BARKLY COPPER-GOLD PROJECT
Blaze International Limited is in a Farm-In Joint Venture Agreement with Meteoric Resources NL over the highly prospective Barkly Copper-Gold Project. Blaze has the right to earn up to an 80% interest in the project. The project is located around 30 km east of the town of Tennant Creek in the Northern Territory (Figure 1).
The highest priority target within the Barkly Project is the Bluebird Prospect. It comprises a 1.6km-long gravity ridge open to the east where shallow geochemical drilling by Meteoric Resources identified a 600m-long copper anomaly, also open to the east. Follow-up drilling confirmed Tennant Creek-style copper-gold mineralisation associated with ironstone. The ironstones and mineralisation are often discordant to the host sediments and are considered to be a high-grade variant of the iron oxide-copper-gold (IOCG) deposits found in Proterozoic terranes in Australia.
Figure 1 - Location of the Barkly Cu-Au Project
EXPLORATION AND DEVELOPMENT STRATEGY FOR BLUEBIRD
Blaze's primary objective is to estimate a JORC compliant mineral resource and ultimately to develop a mining project at the Bluebird Prospect1, 2. Bluebird is the highest priority and most advanced prospect within the Barkly Project area. Systematic close spaced drilling will aim to accurately define the grade and the geometry of the Cu-Au-Bi mineralisation.
Early drilling was very successful with all holes intersecting significant Cu-Au-Bi mineralisation. The standout holes were BBDD-2: 20m at 8.17g/t Au, 0.61% Cu and 0.22% Bi from 157m (Including 4 metres at 37.9g/t Au, 0.66% Cu and 0.80% Bi from 169m) and BBRC-5: 25m at 1.9% Cu and 0.3g/t Au from 69m (Including 4 metres at 8.99% Cu and 1.06g/t Au from 74 metres). Based on our drilling results, the mineralisation is now defined to a depth of at least 150m vertical from surface and over a strike length of up to 120m. The mineralisation starts at less than 50m below surface.
The highest grade mineralisation is located on the footwall contact of the ironstone body. BBRC-2, which was drilled previously by Meteoric Resources, did not penetrate this footwall contact position (Figure 2). This is the reason for the narrower and lower grade intercept in BBRC-2 compared to the recent drilling by Blaze. The very high grade gold intersected by BBDD-2 is a particularly encouraging development for the Bluebird Prospect as it is the deepest hole drilled to date. Gold grades and mineralisation thickness appear to be increasing substantially with depth.
The next phase of drilling at Bluebird will aim to extend the mineralisation to the east, west, and at depth. Blaze estimates that a drilling program of approximately 2200m comprising approximately 14 holes should be sufficient to estimate an initial JORC mineral resource for Bluebird.
Figure 3 - Long section of Bluebird, looking north, showing recent drilling, historic drilling, planned drilling and new geological interpretation.
BLUEBIRD IS COMPARABLE TO HISTORIC MINES
High-grade mineralisation at Bluebird is directly comparable in many respects, including grades, to other Tennant Creek style mines. Research by Blaze International has revealed some similarities between the mineralised system at Bluebird and the Peko and Nobles Nob deposits, both located just 20km away. The ore metal ratio appears to be similar to the Peko deposit. These comparisons are very positive as the Peko Mine produced 3.6Mt @ 3.5g/t Au and 4% Cu for 400,000oz Au and 146,000t Cu, and Nobles Nob produced 2Mt at 17g/t Au for 1.1Moz.
Mineralisation at Bluebird is hosted by a chlorite-hematite breccia body which transitions laterally to a magnetite hematite ironstone. The chlorite-hematite breccia is interpreted to be the result of alteration associated with the Cu-Au-Bi mineralising event of a pre-existing magnetite ironstone body. The main difference between Bluebird and Peko is that the gangue associated alteration at Bluebird is dominated by chlorite–hematite whereas at Peko the dominant gangue associated alteration is hematite-quartz.
The strike length of the Peko deposit was no more than 100m and overall thickness was about 20m (see figures 4 and 5). The deposit was made up of a series of ore shoots hosted within a sub vertical hematite breccia host. The ore shoot positions, which measured no more than 40m strike by 80m plunge by 6m thick, were associated with changes in dip of the hematite breccia host. These changes in dip may have been related to cross cutting shears or thrust faults. The general dip of the ore body flattened with depth. Similarly, Blaze’s Bluebird prospect also appears to be flattening with depth. This should result in higher recoverable ore tonnage if an open pit mining scenario is achieved.2
To date the strike length of the Bluebird prospect is approximately 120m and the overall thickness is approximately 20m. It should be noted that Bluebird is still open along strike and down dip, and appears to be increasing in thickness with depth.
The central cross section at Bluebird has produced two very high grade intercepts in BBRC-5 and BBDD-2 with relatively subdued intercepts in BBDD-1 and BBRC-2. Grade changes appear to be related to changes in dip, similar to the Peko deposit. Structural observations on the diamond core in BBDD-2 revealed the presence of relatively flat dipping east west striking structures associated with the very high grade mineralisation. These structures are interpreted to be related to thrust faulting.
Bluebird is interpreted to be a concealed and therefore previously undiscovered “Tennant Creek Style” copper gold deposit not unlike Peko or Nobles Nob.1
Figure 4 - Comparative cross section through the Peko Deposit3
1 At this stage, the potential quantity and grade of the Bluebird mineralisation is conceptual in nature, as Blaze International has determined that insufficient work has been undertaken to define a mineral resource and it is uncertain if further exploration will result in the determination of a mineral resource.
2 At this stage it is unknown whether a mining scenario will be achieved at the Bluebird Prospect.
Figure 5 - Long section of the Peko Deposit
3 Figures of the Peko Deposit and other relevant information about the Peko mineralisation came from “Geological Report on Peko Gold Mine, Tennant Creek Gold-Field” by J.F Ivanac, 1950. The grades shown on Figure 4 are indications only based on an average of spot grades plotted on the historic cross section.
GEOPHYSICAL DATA REVIEW AND REGIONAL TARGETING
Two important geophysical datasets for targeting Tennant Creek style Cu-Au-Bi mineralisation are aeromagnetics and gravity. A number of companies have collected aeromagnetic and gravity data within the Barkly Project area in numerous surveys over several decades. Blaze has acquired the raw data from these historic surveys and is re-processing, gridding and imaging the data.
The reprocessed, gridded and imaged data, in conjunction with the surface geochemical data, will allow Blaze geologists to fingerprint the signature of the Bluebird mineralisation and to look for other similar features within the Barkly Project area. A series of targets will be generated and ranked based on coincident magnetic, gravity and geochemical anomalies similar to Bluebird and/or other deposits in the Tennant Creek Mineral Field (TCMF).
Any areas of no coverage or poor data quality in the aforementioned datasets will be re surveyed to provide full coverage of the project. This will allow a comprehensive targeting program to be undertaken and maximise the chance of new discoveries.
The magnetite rich ironstones hosting the mineralisation strongly contrast with the relatively weakly magnetic Warramunga Formation country rock sediments. The ironstones and associated sulphide mineralisation are also denser than the country rock and may therefore be amenable to detection by gravity surveying. Gravity is particularly important in targeting nonmagnetic hematite hosted deposits. Peko and Nobles Nob are both examples of hematite hosted orebodies within the TCMF.
LOCATION & ACCESS
The licence that comprises the Barkly Project lies on a Tennant Creek Station pastoral lease which is privately owned. The project is accessed by regional access roads and station tracks via the Gosse River Road.
The Barkly Project is located on granted exploration licence EL28620. The lease is owned 100% by Meteoric Resources. Blaze International has the option to earn an 80% interest in the lease by spending $600,000 on exploration and commencing a feasibility study.