Key points
- Solwara 12, discovered October 24, 2009, returned XRF results up to 23.4% copper and 36% zinc from 10 chimney samples.
- Solwara 13, discovered October 28, 2009, returned XRF results up to 19.3% copper and 38.5% zinc from seven chimney samples.
- Nautilus exercised an option for an additional 28 days of vessel time on the MV Fugro Solstice following 42 days of target generation work.
- Solwara 12 sits near a knoll over 120 metres high on the southeastern edge of the Desmos caldera, while Solwara 13 occurs at the southwest end of the Yuam Ridge, both in the eastern Manus basin.
NAUTILUS DISCOVERS TWO NEW HIGH GRADE SMS SYSTEMS IN THE BISMARCK SEA
Nautilus Minerals Inc. has discovered Solwara 12 and Solwara 13, two new seafloor massive sulphide (SMS) systems on its wholly owned exploration licences in Papua New Guinea. Discovered during the first five days of Nautilus’s 2009 target testing campaign, Solwara 12 returned hand-held X-ray fluorescence (XRF) results up to a maximum of 23.4 per cent copper and 36 per cent zinc from 10 chimney samples collected from the new site. Solwara 13, discovered only four days later, returned XRF results from seven chimney samples up to a maximum of 19.3 per cent copper and 38.5 per cent zinc.
The 42 days of target generation work conducted earlier this year from MV Fugro Solstice yielded a large number of SMS exploration targets. Due to this success and the high conversion in turning generated targets into new SMS discoveries, Nautilus has exercised an option for an additional 28 days of vessel time. The extra time will allow Nautilus to extend its target testing campaign to investigate other high ranking targets.
Stephen Rogers, Nautilus’s chief executive officer, commented: “Nautilus is fast-tracking the exploration and discovery of SMS systems to build an inventory for future drilling and appraisal. This early double success in the MV Fugro Solstice target testing program confirms the prospectivity of Nautilus’s Bismarck Sea tenements and our ability to quickly discover new SMS systems.”
Target testing commenced in the Bismarck Sea on Oct. 20, 2009. On Oct. 24, 2009, Nautilus discovered Solwara 12 during a remotely operated vehicle (ROV) dive on the second target tested. An area containing inactive sulphide chimneys (up to 12 metres high) was mapped using the ROV. Nautilus recovered 12 grab samples comprising 10 sulphide samples and two volcanic samples.
Another map on the company’s website illustrates the distribution of 10 sulphide chimney samples from Solwara 12, near the apex of a knoll (more than 120 metres high), located on the southeastern edge of the Desmos caldera, in the eastern Manus basin. The knoll extends significantly beyond the observed outcrop of Solwara 12, along two sediment-covered ridges — one trending north and the other trending west. The extent of mineralization beneath the sediment is unknown and mineralization as observed to date is open in several directions, particularly to the west and north.
On Oct. 28, 2009, Nautilus discovered Solwara 13. Nautilus recovered seven grab samples comprising massive sulphides from the centre of Solwara 13, plus two scoop samples from the softer outer edges of the mineralized system where iron-manganese oxides dominate.
A third map on the company’s website illustrates the distribution of seven sulphide chimney samples from Solwara 13 which occurs at the southwest end of the Yuam Ridge, in the eastern Manus basin.
SOLWARA 12 XRF ANALYSIS RESULTS OF SULPHIDE SAMPLES
XRF (average (%)(1))
Sample Weight
No. (g) Cu Zn Pb Easting(2) Northing(2) Depth(2) Lithology
22561 4,700 0.4 36.0 4.3 375817 9590023 -1876 Massive sulphide
22562 4,900 0.5 23.2 0.7 375856 9590023 -1866 Massive sulphide
22564 5,500 0.4 18.8 0.6 375870 9589991 -1910 Massive sulphide
Less
than
22565 3,900 15.6 2.0 LOD 375849 9590083 -1922 Massive sulphide
22566 5,200 1.0 30.6 1.4 375888 9590088 -1907 Massive sulphide
22568 5,500 0.7 27.0 1.5 375915 9590092 -1899 Massive sulphide
22569 3,700 0.6 19.4 5.2 375949 9590085 -1887 Massive sulphide
22570 7,300 12.6 14.7 0.1 375852 9590082 -1923 Massive sulphide
22571 4,500 23.4 10.5 1.3 375877 9590024 -1901 Massive sulphide
22573 5,200 1.2 19.1 7.6 375961 9590118 -1905 Massive sulphide
Less
than
Minimum 0.4 2.0 LOD
Maximum 23.4 36.0 7.6
Average 5.6 20.1 2.3
1. Average of 10 analyses per subsample using hand-held XRF.
2. Co-ordinates projected as UTM zone 56 south, using a WGS 1984 datum.
3. Less than LOD equals below detection limit.
SOLWARA 13 XRF ANALYSIS RESULTS OF SULPHIDE SAMPLES
XRF (average (%)(1))
Sample Weight
No. (g) Cu Zn Pb Easting(2) Northing(2) Depth(2) Lithology
22574 2,600 13.2 12.0 0.3 360741 9587443 -2006 Massive sulphide
22576 3,800 0.7 38.5 3.9 360740 9587427 -2002 Massive sulphide
22577 6,500 0.5 32.1 1.0 360766 9587467 -2004 Massive sulphide
22578 3,650 19.3 3.6 0.1 360750 9587449 -2005 Massive sulphide
22579 6,700 0.4 25.2 6.0 360776 9587466 -2006 Massive sulphide
22581 1,600 10.3 11.9 0.2 360757 9587438 -2001 Massive sulphide
22582 6,000 5.8 21.5 1.4 360759 9587433 -1997 Massive sulphide
Minimum 0.4 3.6 0.1
Maximum 19.3 38.5 6.0
Average 7.2 20.7 1.8
1. Average of 10 analyses per subsample using hand-held XRF.
2. Co-ordinates projected as UTM zone 56 south, using a WGS 1984 datum.
Target testing procedure
Sulphide mineralization at Solwara 12 and Solwara 13 was observed using the ROV during target testing traverses. The planned traverses are generally a series of parallel lines, nominally 200 or 300 metres apart. When chimney structures are located, using a combination of video and sonar apparatus, that area is mapped in greater detail with the ROV.
No equipment capable of mapping any mineralization beneath the seafloor is currently fitted to the ROV.
Sampling procedure
Grab samples were collected from the seafloor using a manipulator arm mounted on the ROV. Chimney samples averaging 37 kilograms (from five kilograms to 70 kilograms) were collected using the ROV manipulator arm and placed in a separate sample cage for recovery to the ship. They were then processed on board. Sample selections targeted material exposed at the seafloor surface, across different parts of Solwara 12 and 13. Subsamples from the chimneys averaging 4.8 kilograms (from 1.6 kilograms to 7.3 kilograms) were taken from each of the chimney samples using a pneumatic jack hammer, generally representing a cross-section of the chimney at the base of the chimney. The remaining portions of each sample were retained for reference purposes.
Small volcanic samples (1.4 kilograms to 6.2 kilograms) were collected using the ROV manipulator arm and placed in the sample box attached to the ROV. Scoop samples (1.4 kilograms to 2.0 kilograms) were also taken using the ROV manipulator arm, by scooping the outside of the softer oxide-bearing chimney structures with a small (approximately one-litre) metal container. Once the scoop sample is taken a second manipulator arm releases a tie to secure the lid on the scoop container. The scoop is then placed in the sample box on the ROV. XRF readings for copper, zinc and lead on the iron-manganese-oxide-bearing scoop samples were below the detection limit for the XRF machine and are therefore not reported herein.
Equipment spread
The mapping work described herein was completed using a Fugro FV300 series ROV. The ROV is equipped with sensors used to map the seafloor. These include various video cameras and two magnetometers provided by Ocean Floor Geophysics Inc. In addition, high-resolution mapping sonars housed on the ROV are being successfully used for the first time to identify real-time seafloor features ahead and to the sides of the ROV, beyond the range of the video camera systems used previously.
For seafloor sampling purposes, the ROV is equipped with two manipulator arms and a custom-built sample tray, or geobox, for storing up to 10 hand-sized grab samples or scoop samples. Larger samples are stowed and recovered using a custom built array of salvage bins.
Qualified person
The exploration results reported in this announcement have been compiled under the supervision of Michael Johnston, vice-president, strategic development, of Nautilus. Mr. Johnston is a member of the Australasian Institute of Mining and Metallurgy, has over 25 years experience in mining and exploration geology, and is a qualified person as defined by National Instrument 43-101. He consents to his name being used in this release.
