Heron Resources Limited (ASX:HRR “Heron” or the
“Company”) is pleased to report that it has received
assays for the recently intersected base-metal mineralisation at
its wholly-owned Woodlawn Zinc-Copper Project, located 250km
south-west of Sydney, New South Wales, Australia. The
intercepts at both the G2 and Lisa Lens positions extend the known
limits of the mineralisation in these areas and is expected to
provide additional early-stage production for the
operation.
- Drilling of G2 and Lisa lenses provide additional shallow
intercepts with high-grade assays
- G2 Lens Results - see table 1:
http://www.heronresources.com/tsximages/20180604/20180604_table1.jpg
- Lisa Lens Results - see table 2:
http://www.heronresources.com/tsximages/20180604/20180604_table2.jpg
- The drilling extends both the G2 and Lisa lenses. In
particular, the intercepts at G2 extend the mineralised zone closer
towards the mine portal providing potentially an additional shallow
production source for the early stages of the mine. The Lisa Lens
intercepts confirm the up-dip extension to the mineralisation.
- Ten core holes for 1,770m completed in current program
with further drilling underway
Commenting on the intercepts, Heron Resources Managing Director
and CEO, Mr Wayne Taylor said: “The current program continues to
provide valuable information to assist with the earliest stages of
the underground mine plan. These high-grade intercepts define the
lens boundaries and will help underpin a further update for initial
mine production. The high-grade copper intercept at Lisa Lens
will also be very likely to extend the mining inventory in this
area, all adding additional value to the early stages of the
project.”
G2 Lens Drilling
The G2 Lens is located adjacent to the planned
route of the decline at 120m to 150m below the surface and
represents potentially the first underground production source that
would be processed through the plant. Seven core holes for
1,050m have been completed recently on the southern extent of the
G2 Lens to better delineate this position which was open to the
south of WNDD0133 (see Figures 1-3).
____________________________________
1 Refer to the end of this release for the ZnEq
calculation.
As reported previously the initial DDH intersected significant
sulphide mineralisation with the following assay results now being
reported:
- 6.1m grading 37.2% ZnEq from 120.3m (22.0% Zn, 1.0% Cu,
7.1% Pb, 3.3g/t Au, 115g/t Ag) WNDD0138 G2HW
- 1.9m grading 8.2% ZnEq from 138.3m (4.1% Zn, 0.3% Cu, 2.2% Pb,
0.5g/t Au, 27g/t Ag) WNDD0138 G2 Main
- 8.3m grading 15.6% ZnEq from 128.7m (8.2%Zn, 0.3% Cu, 4.8% Pb,
0.6g/t Au, 62g/t Ag) WNDD0139 G2 Main
- 6.5m grading 5.6% ZnEq from 153.5m (3.7% Zn, 0.2% Cu, 1.2% Pb,
0.1g/t Au, 9g/t Ag) WNDD0140 G2 Main
These results are very encouraging and extend
the G2 Lens approximately 40m to the south in this area. The
very high-grade G2 Hanging Wall (G2HW) position has also been
extended to the south beyond WNDD0116, although its continuity is
expected to be variable. Follow-up DDH around the initial
intercepts have now delineated the rhyolite contact in the area
which defines the limits of mineralisation. Drilling is
continuing at G2 to better define the up-dip extension of the
zone.
Lisa Lens Drilling
The Lisa Lens is located adjacent to the I Lens
in the upper-most horizon within the Woodlawn mineral system
(Figure 4) approximately 80m from the planned decline route at
200-250m below the surface. The current program is designed
to better delineate the lens position here, where a significant
Cu-dominated intercept was returned located approximately 40m up
dip from previous drilling:
- 8.6m grading 3.6% Cu (12.5% ZnEq)
from 202.0m (0.3% Zn, 3.6% Cu, 0.04% Pb, 0.8g/t Au, 8g/t Ag)
WNDD0135
- 3.8m grading 6.9% ZnEq from 228.3m
(2.0% Zn, 0.2% Cu, 1.4% Pb, 1.9g/t Au, 47g/t Ag) WNDD0135
These intercepts from WNDD0135, combined with
results of an electromagnetic survey, suggests the lens has a
strike length of about 35-40m and extends down dip approximately
120m. The copper-rich intercept aligns with the Cu-dominated
intercept in historic hole W145 (8.0m @ 1.9% Cu). Such copper
zones typically occur on the southern edge of the Woodlawn lenses
and it is likely polymetallic mineralisation occurs along strike to
the north as noted in WNDD0104 (12.4m @ 20% ZnEq) and WNDD0015
(4.2m @ 28.5% ZnEq)1.
Figure 1: Long-section of the G2 Main Lens
showing interpreted lens shape, previous drill piercements and the
two recent drill intercepts. View to northeast.
http://www.heronresources.com/tsximages/20180604/20180604_fig1.jpg
Figure 2: Long-section of the G2 Hanging Wall
Lens, located approximately 25m stratigraphically above the G2 Main
Lens, showing interpreted lens shape, previous drill piercements
and the recent drill intercept in WNDD0138. View to
northeast.
http://www.heronresources.com/tsximages/20180604/20180604_fig2.jpg
Figure 3: Massive sphalerite rich drill
core from WNDD0138 in the G2 Hanging Wall position. Handheld
Niton XRF analysis of these sphalerite rich massive sulphide zones
returned an average of approximately 30% Zn (some 25 readings were
taken) over the interval 120.4 to 126.4m. The highest assay
in this zone was 34.6% Zn over a 1m sample interval.
http://www.heronresources.com/tsximages/20180604/20180604_fig3.jpg
Figure 4: Long-section of the Lisa Lens
showing interpreted lens shape, the location of previous drill
intercepts and the recent drill intercept in WNDD0135. View
to northeast.
http://www.heronresources.com/tsximages/20180604/20180604_fig4.jpg
About Heron Resources
Limited:
Heron’s primary focus is the development of its
100% owned, high grade Woodlawn Zinc-Copper Project located 250km
southwest of Sydney, New South Wales, Australia.
Compliance Statement (JORC 2012 and
NI43-101)
The technical information in this report
relating to the exploration results is based on information
compiled by Mr. David von Perger, who is a Member of the Australian
Institute of Mining and Metallurgy (Chartered Professional –
Geology). Mr. von Perger is a full time employee of Heron Resources
Limited and has sufficient experience, which is relevant to the
style of mineralisation 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 and “qualified person” as this
term is defined in Canadian National Instrument 43-101 (“NI
43-101”). Mr. von Perger has approved the scientific and technical
disclosure in the news release.
Zinc equivalent calculation
The zinc equivalent ZnEq calculation takes into
account, mining costs, milling costs, recoveries, payability
(including transport and refining charges) and metal prices in
generating a Zinc equivalent value for Au, Ag, Cu, Pb and Zn.
ZnEq = Zn%+Cu%*3.12+Pb%*0.81+*Au g/t*0.86+Ag g/t*0.03. Metal
prices used in the calculation are: Zn US$2,300/t, Pb US$ 2,050/t,
Cu US$6,600/t, Au US$1,250/oz and Ag US$18/oz. It is Heron’s
view that all the metals within this formula are expected to be
recovered and sold. Metallurgical metal recoveries used for
the formula are 88% Zn, 70% Pb, 70% Cu, 33% Au and 82% Ag; these
are based on historical recoveries at Woodlawn and supported by
metallurgical test work undertaken during the 2015-16 feasibility
study.
Appendix 1
Drill hole details for diamond drill holes
completed as part of the Phase V drill campaign.
Hole No. |
WMGEast (m) |
WMGNorth (m) |
WMGRL (m) |
Surface Dip |
WMG SurfaceAzimuth |
EOHDepth (m) |
Target |
WNDD0134 |
9074.3 |
19544.1 |
2795 |
-74 |
65 |
239.7 |
Lisa Lens |
WNDD0135 |
9074.3 |
19544.1 |
2795 |
-73 |
92 |
242.3 |
Lisa Lens |
WNDD0137W1 |
9074.3 |
19544.1 |
2795 |
-70 |
110 |
242.8 |
Lisa Lens |
WNDD0138 |
9157.8 |
19165.8 |
2794 |
-68 |
99 |
170.9 |
G2HW and G2 Lenses |
WNDD0139 |
9157.8 |
19165.8 |
2794 |
-59 |
125 |
170.8 |
G2HW and G2 Lenses |
WNDD0140 |
9157.8 |
19165.8 |
2794 |
-55 |
138 |
179.4 |
G2 Lens |
WNDD0141 |
9157.8 |
19165.8 |
2794 |
-68 |
125 |
167.8 |
G2HW and G2 Lenses |
WNDD0142 |
9157.8 |
19165.8 |
2794 |
-76 |
100 |
161.8 |
G2HW and G2 Lenses |
WNDD0143 |
9169.7 |
19113.3 |
2794 |
-60 |
135 |
148.3 |
G2 Lens |
WNDD0144 |
9169.7 |
19113.3 |
2794 |
-62 |
95 |
50.4 |
G2 Lens |
Notes: WMG = Woodlawn Mine Grid
Assays results to date for diamond drill
holes completed as part of the Phase V drill
campaign.
Hole No |
From (m) |
To (m) |
Downhole Width (m) |
Estimated True Width (m) |
ZnEq% |
Zn (%) |
Cu (%) |
Pb (% |
Au (g/t) |
Ag (g/t) |
|
|
WNDD0135 |
202.0 |
210.6 |
8.6 |
6.9 |
12.5 |
0.3 |
3.6 |
0.0 |
0.8 |
7.70 |
|
WNDD0135 |
228.3 |
232.0 |
3.8 |
3.0 |
6.9 |
2.0 |
0.2 |
1.4 |
1.9 |
47.4 |
|
WNDD0138 |
120.3 |
126.4 |
6.1 |
4.9 |
37.2 |
22.0 |
1.0 |
7.1 |
3.3 |
115.4 |
|
WNDD0138 |
130.0 |
132.0 |
2.0 |
1.6 |
4.2 |
1.8 |
0.1 |
1.2 |
0.3 |
22.4 |
|
WNDD0138 |
138.3 |
140.2 |
1.9 |
1.5 |
8.2 |
4.1 |
0.3 |
2.2 |
0.5 |
27.3 |
|
WNDD0139 |
128.7 |
137.0 |
8.3 |
6.6 |
15.6 |
8.2 |
0.3 |
4.8 |
0.6 |
62.1 |
|
WNDD0140 |
153.5 |
160.0 |
6.5 |
5.2 |
5.6 |
3.7 |
0.2 |
1.2 |
0.1 |
9.30 |
|
JORC 2012 Table 1
Section 1 Sampling Techniques and Data
(Criteria in this section applies to all
succeeding sections)
Criteria |
JORC Code explanation |
Commentary |
Sampling techniques |
- Nature and quality of sampling (eg cut channels, random chips,
or specific specialised industry standard measurement tools
appropriate to the minerals under investigation, such as down hole
gamma sondes, or handheld XRF instruments, etc). These examples
should not be taken as limiting the broad meaning of sampling.
- Include reference to measures taken to ensure sample
representivity and the appropriate calibration of any measurement
tools or systems used.
- Aspects of the determination of mineralisation that are
Material to the Public Report.
|
- Samples from the diamond-core holes are being taken from HQ3
sized core and sampled on a nominal 1 metre basis taking into
account smaller sample intervals up to geological contacts.
The core is cut in along the core orientation line (where
available). Generally in massive sulphide zones one portion is
quartered for assaying, half the core is preserved for
metallurgical testing and the remaining quarter is retained as
reference material in the core trays. In non-massive sulphide
material half core is sampled.
- These sampling methods are standard industry methods and are
believed to provide acceptably representative samples for the type
of mineralisation encountered.
- A hand held XRF (Thermo Scientific Niton XL3t XRF Analyser)
device is used routinely to provide first pass Zn, Cu and Pb (plus
other elements) analyses of the core. This instrument is
regularly serviced and calibrated by qualified technicians and the
Company conducts its own QAQC on the results to confirm they are
reasonable. The results from this device are not considered
properly representative of the core intervals, however, they do
provide a broad indication of the likely grade of mineralised
zones.
|
Drilling techniques |
- Drill type (eg core, reverse circulation, open-hole hammer,
rotary air blast, auger, Bangka, sonic, etc) and details.
|
- Diamond-core drilling is being undertaken by Sandvik DE710 rigs
with mostly HQ3 sized core being drilled. Various techniques
are employed to ensure the hole is kept within limits of the
planned position. The core is laid out in standard plastic
cores trays.
|
Drill sample recovery |
- Method of recording and assessing core and chip sample
recoveries and results assessed.
|
- The core is transported to an enclosed core logging area and
recoveries are recorded. Recoveries to date have been better
than 95%. The core is orientated where possible and marked
with 1 metre downhole intervals for logging and sampling.
|
Logging |
- Whether core and chip samples have been geologically and
geotechnically logged to a level of detail to support appropriate
Mineral Resource estimation, mining studies and metallurgical
studies.
|
- The diamond core is geologically logged by qualified
geologists. Geotechnical logging is also being undertaken on
selected sections of the core. Samples for metallurgical
testing are being kept in a freezer to reduce oxidation prior to
being transported to the metallurgical laboratory.
|
Sub-sampling techniques and sample preparation |
- For all sample types, the nature, quality and appropriateness
of the sample preparation technique.
|
- All core samples are crushed then pulverised in a ring
pulveriser (LM5) to a nominal 90% passing 75 micron. An
approximately 250g pulp sub-sample is taken from the large sample
and residual material stored.
- A quartz flush (approximately 0.5 kilogram of white,
medium-grained sand) is put through the LM5 pulveriser prior to
each new batch of samples. A number of quartz flushes are
also put through the pulveriser after each massive sulphide sample
to ensure the bowl is clean prior to the next sample being
processed. A selection of this pulverised quartz flush
material is then analysed and reported by the lab to gauge the
potential level of contamination that may be carried through from
one sample to the next.
|
Quality of assay data and laboratory tests |
- The nature, quality and appropriateness of the assaying and
laboratory procedures used and whether the technique is considered
partial or total.
- Nature of quality control procedures adopted (eg standards,
blanks, duplicates, external laboratory checks) and whether
acceptable levels of accuracy (ie lack of bias) and precision have
been established.
|
- Sample preparation and assaying is being conducted through ALS
Laboratories, Orange, NSW with certain final analysis of pulps
being undertaken at the ALS Laboratory in Brisbane QLD.
- Gold is determined by 30g fire assay fusion with ICP-AES
analysis to 1ppb LLD.
- Other elements by mixed acid digestion followed by ICP-AES
analysis.
- Laboratory quality control standards (blanks, standards and
duplicates) are inserted at a rate of 5 per 35 samples for ICP
work.
|
Verification of sampling and assaying |
- The verification of significant intersections by either
independent or alternative company personnel.
- Documentation of primary data, data entry procedures, data
verification, data storage (physical and electronic)
protocols.
- Discuss any adjustment to assay data.
|
- An internal review of results was undertaken by Company
personnel. No independent verification was undertaken at this
stage.
- All field and laboratory data has been entered into an industry
standard database (DataShed) using a contract database
administrator (DBA) in the Company’s Perth office. Validation
of both the field and laboratory data is undertaken prior to final
acceptance and reporting of the data.
- Quality control samples from both the Company and the
Laboratory are assessed by the DBA and reported to the Company
geologists for verification. All assay data must pass this
data verification and quality control process before being
reported.
|
Location of data points |
- Accuracy and quality of surveys used to locate drill holes
(collar and down-hole surveys), trenches, mine workings and other
locations used in Mineral Resource estimation.
|
- The drill collars were initially located with a combination of
handheld GPS and licenced surveyor using a DGPS system, with
accuracy of about 1m. The final drill collars are “picked up”
by a licenced surveyor with accuracy to 1 centimetre.
- While drilling is being undertaken, downhole surveys are
conducted using a downhole survey tool that records the magnetic
azimuth and dip of the hole. These recordings are taken
approximately every 30 metres downhole. As a check, certain
holes are also being surveyed with gyroscopic methods, with some 10
percent of holes drilled in the current program also surveyed by
this method after drilling has been completed.
|
Data spacing and distribution |
- Data spacing for reporting of Exploration Results.
- Whether the data spacing and distribution is sufficient to
establish the degree of geological and grade continuity appropriate
for the Mineral Resource and Ore Reserve estimation procedure(s)
and classifications applied.
- Whether sample compositing has been applied.
|
- The diamond drilling is mostly following-up in various
directions from previous intercepts with a nominal spacing in the
range 20-40m. This drill hole spacing will be sufficient to
provide Mineral Resource estimates in the future.
|
Orientation of data in relation to geological structure |
- Whether the orientation of sampling achieves unbiased sampling
of possible structures and the extent to which this is known,
considering the deposit type.
|
- The drilling orientation is designed to intersect the
mineralised lenses at a close to perpendicular angle. The
mineralised lenses are dipping at approximately 50-70 degrees to
the west and the drilling is approximately at 60 degrees to the
east. This will vary from hole to hole.
|
Sample security |
- The measures taken to ensure sample security.
|
- The cut core samples are secured in green plastic bags and are
being transported to the ALS laboratory in Orange, NSW via a
courier service or with Company personnel/contractors.
|
Audits or reviews |
- The results of any audits or reviews of sampling techniques and
data.
|
- A review and assessment of the laboratory procedures was under
taken by Company personnel in late 2014 resulting in some changes
to their sample pulverising procedure.
|
Section
2
Reporting of Exploration Results
(Criteria listed in the preceding section also
apply to this section.)
Criteria |
JORC Code explanation |
Commentary |
Mineral tenement and land tenure status |
- Type, reference name/number, location and ownership including
agreements or material issues with third parties such as joint
ventures, partnerships, overriding royalties, native title
interests, historical sites, wilderness or national park and
environmental settings.
- The security of the tenure held at the time of reporting along
with any known impediments to obtaining a licence to operate in the
area.
|
- The Woodlawn project is located 250km south-west of Sydney in
the state of New South Wales. The area is on the Great
Australian Dividing range and has an elevation around 800m above
sea-level. The mineral and mining rights to the project are
owned 100% by the Company through the granted, special (Crown and
Private Land) mining lease 20 (SML20). The lease has been
renewed to the 16 November 2029.
- The project area is on private land owned by Veolia who operate
a waste disposal facility that utilises the historical open-pit
void. An agreement is in place with Veolia for the Company to
purchase certain sections of this private land to facilitate future
mining and processing activities. A cooperation agreement is
also in place between Veolia and the Company that covers drilling
and other exploration activities in the area.
|
Exploration done by other parties |
- Acknowledgment and appraisal of exploration by other
parties.
|
- The Woodlawn deposit was discovered by the Jododex JV in 1970
and open-pit mining began in 1978 and continued through to 1987.
The project was bought outright by Rio Tinto Ltd (CRA) in 1984 who
completed the open-pit mining. Underground operations commenced in
1986 and the project was sold to Denehurst Ltd in 1987 who
continued underground mining up until 1998. The mineral
rights to the project were then acquired by TriAusMin Ltd in 1999
who conducted studies on a tailings re-treatment process and
further underground operations. Heron took 100% ownership of
the project in August 2014 following the merger of the two
companies. Some 980 surface and underground drill holes have
been completed on the project to date and various studies
undertaken.
|
Geology |
- Deposit type, geological setting and style of
mineralization.
|
- The Woodlawn deposit comprises volcanogenic massive sulphide
mineralisation consisting of stratabound lenses of pyrite,
sphalerite, galena and chalcopyrite. The mineralisation is
hosted in the Silurian aged Woodlawn Felsic Volcanic package of the
Goulburn sub-basin on the eastern side of the Lachlan Fold
Belt.
|
Drill hole Information |
-
- A summary of all information material to the understanding of
the exploration results including a tabulation of the following
information for all Material drill holes:
|
- A table detailing the drill hole information is given in the
body of the report.
|
Data aggregation methods |
- In reporting Exploration Results, weighting averaging
techniques, maximum and/or minimum grade truncations (eg cutting of
high grades) and cut-off grades are usually Material and should be
stated.
- Where aggregate intercepts incorporate short lengths of high
grade results and longer lengths of low grade results, the
procedure used for such aggregation should be stated and some
typical examples of such aggregations should be shown in
detail.
|
- The reported assays are weighted for their assay interval
width. The majority of the assay interval widths are 1 metre, but
this weighting does take into account the non 1 metre intervals and
weights the average assay results accordingly.
- For the results reported here no weighting was included for
specific gravity (SG) measurements that have been taken for all
sample intervals as the samples within the intervals are of a
similar SG.
|
Relationship between mineralization widths and intercept
lengths |
- These relationships are particularly important in the reporting
of Exploration Results.
- If the geometry of the mineralisation with respect to the drill
hole angle is known, its nature should be reported.
|
- The massive sulphide zone intercepted in the drilling to date
is at an angle to the drill axis and therefore the true width is
estimated to be some 0.8 of down-hole width. That is, a
down-hole intercept of 16m equates to a true width of 12m.
This is only an approximation at this stage and will be better
estimated as the orientation of the Lenses is better defined.
|
Diagrams |
- Appropriate maps and sections (with scales) and tabulations of
intercepts should be included for any significant discovery being
reported These should include, but not be limited to a plan view of
drill hole collar locations and appropriate sectional views.
|
- Where relevant, a diagram showing the hole positions relevant
for current phase of exploration is included in the release.
Other maps and diagrams showing the location of the Woodlawn
Project are included in other recent Company releases.
|
Balanced reporting |
- Where comprehensive reporting of all Exploration Results is not
practicable, representative reporting of both low and high grades
and/or widths should be practiced to avoid misleading reporting of
Results.
|
- The reporting is considered to be balanced and all relevant
results have been disclosed for this current phase of
exploration.
|
Other substantive exploration data |
- Other exploration data, if meaningful and material, should be
reported including (but not limited to): geological observations;
geophysical survey results; geochemical survey results; bulk
samples – size and method of treatment; metallurgical test results;
bulk density, groundwater, geotechnical and rock characteristics;
potential deleterious or contaminating substances.
|
- Selected drill holes are being cased with 50 millimetre PVC
tubing for potential down-hole DHEM surveying which is undertaken
on the majority of the holes drilled.
- Geotechnical logging is undertaken nominally 25m either side of
the massive sulphide lenses.
- Archimedes method SG measurements are determined for all
sampled intervals.
|
Further work |
- The nature and scale of planned further work (eg tests for
lateral extensions or depth extensions or large-scale step-out
drilling).
|
- The fifth phase of drilling at Woodlawn commenced in March 2018
with some 2,000m to be drilled. The program was primarily designed
to infill and expand the Lisa and G2 Lens positions. A number of
geotechnical holes were also planned as part of this program.
- With the positive results of the initial holes at the G2 Lens,
an extra 1,200m was added to program to better delineate the
mineralisation around the planned route of the decline. This
extended program is still underway at the time of writing.
- The results of the program are being assessed as they come to
hand and adjustments to the program made as is warranted.
|
1 WNDD0104: 12.4m @ 20% ZnEq (12.0% Zn, 1.6% Cu, 2.0% Pb, 0.7g/t
Au, 23g/t Ag); WNDD0015: 4.2m @ 28.5% ZnEq (17.7% Zn, 1.6% Cu, 5.0%
Pb, 1.1g/t Au, 28g/t Ag)
For further information, please visit www.heronresources.com.au or contact:
Australia:
Mr Wayne Taylor
Managing Director and Chief Executive Officer
Tel: +61 2 9119 8111 or +61 8 6500 9200
Email: heron@heronresources.com.au
Jon Snowball
FTI Consulting
+61 2 8298 6100
jon.snowball@fticonsulting.com