Summary:
The Seymour Lithium Asset is located within the eastern part of the Wabigoon Subprovince, near the boundary with the English River Subprovince to the north. These subprovinces are part of the Superior Craton, comprised mainly of Archaean rocks but also containing some Mesoproterozoic rocks such as the Nipigon Diabase.
Property Geology
The western part of the Property is underlain by mostly Willet Assemblage mafic volcanic-dominated rocks, with lesser units of Toronto Assemblage mafic volcanics, and minor Marshall Assemblage dacite tuffs and related sediments. The eastern part of the Property is underlain by a tonalite to granite to granodiorite pluton, thought to be the parental intrusion to the rare metal pegmatite dikes and sills exposed at the North and South Aubry showings. All Assemblages have been crosscut by felsic to mafic dikes of various ages and rock types, including the target pegmatite sills and dikes. The most volumetrically significant post-mineralization intrusive rocks are Proterozoic Nipigon mafic sills, which form the caps of the prominent “mesa-like” hills in the Lake Nipigon area (C. Jeffs 2018).
Bedrock Geology
The bedrock is best exposed along the flanks of steep-sided valleys scoured by glaciers during the recent ice ages. Glacial cover is patchy over the deposit and varies in thickness from zero to over 10m, but averages around 3m thickness.
There are four main lithologies within the Seymour Lake Project area. The eastern side of the project is dominated by Archean Granites. The southwest is mostly made up of a large elongate dolerite intrusions.
The central and northwest of the project area are dominated by a folded suite of meta-volcanics.
Based on geological mapping in the region the meta volcanics represent the metamorphosed amphibolite's and pillow basalt and intruded by dolerites and intercalated with volcanic-clastic sediments. Meta-sediments also occur in the far northwestern corner of the project area.
The Seymour Lake area is also crosscut by several north south trending dolerite dykes. These dykes likely follow pre-existing lines of weakness which may indicate faults.
The exposed bedrock is commonly metamorphosed basaltic rock, of which some varieties have well-preserved pillows that have been intensely flattened in areas of high tectonic strain. The rocks have been metamorphosed from greenschist to amphibolite grade and can include garnet and hornblende. Intercalated between layers of basalt are lesser amounts of schists derived from sedimentary rocks and lesser rocks having felsic volcanic protoliths. "These rocks are typical of the Wabigoon Sub province, host to most of the pegmatites in the region', (after Phil Jones et al 2019).
Ore Geology
Pegmatites are reasonably common in the region intruding the enclosing host rocks after metamorphism, evident from the manner in which the pegmatites cut across the well-developed foliation within the metamorphosed host rocks. This post-dating relationship is supported by radiometric dating; an age of 2666 + 6 Ma is given for the timing of intrusion of the pegmatites (Breaks, et al., 2006).
The pegmatites in North Aubry have a north eastly plunge direction with a dip varying from 10 to 35 degrees from horizontal, up to 800m downdip extent and 250-350m strike. The North Upper and North Upper high-grade component, higher grade portion within, appears to wedge towards the southeast but is still open down dip and to the northwest.
Southern pegmatites are thinner and less well developed with higher muscovite and albite content and north-westerly trend and dip moderately to the east. These pegmatites are also hosted in pillow basalts.
The pegmatites are zoned with better developed spodumene crystal appearing as clusters, with radiating spodumene crystals often radiating in from the country rock contact.
The main ore bearing mineral is Spodumene, followed by minor Petalite and Lepidolite.
Associated minerals include quartz, muscovite, microcline, hornblende, albite and other feldspars, tourmaline, with minor carbonate, chlorite, biotite and hematite. Sulphide species are predominantly minor disseminated pyrite and trace pyrrhotite usually hosted by the surrounding basalt.
The updated Seymour Mineral Resource estimate was compiled by John Winterbottom, a fulltime employee of Green Technology Metals and a member of the Australasian Institute of Geoscientists. Mr Winterbottom has extensive experience in Mineral Resource estimation techniques and their application and worked in a wide range of spheres within the mining industry.
Dimensions
The deposit consists of a number of stacked pegmatite units of varying thicknesses.
The deposit consists of two principal areas North and South.
The Northern area of the deposit has a maximum horizontal extent of 800m, 390m wide and varies from 2m up to 43m in thickness. 7 mineralised pegmatites that have been interpreted down to a depth of 350m below surface and is still open at depth. Pegmatites dip approximately 30-35 degrees to the northeast. Only 3 of the North Aubry pegmatites were deemed potentially economic.
The Southern area consists of an Upper and a Lower pegmatite. The Upper pegmatite is continuous over the entire extent of the Southern deposit whilst the Lower pegmatite is broken into a northern and southern half. The Southern area extends up to 740m along a 330 strike direction, up to 170m across with thickness varying from 0 to 22m, with a maximum depth of 130m below surface.