ABN 91 124 752 745
ASX Code: GBZ COMPANY DIRECTORS
Peter Thompson
Managing Director/ Executive Chairman
Neil Norris
Exploration Director - Executive
Hun Seng Tan
Non- Executive Director
CONTACT DETAILS
Principal & Registered Office
Suite 8, 7 The Esplanade, Mt Pleasant, WA 6153
Exploration Office
10 Parker Street,
Castlemaine, Victoria 3450
Website
www.gbmr.com.au
Email [email protected] Phone
+61 (8) 9316 9100
Fax
+61 (8) 9315 5475
Phone (Exploration Office)
+61 (3) 5470 5033
Mining of the existing open cut at Koala ceased in 1996 when the gold price was less than A$500 per ounce. Improvements in mining efficiency during the last twenty years combined with increase in gold price make the deepening of the existing open pit a potentially viable consideration.
A detailed review of the geology of the Koala Deposit confirmed that lower grade stockwork mineralisation extends for several metres on either side of the central high-grade chalcedony zone both below the old open pit, and around the old underground workings.
|
Resource Category
|
Ore Type
|
Cutoff Grade
(g/t Au)
|
Tonnes
(t)
|
Grade
Au (g/t)
|
Contained Gold
(ozs.)
|
|
Indicated
|
open pit
|
Fresh
|
0.4
|
250,000
|
2.9
|
22,800
|
|
Oxide
|
0.4
|
30,000
|
1.1
|
1,100
|
|
Transition
|
0.4
|
90,000
|
3.3
|
9,600
|
|
underground
|
Fresh
|
2.0
|
50,000
|
3.0
|
5,100
|
|
sub total Indicated
|
420,000
|
2.8
|
38,500
|
|
Inferred
|
open pit
|
Fresh
|
0.4
|
600,000
|
2.3
|
44,900
|
|
Oxide
|
0.4
|
40,000
|
0.8
|
1,200
|
|
Transition
|
0.4
|
110,000
|
1.6
|
5,600
|
|
underground
|
Fresh
|
2.0
|
230,000
|
3.9
|
28,500
|
|
sub total Inferred
|
980,000
|
2.6
|
80,200
|
|
total
|
open pit
|
Fresh
|
0.4
|
850,000
|
2.5
|
67,700
|
|
Oxide
|
0.4
|
70,000
|
0.9
|
2,200
|
|
Transition
|
0.4
|
190,000
|
2.4
|
15,100
|
|
underground
|
Fresh
|
2.0
|
280,000
|
3.7
|
33,700
|
|
TOTAL
|
1,400,000
|
2.6
|
118,700
|
Table 1: Koala summary reported by resource category and oxidation state. Please note rounding; tonnes (1,000t), grade (0.1 g/t) and contained gold (100 ounces).
The Koala leases occur within the Drummond Basin (see figure below). Mineralisation in the Drummond Basin is typified by high sulphidation epithermal style precious metal Deposits. Examples include Pajingo (3.0 Moz), Wirralie (1.1 Moz), Yandan (0.6 Moz) and Koala. Mineralisation is typified by fine grained electrum in quartz veins and or breccias. These Deposits are variously interpreted to have formed in locally extensional jogs or bends of transform fault systems.
Figure 1: Mt Coolon Gold Project tenement group location plan.
Mt Coolon Gold Project Forward Programme
The Company will continue the evaluation of the known mineralising systems and aims to advance a number of near-term production options and activities during the September Quarter.
Current activities include:
-
Finalising the Scoping Study - evaluating the viability of heap leaching gold extraction from the known oxide resources at the Eugenia Deposit.
-
Investigating Toll Milling options for the Koala and Glen Eva gold resources.
-
Drilling of the untested high - priority IP drill target adjacent to the Koala Lode system.
-
Complete infill drilling and a resource estimate on the Bimurra Prospect. Previously GBM have estimated an exploration target (Refer ASX announcement dated 21 September 2015).
-
Continue the evaluation of the Conway Prospect which contains multiple prospects and is considered to hold potential for both bonanza epithermal vein style deposits and bulk tonnage low grade disseminated deposits. The highest grade intersects occur within the Wobegong prospect and include 14 m @ 16.08 g/t Au from surface in CFS005 (including 1 m @ 208 g/t Au from 1 m), 2 m @ 26.6 g/t Au from 40 m in CON006 and 8 m @ 4.91 g/t Au from 26 m in C013. (Refer ASX announcement dated 17 February 2016).
For Further information please contact:
Peter Thompson Karen Oswald
Managing Director Marko Communications
GBM Resources Limited Tel: 0423 602 353
Tel: 08 9316 9100 Email: [email protected]
About GBM Resources
GBM Resources Ltd (ASX: GBZ) is an Australian resource company that listed on the ASX in 2007, headquartered in Perth WA, with exploration operations in Victoria and Queensland.
The Company's primary focus is in key commodities of gold and copper-gold, assets in Australia. GBM tenements cover an area greater than 4,300 square kilometres in eight major projects areas in Queensland and Victoria.
GBM is prioritising the exploration and development of the Mount Coolon Gold Project and Mount Morgan Gold Copper Project.
2016 Resource Estimate
The current Koala resource estimate is based on over 30,000 metres of drilling including 20,780 metres of diamond drilling completed by various companies. In addition, stope outlines and details of previous underground mining and open pit mining and grade control data have been used to guide interpretation and estimation.
Gold mineralisation at Koala occurs as high grade colloform quartz (+/- sulphide) veins surrounded by a halo of low grade gold mineralisation comprising quartz stringer vein stockworks in variably altered (propyllitic silica - pyrite) andesite. The high grade veins have been offset and compartmentalised by cross faults.
The gold mineralisation domain was interpreted from raw assays on 25 m spaced sections from gold grades and logged veining percentages. The interpretation was carried out at a nominal 0.2 g/t Au as the raw assay data showed no natural lower grade cut-off 0.2 g/t was selected as the nominal interpretation grade based on being sufficiently below likely open pit mining cut-off grades.
For inclusion in a gold domain, a minimum true width of 2 m above the nominal domain grade was necessary. In addition only mineralisation zones intercepted in at least two sections with at least two holes on both sections were included.
The gold domain was interpreted to honour grade control data from the Ross Mining pit (GC data was not used for grade interpolation) and also used the small scale mineralisation geometries apparent in the GC data as templates for interpretation of the exploration data.
Three gold sub-domains were interpreted. The main sub-domain comprises mineralisation hosted by the main Koala quartz vein and associated low grade halo. The splays sub-domain comprises mineralisation interpreted as being hosted by splayed from, or sub-parallel to, the main zone. The flat sub-domain comprises near flat lying, low grade mineralisation to the east of the main shaft. The flat domain is close to co-incident with the base of transition, however inspection of core from this zone shows that it is in situ quartz stringer stockwork mineralisation and not re-mobilised secondary mineralisation.
Figure 2:. Gold domains showing main (green), splays (pink) and flat (yellow) sub-domains, Sullivans Fault (dark blue wireframe) and Ross Mining pit (brown wireframe) for reference.Top Left; plan view, Bottom Left; longitudinal view, Right; oblique view along strike to the North.