Summary:
The Root Lithium Project is located the boundary between the Uchi Domain and the English River sub province is defined by the Sydney Lake – Lake St. Joseph Fault, a steeply dipping brittle ductile fault zone over 450km along strike and 1 – 3km wide. It is estimated that the fault had accommodated 30km dextral, transcurrent displacement and 2.5km of south side up normal movement.
The Root Lithium Asset contains most of the pegmatites within the Root Lake Pegmatite Group including the McCombe Pegmatite, Morrison Prospect, Root Lake Prospect and Root Bay Prospect. The McCombe Pegmatite and Morrison Prospect are hosted in predominately mafic metavolcanic rock of the Uchi Domain. The Root Lake and Root Bay Prospects are hosted in predominately metasedimentary rocks of the English River Terrane. On the eastern end of the Root Lithium Asset there is a gold showing (Root Bay Gold Prospect) hosted in or proximal to silicate, carbonate, sulphide, and oxide iron formations of the English River Terrane.
The English River Terrane is an east-west trending sub province composed of highly metamorphosed sedimentary rock, including turbiditic sediments and oxide iron formations, abundant granitoid batholiths, mafic to ultramafic plutons and rare felsic to intermediate metavolcanic rock.
Ore Geology
The Root Pegmatites are internally zoned. These zones are classified by the tourmaline discontinuous zone along the pegmatite contact, white feldsparrich wall zone, tourmaline-bearing, equigranular to porphyritic potassium feldspar sodic apalite zone, tourmaline-bearing, porphyritic potassium feldspar spodumene pegmatite zone and lepidolite-rich pods and seams (Breaks et al., 2003). The GT1 drilling at Root Bay has shown that the dominant lithium bearing mineral species is fine – coarse crystals of white and/or green spodumene. Both the McCombe and Morrison have been classified as complextype, spodumene-subtype (Cerný 1991a classification) based on the abundance of spodumene, highly evolved potassium feldspar chemistry and presence of petalite, microlites, lepidolite and lithium-calcium liddicoatite (Breaks et al., 2003), Root Bay pegmatite appear to exhibit similar characteristics.
The Root Bay pegmatites are hosted in foliated, locally pillowed mafic metavolcanic rock that contain metasomatic holmquistite near the contact of the pegmatite (Magyarosi, 2016).
Bedrock Geology
McCombe, Morrison and Root Bay project areas bedrock consist primarily of metavolcanic rocks of the Lake St. Joseph greenstone belt within the Uchi Domain, while the Root pegmatite is within metasedimentary rocks of the English River Terrane.
Property Geology
The Root Lithium Project is covered in a veneer of patchy glacial deposits comprising shallow gravelly soils, boulder till and in places thick moraines. In low-lying areas the bedrock is also obscured by lakes and swamps with the Roadhouse River transecting the southern portion of the McCombe deposit and western Morrison pegmatites.
The local bedrock consists primarily of Archean metavolcanics and intercalated sediments with later cross-cutting felsic intrusions to the east of the McCombe pegmatites. East-west or northeast, steep or moderately dipping lithium bearing pegmatites crosscut the meta-volcanics and sediments. The Root Bay deposit lies along an east-west trending ridge of meta-basalts hosting moderately north-northeasterly dipping pegmatites and sandwiched between meta-sediments to the south and north. The northern sediments host steeply dipping magnetite rich horizons.
Pegmatites
Four spodumene bearing pegmatite groups are found on GTI's Root land holdings, McCombe, Morrison and Root Bay and Root Lake.
The McCombe pegmatites is a combination of several spodumene-bearing granitic pegmatites located on the northwest side of the property. The dykes are exposed over 200m along strike length and vary from east-west to northeast orientations. Dips are the south and southeast and vary from 30-40 degrees to 60-70 degrees. Pegmatite width vary from 2-15m wide.
The Morrison Lake pegmatite is located on the northwest side of the property, 1.7km southeast from the McCombe pegmatite. The pegmatite trends east-west, dips moderately-steeply to the south, is exposed along strike over 195m and is 6.5m wide.
The Root Bay pegmatite is located on the south-eastern side of the property. It is exposed approximately 60m along strike, is 10m wide (Smyk et al., 2008; Magyarosi, 2016) and follows the presumed trace of the Lake St. Joseph Fault (Smyk et al., 2008). The pegmatites are hosted in foliated, locally pillowed mafic metavolcanic rock that contain metasomatic holmquistite near the contact of the pegmatite (Magyarosi, 2016).
The Root Lake pegmatite is located on the southwestern side of the property, south of the McCombe and Morrison pegmatites. The pegmatite is based on an occurrence from a single drill hole. The 168.55m drill hole intersected 7 spodumene-bearing and spodumene-absent granite pegmatite intervals between 0.15-1.22m thick within quartz biotite schists and metagreywackes.
Dimensions
Root Bay
The Root Bay deposit has a total strike extent of approximately 200m and has been drilled to a down dip extent of over 1,200m (700m below ground level). The pegmatites all dip to the south-southeast to southeast at approximately 25-35 degrees with pegmatite RB006 steepening to over 60 degrees dip and rotating in dip direction to the southeast below 0m elevation (400m below ground). The pegmatites are stacked and occur along a 1,500m east-west corridor.
McCombe
The deposit consists of 6 LCT pegmatite units of varying thicknesses and attitudes. The McCombe deposit has a total strike extent of approximately 1,500m and has been drilled to a down dip depth of over 250m. McCombe’s pegmatites varying in strike direction from east-west to southwest-northeast and all dip towards the south or southeast at varying degrees of inclination ranging from 40 to 70 degrees.