Karibib Lepidolite Project
Lepidico became the operator and 80% owner of the Karibib Lithium Project located in Namibia in July 2019, where a global Mineral Resource of 8.8 Mt @ 0.56% Li2O is estimated across six deposits, as detailed in the table below.
A new phase of drilling started in the September 2019 quarter aimed at upgrading portions of the existing Mineral Resource to Measured and Indicated levels to facilitate subsequent definition of an Ore Reserve estimate to support the Feasibility Study for a vertically integrated development of mine, concentrator and downstream small commercial scale L-Max® chemical plant: the Phase 1 Project.
JORC Code (2012) MRE for the Rubicon and Helikon deposits within ML 204, Karibib Lithium Project, Namibia.
Location and Infrastructure
The Karibib Lithium Project is located in central Namibia in southwestern Africa. Lepidico holds an 80% interest in the project, which comprises a Mining License (ML 204) of 69km2 and three Exclusive Prospecting Licences (EPLs 5439, 5555 and 5718) that together cover an area totalling 1,054 km2. Access to the Project is via the national highway from the capital city Windhoek located approximately 180 km to the south east, with the deep-water port of Walvis Bay located 210 km to the south west.
The lithium pegmatites are usually complex, banded and zoned and exhibit a typical pink-violet colour. They are enriched in Al2O3 , MnO, P2O5, Li, Rb, Nb, Ta. In addition to quartz and feldspar they contain Li-bearing minerals of the muscovite-lepidolite series and the amblygonite-montebrasite series, as well as tourmaline, tantalite and beryl.
Exploration and Mining History
The pegmatites of the region (including Lepidico’s Rubicon and Helikon pegmatite fields) have been the subject of a number of geological surveys and research investigations since the early 1930’s. Since then, the Rubicon and Helikon deposits were developed as both open pit and underground operations for processing of mainly petalite and tantalite ores.
Mining commenced in the 1950s, with production data only available from the 1980’s. Between 1980 and 1994, production from Rubicon totaled 14,700 t of petalite, 2,000 t of lepidolite, 880 t of amblygonite and 9,300 t of quartz. Material that was either not required or did not meet grade requirements was stockpiled next to the mines.
Geology and Mineralisation
The Karibib Lithium Project is located in the southern Central Zone of the Damara Belt in which a number of world class economic deposits have been discovered and developed, including the Rossing Uranium mine. Included amongst these deposits are Li-Be-Ta-Sn and tourmaline-bearing lithium caesium tantalum (LCT-type) pegmatites and U-bearing niobium yttrium fluorine (NYF-type) pegmatitic leucogranites, which have been intruded into the tightly folded supracrustal rocks of the Damara Supergroup.
The pegmatites of the Damara Orogen occur in five major east-west striking belts. The Karibib Pegmatite Belt contains numerous LCT-type pegmatite occurrences and workings, with the large Rubicon and Helikon pegmatites being classic examples of highly fractionated and well zoned LCT-type pegmatites.
At Rubicon a series of stacked sub parallel pegmatites intrude a variable dioritic and pegmatitic granite sequence with the Rubicon Main pegmatite body forming a prominent ridge which strikes approximately 900 m northwest and dips between 20º and 65º to the northeast, with dips averaging 45° near surface and flattening to about 18°-25° at depth. The Rubicon pegmatite has so far been identified to over 400 m down dip.
The main Rubicon pegmatite consists of two ellipsoidal well zoned, Li-mineralised bodies developed around two quartz cores and surrounded by a zone of quartz-K-feldspar pegmatite. At Rubicon, the primary lithium minerals present are lithium micas (predominantly lepidolite) and petalite, with trace spodumene. Historical mining also generated rock dumps and slime dumps that contain lepidolite, with minor petalite and tantalite.
The historical Helikon occurrences (Helikon 1 – 5) comprise a series of stacked, sub parallel LCT-type pegmatites that have been intruded into marbles and calc silicates belonging to the Karibib Formation. All five of the pegmatite exposures have in the past been exploited for lithium bearing minerals (lepidolite, petalite and amblygonite), as well as tantalite and beryl. Helikon 1, located 750 m to the south of the Helikon 2 – 5 pegmatites, is the largest exposed pegmatite in the group with a strike length of 350 m, an average thickness of 65m and a dip of 70° to the north. The Helikon 2 – 5 pegmatites define a discontinuous strike length of some 1,700 m with variable dips and thicknesses, decreasing in scale westwards.