Projects & Prospects
Projects
The North Stawell Minerals tenements span the highly
prospective western margin of the Stawell Zone (the
Stawell Corridor) for 60km from Stawell to Murtoa. The gold
prospective geology is mostly (85%) covered by a layer of
un-mineralised Murray Basin sediments (termed ‘cover’). The
cover, although an increased challenge for exploration, has
significant potential to mask shallow, multi-million ounce gold
mineralisation similar to the Stawell Mine to the immediate
south (4.9Moz Au historic mining).
Using the Stawell Mine as a model for mineralisation, and
aided by unprecedented high resolution geophysics to “see
through” the cover, NSM has identified dozens of target
areas that may be similar to Stawell, and has prioritised
twelve for initial focus. Any of these highly prospective areas
has the potential to host shallow, multi-million ounce gold
mineralisation just beneath the thin cover.
North Stawell Minerals (NSM) explores against a Stawell Gold
model. High-resolution gravity and magnetics data allows
interpretation of the possible position of non-outcropping
basalt domes (either deep or under a blanket of cover). The
margins of the domes (and the areas interpreted to have
structural similarities to Stawell are prioritised for drilling. This
has returned a very high ‘hit rate’ for anomalous gold. Even
where the basalt is deeper, potential remains.
The Stawell model indicates mineralisation wraps around the
margins of the basalt buttress, but also as vein systems that
‘ramps off’ the domes into the wall rock above the basalts
where structural pressure shadows are interpreted. At
Stawell, the Mariners-type mineralisation is a good example
this type of veining, extending 300m above the causative
dome (pictured in figure 3). Therefore, by consistently
exploring above the interpreted domes, NSM maximises the
opportunity to hit Mariners-type veins, and follow them down
system to Stawell-type mineralsiation at depth.
Mariners-type Mineralisation
High-grade, shallow gold target type in the Stawell Zone.
The Mariner’s-type mineralization is an important part of the exploration model at North Stawell Minerals. The Mariner’s-types occur as sediment-hosted quartz vein splays above the deeper basalt that can be “followed” to find deeper, basalt-flanking mineralisation as seen at Stawell. The Mariner’s Lode at Stawell is also notable for its excellent historic gold endowment (approx. 1Moz Au at 30 g/t Au historic production[8]) and is attractive target for exploration above identified basalts.
Interested in some extra geological detail?:
The Mariners Lodes, part of the Hanging Wall Lodes at Stawell, is a significant part of the Stawell gold mining complex in Victoria, Australia. It represents a specific type of gold mineralization within the larger Stawell gold system[1][2] – a series of sub-parallel lodes hosted by faults and shear zones above the western flank of the large basalt butress known as the Magdala Anticline[4].
The Hangingwall Lodes were an important source of early production, yielding ~30t of gold between 1856 and 1880 at ~30 g/t Au [8] (nb this is historic production – not in-ground resource). They are hosted by white mica-altered portions of the Albion Formation, located within and adjacent to the Stawell Fault and in intersecting flat faults. These lodes occur ~100 to 300 m above the Magdala Basalt (boxed area, Figure 1)
Geologically, the Mariners Area is a fault zone formed by the diverging Fault Splays which form a ‘wedge’. The faults have a high graphite content, which has enabled both faults to capture remobilized gold [7]. The Mariners Lode also differs to Stawell-types in that it is mostly brecciated quartz rather than a laminated quartz vein. The lode structures are generally identified as a quartz-sulphide rich shear zone with varying widths of 2m to 10m. Gold occurs as free native grains in quartz and in association with an arsenopyrite-pyrite-chalcopyrite-sphalerite-galena assemblage [5].The mineralized zones of the Mariners Area strike at around 335° and dip around 50° towards the southwest. All shear zone lodes differ from the typical Central Lode structure due to having diffuse boundaries on both the hangingwall and footwall of the structures.
In the broader context of the Stawell gold field, the Mariners system ultimately links to the Central Lode and Golden Gift lodes, which occur on the margin of the basalt and continue to a depth of 1.6km[1]. This interconnected system has contributed to 40 years of current mining operations, as well as the 70 years of historic production.
Projects by location
Ashens
The Ashens Prospect. Background: AGG Gravity
(Warmer Colours = Greater Chance of Basalt Dome at Depth).
RESULTS:
- 5m at 1.21 g/t Au from 56m (ASA115), and
- 7m at 1.11 g/t Au from 58m (ASA184)
Ashens Prospect Overview.
The Ashens Prospect, located in
the far north of NSM’s tenements,
features a 4.1 km basalt unit
bounded by significant faults and is
fully under cover. The southern
end is intruded by late rocks along
northeast-trending faults, and
its structure and intrusive history
closely resemble that of Stawell.
Airborne gravity data has refined
the basalt interpretation, guiding
NSM’s exploration efforts.
Historic drilling consists of five
lines spaced about 1 km apart,
with all lines intersecting basalts
and returning anomalous gold.
Notably, two northern lines showed
significant gold grades along the
basalt’s ‘hinge,’ suggesting a 1.8
km trend of higher grades and
the potential for Stawell-type
mineralization along the basalt
margins.
Challenger
Challenger extends south from
Ashens and is entirely under cover.
The northern half (about 3.5 km of
the 7 km target) has been drilled,
but the southern portion remains
untested. The prospect shows high
arsenic anomalies and continuous
low-grade gold results, mainly
on the western side of the basalt,
though significant grades (+1 g/t
Au) have not been found. The
basalt has not been intersected,
suggesting that Challenger is
deeper than Ashens, which may
explain the lower grades while
indicating potential at depth.
Effective exploration at Challenger
will require identifying near-surface
mineralization conduits through
drilling or geophysics and pursuing
them deeper.
Lubeck Tip
Lubeck Tip Prospect: Background: AGG Gravity
(Warmer Colours = Greater Chance of a Basalt Dome at Depth).
RESULTS:
- 1m @ 5.05 g/t Au from 56m (NSAC0172)
- 1m @ 3.00 g/t Au from 42m (NSAC0173)
Lubeck Tip represents an
exceptional application of the
NSM exploration model through
cover. Interpreted as a covered,
structurally bounded basalt slice
in the eastern Stawell Corridor,
this previously untested target
was identified in geophysics and
returned +1 g/t Au grades within the
first (16 hole) air core program.
The target is 1.6km in length and
interpreted to be truncated to
the south by a northeast trending
fault that trends towards a small
interpreted intrusive, 500m to the
east. Sheared basalts have been
intersected to the northern end
of the target, indicating that the
prospective dilation zone in the
roof of the basalt may be shallow,
and not eroded off the target,
preserving gold potential.
Lubeck
The 4.2 km Lubeck Prospect lies
immediately west of the Coongee
Fault, the eastern boundary
of the Stawell Gold Corridor. It
occurs in the same structural
position as the mineralisation at
Wildwood and Darlington (NSM).
Lubeck is interpreted as a faultbounded slab of basalts within
carbonaceous sedimentary
rocks, a strong analogy for the
mineralsiation at Stawell. An
interpreted intrusive occurs to the
northwest.
Historically, only three air core
lines are drilled across the target,
without returning significant
gold grades. Most of the gold anomalous results are in the
northern end of the target, but high
resolution gravity data indicates
potential structural complexity
to the south that might increase
prospectivity.
Old Roo
RESULTS:
- 2m @ 1.48 g/t Au from 25m* (NSAC0380) –
- ending in mineralisation
The Old Roo basalt is one of
the largest in the tenements,
measuring 4.5 km long and 1.5 km
wide. Historical drilling, totaling
210 holes, shows the basalt lies
just beneath the cover, though
its top has been eroded. The
margins have been well-tested,
yielding multiple anomalous gold
intercepts but no significant results
so far. Geophysical modeling has
identified potentially prospective
features within the basalt,
suggesting a departure from the
Stawell gold model. NSM’s follow-up
work on air core holes has shown
significant grades, enhancing its
prospectivity.
Regional geology suggests
early faults could cut the basalt,
potentially serving as conduits for
later mineralization, presenting
intriguing opportunities at Old Roo
and other NSM prospects.
Forsaken
RESULTS:
- 1m @ 1.24 g/t Au from 31m (NSAC0244)
- 2m @ 3.08 g/t Au from 23m (GLA172)
- 2m @ 3.45 g/t Au from 23m (GLA184)
- 10m @ 1.34 g/t Au from 33m (GLA204)
The Forsaken target lies in the
eastern side of the Mt Pleasant
Fault – one of the major faults
in the centre of the Stawell
Corridor and interpreted as the
western boundary of the most
prospective geology. The geology
at Forsaken appears to form a
large fold-fault system across
the fault boundary, resulting in
a regional scale anticlinal in the
hanging wall position – a highly
favourable geometry to focus gold
mineralisation.
The Forsaken prospect occurs at
the northern end of a 7 km basalt
dome, where the basalt drags
towards the fault, with at least
two interpreted mineralisation
trends occurring adjacent to the
basalt. Multiple anomalous gold
intercepts occur, as well as multiple
significant gold grades in air core
drilling.
The interpreted mineralisation
trends remain open along strike,
and along the margins of the
interpreted basalt.
Wildwood
RESULTS:
- 7.40m @ 18.35 g/t Au from 39.70m (WWD041)
- 10m @ 12.69 g/t Au from 54m (WRC076)
- 12m @ 9.49 g/t Au from 34m (NSR0052)
- 12m @ 7.73 g/t Au from 36m (WRC062)
- 5m @ 11.22 g/t Au from 63.60m (WWD043)
- 15m @ 3.04 g/t Au from 46m (NSR0060)
- 11m @ 4.08 g/t Au from 73m (WRC066)
- 16m @ 2.60 g/t Au from 27m (WRC001)
- 3m @ 13.01 g/t Au from 62m (WRC031)
Wildwood, 25km north of Stawell, stands out through a blanket of unmineralised cover because of its geophysical (magnetic) signature. Identified in 2003, it has multiple similarities to Stawell, and has been explored against a Stawell-type gold mineralisation model.
Wildwood includes a compliant Mineral Resource of 87,300 oz Au at 2.4 g/t Au (ASX:NSM 29 June 2023), reported against the 2012 JORC Code.
The basalt structure at Wildwood features double plunges with mineralization along its crest and shoulders. However, drilling indicates that the steep flanks are faulted, affecting mineralization in the north of the basalt.
Extensive drilling in the early 2000s aimed to assess its potential as a satellite ore source for the Stawell Mine, suggesting a small deposit could enhance mill feed. Recent drilling results have been promising, particularly on the crests, and a project review indicates that Wildwood is still open for exploration along the dome hinge, presenting opportunities for deeper mineralization and possible higher-grade zones.
Germania
RESULTS:
- 1.m @ 1.30 g/t Au from 17m (SD318)
- 2m @ 1.20 g/t Au from 40m (SD315)
Germania is the northern-most
historic mine in the Stawell Corridor
before the prospective geology
disappears under a blanket of
Murray Basin cover. The Prospect
occurs at the northern end of the
14km long Darlington-Germania
trend – a mineralised fairway that
includes four small but significant
historic mines to the immediate
west of the regional Coongee Fault.
NSM has reconstructed the old
mines from records (Germania
East – 768 oz Au at 9.7 g/t Au and
Germania West – 683 oz Au at
15.6 g/t Au) and interprets the
geology as two north-trending,
west-dipping parallel lodes. Historic
drilling beneath the working has
returned encouraging results under
the old workings.
The mineralisation is open to the
north and to the south.
Caledonia
RESULTS:
- 1.00m @ 12.15 g/t Au from 36.00m (NSR0077)
- 6.00m @ 1.40 g/t Au from 63.00m (NSAC0451)
- 3.00m @ 2.34 g/t Au from 45.00m (NSR0077)
- 3.00m @ 1.61 g/t Au from 75.00m (NSAC0442)
- 1.00m @ 4.53 g/t Au from 6.00m (SEXC41)
- 1.00m @ 4.31 g/t Au from 0.00m (NSAC0410)
- 3.00m @ 1.32 g/t Au from 66.00m (NSAC0464)
- 3.00m @ 1.22 g/t Au from 48.00m (NSAC0463)
The Caledonia Prospect, a recent
discovery in the Darlington-Germania
trend, is located 700 m north-northwest
of the historic Bonny Dundee Mine
(1,116 oz at 20.6 g/t Au). Under shallow
cover (5 m), it was identified through
geophysics and geochemistry. Drilling
has extended the gold target to 620
m, with mineralization reaching 100
m in depth. The mineralization trends
northwest, parallel to Darlington (2 km
south), suggesting ore shoots may form
in en-echelon zones along the trend.
Recent drilling by NSM has returned
promising gold grades.
The higher grades and mineralization
at Bonny Dundee suggest significant
potential at Caledonia. Positioned east
of an interpreted basalt, it may reflect a
shear branching off this deeper feature.
Prioritizing the pursuit of mineralization
downward and identifying higher-grade
controls is key.
Darlington
RESULTS:
- 3.00m @ 2.83 g/t Au from 42.00m (SEXR1314)
- 1.00m @ 3.15 g/t Au from 57.00m (SEXR1319)
- 1.00m @ 2.24 g/t Au from 34.00m (SEXR1314)
- 1.00m @ 1.72 g/t Au from 31.00m (SEXR1314)
- 1.15m @ 1.37 g/t Au from 374.85m (DAD001)
- 1.00m @ 1.58 g/t Au from 23.00m (SEXR1322)
- 1.00m @ 1.53 g/t Au from 76.00m (NSR0080)
- 1.00m @ 1.10 g/t Au from 50.00m (SEXR1323)
- 0.80m @ 5.65 g/t Au from 201.20m (DAD001)
Darlington is an historic mining area, 6km northeast of Stawell at the southern end of the Darlington-Germania trend, that produced 2,364oz at 18.2 g/t Au. The mineralisation is oriented northwest over 550m strike, dips southwest and may occur as multiple parallel lodes. Along the strike extent, the prospect has only been drill-tested to approximately 50m, and results include:
Resampling of historic core (DAD001) delivered additional grades that expand the potential at Darlington. A central area (150m strike) has potential to include higher grades, and plunge either steeply to the north or south (open in both directions).
Wimmera Park
The Wimmera Park prospect
occurs at the contact between
the eastern margin of the Stawell
Corridor and a late, 2.5km intrusion.
Air core drilling by NSM intersected a
gold and arsenic (up to 400ppm)
anomalism over 300m immediately
adjacent to the granite. A magnetic
high, that extends 2km south,
correlates with the anomalous gold
and arsenic, locally extending into
the footprint of the intrusion.
The geology and mineralisation
have similarities to Wonga, an
historic mine (294koz Au at 4.38
g/t Au) on the margin of the
Stawell granite where the intrusion
is interpreted to have mobilised
or upgraded the mineralisation
within the thermal aureole (heat
affected) area of the pre-intrusion
metasedimentary rocks.
Doctors Hill
The Doctors Hill prospect is centred
on an elongate, Northwest trending intrusion that has exploited one of the late faults that cuts the
Magdala (Stawell Mine) basalt
dome – the Wildcat Fault. The
prospect, because of its intrusion
association, is explored as a
possible repeat of the Wonga Mine
model (potential intrusion-related
gold). Elevated gold and arsenic
returned from drilling on the
southern margin of the intrusion
is encouraging for future work.
Surface geochemistry indicated
that arsenic anomalism extends
400m from the granite, also on
the southern margin, as well as
minor, localised antimony over the
intrusion.
