Havilah Resources Limited ('Havilah' or 'Company') has completed review of data and announces results from a gravity survey in the vicinity of the Jupiter magnetotelluric ('MT') anomaly target ('Jupiter') (refer to ASX announcement of 27 October 2017).

Several features of interest are apparent in the new data, including a gravity anomaly (G2) lying north of Jupiter. Notably, G2 lies on a prominent north-northwesterly trending lineament that parallels the structural trend of the copper-gold mineralised Benagerie Ridge. This lineament coincides with the MT conductive zone, possibly indicating a connection. Also evident are a few crosscutting northeasterly trending linear features, which are interpreted to be later off-setting faults.

Experienced geophysical contractor, Haines Surveys, completed field readings prior to Christmas 2019. High quality semi-detailed 500m x 200m spaced gravity data was collected between Jupiter and existing 500m x 100m spaced gravity data to the south. Prior to the current gravity survey there was only 2 km spaced gravity data available that was insufficiently detailed to allow meaningful interpretation.

As reported earlier, open file gravity data available on the SARIG website showed a distinctive circular gravity anomaly (G1) about 2 km across lying roughly 5 km south of the MT survey line (refer to ASX announcement of 6 November 2019). This feature was confirmed by the current gravity survey, which also revealed that it is located at the intersection of the north-northwesterly trending lineament mentioned above and an interpreted northeasterly orientated off-setting fault.

Since the MT survey was the result of 2 km spaced readings along a single survey line, the north-south extent of the Jupiter conductive zone is not certain at this stage. Additional short MT survey lines are required to achieve more detail for the Jupiter conductive zone. New MT data, to be collected in the future, will be combined with the gravity and other geophysical data with the objective of defining a drilling target to test Jupiter.

Commenting on the results of the recent gravity survey, Havilah's Technical Director, Dr Chris Giles, said: 'Jupiter is an intriguing conductive zone as defined by previous MT surveys.

'Our new gravity survey provides independent supporting data in the form of two discrete gravity anomalies lying on a regional north-northwesterly trending lineament that is coincident with the MT conductive zone.

'Our aim is to narrow down the geophysical indicators to a specific drilling target and the results of the present gravity survey will assist us in that regard' he said.

About Jupiter and MT geophysics

Jupiter was identified by Professor Graham Heinson and his team from the University of Adelaide during 2017, following collection and analysis of 2 km spaced MT readings across the Curnamona Craton . Notably, the volcanic rocks and associated granites in this part of the Curnamona Craton are almost identical in age and origin to those in the Gawler Craton that host the Olympic Dam deposit, a point which encouraged previous explorers like MMG Limited and Newcrest Limited in their quest for IOCG (iron oxide copper gold) deposits in this region.

MT is a geophysical method that relies on measuring the very small natural time variations of the Earth's magnetic and electric fields to determine the electrical resistivity in the subsurface. The method is able to distinguish zones of varying electrical conductivity in the earth's crust to depths of more than 20 km. It is a powerful technique because it can potentially identify major conductive zones in the earth's crust that could represent the feeder zones to large metal accumulations. For example, research work in the Gawler Craton has identified a large conductive zone at depth beneath the Olympic Dam deposit with a distinctive conductive feature rising up towards the surface immediately beneath the orebody. This vertical feature has been interpreted as a possible feeder zone for metalliferous fluids from a more conductive and potentially copper rich part of the deep crust in this region.

About gravity surveying

Gravity measurements are influenced by the density of underlying rocks in relation to the earth's surface. Hence, at a given depth denser rocks (which can include metalliferous deposits or their host rocks) will generate a positive gravity anomaly or gravity high at surface. Circular gravity features can sometimes indicate intrusive igneous rocks or a pipe-like alteration zone that can be host to mineralisation. While the source of the circular gravity features identified in this announcement are unknown at this stage, it does indicate the potential usefulness of gravity as a targeting tool in this region.

Contact:

Email: info@havilah-resources.com.au

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