ABM Resources NL (ASX:ABU) Announces More Excellent Trenching Update from Old Pirate South, Twin Bonanza Gold Camp Project
Perth, Jan 5, 2012 AEST (ABN Newswire) - ABM Resources NL (
ASX:ABU) is pleased to announce results from Phase 3 (137 samples) of the systematic Old Pirate Bulk Sampling and Trenching Program, which is part of the Company's Twin Bonanza Gold Camp Project. These results are for separate veins than those previously reported and are principally from Old Pirate South veins located approximately 100 metres south of the main Old Pirate zone.
Old pirate south trenching identifies a separate vein set to previously reported old pirate trench results:
- Phase 3 results average 29.77g/t gold over a combined vein strike length of 155 metres (137 samples) with a peak value of 215g/t gold.
- 51 samples (out of 137 Phase 3 samples) graded greater than 10g/t gold and averaged 68.61g/t gold.
- 14 samples (out of 137 Phase 3 samples) graded greater than 100g/t gold and averaged 146.07g/t gold.
- Individual veins exposed range from 0.3 to 6 metres in width (averaging 1.2 metres) including results of:
24 metres strike length averaging 83.9g/t gold.
Newly exposed hinge zone of quartz reef over an area of approximately 6 metres by 6 metres and sampled with 23 samples with average grade of 71.80g/t gold.
- Combined Phase 1, 2a, 2b and 3 show overall results of:
2,296.9 kilograms of surface quartz vein material sampled with a combined total strike length of 582 metres and a weighted average of 23.98g/t gold.
- 645 square metres of quartz veins exposed indicating average vein width of 1.2 metres.
- A further 255 longitudinal strike length trench samples and 481 costean samples (across the vein) pending assay and compilation along with duplicate samples.
Darren Holden, Managing Director said, "The longitudinal quartz surface sampling program at Old Pirate continues to add a great deal of understanding to the statistical and spatial distribution of gold in this spectacularly high grade system. These latest results are from Old Pirate South and hence represent an entirely different vein set to those previously reported. Of particular interest is a 6 metre by 6 metre zone of exposed quartz vein reef in the hinge of folded sedimentary rocks that returned an average grade of 71.8g/t gold and a 24 metre strike length of vein that returned an average of 83.9g/t gold."
Bulk Trenching at Old Pirate
Figure 1 (see link at the bottom of the release) shows the sample location of the Old Pirate South vein sampling and Figure 2 (see link at the bottom of the release)shows this sampling relative to Phase 1, 2a and 2b results previously reported for this area. The statistics of 137 samples from Phase 3 are shown in Table 1 (see link at the bottom of the release). A total of 48 samples from this phase were omitted from these statistics as they represented a separate set of veins that were sampled but were not mineralised, however, these are included in Figure 1 (see link at the bottom of the release) and Figure 2 (see link at the bottom of the release) for completeness. Table 2 (see link at the bottom of the release) shows the combined statistics from Phases 1, 2a, 2b and 3.
About the Old Pirate High-Grade Gold Prospect
The high grade Old Pirate Gold Prospect is located approximately 1,800 metres from the 1.67 Moz Buccaneer Porphyry Gold Inferred Resource. Gold at Old Pirate is distributed throughout a series of quartz veins within interlayered sandstone and shale sedimentary rocks. The veins range from centimetres to several metres wide and are defined by drilling, surface mapping and trenching over an area of 600 metres by 250 metres and to a depth of 200 metres within an overall anomalous trend in excess of 3 kilometres. The veins and sediments are folded into a plunging anticline (an arch shaped geological structure). In addition a diorite intrusive rock has been emplaced within the sedimentary rocks and is thought to have been a focus of the mineralising fluids. Previously ABM had contracted Dr Charles Butt of the CSIRO in Perth to conduct preliminary Scanning Electron Microscope Analysis work on surface gold samples and Dr Butt concluded that, based on the samples provided, the gold in the veins is not supergene enriched and is hence primary gold in quartz (refer ASX announcement 15/11/2011).
Due to the uneven distribution of the gold within the quartz veins, ABM geoscientists focus on the location and distribution of the actual veins as well as the gold within the veins. Based on the trenching results to date approximately 30% of the quartz vein samples grade greater than 10g/t gold averaging 70.53g/t gold; and 7% grade greater than 100g/t gold averaging188.72g/t gold. The overall average of all trench results to date is 23.98g/t gold.
Rationale and Sampling Method
ABM has previously drilled several high grade intercepts including 9 metres averaging 100.9g/t gold and 5 metres averaging 274g/t gold interspersed with generally lower grade intercepts. The gold can be coarse (up to 2 to 3mm grains) at Old Pirate and is hosted within quartz veins. However, the distribution of the gold within these veins is not uniform, and hence drilling will likely under-call the overall grade due to the fact that there is a less than 1 in 3 chance of intersecting high grade in any particular part of the vein. Upon advice from external consultants, rigorous and systematic bulk sampling of the quartz along the strike length of veins at Old Pirate was proposed, of which the on-going work is presented here. This information, along with statistical parameters and extents of mineralisation, will be used to determine the minimum drill spacing required for further resource work.
The process for the bulk-trenching program is:
1. Natural outcropping veins are mapped for location and width and sampled at 1 metre intervals.
2. The backhoe digger then digs a trench that exposes those parts of the veins that are hidden underneath shallow soil cover to provide a combined map of natural outcrop and trench exposed quartz vein.
3. For each metre of exposed quartz vein (both in natural outcrop and trenched veins) two representative samples of approximately 3 to 4kg are collected. Quartz is selected systematically so as not to bias individual samples. One sample is sent to the laboratory with the remaining sample retained for future checking.
4. The sample width depends on the width of the vein. In cases where the vein width is greater than 1 metre, multiple samples are collected across the vein.
5. The maximum depth of the trench is 60cm (due to permit regulations, safety considerations and to minimise environmental impact). If the soil cover is greater than 60cm then sampling does not take place.
6. Samples are processed by ALS Global in Alice Springs (NT), ALS Global in Orange (NSW) and ALS Global in Perth (WA) where they are weighed and analysed using regular fire assay. Samples greater than 10g/t are re-assayed using AA25 ore-grade method, and samples >100g/t are re-assayed using AA25 / Over Limit Dilution method.
7. Overall statistics and spatial distribution for vein strike length and grade are calculated by measuring sampled portions of vein (including a projection of short lengths (<10 metres) where the vein is inferred to have extended under cover) and then averaging all of the samples along the length.
8. Samples were originally surveyed with a hand-held GPS and re-surveyed with a differential GPS (20cm accuracy).
About the Twin Bonanza Gold Camp
The Twin Bonanza Gold Camp is centred approximately 22 kilometres south of the Tanami Road and 14 kilometres east of the Western Australia - Northern Territory border. The Project spans the highly prospective "Trans Tanami Structure" an inferred regional / tectonic geological feature which hosts numerous gold deposits including Newmont's multi-million ounce Callie Gold Mine. In 2010 ABM focused its effort at Twin Bonanza on the Old Pirate Prospect - a 3 kilometre anomaly with multiple high-grade zones in quartz veins hosted in sedimentary rocks and the Buccaneer Porphyry Gold Deposit - an intrusive related bulk tonnage gold deposit where the Company reported a 1.67Moz gold maiden resource in February 2011. In 2011 ABM has reported several extensional discoveries around Buccaneer including the Cypress, Caribbean, Empress and Eastern Contact Zones as well as high grade gold in drilling and trenching at Old Pirate. The Company aims to complete a revised resource in the first quarter of 2012.
About ABM Resources
ABM is a mineral exploration company focused on gold and gold/copper discovery in the Tanami-Arunta regions of the Northern Territory, Australia. The Company is one of the largest exploration license / license application holders in Australia. The Company has an aggressive exploration approach.
For the complete ABM announcement incluing figures and tables, please view the following link:
http://media.abnnewswire.net/media/en/docs/ASX-ABU-573326.pdf
About ABM Resources NL
ABM Resources (ASX:ABU) is developing several gold discoveries in the Central Desert region of the Northern Territory of Australia. The Company has a multi-tiered approach to exploration and development with a combination of high-grade production scenarios such as the Old Pirate High-Grade Gold Project, large scale discoveries such as Buccaneer, and regional exploration discoveries such as the Hyperion Gold Project. In addition, ABM is committed to regional exploration programs throughout its extensive holdings including the alliance with Independence Group NL at the regional Lake Mackay Project.
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