India Bore Diamond Holdings Pty Ltd (IBDH) is a privately held Australian mining junior and Australia's newest producer of rare Fancy Coloured diamonds.
The company and the project both derive their name from the historic nearby stock watering hole of "India Bore".
The India Bore project is located on the pastoral lease of the Jumbuck Pastoral Company and on the traditional lands of the Bunuba people.
At the heart of our project is the discovery in 2015 of a previously unkown buried ancient river system draining in a southward direction through the Ellendale diamond field.
A drilling and trenching program begun in 2017 proved the drainage system contained large expanses of diamondiferous gravels. At the time, the notion of a south flowing drainage system ran against years of conventional wisdom that the natural drainage systems at Ellendale generally flowed to the North/North-West.
IBDH identified that the new system consisted of a well defined and deeply incised canyon with shallower downstream tributaries. In keeping with convention, in order to distinguish it from previously identified drainage systems, the new system was given the alphabetical "L" designation and became known as the "L-Channel".
Geological evidence suggests that the "L Canyon" system was in place long before the diamond baring pipes of Ellendale erupted bringing their famous yellow diamonds to the surface. As these volcanic pipes slowly eroded, their diamonds were washed into the pre-existing L Canyon and transported downstream to the south.
Today, part of this ancient drainage complex lies within a clearly visible armoured and raised promontory (pictured above).
IBDH has drilled and mapped extensive river gravels along an initial 2km section of the L Channel in 2017, recovering commercial grades of diamonds in test trenches in 2018 and 2019.
FIRST DIAMONDS RECOVERED IN 2018
By mid 2018 IBDH had recovered its first gem quality diamonds from our exploration trench in the L Channel promontory. The diamonds recovered are typical of the Ellendale E9 and E4 morphology providing further hard evidence of the broader significance of the IBDH discovery. Subsequently, diamonds up to 3+carats have been recovered as well as fancy yellow and other colours. Commercially viable grades have been recorded in 2 large exploration trenches.
INITIAL RESOURCE OF 1.3 MILLION CARATS
In its 2018 Mineralisation report to the West Australian Government IBDH has estimated an initial diamond resource of 1,300,000 carats based on a prudent analysis of our first diamond recoveries. A 3rd phase drilling and trenching program is now underway to be followed by the planned commencement of trail mining in 2020.
The narrative of the "Lost Alluvials of Ellendale" arose because no major alluvial deposits associated with the Ellendale diamond producing volcanic pipes have ever been found. In 2015 IBDH determined that an ancient hidden canyon and river system laid buried more than 15 metres below todays surface.
It is this drainage system that carried the alluvial diamonds to the south, rather than north-west as has been previously thought, and into the areas now covered by the IBDH tenements.
The SEEBASE grid model (above) developed by the Goelogical Survey of Western Australia with the position of the Ellendale Diamond Field ancient inland ocean.
The 2019 exploration trench campaign at the project site has confirmed that an extensive alluvial gravel complex of thick gravel beds containing gem quality diamonds lies within the "L channel". The existence of these diamondiferous gravel beds resting on Permian basement is further evidence that a major diamond bearing alluvial paleo channel resides within the India Bore project area. An initial review of the recovered diamonds reveals typical Ellendale forms including dodecahedral diamonds and multiple colours with rare gem quality yellow diamonds also being recovered.
The excavated bulk test trenches have now been backfilled and rehabilitated. Very strong grades have been recorded from river channel trap sites with lower grades in the channel margins and this grade data is now being complied and analysed to assist in future exploration and mining of the L Channel.
The thick diamondiferous river gravel beds uncovered in the 2019 trench were deposited circa 22 million years ago and lie between 15 and 18 metres below the current surface. The beds were formed downstream of the Ellendale E9 and E4 lamproites, which are likely to be the primary source of the diamonds.
Alluvial diamond deposits are particularly difficult to locate and the depositional environments are complex. Key to success is understanding the profiles and characteristics of the various gravel layers and their interface with the basement country rock.
L Channel Stockpiles await processing - Sept 2019
Large river boulders and gravels from the L Channel await processing
Specimens of decayed volcanic tuff material have been found in the buried L Channel gravels - clear evidence that the gravels passed by the volcanic vents
Large quartzite clasts including one massive sample weighting nearly 400kgs are distributed in the basal gravels indicating they have been washed downstream in the alluvum from the volcanic vents.
Samples of almost in-tact chromites, a key diamond indicator mineral taken from the basal gravels in the L-Channel in 2018
Large river boulders up to 600mm in diameter are separated from the L channel gravels at the grizzly
L Channel gravels presenting for first stage processing
Washed oversize and light materials are discarded during processing
The Gouldian Finch was first recorded at the Project site in November 2018. An intense bushfire in the local Ellendale area at the time is thought to have concentrated the finches around the project area (water source).
The flat plains of the project area contain no rocky and hilly areas which are the preferred nesting habitat of the semi-nomadic Gouldian Finch. Nonetheless, following the initial 2018 sightings the company has established an active monitoring program and a detailed management plan will be implemented to support any local populations.
A pair of Wedgetail Eagles (Aquila audax) drinking from a small puddle created by a water pipe valve at the project site. The Wedgetail is the largest bird of prey found in Australia with a wingspan up to 2.84M across or almost 9 1/2 feet.
Local wildlife are easily observed near water sources during the dry season.
An Agile Wallaby (Macropus agilis) with joey captured by our thermal wildlife survey cameras at the project site. This wallaby is common in the area and a gregarious grazer.
The Australian Bustard (Ardeotis australis) also known locally as the Bush Turkey is a semi-nomadic bird standing up to 1 metre tall. These birds are commonly seen at the project site.
Despite the remote location of the project, the company has recorded a significant feral cat population in the area. Feral cats are often captured on our infrared wildlife survey cameras (above).
Each feral cat can kill between five and ten native animals a day. The company is working with the WA authorities to initiate a feral cat control program.