Great Thunder Summarizes Mineralogical and MAG and IP Results From Chubb and Bouvier Lithium Properties
Victoria, British Columbia (FSCwire) – January 26, 2017 – Great Thunder Gold Corp. (TSXV: GTG) is pleased to announce the results of the mineralogical study and 3D MVI inversions model carried out on its Chubb and Bouvier lithium properties located in the Preissac-Lacorne area of the Abitibi Greenstone Belt of Quebec. That area hosts the operating Québec Lithium mine which, according to Canada Lithium’s June 2011 NI 43-101 technical report, has previously reported measured and indicated resources of 29.3 Mt grading 1.19% Li2O and 20.9 Mt of inferred resources grading 1.15% Li2O.
The mineralogical study was completed by SGS Canada Inc. on two samples of spodumene-bearing granitic pegmatite collected from the Bouvier and Chubb sites. Highlights of the results are:
- The QEMSCAN analysis shows that the Bouvier sample consists of plagioclase (47%), quartz (29%), spodumene (17%), K-feldspars (3%), garnets (2%), and micas (1%). The Chubb sample consists of plagioclase (34%), quartz (29%), spodumene (27%), K-feldspars (9%), and micas (1%).
- The calculated lithium concentration from the QEMSCAN analysis is 0.63% (1.36 wt. % Li2O) and 1.0% (2.25 wt. % Li2O) and that calculated from the actual assays is 0.56% (1.21 wt. % Li2O) and 0.92% (1.98 wt. % Li2O) for the Bouvier and Chubb samples.
- Spodumene mineral separated from the Bouvier and Chubb samples yielded of 65.34 wt. % and 65.11 wt. % SiO2, and 27.20 wt. % and 26.74 wt. % Al2O3, respectively. The FeO in spodumene is lower in Bouvier at 0.56 wt. % than that in Chubb (1.07 wt. %), with other major elements such as K2O wt. % (0.00-0.01), CaO wt. % (0.01-0.02) and MgO wt. % (0.00) displaying very low concentrations.
- Free and liberated spodumene calculated for the head sample for Bouvier and Chubb accounts for 87% to 88% in both samples for a specific grind size (P80 of 425 μm). Therefore, these two samples could be processed together.
- The predicted ideal grade-recovery curves based on the liberation of the minerals indicate similar lithium grades of 3.6 wt. % (7.8 wt. % Li2O) to 3.3% (7.1 wt. % Li2O) for recoveries of 88% to 99%, respectively.
Comparison of the mineralogical results gathered from the Chubb and Bouvier samples with the ore material provided from the Whabouchi Mine (Nemaska Lithium) in northern Quebec indicates similar characteristics. For instance, the Nemaska Lithium ore displays:
- Mineral composition consisting mainly of Na-feldspar (25.3%) and microcline (15.9%), quartz (31.4%), Li minerals (spodumene+petalite) (22.4%) and muscovite (3.4%).
- The FeO content of spodumene varies from 0.58 to 1.71 wt. %, averaging 0.92 wt. %.
Grades and recoveries increase from the coarse to the fine fraction as expected from the liberation values. Overall, the grade recovery curve representing the whole sample indicates grades between 3.4% (7.32 wt. % Li2O) and 3.2% Li (6.89 wt. % Li2O) for recoveries of 86% to ~99%, respectively.
Reprocessing and plotting of the MAG and IP data acquired in 2009 on the Chubb and Bouvier properties by Abitibi Geophysics for Mineral Hills Exploration was conducted by Mr. Joel Simard, Geophysicist (P.geo). A summary of the results is presented below:
- Inversion results (MVI) as a 3D voxel on the Chubb magnetic data is presented once the effect of less magnetic lithologies (MS < 0.0015 SI) has been removed to isolate the ferromagnesian rich lithological units. This allows the highlight of a magnetic lithological unit striking in a NW-SE direction that crosses the center of the grid. It encompasses towards the west the Chubb showing and towards the east a relatively broad outcrop area, intersected by a major granitic pegmatite dyke (Main Dyke).
- At Bouvier, three magnetic lithological units can be observed on the grid. Two of these units are striking in an EW direction; one of them is located in the northern part of the grid, whereas the other one crosscuts the southern part. The third one is observed in the central part of the grid and is oriented in a NW-SE direction. The more magnetic unit encompasses the Bouvier showing just north of the area where several historic drill holes were collared by Lithium Corporation of America in 1953 (GM01136D). This more magnetic unit appears to map the granitic pegmatite dykes that are associated with the lithium bearing mineralisation that have been delineated in this area.
The 3D MVI allows viewing with clarity the higher magnetic susceptibility bodies that likely define the lithium-bearing granitic dykes located on both the Chubb and Bouvier properties. In particular, the generated 2D and 3D maps will be used to spot with greater accuracy the future drill holes in an upcoming campaign
The technical contents of this release were approved by Michel Boily, Ph.D, geo., an independent Qualified Person as defined by National Instrument 43-101.
About the Chubb and Bouvier Lithium Properties
The Chubb property is located in northern Québec in the Abitibi-East County, Lacorne municipality, NTS map sheet 32C05. The claims are situated within the Preissac-Lacorne plutonic complex of the Abitibi Greenstone Belt; the complex forming one of the best prospective areas for lithium mineralization. The Chubb property consists of 35 contiguous recorded mineral claims for a total area of 1,509 hectares or 15.1 km2. The property geology is dominated by quartz monzodiorite and metasomatized quartz diorite (tonalite). A swarm of spodumene-rich granitic pegmatite dykes intrude fractures and small faults within the plutonic rocks. There are three important granitic pegmatite dykes containing spodumene mineralization (Dyke #1, #2 and Main Dyke). In 2010, International Lithium carried magnetic and IP geophysical surveys, mapping and channel/ grab sampling in the area surrounding the three principal spodumene-bearing dykes. The main dyke, which is 300 m long, was shown to have Li2O concentration of 1.00 wt. % (n=41).
The Bouvier property is located within the Preissac-Lacorne plutonic complex of the Abitibi Greenstone Belt, in the Saint-Mathieu municipality of Figuery Township (NTS map sheet 32D08). The geological setting and structure of the volcano-sedimentary assemblages form an ideal host for lithium-rich pegmatites being located between the Northern Manneville Deformation Zone and the northern edge of the fertile Lacorne monzogranite pluton. The Bouvier property consists of 16 contiguous recorded mineral claims for a total area of 692 Ha or 6.92 km2. Spodumene-bearing granitic pegmatite dykes occur only south of the Manneville Fault and were emplaced principally in metasediments. The dykes are oriented parallel to the Manneville Fault and can reach 100 m in length and 10 m in apparent thickness. In 2010, Mineral Hill Industries Ltd. carried out an exploration program involving line cutting, a magnetic and IP survey, trenching and panel and grab rock sampling. The work unearthed EW-oriented spodumene-bearing granitic pegmatites parallel to the Manneville Deformation Zone. The main dyke displayed an average lithium concentration of 1.51 Li2O wt. % (n=20).
ON BEHALF OF THE BOARD
Signed “Kevin C. Whelan”
Kevin C. Whelan, President
Direct line: (250) 474-6640
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Source: Great Thunder Gold Corp. (TSX Venture:GTG)