19.9 metres of massive sulphides from 340.2 to 360.1m down-hole
(true width not known at this time, top of intercept is approximately 286m vertically below surface)
Geological Discussion of the Lower Zone and TLDD0026
Ongoing work at Monty has provided sufficient detail to enable Sandfire to provide an updated interpretation of the geological setting of the known mineralisation at Monty. An updated vertical longitudinal projection (looking to the south-east) is shown in Figure 2.
The Lower Zone at Monty incorporates the massive sulphide mineralisation intersected in TLDD0004A, TLDD0005, TLDD0009, TLDD0010 (previously reported), TLDD0021 (previously reported, assays pending) and TLDD0026 (reported above, assays pending).
Figure 2: Vertical longitudinal projection of Monty showing drill-hole piercepoints at the top of the primary intercept shown in bold. All intercepts are down-hole widths.
The 19.9 metre intersection of massive sulphides in TLDD0026 is interpreted by Sandfire to be a continuation of the 7.3m (down-hole width) primary mineralisation previously reported from TLDD0021 (see TLM ASX announcement - 2 October 2015) (see Figure 2 above and Appendix 3). The mineralisation in the upper two intersections in TLDD0026 appears to be consistent with that of the higher level, subordinate mineralisation zones intersected in TLDD0021 (see Appendix 3).
Based on field observations by Sandfire, the mineralogy of the 19.9 metre intercept in TLDD0026 differs from that observed in the previously reported intersections of the primary mineralisation in TLDD0004A, TLDD0005, TLDD0009, TLDD0010, and TLDD0021.
The massive sulphides intersected in these earlier holes comprises variable amounts of chalcopyrite (main copper-bearing sulphide mineral), pyrite and pyrrhotite, minor sphalerite and galena, along with silicate and talc gangue minerals (with gold and silver).
The primary mineralisation in TLDD0026 has a similar composition to that of the earlier holes, but also contains variable amounts of bornite (a copper-bearing sulphide). Photos of the drill core from the mineralised intervals in TLDD0026 are provided in Appendix 2 to this release.
Bornite is an important copper mineral and commonly occurs in VMS deposits globally, along with the more common copper mineral; chalcopyrite. Bornite, in isolation, typically has a copper content of approximately 63 per cent by mass compared with chalcopyrite's typical copper content of ~35% by mass.
Both the bornite and other sulphide minerals are deformed and exhibit features consistent with re-crystallisation, which suggests that modification of the massive sulphide may have occurred during deformation.
Photo: TLDD0026 NQ2 drill core showing bornite in foliation (right) and rimming pyrite and pyrrhotite (left) - intercept shown is from 351m down-hole.
Talisman understands that Bornite has not previously been seen at the DeGrussa mine to any material extent.
This potentially significant sighting of Bornite mineralisation at Monty will require additional work to put its presence in TLDD0026 into context and determine its significance in the exploration campaign at Monty and further afield at Springfield, but is considered by Talisman to be highly encouraging at this stage.
Diamond core from TLDD0026 will be despatched by Sandfire for analysis.
Additional Recent Lower Zone Drilling Results
Sandfire have also advised Talisman of the results from two other diamond drill holes targeting the Lower Zone at Monty; TLDD0024 and TLDD0028.
TLDD0024 was drilled approximately 66 metres down-dip of previously reported hole TLDD0010 (intercepts including 10.5m grading 18.9%Cu and 3.1 g/t Au from 359.7m down hole and 4.7m grading 12.8%Cu and 2.5 g/t Au from 373.6m down hole ) (see TLM ASX announcement - 8 September 2015) (see Figures 1 and 2).
Sandfire have advised that TLDD0024 intersected a single horizon of 1.8 metres of massive sulphides within the host sequence of the Lower Zone from 445.6m to 447.3m down-hole (true width not known at this time, top of intercept is approximately 381m vertically below surface). Assays are awaited.
TLDD0028 was drilled approximately 37 metres along strike to the south-west from previously reported hole TLDD0021 (7.3 metres of massive sulphides from 363.1m down-hole) (see TLM ASX announcement - 2 October 2015) and 46 metres from the mineralisation intersected in TLDD0020 (1.2 metres of massive sulphides from 272.6m down-hole), (see Figures 1 and 2).
TLDD0028 intersected the prospective horizon with weak haematite, jasper and minor disseminated sulphides logged in the core. No massive sulphides were encountered and Sandfire have advised that further drilling will be undertaken down-dip to help define the extents of the mineralisation in this area.
Recent Lower Zone Assay Results
Sandfire have also advised that it has received assay results from the previously reported Diamond drill holes
TLDD0014 and TLDD0011 (see Figure 1, Figure 2 and Table 1)
TLDD0014 was located 45 metres along strike of TLDD0026 (see Figures 1 and 2) and intersected:
0.4 metres grading 1.2% Cu and 1.3g/t Au from 370.9m to 371.3m down-hole
(true width not known at this time).
Monty Upper Zone
Upper Zone Drilling Results and Geological Discussion / Interpretation
Sandfire have advised that reverse circulation drill holes TLRC0015, TLRC0016 and TLRC0017 were drilled up- dip of, and at the opposite orientation to, previously reported holes TLRC0004, TLRC0008 and TLRC0009 to test for potential mineralisation (see Figures 1 and 2).
No visible mineralisation was observed by Sandfire and the mineralised zone is therefore interpreted by Sandfire to not extend to the surface (see Figure 2).
Sandfire advise that the spatial position of the host horizon intersected in TLRC0016 and TLRC0017 indicates at this time that the host horizon in the near-surface portion of the Upper Zone may be locally overturned and dip at approximately 75° to the south-east.
As the earlier drill-holes that intersected mineralisation in the Upper Zone (TLRC0004, TLRC0008 and TLRC0009) were drilled at a dip of 60 - 62° to the south-east, as previously reported the true widths of mineralisation in these holes is anticipated to be significantly lower than the down-hole widths.
Additional diamond holes are planned by Sandfire to be drilled below TLRC0004, TLRC0008 and TLRC0009 in order to test for down-dip mineralisation as well as to provide information to accurately constrain the dip of the Upper Zone.
Assay Results Upper Zone
Sandfire have also advised that it has received assay results from the previously reported reverse circulation drill hole TLRC0009 (see Figures 1 and 2 and Tables 1 and 2).
TLRC0009 intersected mineralisation approximately 40 metres along strike to the north-east of TLRC004 (see Figures 1 and 2) and returned an intersection of: