SOLWARA 1
Nautilus Minerals Inc. has successfully completed 29 holes of a 90-hole program with 38 per cent of holes terminating in copper sulphide mineralization, with the longest mineralized sulphide intercept being 18.2 metres. Nautilus also reports high-grade assay results for its recently discovered Solwara 8 prospect.
David Heydon, Nautilus chief executive officer, commented: “The results of the drilling at our Solwara 1 project in the territorial waters of Papua New Guinea, demonstrate that we have a strong mineral system persisting at depth. This is in addition to the system of high-grade massive sulphide spires that are often 10 metres high above the system currently being drilled.”
Mr. Heydon elaborated: “We are actively promoting the development of new tools for this new industry. In less than a year we have, with remote-operated vehicle (ROV) builder Perry Slingsby Systems and operator Canyon Offshore, taken the ROV drill from the drawing board to operational status. These new remote controlled drills operating in water depths up to 1,800 metres are providing good core recovery, allowing us to define the mineralized system at Solwara 1, and provide quality samples for resource evaluation, metallurgical and geotechnical studies.”
Mr. Heydon added: “We are also impressed by the results from Solwara 8, where the 12 surface samples taken from Solwara 8 averaged 16.9 grams per tonne gold, 6.1 per cent copper, 32.5 per cent zinc and 328 grams per tonne silver, with individual samples returning up to 34 per cent copper and 50.7 per cent zinc.
“This confirms that we have yet another high-grade gold-copper-zinc system, supporting the hit rate during the target testing phase of this year’s program of four systems discovered in four weeks.”
Solwara 1 program
Since drilling commenced on June 14, 2007, at Solwara 1, 29 holes have been completed for a total of 305.8 metres with an average massive sulphide core recovery of 72 per cent. Selected intercepts are outlined in an attached table and all drill holes are listed in an attached table. Assay results are expected in four to six weeks.
The evaluation drilling of Solwara 1 is conducted on a nominal 50-metre grid with the aim of collecting quality samples preparation for a mineral resource statement and for metallurgical and mine planning purposes, specifically to undertake assaying and metallurgical and geotechnical testwork. Between 70 to 90 holes are planned.
This drilling is mostly adjacent to the exposed high-grade sulphide outcrop zones defined by previous surface sampling and mapping. The geology encountered in drilling to date has been relatively consistent comprising:
A locally developed, thin fine-grained sediment “drape” typically about one metre thick;A chalcopyrite-rich massive sulphide ore zone in places at least 18 metres thick; andA highly altered (clay-pyrite-anhydrite) footwall.
- A locally developed, thin fine-grained sediment “drape” typically about one metre thick;
- A chalcopyrite-rich massive sulphide ore zone in places at least 18 metres thick; and
- A highly altered (clay-pyrite-anhydrite) footwall.
SOLWARA 1 — 2007 ROV DRILL SELECTED INTERCEPTS
Sulphide intersection
Hole No. TD Core recovery from to intersection Cu % (hand-
(m) in sulphide % (m) (m) width held XRF)
SD038 13.6 75 1.1 4.8 3.7 10.3
SD052 16.7 45 0.3 8.1 7.8 11.1
SD056 18.9 91 1.0 18.9 17.9 4.9
SD064 19.5 85 0.0 18.2 18.2 7.0
The drill core diameter is 52 millimetres (NQ size). On-board preliminary hand-held XRF analyses indicate that the Solwara 1 massive sulphide is copper-bearing with average result for the massive sulphide intervals. Measurements by hand-held XRF are not assay results and do not measure gold or silver. Samples will be formally assayed by the ALS Group in Brisbane. Initial results are expected in four to six weeks.
High-grade assays confirmed at Solwara 8
Assay results confirm high-grade gold-copper-zinc mineralization at the recently discovered the Solwara 8 prospect. The Solwara 8 prospect lies in a water depth of between 1,680 metres and 1,750 metres, approximately 750 metres west-southwest of Solwara 6 and approximately 47 kilometres west of the Solwara 1 prospect.
The Solwara 8 prospect covers an area of approximately 280 metres by 60 metres and lies within a north-northwest-trending structural zone approximately one kilometre south of, and possibly linked with, the greater Solwara 4 system.
SOLWARA 8 — SURFACE SAMPLING RESULTS
Assay results Preliminary results
Samples Au Cu Zn Pb Ag XRF Cu XRF Zn XRF Pb
g/t % % % g/t % % %
12 16.9 6.1 32.5 2.3 328 6.6 31.5 1.1
The laboratory assay results are on average 0.7 per cent lower for copper and 0.2 per cent higher for zinc than the preliminary hand-held XRF results for Solwara 8 reported on June 14, 2007, and suggest that the XRF units can play an important preliminary guide, in advance of full laboratory results given the four- to six-week time lag of recovering samples and getting them off the ship, back to Australia and assayed.
Samples were recovered using a Triton 200 series ROV at water depths from 1,650 metres to 1,800 metres.
Sample sizes ranged from 1.6 kilograms to 7.55 kilograms with a representative cross-sectional slice from the end of the rock or chimney sample dispatched to ALS Laboratory Group in Brisbane, Australia, for analysis. Ancillary information on sampling is included in the appendix attached to this release. In addition, a table attached provides full set of sample assay data.
Additional listing
As a result of the exercise of certain options, the company has made application for 150,000 common shares to be admitted to Alternative Investment Market. The shares are expected to be admitted to trading on July 17, 2007.
Qualified person
The exploration results reported in this announcement have been compiled under the supervision of Anthony O’Sullivan, chief operating officer of Nautilus. Mr. O’Sullivan is a member of the Australasian Institute of Mining and Metallurgy, has 20 years experience in mining and exploration geology, and is a qualified person as defined under National Instrument 43-101. He consents to his name being used in this release.
SOLWARA 1 — 2007 ROV DRILL INTERCEPTS
Sulphide intersection
Sulphide Cu %
Hole Depth Easting Northing core From To Sulphide (hand-
No. (m) recovery (m) (m) width held
% XRF)
SD036 2.3 398849 9581099 89 0.4 2.3 1.9 7.6
Hole ended in massive sulphide
SD037 3.0 398850 9581099 88 1.0 3.0 2.0 3.2
Hole ended in massive sulphide
SD038 13.6 398858 9581051 75 1.1 4.8 3.7 10.3
SD039 5.6 398861 9581012 68 2.0 5.6 3.6 8.8
Hole ended in massive sulphide
SD040 2.8 398897 9581004 64 1.6 2.8 1.2 5.5
Hole ended in massive sulphide
SD041 9.2 399003 9580992 49 1.3 9.2 7.9 3.4
Hole ended in massive sulphide
SD042 8.9 399052 9580997 44 0.4 4.2 3.8 5.9
SD043 7.8 399084 9580950 62 2.8 7.8 5.0 7.0
Hole ended in massive sulphide
SD044 6.1 399244 9580960 Poor recovery — altered volcanic rock
SD045 2.7 399200 9580932 Poor recovery — altered volcanic rock
SD046 13.2 399151 9580935 96 0.4 4.4 4.0 3.8
SD047 9.5 399106 9580926 80 0.3 6.0 5.8 7.5
SD048 14.9 399102 9580980 Poor Recovery — massive sulphide
SD049 17.2 399137 9580962 68 1.1 7.6 6.5 8.1
SD050 10.1 399231 9580970 Poor recovery — volcanic rock
SD051 13.3 399138 9580959 Poor recovery — altered volcanic, disseminated sulphide
SD052 16.7 399292 9581026 45 0.3 8.1 7.8 11.1
SD053 15.3 399352 9581070 39 1.8 6.1 4.4 6.4
SD054 17.2 399341 9581047 77 1.2 5.9 4.7 4.0
SD055 6.8 399401 9581152 Altered volcanic breccia, disseminated sulphide
SD056 18.9 399397 9581223 91 1.0 18.9 17.9 4.9
SD057 3.1 399386 9581239 Poor recovery — ended in massive
sulphide
SD058 12.0 399386 9581239 Poor recovery — ended in massive sulphide
SD059 7.2 399404 9581234 76 1.0 7.2 6.1 7.6
Hole ended in massive sulphide
SD060 18.1 399343 9581219 51 0.0 3.3 3.3 2.7
SD061 4.7 399444 9581180 75 0.0 4.7 4.7 7.2
Hole ended in massive sulphide
SD062 14.3 399443 9581179 73 0.0 8.8 8.8 3.3
SD063 11.9 399446 9581291 55 4.1 8.0 3.9 6.6
SD064 19.5 399486 9581276 85 0.0 18.2 18.2 7.0
Total 305.8
Results of indicative analyses from hand-held XRF unit
Nautilus is using a hand-held Niton XLT 592 X-ray florescence (XRF) instrument on the Wave Mercury to obtain indications of the grade of materials recovered from the sea floor. This system provides indicative information on grade tenor of samples for copper, zinc and lead mineralization, but does not measure for many elements including gold and silver. It is unable to provide gold and silver assays.
The instrument used for this application does not provide the accuracy required to report assays. These analyses are the mean of 10-point measurements on unprepared wet surfaces of each of the samples reported. XRF readings are taken at 10-centimetre intervals along the drill core to provide indicative grade data for mineralized intervals. The instrument is not calibrated using certified standards and the samples have not been crushed and prepared to minimize matrix effects which may affect the accuracy of the analysis. However, comparison of results to date with assay data for surface samples indicate the XRF tool is a reliable method for providing indicative results of the tenor of mineralization and providing data for “real-time” decisions in the field.
Laboratory analysis
All analysis was carried out by ALS Laboratory Group in Brisbane, Australia. ALS operate quality systems based on international standards.
Sample custodianship
All sampling, sample handling and analysis was completed under the supervision of Nautilus personnel. Sampling was carried out aboard the Wave Mercury whilst at sea. All subsamples were placed into numbered plastic vacuum sealed bags. The bagged samples were then subsequently placed into boxes. The boxes were sealed with security tape and signed by the supervising geologist on site at the time.
Quality assurance
External certified geochemical reference materials were prepared by Geostats Pty. Ltd., of Perth, Western Australia, and independently tested, and field duplicate samples were interspersed at regular intervals between the 12 samples submitted for analysis.
SOLWARA 8 — SURFACE SAMPLING RESULTS
Assay results Preliminary results
SAMPLE East North Au Cu Zn Pb Ag XRF Cu XRF Zn XRF Pb
g/t % % % g/t % % %
58577 352775 9587558 15.5 13.2 25.4 1.0 274 10.7 25.6 1.0
58578 352798 9587548 19.6 0.7 50.7 2.4 417 0.8 43.8 0.8
58579 352794 9587540 24.9 0.6 29.1 7.8 702 0.9 26.7 2.0
58580 352766 9587538 13.4 0.5 42.1 3.7 653 0.7 33.5 0.6
58581 352801 9587559 50.1 0.9 34.5 1.9 242 1.2 37.1 2.2
58582 352806 9587576 23.9 0.7 34.0 0.7 208 0.8 37.3 0.8
58583 352790 9587576 5.3 9.9 26.4 0.9 286 12.6 26.2 0.7
58584 352808 9587581 14.0 4.0 46.3 2.2 245 2.8 50.4 1.3
58585 352795 9587581 0.8 0.6 29.2 4.7 343 0.8 33.4 2.7
58586 352760 9587559 9.5 6.0 31.4 0.8 264 7.8 28.1 0.6
58587 352668 9587670 1.0 2.2 36.2 1.1 156 3.5 33.9 0.4
58588 352676 9587684 24.6 34.0 4.6 0.1 142 37.2 2.4 0.1
16.9 6.1 32.5 2.3 328 6.6 31.5 1.1
