Robust intersects high grade copper, gold-silver zone on Romang project
Tuesday, March 30 2010 - 03:41 AM WIB
Final assay results have been received from six holes, three from Batu Mas, two from Batu Hitam and one from Batu Jagung. Five of these holes encountered precious metal and / or base metal mineralisation of potentially economic grades and widths extending the identified zones of mineralization, the company said.
Managing Director Gary Lewis said, ?The results from Lakuwahi continue to go from strength to strength and these latest results are further indications that not only are we looking at a significant body of gold-silver mineralisation, but given the width, near surface nature and increasing grades, we are now also building towards a substantial accumulation base metals, including copper. The coarse-grained nature of the sulphide minerals suggest favourable metallurgy and we are currently preparing samples for preliminary metallurgical testing. For a company of our size we find ourselves in an increasingly fortunate position as our current drill programme is firming up the large scale of both gold and base metal mineralising systems.?
Batu Mas Prospect
Hole LWD 068 was drilled on the eastern-most section of drilling at Batu Mas. The outstanding zone of base metals, including some shoots of high grade copper, lead and zinc, further underline the strength and untested potential of the Batu Mas mineralisation. A summary of the results from hole LWD 068 include:
39 metres at 1.03 g/t Au equivalent (0.71 g/t Au and 19 /Ag) from 1 metre
Including 13 metres at 1.73 g/t Au equivalent (1.23 g/t Au and 30 glt Ag) from 11 metres 74 metres at 2.4% combined Zn + Pb + Cu from 58 metres
Including 9 metres at 1.7% Cu from 58 metres
Including 3 metres at 4.3% Cu from 62 metres
and 6 metres at 5.7% combined Zn + Pb + Cu from 84.5 metres
Hole LWD 065 is the deepest hole drilled by Robust into the Batu Mas Prospect to date, reaching a final depth of 248 metres, with anomalous gold and base metals encountered for the entire depth. The strongest zones of mineralisation were encountered in the upper sections of the hole, in summary.
61.5 metres at 1.30 g/t Au equivalent (0.59 g/t Au and 43 g/t Ag) from 2 metres
20 metres at 2.4% combined Zn + Pb + Cu from 63.5 metres
And 3 metres at 5.6% combined Zn + Pb + Cu from 157 metres
Through these latest results, the geology of the Batu Mas mineralisation is now becoming clearer. The cross sections in Figures 1 and 2 show the extensive thick development of the gold-silver plume style mineralisation and its juxtaposition across the base of oxidation. Higher grades are loosely associated with vertical to sub vertical early stage silicified breccia zones. Late-stage base metal, gold and barite fluids are thought to have been introduced along low-angle faults, forming fracture-fill mineralisation in the structurally prepared volcanic and breccia units.
Hole LWD 064, located to the north of LWD 065 was also drilled deep to a depth of 204 metres and also intersected altered units within mineralised brecciated volcanics over the entire depth of the hole. The total length of the hole assays higher than 1% combined Zn + Pb + Cu. Summary result are as:
5 metres at 0.99 g/t Au equivalent (0.35 g/t Au and 38 g/t Ag) from 10 metres
12 metres at 1.48 g/t Au equivalent (0.58 g/t Au and 54 g/t Ag) from 37 metres
12 metres at 2.1% combined Zn + Pb + Cu from 37 metres
13 metres at 2.6% combined Zn + Pb + Cu from 73 metres
Batu Hitam Prospect
Hole LWD 066 drilled altered and mineralised brecciated volcanic rocks for the entire length of the hole, ending in mineralisation at 120 metres averaging 1.9% combined Zn + Pb + Cu. Summary results from LWD 066 are
12 metres at 1.79 g/t Au Equivalent (0.43 g/t Au and 81 g/t Ag) from 8.5 metres
74.5 metres at 2.6% combined Zn + Pb + Cu from 31.5 metres
Including 12 metres at 3.4% combined Zn + Pb + Cu from 31.5 metres
and 2.15 metres at 21.9% combined Zn + Pb + Cu from 101.85 metres
This hole was drilled on the easternmost section so far completed, 50 metres south of hole LWD 059, which intersected 18 metres at 2.8% combined Zn + Pb + Cu (ASX announcement 16.03.10). As such it represents a significant strengthening of the mineralisation southwards on this section and points to untested mineral potential to the east.
Hole LWD 067 drilled 40 metres south of LWD 066 and also intersected a broad zone of mineralised brecciated volcanic rocks for the entire length of the hole; averaging over 1.1% combined Zn + Pb + Cu over 120.5 metres. Summary results from LWD 067 are as follows:
54.5 metres at 2.0% combined Zn + Pb + Cu from 55 metres
Geophysics
Geophysical contractors have now commenced the IP - Resistivity survey across the Lakuwahi Project area on Romang Island. This work is expected to take approximately 3 months. Results will be available as the survey proceeds and will therefore be an aid in the early targeting of previously undrilled prospects.
QAQC
Re-assays of sample residues from high-grade gold and silver intersection previously reported in hole LWD 051 (57.5 m at 6.75 g/t Au Equivalent) have been completed by Ultratrace Laboratory in Perth. The results clearly show that there is no appreciable bias in gold or silver assays between Ultratrace and Robust?s regular laboratory, Intertek Testing Services, in Jakarta.
Re-calculation of the intersection using only the Ultratrace assays produces an intersection that is slightly higher (57.5m @ 6.93 g/t Au Equivalent) than the original Intertek assays but still well within the acceptable boundaries of repeatability. (end of edited release)