The Nickel Industries holds an 80% interest in PT Hengjaya Mineralindo, the owner of 100% of the Hengjaya Mine, with the remaining 20% interest owned by the Company’s Indonesian partner.
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Summary:
The dunite is black, welded and massive with an aphanitic texture. Constituent minerals are olivine, pyroxene, plagioclase, some serpentine and magnetite; the rock is fine to medium grained. Olivine is a principal mineral amounting to 90 % of the rock volume. Deviations and bending of twinning in the pyroxene indicate deformation of rock. In some places the rock is intensively serpentinised, as indicated by remnants of structures such as net and veinlets of olivine and pyroxene, serpentine and talc as replacement minerals.
The nickel deposits within the HM concession comprise a lateritic sequence and composed of highly oxidized materials derived by intense weathering of ultramafic rocks. Limonite ore (LIM) is clayey, red ferrous oxide facies material that overlies and grades into the saprolite facies (SAP). Below the saprolite, the interface is often rocky, with zones of saprolite mixed with boulders and fragments of bedrock (previously CST or rocky saprolite) and occasional boulders higher in the saprolite sequence (previously CST). The interface between the saprolite and bedrock is coloured towards yellow-grey before transitioning to solid bedrock (BRK), which is often highly oxidised and fractured with garnierite occurring along fractures in the bedrock interface with the rocky saprolite and saprolite.
Geochemically and mineralogically, the sequence is divided into 3 main units of interest based on its composition of mineral and mineralization:
- Limonite (LIM) with typically hosting minerals such as goethite, hematite with high Fe content (>25%), low MgO (<10%), Ni content occasionally high (>0.8%);
- Saprolite (SAP) with goethite, olivine, antigorite, serpentinite, garnierite, silica commonly with lower Fe content (<25%) and higher MgO (>10%), higher Ni content (>1.5%) content; and,
- Bed Rock (BRK), which is unaltered ultramafic rocks typically with lower Ni (<0.5%) and higher MgO content.
The category of “Fresh Rock” noted in the geology map is unclear but may represent exposures of non-Ultramafic Complex rocks belonging to the Tomata Formation. The main area of “Fresh Rock” is exposed outside of the nickel laterite area, west of the Bete-Bete deposit area and in the far west of the concession.
Resource dimensions: approximately 8000m in length, 4000m in width, laterization thickness for up to 40m to bedrock in some places. Limonite thickness varies from 4-9m and saprolite thickness is consistently 8-10m. Laterization of ophiolite formations occurs between an elevation range of 300 – 600 meters above mean sea level.