TORONTO, Feb. 19, 2019 (GLOBE NEWSWIRE) — Xanadu Mines Ltd (ASX: XAM, TSX: XAM) (“Xanadu” or “the Company”) is pleased to report that diamond drill hole KHDDH488, which is currently being drilled at the Company’s Kharmagtai porphyry copper and gold deposit in the south Gobi region of Mongolia (Figures 1 and 2) has intersected a significant zone of visible bornite-chalcopyrite copper mineralisation. The current drilling is targeting high-grade mineralisation associated with a causative copper and gold porphyry at depth, which is yet to be drilled.
- Current drill hole (KHDDH488) has intersected porphyry style veining and tourmaline breccia with visible sulphide chalcopyrite mineralisation from 178m to current depth of 891m, with drilling continuing;
- Within this larger interval is a 100m-wide zone of visible bornite-rich mineralisation occurring from a depth of 580m. Bornite visual estimates within this zone range from 0.1% to 1% bornite
- Drilling is revealing a transition to higher temperature sulphide mineral assemblages such as bornite in the intrusive root to the deposit;
- Assays are pending.
Xanadu’s Managing Director & Chief Executive Officer, Dr Andrew Stewart, said “The current focus on drilling for extensions to the high-grade resource at Kharmagtai is proceeding at pace and the mineralisation we are encountering supports this approach. The bornite‐rich cores of the Stockwork Hill and Copper Hill deposits provide encouragement that the Kharmagtai deposit has the capacity to produce high-grade ore zones characterised by bornite-gold mineralisation.
Hole KHDDH488 has successfully demonstrated the existence of high-grade mineralisation along strike and at depth outside the current resource. This represents an exciting new development for the project following the release of an interim open-cut resource last year and
we are particularly excited with the new results from this hole which are expanding a new zone of bornite porphyry mineralisation. Bornite mineralisation typically carries significantly higher gold grades than chalcopyrite only zones.
Based upon detailed modelling, this new zone of mineralisation remains open in all directions. We have not yet found the core or the causative intrusion to mineralisation. The new high-grade extensions we have identified potentially provide the opportunity to assess Stockwork Hill as a larger open pit and as an underground resource that has the potential to deliver significant additional value to the Project.
We see these results as another step towards our goal of becoming a globally significant copper-gold company.”
STOCKWORK HILL DRILLING PROGRAM
The current drilling is targeting high-grade mineralisation associated with a causative copper and gold porphyry at depth which remains to be delineated. Drilling is targeting mineralisation below chalcopyrite‐gold mineralisation to test for a higher grade bornite core in the root zones of the causative porphyry intrusion. High grade mineralisation may be manifested as bornite‐gold‐cemented breccia or as bornite‐gold stockwork mineralisation in the causative intrusive intrusion.
Current diamond drill hole KHDDH488 is located approximately 100m east of KHDDH419 which intersected (see Xanadu’s ASX announcement – 26 September 2017; Figure 2):
− 294m @ 0.47% Cu & 0.85g/t Au (1.01% eCu or 1.59g/t eAu) from 466m, including 86m @ 0.78% Cu and 1.91g/t Au (2.0% eCu or 3.14g/t eAu) from 558m
Drill hole KHDDH488 is at a current depth of 891m, intersecting a quartz-diorite intrusion containing porphyry-style veins and tourmaline breccia with visible chalcopyrite and trace molybdenite and bornite mineralisation from 178m depth to the current depth of 891m (Figure 3 and 4).
Between the depths of 178 and 422m mineralisation occurs as porphyry vein infill, disseminations and infill to tourmaline breccias. Copper mineral species are dominated by chalcopyrite which ranges between 0.5% chalcopyrite and 1.5% chalcopyrite as a percentage of the whole rock.
Between the depths of 422m and 512m chalcopyrite mineralisation drops to between 0.1% to 0.5% chalcopyrite as disseminations and porphyry vein infill.
From the depth of 512m to the current hole depth 891m mineralisation occurs as both chalcopyrite and bornite sulphide, both occurring as disseminations and porphyry vein infill. Chalcopyrite abundances range between 0.5% to 4.5%. Within this interval is distinctive zone of bornite mineralisation between 580 to 680m ranging between 0.1% to 1% bornite in addition to the chalcopyrite.
These are visual estimates and do not represent assay results. Assay results are expected in the coming weeks.
The abundance of porphyry-type quartz veins, visual estimations of volume-percent chalcopyrite and the chalcopyrite-bornite ratio increases between 580m and 680m indicates that drilling is advancing towards higher temperature core of the Kharmagtai porphyry system (Figure 4).
It is likely that deeper drilling in the Kharmagtai deposit will reveal a transition to higher temperature sulphide mineral assemblages such as bornite in the intrusive root to the deposit.
Photos accompanying this announcement are available at
COMPETENT-QUALIFIED PERSON STATEMENT
The information in this announcement that relates to exploration results is based on information compiled by Dr Andrew Stewart who is responsible for the exploration data, comments on exploration target sizes, QA/QC and geological interpretation and information. Dr Stewart, who is an employee of Xanadu and is a Member of the Australasian Institute of Geoscientists, has sufficient experience relevant to the style of mineralisation and type of deposit under consideration and to the activity he is undertaking to qualify as the “Competent Person” as defined in the 2012 Edition of the “Australasian Code for Reporting Exploration Results, Mineral Resources and Ore Reserves” and the National Instrument 43-101. Dr Stewart consents to the inclusion in the report of the matters based on this information in the form and context in which it appears.
COPPER EQUIVALENT CALCULATIONS
The copper equivalent (CuEq) calculation represents the total metal value for each metal, multiplied by the conversion factor, summed and expressed in equivalent copper percentage. Grades have not been adjusted for metallurgical or refining recoveries and the copper equivalent grades are of an exploration nature only and intended for summarising grade. The copper equivalent calculation is intended as an indicative value only. The following copper equivalent conversion factors and long-term price assumptions have been adopted: Copper Equivalent Formula (CuEq) = Cu% + (Au (ppm) x 0.6378). Based on a copper price of $2.60/lb and a gold price of $1,300/oz.
Table 1: Currently returned assay intercepts for Stockwork Hill
|Hole ID||Prospect||From (m)||To (m)||Interval (m)||Au (g/t)||Cu (%)||CuEq (%)||AuEq (g/t)|
|KHDDH488||Stockwork Hill||Assays pending|
Intercepts are weighted averages to ensure different sample lengths do not skew the results. There is insufficient information to understand true widths at this stage. Due to the size of the system and current ambiguity around orientation of the drill hole relative to minor diluting intrusives, a larger than normal internal dilution of 9m has been used to calculate a geologically relevant intercept. Cut-off grades and maximum dilution details are included in the tabulated intercepts for clarity.
For further information, please contact:
Managing Director & Chief Executive Officer
T: +612 8280 7497
M: +976 9999 9211
SOURCE: XANADU MINES
DATE: FEBRUARY 18, 2018