Trigg Mining Ltd has recently announced encouraging results from ground-based gravity surveyed completed across its 100%–owned Lake Throssell Sulfate of Potash Project in Western Australia.
Modelling of the ground gravity data acquired at Lake Throssell in March and July 2020 has indicated the presence of a significant palaeovalley sequence below the main playa lake system, which was successfully tested recently by a heli-supported rotary drilling programme.
The modelled depth of the palaeovalley below the surface is up to ~120 m in places, with the deepest sections, or thalweg, considered to be the most prospective for sand-rich aquifers with the potential to host significant potassium-rich brines.
The parts of a thalweg that represent the section of the palaeochannel where the flowing water in the palaeovalley system had the highest velocity are typically found at the outer bends of meandering systems. Due to the higher water velocity, erosion of the channel floor typically occurs – resulting in the thalweg being the deepest section of the channel.
As a result of the increased water velocity, sediment deposits within the thalweg typically comprise a higher proportion of sand as opposed to finer clay-rich sediments, which is why they are subsequently the most prospective part of the palaeovalley due to their typically high porosity and permeability. This in turn provides the greatest yields for brine production bores.
Detailed modelling of the gravity data has further refined Trigg’s understanding of the sedimentary system and depth to basement beneath the playa lake. These detailed cross-sections will enable the company to better target the most prospective part of the palaeovalley for the upcoming air-core drilling programme.
Trigg Mining’s Managing Director, Keren Paterson, said: “The gravity results are significant as they indicate the presence of a substantial palaeovalley below the surficial aquifer which we recently tested with the helicopter supported rotary drilling programme. In simple terms, this confirms the strong potential to delineate a sulfate of potash deposit of significant scale at Lake Throssell.
“The upcoming air-core drilling programme will drill through to the bottom of this palaeovalley, which is modelled to a depth of ~120 m below surface, while focusing on the deepest sections – known as the thalweg – which are considered to be the most prospective for sand-rich aquifers with the potential to host significant potassiumrich brines.
“This is very important development for our exploration programme and significantly increases our confidence in the potential of the Lake Throssell Project. Detailed modelling of the gravity data has greatly improved our understanding of the sedimentary system and depth to basement at the project and we are now eagerly looking forward to the commencement of our maiden air-core program next month. Drill locations are currently in the process of being finalised and we provide further information on the programme in due course.”
Read the article online at: https://www.worldfertilizer.com/project-news/24082020/gravity-anomaly-confirms-potential-at-lake-throssell-sop-project/