The Lulo kimberlite exploration program aims to identify the primary sources of the exceptional alluvial diamonds being mined at Lulo, which achieved the highest average per carat prices in the world in 2016 (US$2,983 per carat). The exploration program is being funded from Lucapa’s share of distributions from the alluvial diamond mining operations.
During H1 2017, an 8,566 line km helicopter-borne Time Domain Electromagnetic (TDEM) survey was flown over the Cacuilo River valley area to guide and update the drilling program by identifying new non (or low) magnetic targets and to further define known magnetic targets previously identified from aeromagnetic surveys flown over the entire 3,000km2 Lulo concession.
The TDEM results identified 11 new kimberlite targets of up to 150 hectares with conductive EM signatures, including five located along drainage systems feeding into the prolific Mining Block 8 alluvial area and three near the L165-L170 kimberlite area, which was previously highlighted as an area of exploration interest.
The TDEM results and the re-interpretation of existing magnetic data highlighted 34 priority one targets within the Cacuilo Valley demonstrating strongly conductive EM signatures, supporting the existence of favourable near-surface pyroclastic kimberlite (PK) material associated with kimberlite pipes. A further 28 targets were classified as priority two and three.
These priority targets will be drilled throughout 2017 with the three rigs now on site at Lulo. Drill core will be progressively sent to Cape Town for mineral chemistry analysis to prioritise likely diamondiferous kimberlite pipes for follow up geological work, including further drilling and bulk sampling to test for diamond content and grade.
The first laboratory results are expected during Q3 2017.
Figure 2: Three of the ~150 hectare priority kimberlite targets identified at Lulo in the TDEM survey