Drilling underway in the Quondong Vale region.
The second phase of drilling in the Geological Survey of South Australia (GSSA) and MinEx CRC National Drilling Initiative (NDI) in the Delamerian Orogen began in late January 2022. Three holes have been completed to date in the region which is located about 150 km northeast of Burra.
In line with estimates, cover thickness has been less than 200 m and basement rocks intersected so far indicate both deformed and undeformed volcano-sedimentary packages are present, as well as felsic–intermediate plutonic rocks.
Around 15–20 drillholes are planned. Drillholes are targeting a broad range of geophysical signatures. Results will help characterise how the Cambro-Ordovician Loch Lilly-Kars Belt extends from New South Wales across into South Australia.
All holes are being completed using the MinEx CRC coiled tubing (CT) drill rig as it has performed well in advanced trials in the Alawoona drilling area. Cuttings are recovered from surface through to about 50 m below the basement unconformity, then the selective coring tool is used to obtain around 3 m of diamond core in fresh basement rocks.
Phase one drilling targeted the Alawoona region in the last quarter of 2021. Four of the 7 holes drilled were twinned with the CT rig. Results were presented at the GSSA Discovery Day 2021 – view the presentations on the Energy and Mining SA YouTube channel. The drillhole field data is being added progressively to the South Australian Drilling Atlas. One final hole in the Alawoona region will be drilled with the CT rig once the Quondong Vale work is completed.
Marginal facies of the Murray Basin, drillhole NDIQV_D08, cuttings 0–228 m. Murray Group limestones, prevalent in the Alawoona drilling, are absent. (Photo 418480)
Highly altered and fractured basement claystone, drillhole NDIQV_D08. (Photo 418481)
Fresh granite; drillhole NDIQV_D09. (Photo 418482)
– Tom Wise, March 2022
