The Little Sandy Desert region, within which the LD Project is located, is underlain by the Savory Basin.

The shallow sediments of the Savory and southwestern Yeneena Basins generally comprise gently eastdipping medium to coarse-grained sandstone and pebbly conglomerate. The underlying bedrock outcrops infrequently: more than 90% of the basin is covered by unconsolidated or semi-consolidated Cainozoic deposits, consisting largely of windblown sands in the form of dunes and sandplains (Williams, 1992). The sand is composed of medium to medium-coarse quartz grains, with occasional ferruginised grains or ironstone pebbles. The wide-spread longitudinal dunes that occur throughout the Savory Basin are thought to have formed during the intensely arid conditions that prevailed during the last glacial maximum. Colluvial deposits occur to a limited extent in the Basin and are mostly located adjacent to infrequent rocky outcrops. Alluvial deposits of unconsolidated silt, sand and gravel are also relatively uncommon and are restricted mostly to drainage lines and to the terminal Lake Disappointment playa.

The superficial sequences are underlain at variable depth by members of the Neoproterozoic Tarcunyah Group, which comprises an interbedded sequence of sandstone, siltstone and shale deposited around 800 Ma. These bedrock materials outcrop locally to the east and the south-west of LD.

The stratigraphy beneath and adjacent to LD reported in published lit ........

The project will extract brine from the surface of the playa via infiltration trenches and then be moved from the infiltration trenches to the main feed channel and then into a series of evaporation ponds.

The total length of the initial trench system will be approximately 133 km including 116 km of infiltration trenches. These will be relatively shallow at around 1.8 m which is 0.5 m below the nominal base of the gypsum sand layer, although further tests are being conducted on deeper trenches.

Excavators (30 t machines with 15 m reach and amphibious tracks) will operate on a permanent basis for ongoing trench maintenance to ensure that they remain in an open, free flowing condition. The material from trench excavation will be used to construct road bunds and flood protection bunds alongside the trenches.

The brine from the infiltration trenches will flow into the plant feed channel and then onto the halite ponds at the start of the brine evaporation system. The feed channel will be 6 m wide and 2.5 m deep at the start in the infiltration area and gradually increase in depth along the 16.3 km distance from the trenches to the corner of the halite pond area.

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