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Behind the inevitable headlines describing the 'lucky discovery' of the Sinclair Pollucite Deposit by Pioneer Resources in a drilling campaign targeting lithium mineralisation, the identification, delineation and development of this resource present a deeper and more substantial tale of fundamental mineral exploration strategy and agile management. A window of opportunity provided by booming global interest in Li exploration delivered Pioneer the impetus and capital to leverage deep geological knowledge of the Pioneer District, innovative exploration technologies, and lean and agile management practices in the development and implementation of a successful exploration campaign targeting the previously unappreciated pegmatites of the Pioneer Dome. While not the target of the original drilling, the intersection of high-grade pollucite at Sinclair was fully consistent with the mineral systems model underlying Pioneer's exploration plan. By pursuing a flexible process-based targeting approach and retaining the capacity to pivot the focus of their exploration team onto this find, Pioneer were able to rapidly define and exploit the pollucite resource at Sinclair, despite the absence of national precedent. The Sinclair pollucite resource is without precedent in Australia. Discovery of this deposit followed from consistent long-term investment in district mineral exploration. Responsiveness and rapid decision-making were critical to the successful development of this unexpected discovery. [ABSTRACT FROM AUTHOR]

Field observations integrated with new petrographic and sensitive high-resolution ion microprobe (SHRIMP) U–Pb age data for detrital zircons from the Paleoproterozoic Speewah Group of northern Western Australia provide evidence of depositional conditions, source of detritus, timing and evolution of the sedimentary rocks in the Speewah Basin. The Speewah Group is a 1.5 km-thick succession of poorly outcropping, predominantly siliciclastic rocks that preserve a fluviatile to marine, transgressive and regressive event. The Speewah Group unconformably overlies crystalline rocks of the Lamboo Province that were stabilised by the 1870–1850 Ma Hooper Orogeny, then accreted as the Kimberley region onto the North Australian Craton during the 1835–1810 Ma Halls Creek Orogeny. Unconformably overlying the Speewah Group is about 4 km of predominantly siliciclastic marine sedimentary rocks of the Kimberley Group in the Kimberley Basin. This study has detected a detrital zircon component within the Speewah Basin at 1814 ± 10 Ma, with a youngest zircon at 1803 ± 12 Ma (1σ) in fluviatile sandstones located beneath a volcaniclastic rock with magmatic zircons that have been dated atca1835 Ma. Previous studies proposed that the Speewah Basin developed as a retro-arc foreland basin during accretion of the North Australian Craton. We interpret theca1835 Ma zircons in the volcaniclastic rocks to be xenocrystic in origin. This new 20 million years younger maximum depositional age indicates that the Speewah Group in the Speewah Basin, similarly to the overlying Kimberley Group in the Kimberley Basin, developed in a post-orogenic setting on the North Australian Craton rather than in a syn-orogenic setting associated with the 1835–1810 Ma Halls Creek Orogeny. [ABSTRACT FROM AUTHOR]