord body which was extracted in the 1920s.