|
PARKER
RANGE Gondwana holds interests in a
large portfolio of prospective tenements located in the Southern Cross
Greenstone Belt immediately south of St Barbara’s Marvel Loch Gold Operations
and 80km north of Western Areas Forrestania Nickel Operations. The Southern Cross area is a well recognised
regional mining centre offering excellent established infrastructure and a long
gold mining tradition. Past production
and current resources in the region exceed 12Mozs of gold and 1,100,000t of
nickel.
Location Map showing
Parker Range tenements with TMI Magnetic Image The Southern
Cross-Marvel Loch region exhibits zones of near surface gold depletion related
to oxidation of the profile (noted at the Marvel Loch and Yilgarn Star gold
mines). Drill data for Gondwana's
landholding reveals large strike lengths of favourable host rocks that remain
untested below the base of oxidation.
The Company is focusing its gold exploration efforts on the three styles
of mineralisation that have been identified within the greenstone belt: n
Centenary-Spring Hill type (Parker Range Banded Iron
Formation (BIF)) n
McIntosh type (Ultramafic Contacts) n
Mt Caudan type (Sulphide-Rich Felsic Sediments &
Banded Iron Formation (BIF)) Gondwana's immediate
priority is to complete its pre-feasibility study for the Buffalo Gold Project,
and actively explore and re-evaluate known gold mineralisation at nearby sites
to increase the resource base available for the Buffalo Gold Project. In addition, the
Company will prioritize exploration at its new Lindsay’s Nickel prospect at
Jilbadji, Parker Range East. The Company’s current tenement
holdings at Parker Range are shown below:
Location Map
showing Parker Range, Marvel Loch tenements and ownership
Tenements over 500K scale geology identifying prospects described in
this report Gold Exploration
and Resource Development at Parker Range During the 2009 year, substantial
RC drilling occurred at Parker Range for both gold exploration and resource
development. n
A revised mineral resource estimate for Buffalo has been
released following recent diamond drilling.
n
A new mineral resource for Spring Hill has been released
based on new RC drilling. n
Substantial programs of exploration drilling were completed
at the Centenary, White Horseshoe, Zeus and Rokeby Prospects, principally aimed
at generating additional resources for the Buffalo Gold Project in due course. Summary of 2009
Gold Exploration and Resource Development at Parker Range
Buffalo
Gold Deposit (Gondwana 70%) A JORC-compliant mineral resource
estimate of 292,000t @ 2.12 g/t for 20,000oz contained Au (using a 1.0g/t lower
cut off) was reported for the Buffalo deposit in early 2009. During preparation of the 2009 resource estimate,
a lack of density data for the rocks in the Parker Range area resulted in
conservative assumptions being made as to the density values assigned in the
resource model. More recently, a diamond
drilling program at Buffalo allowed density measurements on the diamond core to
be taken throughout the mineralised and waste zones. The new density data was used in conjunction
with the diamond drilling assay results to produce the updated resource model. Intersects through Buffalo lower (100 zone) and upper (200 zone)
resource wireframes
Genalysis
Laboratory Services using Fire Assay techniques (FA50/AAS) Core loss through ore zones has been included as
internal dilution at 0 g/t Intersections represent true width of the resource
wire frame with no lower or upper cut The revised JORC-compliant mineral resource estimate for the Buffalo
resource is 355,000t @ 2.23 g/t for
25,400 oz contained Au using a
1.0 g/t lower cut off, which is a 25% increase in contained gold compared with
the early 2009 resource estimate. Results of the Buffalo 2010 updated mineral resource estimate (>= 1.0
g/t)
* A
top cut has been applied to the assay data and the estimated cut grade is
reported In
the Figure below, the 100 and 200 zones refer to two major gold mineralisation
envelopes dipping to the west. The 100
zone is the lower zone and the 200 zone is the upper zone. Lower
grade mineralisation is also contained within the 300 and 400 zones, however
these zones are not significant. Metallurgical tests already
completed and proposed to be completed in early 2010 on Buffalo ore samples are
described below.
Buffalo wire frame
showing mineralised zones - lower “100” is pink & upper “200” is red Buffalo Gold Project - Metallurgical
Testwork Background The following preliminary
metallurgical test work on the Buffalo Gold Project was completed during 2009: n
Petrographic analysis and bottle roll tests have been
completed on the samples with encouraging results. The bottle roll tests were carried out on
material crushed to -10mm, a reasonably coarse size, and the cyanide solution
was changed and analysed at 24, 48 and 72 hours to determine the maximum
extractable gold and approximate leach times for each of the samples. n
Results of the bottle roll tests indicate that an average of
80% of the gold was recovered over a 72 hour period. The test work also indicated that although
there was a significant increase in sulphide in the composite from the fresh
rock, there was no decrease in gold recovery.
The inference that can be made from these results is that there is no evidence
of gold being metallurgically “locked-up” within the sulphides. Since then, a more comprehensive
programme of metallurgical testing has been designed to test the core from
diamond drilling. Six metallurgical
diamond holes have been drilled in late 2009 to intercept the known mineralised
zones within the Buffalo ore body. From
this core, 5 composite samples will be selected to represent the ore body. Using these samples, a
metallurgical testwork program has been devised to assess the heap leach
potential for the Buffalo project based on heap leach amenability testwork and
a first pass estimate of capital and operating cost using information derived
from similar, recent heap leach studies undertaken in the area. The viability of the heap leach
will be assessed against alternative agitated cyanide leach toll treatment
options available in the local area. Scope of Work The scope of work comprises a
staged programme as detailed below. n
Stage 1 - Preliminary Testwork Stage 1 testwork involves the scoping, management and
reporting of preliminary heap leach amenability and alternative gravity/CIL
recovery. n
Stage 2 – Conceptual Heap Leach Study The development of conceptual process capital and operating costs based
on contract crushing and stacking with 250Kt crushed over a period of 6 months. Given the need to establish heap leach
amenability, it is intended that this stage of work would only proceed on
establishing the amenability of the ore to heap leaching as described in Stage
1. n
Stage 3 – Heap Leach Column Testwork Stage 3
Heap leach column testwork programme to generate design criteria for a heap
leach development. The performance of
Stage 3 is predicated on an economically acceptable outcome derived from Stage
2 heap leach conceptual study. Spring
Hill Gold Deposit (Gondwana 70%) A JORC-compliant mineral resource
estimate for the Spring Hill gold deposit, located approximately 500m south of
Buffalo, has now been completed. The
style of gold mineralisation at Spring Hill is equivalent to Buffalo; however
the deposit contains a single mineralised zone within and beneath historic
workings. Recent RC drilling has
identified that mineralisation is continuous over a 260m strike length, and
remains under-drilled to the north, south and at depth. The Spring Hill mineral resource
estimate incorporates new geological data and assay results from the recent RC
drilling program and utilises core density measurements from the Buffalo
diamond drill holes. It is estimated
that the Spring Hill deposit contains a total of 407,000t @ 1.97 g/t for 25,750 oz contained Au when reported using a 1.0 g/t lower cut off. The Inferred component of the Spring Hill
resource is located down dip in areas of sparse drilling (>= 40 x 40m spaced
sampling). Results of the Spring Hill 2010 mineral resource estimate (>= 1.0
g/t)
* A top cut has been applied
to the assay data and the estimated cut grade is reported
Spring Hill wireframe & drill holes showing location of Buffalo 500m
to the north Centenary
Gold Prospect (Gondwana 100%) Gondwana’s previous drilling at the
Centenary prospect has identified high-grade gold mineralisation in narrow
quartz veins at the base of a BIF unit, including 3m @ 167.26g/t Au from 40m
and 4m @ 34.28g/t Au from 51m. September 2009 drilling into the
Centenary area intersected numerous high grade intersects, including 1m @ 60.61
g/t Au (32.43 g/t by screen fire) from 50m, 1m @ 45.01 g/t Au (34.19 g/t by
screen fire) from 54m and 1m @ 13.25 g/t Au from 57m. Significant intersects 150m east of the
Centenary high grade lode have delineated a new area of mineralisation on the
Eastern BIF unit. The Phase 1 program
intersects from shallow depth include 3m @ 7.57 g/t Au from 7m in hole
09CTRC009 and 7m @ 13.91 g/t from 29m including 2m @ 36.8 g/t Au in hole
09CTRC010. Shallow drilling around this lode
had been sparse to date and significant mineralization had been intersected
either side of the tenement boundary along the line of lode, this new discovery
warranted additional drilling. A two-stage
Phase 2 RC drilling program was therefore designed to infill between the
existing 2009 drill holes and to extend drilling north and south along strike
of the eastern BIFs.
Section 9400N at Centenary
showing major rock units & eastern BIF mineralisation The second phase drilling program
was successful, with gold mineralisation intersected in 19 of 24 drill holes. The quartz vein carrying the high grade gold
in hole 09CTRC010 was not duplicated along strike but remains open at
depth. Using a 0.5 g/t lower cut off,
drill hole 09CTRC036 intersected two gold bearing lodes being 2m @ 5.62 g/t Au
from 18m and 3m @ 1.59 g/t Au from 24m.
Hole 09CTRC038, 20m south, also intersected two gold bearing lodes being
3m @ 1.66 g/t Au from 24m and 3m @ 4.89 g/t Au from 28m. These results may alternatively be expressed
as 9m @ 1.89g/t in hole 09CTRC036 (including 3m of <0.5g/t waste) and 7m @
2.82 g/t in hole 09CTRC038 (including 1m of <0.5g/t waste). This program confirmed west-dipping
gold mineralisation associated with oxidised BIF. Drilling south of 09CTRC010 increased in
grade, mostly within the deeper holes, indicating possible near-surface
depletion. With mineralisation open to
the south and down plunge, the southern area will be the focus of the third
phase RC program, tracking the near-surface gold past 30m depth later in 2010. White Horseshoe Gold Prospect (Gondwana 100%) The White Horseshoe historic
deposit consists of a modern head frame and two vertical dewatering bores which
were utilised in the last underground operation in 1984. Underground mine plans show the underground was
stoped to approximately 35m depth and is shallowly plunging to the south
west. The in-fill resource drilling
program was aimed as locating remnant ore beyond 35m depth off the base of the
underground stope and to test for a second plunging mineralised shoot off the
base of the northern open cut pit. The
northern pit area was drill tested with 4 holes, and showed only one
significant intersections being 1m @ 9.27 g/t from drill hole 09WHRC002 which
is still open at depth. The area south of the plunging
ore shoot was drilled with 4 holes which intersected 3m @ 2.89 g/t from 59m in
hole 09WHRC005, 3m @ 4.61 g/t from 66m in hole 09WHRC006, 3m @ 3.73 g/t from
71m in hole 09WHRC007 plus 1m @ 26.55 g/t from 45m and 2m @ 4.04 g/t from 56m
in hole 09WHRC008. A preliminary 3D wireframe indicates
both 1m high grade intersects in the north and the south are open down plunge
to the north west, and will be followed-up later in 2010 with additional
drilling. Zeus Gold Prospect (Gondwana 100%) Gold mineralisation at the Zeus
prospect was identified in the late 1980’s, south of the Bronco and Great
Victoria open cut gold mines. Drilling
along the geological contact south of Bronco intersected gold mineralisation in
a vertical structure, above an oxidised massive sulphide unit on a contact
between metasediments and mafic volcanics. High grade gold intersects in the
historic drilling database were identified by Gondwana geologists and the Company’s
first in-fill drill program testing for supergene enrichment above this
structure intersected 8m @ 14.8 g/t from
6m depth in hole 09ZERC003. This high
grade shallow intersect provided encouragement to further infill drill along
strike and at depth. Results from the second infill
drill program at Zeus included 5m @ 4.2
g/t from 39m in hole 10ZERC012 and 6m
@ 4.8 g/t from 34m in hole 10ZERC010 to the north of 09ZERC003. Near-surface intersects were sporadic along
strike because of a gold depletion zone apparent to 30m depth. Reviewing the deeper intersects
in light of a near-surface depletion zone, a paleochannel has been interpreted
to cross the centre of the mineralisation, effectively removing most of the
supergene gold mineralisation deposited above the massive sulphide. High grade supergene mineralisation still
exists on the margin on the channel such as was intersected with 09ZERC003. Results from the third infill
drill program include 6m @ 4.59 g/t from
12m depth in hole 10ZERC023 and 10m
@ 2.2 g/t from 33m depth in hole 10ZERC025.
Drill hole 09ZERC004 in the centre of the interpreted mineralisation,
which failed to reach target depth in the first drilling program, was
re-entered and extended to 130m depth to intersect the fresh massive sulphide
zone. The massive sulphide zone at Zeus
was intersected at 122m and high grade gold was located on the margins of the
massive sulphide being 1m @ 10.98g/t
from 121m and 1m @ 8.01g/t from
130m. The drill hole ended in
mineralisation of 0.78 g/t at 132m depth because of no additional drill rods. The massive sulphide in 09ZERC004
contains abundant marcasite with minor pyrite and pyrrhotite. The presence of marcasites indicates
alteration of primary pyrrhotite and possible re-mobilization of gold. Similar
marcasites zones are present near the water table in the Great Victoria gold
mine located 2.8km to the NNE, where mineralisation continues in the fresh
massive sulphide to at least 500m below surface. Drill hole 09ZERC004 is the
deepest hole in the area and still has not intersected fresh massive
sulphide. Additional deeper drilling is
warranted to test for high grade mineralisation in the fresh massive sulphide
within the Zeus project area. Deeper
holes being planned (+170m) will test mineralisation at depth and provide
samples for preliminary metallurgical testwork to assess gold liberation and
recoveries in the fresh zone. Wireframing is currently in
progress for the Zeus mineralised zone to assist in current planning for infill
drilling on the near surface supergene areas, along with the deeper drill holes
into the un-weathered primary massive sulphide. Results of the 2010 Zeus RC drilling program
Samples
composited based on a 0.5g/t lower cut and maximum 2m internal dilution. All samples analysed by Genalysis Laboratory
Services Pty Ltd. Widths relate to down hole thickness. Omitted holes
had no significant intersections. *Interval to EOH
#4m Composite sample Rokeby Gold Prospect (Gondwana 100%) The 2009 RC drill program at
Rokeby gold exploration prospect, Parker Range, drill tested an MMI in-soil
gold geochemical anomaly, with the best intersection of 6m @ 1.92 g/t from 50m depth in hole 09RKB014. The MMI gold anomaly
was discovered to be a surface laterite scavenging gold 300m downstream from
the location of buried gold mineralisation. Drill hole 09RKB014 was the only
hole which intersected the primary sulphide mineralised that hosts similar gold
mineralisation at Buffalo and Spring Hill.
Assessment of the detailed airborne magnetic data identified a
marginally more magnetic eastern BIF unit, which trends south west from hole
09RKB014. A 9 hole in-fill drilling program
focusing on the eastern BIF unit has since been completed and intersected gold
in 7 holes. A lack of sulphide enrichment in the drill chips corresponded to
lower gold values than was encountered in the first program, downgrading the
prospectivity of this southern target area. The drilling results (see table) include intersects 4m @ 1.43 g/t from 27m in hole
10RKRC001 and 5m @ 1.07 g/t from 20m
in hole 10RKRC005. An infill program
around the 6m @ 1.92 g/t intersect has been planned for later in the year. Results of the 2010 Rokeby RC drilling program
Samples composited based on a 0.5g/t lower cut and
maximum 2m internal dilution. All
samples analysed by Genalysis Laboratory Services Pty Ltd. Widths
relate to down hole thickness. Omitted holes had no significant intersections. Other Marvel
Loch/Parker Range Gold Prospects During the year, RC drilling
programs were also completed at Southern
Star Extension Gold Prospect and the nearby Zorro and Omega Gold Prospects.
Results were released during the year. Nickel
Exploration at Parker Range Lindsay Nickel Prospect, Jilbadji (Gondwana 100%) A V-TEM airborne electromagnetic
survey was flown over 3 areas south of Marvel Loch, at Jilbadji. The data is
still being assessed and additional targets will be released in due
course. Survey area 3 was flown over
interpreted ultramafic rocks 75km north of Forrestania, and a number of
conductive targets have been identified along linear aeromagnetic units. Using electromagnetic profile
data, the strongest AEM (airborne
electromagnetic) anomaly in this tenement has been named the Lindsay conductor. The Lindsay conductor is measured across 3
flight lines, 200m apart with a strike length of approximately 300m. The Figure below shows the
B-Field late channel profiles (deepest penetrating) across these 3 flight lines
with associated CDI sections (Conductivity Depth Images) showing the conductor
is buried approximately 250m to 300m below the surface. This target is located within the
Jilbadji nature reserve. Once the target has been outlined and the drill holes
have been designed, a vegetation survey will be required so the company can
apply for a clearing permit, which is required for clearing of drill lines and
pads in nature reserves. If the clearing permit application is approved, the
drill program should be permitted by December 2010.
Lindsay Nickel
Prospect AEM Conductor is
measured across 3 flight lines 200m apart along magnetic units |
