MEDUSA MINING LIMITED
ABN: 60 099 377 849
Unit 7, 11 Preston Street
Como WA 6152
PO Box 860
Canning Bridge WA 6153
Telephone: +618-9367 0601
Facsimile: +618-9367 0602
Email: admin@medusamining.com.au
Internet: www.medusamining.com.au
13 November 2007
MEDUSA MINING LIMITED
(AIM: MML)
LINGIG PORPHYRY COPPER DISCOVERY
Medusa Mining Limited ("Medusa" or the "Company"), the Australian
based company operating and developing gold mines in the Philippines,
advises that drilling will commence at the Lingig Porphyry Copper
Discovery in the first quarter of 2008. The first drill hole will
repeat and drill past the 1974 bottom of hole intersection of 150
metres that showed 0.4% copper with increasing grades down the hole.
Detailed compilation of historical drilling and mapping data has been
recently completed and is provided in this announcement.
KEY POINTS:
* The 150 metre intersection ended in high grade mineralisation at a
pre-set depth of 250 metres with the last 2 metres containing 4.93%
copper, 0.4 g/t gold and 10 g/t silver;
* The bottom 52 metres of the hole encountered higher grade
mineralisation of 0.65% copper in a phylitically altered quartz
diorite intruding overlying altered doleritic and basaltic rocks;
and
* A 98 metre wide halo of 0.27% copper mineralisation within the
immediately overlying altered volcanic host rocks suggests an
intense mineralising system.
Background
The Das-Agan project consists of Mining Production Sharing Agreement
application ("APSA") number 000024-XIII situated in Surigao del Sur
province in east Mindanao. This consists of two parcels and totalling
8,019 hectares, one to the north and one to the south-east of the
Co-O mine and millsite, as shown on Figure 1 (please see the link at
the end of this announcement).
The Lingig porphyry copper discovery is contained in the
south-eastern parcel of the MPSA application.
The Lingig area was located as a result of an aid programme between
Filipino and Japanese geologists and technicians in 1972 to 1974 over
eastern Mindanao (Dept of Natural Resources, 1974). An initial 3,000
km² prospective area was located by geological and geochemical
surveys and was subjected to additional geological mapping and
geochemistry. A smaller 170 km² area was selected and subjected to
detailed geological mapping and geochemistry followed by Induced
Polarisation ("IP") geophysical surveys.
A programme of five holes with pre-set depths of 250 metres was
completed on five different targets.
Geology and drilling results
Figure 2 (please see the link at the end of this announcement) shows
the current geology of the area as well as copper soil geochemistry
and contoured resisitivity and frequency effect results of the
Induced Polarisation survey. The surface mapping and drilling
suggests that this is an intrusive complex with dacite, dolerite,
diorite and quartz diorite rocks intruding a basaltic sequence.
Previous mapping also identified epithermal veins up to 1 metre wide,
which are generally gold poor and relatively base metal enriched.
They have been worked sporadically by local prospectors.
In 1997 Barrick Gold Philippines ('Barrick') assessed the project for
its gold potential through mapping and the collection of 110 rock
samples. This work identified a circular feature that contains most
of the mapped argillic alteration and a large elongate quartz veined
breccia measuring 750 metres x 1,200 metres and located approximately
1,500 metres south of drill hole DDH1.
Sampling by Barrick of the breccia returned gold values between 0.1
and 1.3 g/t gold. Fresh rocks with disseminated grains of sphalerite
(zinc) and galena (lead) were found to have higher gold values
ranging from 0.3 to 1.3 g/t gold than intensely weathered rocks. The
lead-zinc association is consistent with generally accepted metal
zoning that occurs around the periphery of porphyry copper deposits
In addition, within the circular feature, a second zone of silicified
rocks with quartz stockworking was identified over an area of
approximately 500 metres x 600 metres which assayed from 0.03 to 1.5
g/t gold.
Recent reconnaissance has located bleached and silica-clay altered
rocks with quartz veinlets approximately 300 metres to the north of
DDH1.
Drill hole DDH1
After passing through 100 metres of propylitically and argillically
altered doleritic and basaltic rocks with erratic copper
mineralisation, drill hole DDH1 intersected disseminated and stringer
style pyrite and chalcopyrite mineralisation for 98 metres in
increasingly argillically altered basaltic and doleritic rocks before
entering higher grade mineralisation in phylitically altered quartz
diorite porphyry. The graphic log of the drill hole is shown in
Figure 3 (please see the link at the end of this announcement).
Table I: Summary of intersections in drill hole DDH 1
Depth (metres) Intersection Host rocks, alteration &
mineralisation
0 to 100 Erratic values to Propylitically (chlorite and
0.89% Cu epidote) and argillically altered
dolerite and basalt with
disseminated and stringer pyrite,
rare chalcopyrite.
100 to 198 98 metres @ 0.27% Propylitically and argillically
Cu (clay) altered dolerite and basalt
with a moderate increase of
disseminated and stringer pyrite
and chalcopyrite.
198 to 250 52 metres @ 0.65% Phylitically altered
Cu (silica-sericite) quartz diorite
porphyry with disseminated and
stringer pyrite and chalcopyrite
increasing with depth.
Incl. 248 to 2 metres @ 4.93%
250 Cu,
[End of Hole] 0.4g/t Au,10g/t Ag
TOTAL: 100 to 150 metres @ 0.40%
250 Cu
The DDH1 drill hole results bode well for a fully preserved porphyry
copper deposit which is exhibiting increasing grades with depth, and
suggests that DDH1's pre-set depth stopped short of the high grade
core that is commonly present in these styles of deposit. Further
drilling at this site was recommended but not carried out. The other
four holes to the south intersected minor copper mineralisation.
Drill holes DDH2 to DDH5
DDH2 intersected quartz diorite intruded by diorite dykes from 11
metres to the bottom of the hole at 250 metres. Both rock types
exhibit weak propyllitic alteration. Minor copper mineralisation of
0.16% was encountered from 16 to 20 metres and 0.24% from 48 to 50
metres.
DDH3 intersected basaltic rocks from nine metres to the end of the
hole at 250 metres and which have been intruded by doleritic and
quartz diorite dykes. The rocks have been affected by weak
chloritisation and rare epidotisation. Minor pyrite occurs along
fractures and pyrite-chalcopyrite stringers are rare with the highest
copper value of 0.99% at 12 to 14 metres and all other values are
less than 0.1% copper.
DDH4 intersected basaltic and doleritic rocks from 7.5 metres to 96
metres and quartz diorite to the bottom of the hole at 250 metres.
The quartz diorite exhibits an upper chilled margin and is cut by
quartz diorite dykes at 138 and 216 metres. Except for one assay of
0.69% copper at 128 metres, all other copper values are less than
0.1% copper.
DDH5 intersected dolerite from 15.20 metres to 69 metres, quartz
diorite to 210 metres and dolerite to the end of the hole at 250
metres. The dolerite's alteration is propylitic and of a similar
intensity as in holes DDH3 and DDH4. Hydrothermal alteration of the
quartz diorite is weak. Copper mineralisation was encountered from
15.20 metres to 34 metres with 18.80 metres at 0.34%, from 52 to 54
metres with 2 metres at 0.69%, 68 to 70 metres with two metres at
0.69% and four metres from 230 to 234 metres with 0.34%. All other
intervals were less than 0.1% copper.
Results analysis
Drill hole DDH1 intersected the top of a mineralised
copper-gold-silver quartz diorite porphyry. The other drill holes
indicate varying degrees of low intensity alteration and minor copper
mineralisation probably associated with lithothogy boundaries and
faults.
Of particular note is the 98 metre disseminated copper halo above the
quartz diorite, suggestive of an intense mineralising system, as well
as the erratic copper values in the propylitic alteration envelope
above this dissemianted zone. This has similarities to the Lutopan
orebody of the Atlas Toledo Mine where ore grade replacement
mineralisation is hosted in volcanics for a width of 120 metres along
a strike length of 900 metres (Mines & Geosciences Bureau, 1986). The
Atlas Toledo orebodies are also similarly bounded by two parallel
northeast-trending faults as seen at Lingig.
Diorite and quartz diorite intrusive rocks are commonly closely
associated with many porphyry copper deposits in the Philippines.
Some examples are the Tampakan Deposit (resources of 2 billion tonnes
at 0.59% copper and 0.23 g/t gold, www.indophil.com and Middleton et
al., 2004), the Boyongan Deposit (resources of 300 million tonnes at
0.6% copper and 1.0 g/t gold, www.mgb.gov.ph,
www.philexmining.com.ph), the Atlas Toledo deposits (resources of
1.53 billion tonnes at 0.41% copper and 0.24 g/t gold,
www.atlasphilippines.com), the Hinoba-an Deposit (resources of 293
million tonnes at 0.36% copper, www.copperresources.com), and others.
It is also noteworthy that copper mineralisation is more common in
DDH5 than DDH2 to DDH4 and that DDH5 is located on the edge of the
circular feature and its contained extensive argillic alteration zone
and large breccia and stockwork bodies.
Geoff Davis, Managing Director, commented:
""The drill programme scheduled for early 2008 will initially confirm
the discovery results from the 1974 programme and then commence
outlining the size of the mineralised zone.
"Recent reconnaissance has extended the surface indications to the
north and we are optimistic that further drilling will confirm the
existence of a significant resource."
Enquiries:
Medusa Mining Limited +61 8 9367 0601
Geoffrey Davis, Managing Director
Roy Daniel, Finance Director
Ambrian Partners +44 (0)20 7776 6400
Richard Brown / Richard Greenfield
Bankside Consultants +44 (0)20 7367 8888
Michael Padley / Louise Davis
References:
Department of Natural Resources, 1974: Report on Geological Survey of
Eastern Mindanao, Phase III.
Middleton C., Buenavista A., Rohrlach B., Gonzalez J., Subang L., &
Moreno G., 2004: A Geological Review of the Tampakan Copper-Gold
Deposit, Southern Mindanao, Philippines.
Mines and Geosciences, Ministry of Natural Resources, 1986: Geology
and Mineral Resources of the Philippines, Vol. II.
Information in this report relating to Exploration Results is based
on information compiled by Mr Geoff Davis, who is a member of The
Australian Institute of Geoscientists. Mr Davis is the Managing
Director of Medusa Mining Limited and has sufficient experience which
is relevant to the style of mineralisation and type of deposits under
consideration and to the activity which he is undertaking to qualify
as a Competent Person as defined in the 2004 Edition of the
"Australian Code for Reporting of Exploration Results, Mineral
Resources and Ore Reserves". Mr Davis consents to the inclusion in
the report of the matters based on his information in the form and
context in which it appears.
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