02 April 2024
Kavango Resources
("Kavango" or "the
Company")
BOTS - Preliminary KCB Heliborne
Geophysics Interpretation
Kavango Resources plc (LSE: KAV), the Southern
Africa focussed metals exploration company, is pleased to announce
preliminary interpretation for geophysical survey data on its
property in Botswana's Kalahari Copper Belt ("KCB"), from South
Africa based New Resolution Geophysics ("NRG").
Highlights
·
Helicopter-borne gravity has clearly defined a WSW-ENE
trending ~9 milliGal gravity high (Kara) underlying the Kara
Anticline.
· The
Kara gravity high is one of two linear features in the regional
gravity (Kara & Tsootsha gravity highs) possibly linked to the
Okwa Complex, that may indicate the presence of basement highs
defining multiple edges between two deeper basins, one to the south
(Ncojane Basin) the other to the northeast (Ghanzi Basin) with a
sub-basin to the north (Talismanis Basin).
·
Basin margins along the KCB are considered prospective sites
for Cu-Ag mineralisation.
·
Preliminary interpretation of magnetic data from this survey
combined with re-processed regional magnetic data and satellite
images, clearly define fold hinge targets in the D'Kar Formation
(DKF) that correlate with preliminary AEM targets. Fold hinges are
associated with mineralisation elsewhere on the KCB, such as at
Sandfire Resources' (ASX:SFR) Motheo Mine
· The
updated geological interpretation is supported by recent regional
mapping traverses that identified sub-cropping units within the
lower D'Kar Formation, the target stratigraphic unit for
mineralisation.
·
Historic drilling by ENRG, from whom Kavango in 2023 acquired
a 90% interest in 6 licences, confirms the existence of lower DKF
in the fold structures recently mapped and noted pathfinder
minerals, pyrite, sphalerite, and galena.
Ben Turney,
Chief Executive Officer of Kavango Resources,
commented:
"Based on its
analysis of regional copper-silver deposits in the KCB, Kavango
believes the configuration of basin and sub-basin structures,
including basin margins and intra-basinal highs, plays a pivotal
role in many sedimentary copper models.
We're quietly
confident our Kalahari Copper Belt exploration programme is going
to deliver.
The different
exploration data sets we've gathered appears to point in the same
direction, namely that our ground covers the style of large-scale
system that could host significant copper-silver
deposits.
We are now
defining final target areas to test with ground geophysics and then
drilling a little later this quarter.
This is great
work from the Kavango team. Thank you
all."
Preliminary
Gravity, Magnetic and AEM interpretation
The NRG geophysical survey covered 2,374
line-km of helicopter heliborne Time Domain Electromagnetic ("EM"),
Magnetic, and Gravity data (announced
>>> 22 March 2024)
The majority of sediment hosted deposits are
found in failed rift and passive margin settings, and it is
generally agreed that basin-scale hydrothermal circulation is
required to scavenge sufficient metals to form large deposits
(Hoggard et.al. 2020). The
configuration of basin and sub-basin structures, including basin
margins and intra-basinal highs, plays a pivotal role in many
sedimentary copper models. Faults along these boundaries frequently
serve as pathways for fluids during basin formation and conduits
for mineralising hydrothermal fluids during subsequent deformation
and inversion (with localised dome formation). The intracratonic
setting of these basins allowed the development of a hydrologically
closed basinal architecture in which highly oxidized and saline,
moderate-temperature basinal brines were produced that were capable
of supplying reduction-controlled sulfide precipitation over very
long time periods, (Hitzman et.al
2010). Sub-basins, in particular, create restricted systems
conducive to concentrated fluid flow, oftentimes enhancing the
metal content of potential deposits,
Heliborne gravity data offers an additional
approach to delineating original basin architecture. The density
contrast in the geological profile, between the dense Okwa Group
Basement Complex and the less dense Kgwebe and Ghanzi Group
volcano-sedimentary sequence, enables the identification of large,
deeper basins and smaller restricted sub-basins as gravity lows.
Basin margins are common settings for the formation of sedimentary
copper deposits.
The NRG gravity data, when viewed together with
the regional gravity data, appears to indicate the presence of two
linear features, possibly linked to the Okwa Complex, trending
NNW-SSE (Tsootsha) and WNW-ENE (Kara) that may indicate the
presence of basement highs defining edges between two deeper basins
to the south (Ncojane Basin) and northeast (Ghanzi Basin). During
inversion basin margin structures frequently form conduits for
mineralising hydrothermal fluids and form ideal locations for
deposit formation, (Figure 1 & 2).
The data also indicates a possible restricted
sub-basin to the north (Talismanis). Sub-basin margins
are identified as priority locations for deposit formation, due to
enhancement of metal content in the fluids.
Interpretation of re-processed regional
government airborne magnetics together with detailed geological
mapping have identified thrusts, that appear to be bounding faults
for the gravity high, possibly marking original basin structures,
Figure 2.
Regional folding interpreted from aeromagnetic
data and geological mapping have also identified doubly plunging
domal structures, at a regional and local scale. The gravity data
may also be emphasising these same domal features. The domes appear
to be separated by zones of more concentrated faulting, shearing
and local fracturing, (Figures 2 & 3).
Figure 1, NRG
Bouguer gravity images with Kavango licences overlain on regional
satellite Bouguer gravity data. Exploration targets and deposits
together with their respective resources (data sourced from company
web sites). Most deposits and exploration targets on the KCB appear
to be associated with basin and sub-basin margins and bounding
structures.
Figure 2, NRG
bouguer gravity images overlain on regional geology with magnetic
1VD image. Doubly plunging folds (domes) can been seen in the
regional geology and locally in the gravity data within the Kara
Antiform. Major thrusts appear to form bounding faults on either
side of the gravity high.
Recent field mapping has identified a number of
tight, upright folds corroborated in magnetic data, which present
potential trap-sites for deposition of copper-silver
mineralisation. These folds are typically bounded by district scale
thrusts and major shears, possibly providing the necessary conduits
for movement of copper-rich fluids during basin formation and
subsequent closure and basin inversion (dome formation), Figures 3
& 4.
Promising targets identified as tight folds in
the DKF, resembling Sandfire Resources' Motheo Mine and A4 deposits
directly along strike, are evident in satellite imagery, magnetic
data and correlate with interpreted AEM conductors, (Figure
5).
Figure 3,
Sentinel 2B 16bit_20231020_0000000_2500mm_multispectral image over
Karakubis area, clearly showing well defined fold
patterns.
Figure 4, NRG
RTP High Pass Filter images overlain on regional geology with
magnetic 1VD. The northern and southern limbs of the Kara Antiform
define the upper and middle D'Kar sequences with the lower D'Kar
underlying the core of the fold. Local shears and faults cause
dislocations in the stratigraphy forming potential trap sites for
mineralisation.
Figure 5,
LANDSAT 9 16bit_20231019_0000000_15m_multispectral image over
Sandfire Motheo Mine (pink dot) & A4 (yellow dot [can't see the
yellow dot]), showing similar fold patterns to the SW of the mine
to those observed and mapped at Karakubis.
Preliminary AEM data also maps out the regional
scale fold structures while also defining blocks with different
resistivity and conductivity contrasts on either side of shears and
faults.
Figure 6, NRG
AEM image overlain on regional geology with aeromagnetic 1VD
shading. The northern and southern limbs of the Kara Antiform can
be seen closing around and plunging towards the southwest. A large
shear trending SW-NE in the centre of the Antiform appears to
separate blocks of contrasting resistivity and
conductivity.
Inversions for the historical ENRG
AEM data have just been received and inversions on the new Kavango
AEM data are being processed. These will be merged and will
supply a single set of uniformly sourced inversions across the new
contiguous licence block, which will be interpreted for target
areas for ground geophysical follow-up. Specific targets will
then be picked for drilling.
Further information in respect of Kavango and
its business interests is provided on the Company's website at
www.kavangoresources.com and on Twitter at #KAV.
For further information please
contact:
Kavango
Resources plc
Ben Turney
+46 7697 406 06
First Equity (Broker)
Jason Robertson
+44 207 374 2212
Kavango
Competent Person Statement
The technical information contained in this
announcement pertaining to geology and exploration have been read
and approved by Brett Grist BSc(Hons) FAusIMM (CP). Mr Grist is a
Fellow of the Australasian Institute of Mining and Metallurgy with
Chartered Professional status. Mr Grist has sufficient experience
that is relevant to the exploration programmes and geology of the
main styles of mineralisation and deposit types under consideration
to act as a Qualified Person as defined in the 2012 Edition of the
'Australasian Code for Reporting of Exploration Results, Mineral
Resources and Ore Reserves';.
The technical information contained
in this announcement pertaining to geophysics have been
read and approved by Mr. Jeremy S. Brett, M.Sc., P.Geo., Senior
Geophysical Consultant, Jeremy S. Brett International Consulting
Ltd. in Toronto, Canada. Mr. Brett is a member of
the Professional Geoscientists of Ontario, the Prospectors and
Developers Association of Canada, the Canadian Exploration
Geophysical Society, and the Society of Economic Geologists.
Mr. Brett has sufficient experience that is relevant to geophysics
applied to the styles of mineralization and types of deposits under
consideration to act as a Qualified Person as defined under
the Canadian National Instrument 43-101, Standards of Disclosure
for Mineral Projects.
References
https://doi.org/10.2113/gsecongeo.105.3.627
https://doi.org/10.1038/s41561-020-0593-2