Beaver Deep Drilling Final Report Round 16 Geophysics and drilling collaborations 2023

Abstract

The Tanami Desert hosts the gold prospective Central Tanami Project (CTP), an area intruded by granites and encompasses Proterozoic volcanic and sedimentary rocks of lower greenschist to amphibolite metamorphic facies that overlie Archean basement. CTP gold deposits are typically hosted within Mt Charles Formation, characterised as interbedded sediment units and basalt sequences sometimes referred to as 'Mine Basalts' or 'Tanami Mine Sequence'. Mount Charles Formation forms a broad syncline dipping west-northwest in the CTP area and extends around the dome-like intrusions of the Coomarie and Frankenia granites. It outcrops sparsely and is often overlain by transported cover or by the Birrindudu Sandstone, which is not considered prospective for gold. The Beaver prospect was discovered in 1995 through bedrock geochemical and Reverse Circulation (RC) drilling across the Molech MLS 180 tenement after previous success with the adjacent prospects Cheeseman, Orion, Banjo and Bonsai prompted expansion of exploration efforts within the tenement area. Beaver was mined as an open pit from 1999 until 2001, producing 57,380 ounces of gold grading at 3.33 grams per tonne. Mining operations ceased before the entire pit design was mined to completion due to concerns over the instability of the southern and western walls. Some 72,000 tonnes, grading at 5.2 grams per tonne, remain underneath the base of the Beaver pit. The possibility of gold mineralisation extending at depths deeper than the resource model was not tested to close out the resource model. Northern Star Resources Limited (Northern Star) and Tanami Gold NL (Tanami Gold) established a joint venture agreement for gold exploration of Central Tanami tenements, including Molech MLS 180, in 2015. Northern Star was awarded partial funding for the Beaver Deep Drilling Program from the Northern Territory Government Geophysics and Drilling Collaborations program in 2023. The diamond drillhole BVDD0002 was designed as part of a targeted effort to assess gold mineralisation potential beneath the established resource at the Beaver pit. The primary objective was to ascertain whether the vertically plunging deposit extended beneath the original drilling base. BVDD0002, reaching a depth of 610 meters, was modelled to intersect Mount Charles Formation at previously untested depths to assess gold mineralisation. Top Drill Pty Ltd commenced diamond drilling of BVDD0002 during the Northern Territory dry season from 30th August 2023 until 7th September 2023. The hole intersected sedimentary units and basalt of the Mount Charles Formation but did not encounter significant quartz veining, silicification, or gold mineralisation. Drilling and sampling of BVDD0002 effectively closed out the possibility of continuous gold mineralisation extending at depth in the Beaver pit and provides valuable downhole stratigraphic data for what is understood to be a structurally complex area.