Melbourne, Oct 1, 2008 AEST (ABN Newswire) - Dart Mining NL (ASX:DTM) is pleased to announce that the significant molybdenum anomaly expressed in initial geochemistry surface results has been confirmed by a recent drilling program at the Unicorn Prospect.
HIGHLIGHTS
- Initial RAB assays confirm surface molybdenum expression extends at depth
- Highly encouraging results support original hypothesis of a major find
- Deeper diamond drilling to 320m is underway
- Dart is in the process of confirming a new mineral province for Victoria
"The drilling follows outstanding assay results from infill grid geochemistry, which highlighted a significant molybdenum anomaly at the Unicorn Porphyry. The continuity of these results reinforces our confidence that Unicorn is a world class molybdenum target," said CEO John Quayle.
A 15 hole Rotary Air Blast (RAB) program has been completed at the Unicorn Prospect with assay results now to hand from the first two holes (DUNRAB008/09). The drill holes returned very significant intersections of 70m @ 0.0374% Mo and 50m @ 0.0623% Mo respectively with both holes ending in mineralisation. These two holes shoulder the main central molybdenum geochemical zone.
Significantly, fresh rock (showing sulphides) was intersected from 35 metres, with the bottom 15 metres of hole DUNRAB009 (a vertical hole) averaging 0.0763% Mo, along with 0.174% copper, 5.38 g/t silver, and 2.27 g/t Rhenium. Hole DUNRAB008 was drilled at a -50 degree inclination and only traversed partly weathered rock over its length. The fresh rock hosts the molybdenum sulphides which offer better recovery yields.
"Given that the average grade of new world class molybdenum mines being developed worldwide is around 600ppm or 0.0600% Mo, we are very excited about the results we are seeing and the potential for future development at Unicorn," said Mr Quayle.
The RAB drill program has tested the full width of the reported molybdenum soil anomaly, and results to date confirm the presence of a significant zone of Mo mineralisation within the silicious alteration zone above and adjacent to the Unicorn Porphyry. Mineralisation intersected to date also shows strong copper and silver association with rhenium, a possible strategic mineral credit. These results, along with additional diamond drilling now underway, will provide a clear picture of the potential of the prospect.
"These results are now confirming what we have been saying, that we are on the verge of a major discovery and potentially a new mineral province and an amazing opportunity for regional Victoria," said Mr Quayle.
INITIAL RAB DRILLING
The 15 hole RAB program was designed to establish the bedrock geochemistry underlying the surface molybdenum anomaly. The RAB drill program traversed 800m of the Mo soil anomaly; and with the additional diamond drilling now underway will provide a clear picture of the potential of the prospect.
The majority of the drill holes (DUNRAB001 to DUNRAB006 and DUNRAB011 to DUNRAB015) were designed to test the zonation of Mo about the siliceous alteration in the sediments overlaying the buried lithocapand for depth targeting. Geological logging of these holes shows a systematic increase in silica / sericite / haematite alteration intensity as the central soil anomaly zone (450ppm Mo) is approached. This bedrock geochemistry investigation provides samples for spectral alteration analysis and will greatly assist in the design and targeting of future drilling into this mineralised system.
Two of the RAB holes were collared adjacent to the zones of highest surface Mo anomalism. RAB drill hole DUNRAB008 was collared within the 370ppm Mo contour (0.037% Mo) (Figure 1) and shows 70m @ 0.0374% Mo over the full sampled length of the hole. The intersection includes 28m @ 0.0549% Mo from 2m. The hole also shows significant copper and silver credits with 23m @ 978.9ppm Cu from 49m.
RAB hole DUNRAB009 was collared within the (0.045% Mo) 450ppm Mo contour and shows 48m @ 0.0648% Mo over the full sampled length of the hole. The intersection includes 11m @ 0.099% Mo from 32m with a highest assay of 1325ppm Mo. Copper and silver credits are also present with a highlight of 29m @ 1383.3 ppm Cu from 21m.
Both holes intersected variably weathered, highly altered siliceous sediments and volcanic aplitic rock of the lithocap. The alteration shows disseminated pyrite and pyrite veining with visible molybdenite present as fine / dusty veinlets. Silica and sericite are the dominant alteration species and totally replace the original sediments above the Unicorn Porphyry.
DIAMOND DRILLING PROGRAM
The diamond drilling program (currently underway on DUNDD001) has been planned to provide detailed structural information (via scissor holes DUNDD001 and DUNDD002) and also to provide geological information on the alteration and zonation of Mo, Cu and Ag about the identified central Mo surface anomaly with hole DUNDD003. Additional drilling may be undertaken if required to ensure a robust Geological Model is developed to assist in the design of future drilling programs.
DUNDD001 is planned as a 250m long hole at 2800 MGA Grid azimuth and -500 dip. To date the hole has intersected silicified lithocap host showing multiple generations of vein emplacement and sulphides.
Molybdenite is visible below the transition zone of weathering (within fresh rock zones) and is present as dusty veinlets that concentrate to form Molybdenite lenses / stringers up to 5mm thick. Inspection also suggests additional Molybdenite may occur as fine disseminated inclusions within the host silicified sediments (lithocap).
Drill core samples will be submitted for assay immediately geological logging and core photography has been completed. Geological logging and sampling is currently up to date and will be a priority for the company to allow rapid assay data turnaround.
Diamond drilling will continue at the Unicorn Prospect while further work is conducted to investigate the potential of the mineralised system to host gold mineralisation. Mapping and chip sampling over anomalous gold zones defined during soil sampling is planned over the coming weeks.
SUMMARY
The geological interpretation of the drilling to date confirms the presence of a very large molybdenum bearing alteration system associated with the high level Unicorn porphyry. The alteration system forms a halo to the already reported surface Mo, Cu and Ag soil geochemistry anomaly, covering an area of 0.55 sq km. The pre-drill geological model is still considered to be robust with drilling confirming the open depth extent of the central Mo surface anomaly. The assay results from the first two holes confirm the presence of a significant zone of Mo mineralisation peaking at 1325ppm within the siliceous alteration zone above and adjacent to the Unicorn Porphyry.
COMPETENT PERSON'S STATEMENT
Information in this report that relates to a statement of exploration results of the Company is based on information compiled by Dean Turnbull, B. App. Sc (Geol)., AIG. Mr Turnbull is a Director of Dart Mining NL and has sufficient experience relevant to the style of mineralisation and type of deposits under consideration and to the activity undertaken. He is qualified as a competent person as defined in the 2004 Edition of the "Australasian Code for Reporting of Mineral Resources and Ore Reserves" (or "JORC Code"). Mr Turnbull consents to the inclusion of this information in the form and context in which it appears in this report.
Contact
John Quayle
CEO Media
Dart Mining
TEL: +61 (0) 3 9621 1322
Web: www.dartmining.com.au
| ||
|
