ASX Announcement March 2014
GUNDAROO GOLD PROJECT
General Manager 5th March 2014
The Company Announcements Office Australian Securities Exchange Electronic Lodgement System
Dear Sir/Madam
CENTREX COMPLETES MAJOR GEOCHEMICAL PROGRAM FOR GOLD PROJECT IN NSW
Highlights 245 stream sediment sample points collected over southern half of Gundaroo Gold Project 9 anomalous gold target areas identified for further evaluation Geological setting favourable for intrusion-related gold deposits Detailed mapping and shallow drilling will further prioritise targets
Summary Centrex Metals Limited (“Centrex”) has completed a major stream sediment geochemical program over the southern half of its Gundaroo Gold Project in NSW. A total of 245 stream sediment sample points were taken and analysed for both path finder elements and gold. Centrex planned this program around a high-resolution magnetic and radiometric survey it completed in October 2013. The Company is targeting intrusion-related gold deposits surrounding a large granodiorite intrusion and its associated contact metamorphic halo within a host turbidite and black shale sequence. The project lies within a regional scale fault zone, with 11 historic gold workings identified in the area during the field investigations.
The assay results have identified 9 target areas of gold anomalism for further evaluation. Detailed mapping and shallow drilling will be used to further prioritise the targets. ASX Announcement — March 2014
Gundaroo Gold Project
The Gundaroo Gold Project encompasses a 281km2 exploration licence (EL8133) located 18km east of Yass within the East Lachlan Fold Belt in NSW. The project is located roughly 10km due west of Centrex’s existing Goulburn Zinc-Lead Joint Venture with Shandong 5th Geo-Mineral Prospecting Institute (“Shandong”).
Centrex has concentrated its exploration efforts to date on the southern half of the exploration licence, the site of at least 11 historical gold workings noted during recent field work by the Company. The historic gold workings are peripheral to a large grandiorite intrusion which was emplaced into a series of turbidite and black shale host units. A contact metamorphic halo of hornfelsed host rock (thermal aureole) surrounds the granodiorite as shown below.
Figure: Local geology of Gundaroo obtained from the Canberra 100K map sheet with location of identified historic gold workings.
Centrex previously conducted a high-resolution airborne magnetic and radiometric survey over the area in October 2013. The survey identified several large scale structural trends in proximity to the granodiorite. Structural interpretation of the magnetic data highlighted numerous cross cutting fault and likely shear intersections presenting structural targets for further exploration.
CENTREX METALS LIMITED Unit[Type 1102, text] 147 Pirie Street, Adelaide, South Australia, 5000 | P: +61 8 8100 2200 | centrexmetals.com.au | ABN 97 096 298 752
ASX Announcement — March 2014
Figure: Structural interpretation of Gundaroo overlying magnetic image.
The project area is thought to be prospective for intrusion-related gold mineralisation due to its geological setting. A generalised model (shown below) for an intrusion-related gold system shows metal zonation developing outward from the margins of an intrusive pluton (granodiorite in the case of Gundaroo) out just beyond the contact metamorphic halo. Proximal gold mineralisation (proximal to the intrusion) may be associated with bismuth (Bi) or tellurium (Te), while aureole gold mineralisation (contact metamorphic halo related) may be associated with arsenic (As) or antimony (Sb).
Based on this model, Centrex designed its major stream sediment geochemical program over the area to look for not only gold anomalism but also metal zonation trends.
CENTREX METALS LIMITED Unit[Type 1102, text] 147 Pirie Street, Adelaide, South Australia, 5000 | P: +61 8 8100 2200 | centrexmetals.com.au | ABN 97 096 298 752
ASX Announcement — March 2014
Figure: General plan model of an intrusion-related gold system from the Tintina Gold Province (Hart 2005).
Stream Sediment Program Results Centrex collected a total of 245 stream sediment samples plus duplicates from across the area of interest. Land access to some properties within the program area remains to be finalised and further samples from these properties are expected to be collected in the coming months.
A sieved -1.6mm 3-5kg sediment sample was taken at each location. 100g subsamples were pulverized and a 20g split used for aqua regia digest and ICP-MS analysis primarily for path finder elements. A separate 2kg subsample was used for a bulk leach extractable gold (“BLEG”) test.
Overall metal zonation trends from the stream sediment program were generally as predicted by the intrusion-related gold system model, and is shown in the sequence of grid plots below. Bismuth and tellurium trends were relatively as expected being concentrated proximal to the main granodiorite intrusion as well as to smaller granitoid intrusions identified in the area. Arsenic and antimony were generally concentrated on the edge of the metamorphic contact halo. There is a general correlation between arsenic and identified historic workings, with arsenopyrite noted in spoil piles.
CENTREX METALS LIMITED Unit[Type 1102, text] 147 Pirie Street, Adelaide, South Australia, 5000 | P: +61 8 8100 2200 | centrexmetals.com.au | ABN 97 096 298 752
ASX Announcement — March 2014
Figure: Intrusion-related system metal zonation trends. Gold results were analysed by 75th, 90th, 95th and 99th percentile trends. Results shown below identify 9 target areas containing anomalous results for prioritisation:
Analysis of the digital terrain model shows Targets 1 and 2 to have anomalous gold values up gradient from identified historic workings along identified structural trends, outside the contact metamorphic halo within the turbidite and black shale host units. Potential exists for mineralisation extensions below the historic workings or along strike; Target 3 shows anomalous gold down gradient from a historic working again outside the mapped contact metamorphic halo within the turbidite and black shale host units. Potential exists for mineralisation extensions below the historic working; Target areas 4 though to 7 also show anomalous gold levels related to structural trends in the turbidite and black shale host units; Target 8 displays a 4 km long trend of anomalous gold values following a north-south structure proximal to the main granodiorite intrusion; and
CENTREX METALS LIMITED Unit[Type 1102, text] 147 Pirie Street, Adelaide, South Australia, 5000 | P: +61 8 8100 2200 | centrexmetals.com.au | ABN 97 096 298 752
ASX Announcement — March 2014
Target 9 shows weak gold anomalism proximal to the main granodiorite intrusion and coincident with both bismuth and tellurium anomalies. Targeted detailed field mapping, gridded soil sampling and/or shallow drilling will be considered as the next steps in further refining and evaluation of the target areas.
Figure: Gold stream sediment BLEG results and target areas for follow-up.
For further information please contact:
Ben Hammond Alastair Watts Chief Executive Officer General Manager Exploration Centrex Metals Limited Centrex Metals Limited Ph (08) 8100 2200 Ph (08) 8100 2200
CENTREX METALS LIMITED Unit[Type 1102, text] 147 Pirie Street, Adelaide, South Australia, 5000 | P: +61 8 8100 2200 | centrexmetals.com.au | ABN 97 096 298 752
ASX Announcement — March 2014
Competent Persons Statement
The information in this report relating to Exploration Results is based on information compiled by Mr Alastair Watts who is a Member of the Australasian Institute of Mining and Metallurgy. Mr Watts is the General Manager Exploration of Centrex Metals Limited. Mr Watts has sufficient experience, which is relevant to the style of mineralization and type of deposit under consideration and to the activity, which he is undertaking to qualify as a Competent Person as defined in the 2012 Edition of the “Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves”. Mr Watts consents to the inclusion in the report of the matters based on his information in the form and context in which it appears.
The checklist for reporting of exploration results is included in the table below: Criteria Explanation Sample points were determined from DTM and topographic maps as being located within drainage lines, creeks and river beds. Sediment locations were then located on ground with the samples taken at the most Sampling Technique likely location of active sediment deposition Samples were passed through a 1.6mm mesh sieve until approx. 3-5Kg was collected Samples were submitted to Bureau Veritas for sample preparation Drilling Technique Not applicable.
Drill Sample Recovery Not applicable.
Logging Not applicable. Samples were dried and weighed Sub-sample techniques and sample 100g was split, pulverised and analysed by Aqua Regia for pathfinder elements preparation The remainder of sample underwent 2Kg BLEG analysis for AU, Ag and Cu. Field duplicates where submitted at 1 in 20 and were within acceptable levels of accuracy and precision. Standards were submitted at 1 in 20 and were within acceptable levels of accuracy and precision. Quality of assay data and Blanks were submitted at 1 in 40 and were within acceptable levels of accuracy and laboratory tests precision. Internal laboratory QAQC was within acceptable levels of accuracy and precision. The BLEG and Aqua Regia techniques are partial digest and appropriate for gold and multi element surface geochemical analysis.
Primary data is stored in MS Excel and provided by the laboratory as .csv files. Verification of sampling and Verification of sample and assay data is visually checked and compared in MS Excel assaying prior to entry into a Datamine Fusion database. Location of data points See map of gold stream sediment results showing sample point locations.
Data spacing and distribution See map of gold stream sediment results showing sample point locations. See map of gold stream sediment results showing sample point locations. Geology is shown Orientation of data in relation to shaded underneath and can be referenced to the local geology map also shown. Structural trends geological structure interpreted from magnetic survey also shown for reference. No external audits were undertaken other than general advice on sampling and Audits or reviews assaying techniques. Mineral tenement and land tenure The Exploration Licence EL 8133 for Group 1 minerals was granted on July 8th 2013 for status a period of 2 years. Exploration done by other parties
CENTREX METALS LIMITED Unit[Type 1102, text] 147 Pirie Street, Adelaide, South Australia, 5000 | P: +61 8 8100 2200 | centrexmetals.com.au | ABN 97 096 298 752
ASX Announcement — March 2014
Criteria Explanation The exploration model is for an Intrusive Related gold style of mineralisation. The regional geological setting is the East Lachlan Fold Belt and the local geological Geology setting consists of a granodiorite intrusion into the host turbidite and black shale sediments. Contact metamorphism has resulted in a halo of hornfelsed host rocks. Data aggregation methods No data aggregation has been undertaken.
Relationship between mineralisation widths and intercept Not applicable. lengths See diagrams above displaying the geochemical sample locations and results, local Diagrams geology and historical workings. All relevant metal trends related to intrusion related deposits have been displayed. Balanced reporting The BLEG gold assays have been displayed instead of Aqua Regia gold assays due to the larger sample mass and representivity of BLEG samples. Other substantive exploration The airborne magnetic survey result has also been displayed. results Follow up geological mapping of anomalous areas is planned to identify areas for Further work shallow drilling.
CENTREX METALS LIMITED Unit[Type 1102, text] 147 Pirie Street, Adelaide, South Australia, 5000 | P: +61 8 8100 2200 | centrexmetals.com.au | ABN 97 096 298 752