Poster - Terra Search Pty Ltd

BRILLIANT BRUMBY PROJECT
Jodo Gold Pty Ltd
LOLWORTH RANGE, QLD.
R J Morrison
Brilliant Brumby looking east to Townsville
Drilling BBRC037, Silica Ridge.
(Qld-Globe GoogleEarth).
Introduction
Jodo Gold and InterGroup Mining Ltd hold three
EPMs in the Lolworth Range 95 km WSW of
Charters Towers. The main group of prospects lie
over 2km strike on the Brilliant Brumby Line on
MLa 100008. Other prospects include the Brandy
Creek, Newcrest Anomaly 1, Golden Ridge and
others. The Brilliant Brumby was a very late gold
discovery, not found until 1937, five years after
Brandy Creek.
Geological setting
The Project is dominated by Middle Palaeozoic
granites which intruded earlier metamorphics and
volcanics. In the eastern sub-blocks the older
lithologies were intruded by Permian stocks and
subsequently by NW striking andesitic and NE
striking dacitic dykes. Dissected Tertiary fluvial
sediments and residual deposits lie on the eroded
intrusive rocks both on the Lolworth Range
plateau and the plains below.
Ore controls
Gold at the Brilliant Brumby Line and Brandy
Creek is found in mesothermal quartz veins within
sericitic alteration cutting the Devonian Amarra
Granite. If the 382 Ma dating of the Granite is
correct, the lodes are younger than at the 410 Ma
Charters Towers Goldfield. The steeply dipping
en-echelon structural style, and less sulphide
content is also different to Charters Towers.
On the Brilliant Brumby Line the lodes occur in a
northerly trending sinistral shear system over 2
km long. The orientation of the lodes changes
along strike highlighting the varying stress
regime, with the best mineralization occurring in
North and NNW striking lodes, a favourable
dilational orientation at the time of mineralisation,
Further north, the shear zone swings north,
providing a favourable structure for the lodes at
Silica Ridge. North of Silica Ridge the controlling
structures separate further and the NW trending
Loafer lodes were deposited. In the far northeast
the Surprise lode strikes northerly.
Contract Geologist
Brilliant Brumby Line RC gold intersections
(D Morrison).
Successful exploration methods
Exploration methods have included detailed
geological mapping, mullock and rock chip
sampling, ground magnetic surveys, stream
sediment sampling, soil sampling, auger drilling
and 4,633m of reverse circulation drilling.
Reverse Circulation Drilling
RC drilling of sub-cropping lodes was the most
successful method providing intersections of
potential economic interest including:
Brilliant Brumby North
BBRC_039
1m
@
2.2 g/t Au
BBRC_039
1m
@
3.2 g/t Au
BBRC_039A 1 m
@
74.9 g/t Au
Silica Ridge
BBRC_037
6m
@
4.6 g/t Au
Mystery Lodes
BBRC_036
1m
@
4.5 g/t Au
BBRC_036A 2 m
@
2.7 g/t Au
Brilliant Brumby:
BBRC_041
1m
@
3.0 g/t Au.
The work identified open pit potential at the
Brilliant Brumby North, Silica Ridge confirmed
that high gold grades are open at depth. Logprobability plots of estimated true width gold
intersections show a log-normal distribution
which enabled estimates of the mean grade of
richer ore to be made. At a 1 m x g/t Au cut-off the
mean gold “accumulation” is ~3.9 m x g/t Au.
The potentially ore grade intersections resulted in
the application for ML 100008 over the 2.4km
strike length of the Brilliant Brumby Line.
“Niche” rock chip sampling
To identify zones of better gold mineralization
along the Brilliant Brumby Line, closely spaced
“niche” style rock chip samples of quartz mullock
and outcrop quartz were assayed. These found
high values at Brilliant Brumby North with
scattered high gold also at Mystery and Silica
Ridge. The other prospects were generally lower
grade and less consistent.
Assay results from Brandy Creek mullock show a
clear Au-Ag-Pb association with the maximum
assay being 15 g/t Au / 1.4% Pb. Rock chip
assays from the Golden Ridge area in the east
showed low gold but anomalous Ag, Bi, Mo & W
indicative of possible Permo-Carboniferous
mineralization. In the south, Newcrest Anomaly 1
quartz veins rock chip samples near a 60ppb Au
BCL stream sediment anomaly assayed 0.7 g/t Au.
Western Brumby Project EPMs & prospects
(Mines Online Maps).
Brilliant Brumby Line lodes looking NNE.
(Digital Reflections).
Map to Mine Pty Ltd
Mapping and sampling at Brandy Creek.
1:1,000 Geological Fact Mapping
Detailed fact mapping proved quick, cheap and
effective in areas of reasonable outcrop. Along
the Brilliant Brumby Line it was undertaken to
assist the evaluation and resource estimation of
the lodes. Mapping was also undertaken at the
Worm and Brandy Creek.
A standard Garmin GPS was used for survey
control. Where GPS readings were not sufficiently
accurate, laser rangefinder and compass survey
was used from GPS fixed positions.
At Brilliant Brumby the results enabled correlation
of drilling results to be made on individual ore
shoots establishing the northerly plunge of the
Brilliant Brumby lodes. The mapping also:
•
defined the en-echelon lode geometry,
•
located the extent of previously unmapped
Loafer prospects and other 1930s “lost” lodes,
•
established the pre-ore age of crosscutting pegmatites and andesitic dykes.
•
showed magnetic lows to be partly related
to close-jointed granite (deeper weathering?),
•
verified the under-cover lode potential of
the system north of Surprise,
1:1,000 fact mapping around the >1 g/t Au soil
gold at the Worm located promising quartz float.
The quartz however is mostly lag on the granite
beneath the flat lying Tertiary cover sediments.
RC drilling will be required to establish whether
the gold has a local or a distal source.
Unsubstantiated reports of old mines WNW of
Brilliant Brumby were followed up leading to the
location of the 1932 Brandy Creek workings.
Geological mapping established five lodes similar
to Brilliant Brumby containing six significant
workings over a strike length of >400m.
Brilliant Brumby Line mapped lodes on
ground magnetics (Terra Search).
Ground Magnetics
Detailed ground magnetic surveys over the
Brilliant Brumby Line and the Worm undertaken
by Terra Search in 2013 targeting gold-related
magnetite destruction zones defined linear
magnetic lows within the granite. Overlaying the
2014 mapping on the magnetics shows that
although there is some correlation with the
linears, the majority are not mineralized. Some
drill holes also tested magnetic lows without
intersecting sericitic alteration. It is concluded
that the sericitic alteration event locally
reactivated older magnetite depletion structures,
but elsewhere cross-cuts them.
Auger drilling.
Experimental shallow auger drilling at Surprise to
check the potential for extensions to the lode
beneath the Tertiary cover. Anomalous gold was
detected on the projection of the Surprise lodes.
High Pb in Ionic Leach assays suggests a masked
lode to the east. Pattern (25m x 100m) shallow
auger holes drilled along 400m strike of the main
Worm soil gold area found that gold above
detection was mainly in the vicinity of the high
soil gold. The maximum assay was 0.16 g/t Au.
Stream sediment sampling
Conventional BCL gold stream sediment sampling
was undertaken in conjunction with orientation
Ionic Leach partial leach geochemistry to also
obtain "pathfinder" geochemistry. BCL results
gave mixed results with assays not always
consistent with historical results. “New”
anomalous Au was found at Anomaly 1 and
upstream from Brandy Creek.
Auger drilling Tertiary cover, Surprise North.
Exploration Strategy
The strategy is to delineate adequate gold
resources at several localities sufficient to enable
early commencement of profitable mining
operations.
Additional drilling programs are required to
delineate resources at the open pit targets defined
at Brilliant Brumby North and Silica Ridge. The
down plunge underground mineable potential of
these and the Brilliant Brumby and Surprise lodes
warrant testing. Drilling to assess other targets at
Brandy Creek, Pactolus, Loafer , Loafer South and
beneath the Tertiary cover north of Surprise and
the Worm are also required.
Geological assessment, mapping and sampling of
the other prospects should continue particularly
at Newcest Anomaly 1, Metana Reef, Golden Spur,
GSQ 386575, Worm North, Early Bird, Surprise
North, Newcrest West Brumby, Python / Adder,
and GSQ 320562.
Undiscovered gold lodes beneath the Tertiary
cover should be explored with partial leach soil
geochemical surveys and auger drill geochemical
assisted by resistivity surveys and ground
magnetics where appropriate.
References
Beams S, Bates T, Markey P, & Beams T, 2014. Drilling Report, Brilliant Brumby Prospect,
EPM 18419, 36 RC Drilling Program, Dec. 2013 – Jan. 2014. Terra Search Pty Ltd
Document # JODO2014001, Townsville.
Campbell M D, King J D, 2011. Brilliant Brumby Project: Northeast Queensland, Australia.
Competent Persons Report for Brumby Group Pty Ltd. 138p. Unpublished Internal Report,
12M Associates, Houston, Texas.
Duckworth R, 2014. EPM 18419 North Queensland, Annual Report for 12 Months to 9th
May 2014. Map to Mine Report MTM2014-15 (Unpubl.).
Morrison D, 2015. EPM 25299 ‘Spear’ North Queensland, Annual Report for 12 Months to
7th April 2015. Map to Mine Report MTM2015-14 (Unpubl.).
Morrison D, 2014.
Brilliant Brumby Open File Data Assessment Report. Map to
Mine Report MTM2014-07 (Unpubl.).
Morrison G W and Beams S D, 1995. Geological Setting and Mineralization Style of Ore
Deposits of Northeast Queensland: In: Mineral Deposits of North east Queensland Geology
and Geochemistry. (Ed. S D Beams), pp1-32. 17th International Geochemical Exploration
Symposium, EGRU contribution 52.
Purcell P W, 1988. A-P 4669M, Lolworth, Six monthly report for the period ending 26
March 1988. Elliott Exploration Co Pty Ltd for Bruce Resources. Unpublished company
report CR 18243.
Acknowledgements Thanks to Jodo Gold Pty Ltd and InterGroup Mining Pty Ltd Directors
Walter Doyle, Kev Doyle and Steve White for permission to participate.
Acknowledgements
Thanks to Jodo Gold Pty Ltd InterGroup Mining
Ltd and Directors Walter Doyle, Kev Doyle and
Steve White for permission to participate.
Contact
Jim Morrison, 0438 404 886
Map to Mine Pty Ltd
22 Bell Street
SOUTH TOWNSVILLE, Qld, 4810.
[email protected]
Brilliant Brumby 1:1,000 fact mapping.
Stream sediment sampling EPM25299.