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A bit more research on the area led to a flipping of the age of...

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    A bit more research on the area led to a flipping of the age of the Hidden Basin Beds back to around Murraba Basin age. Source data was Open File A131217 from Newmont's summary of work done in the area including aircore in 2021. Couple of extracts and Source document:

    A131217_v2_REPORT-1.pdf NEWMONT STANSMORE Au EXPLN.pdf


    Local Geology
    The predominant Proterozoic rocks outcropping within the Project area are the Hidden Basin Beds. Haines and Allen (2017) suggested apossible Mesoproterozoic age and Birrindudu Basin affinity for these rocks,but recent dating by Wingate et al. (2019a,b) indicates maximumdepositional ages of c. 1000 Ma and c. 986 Ma. This suggests that the Hidden Basin beds instead represent Supersequence 1 of theCentralian Superbasin, and are possible correlatives of units in the Yeneena Basin. Outcrops of the Hidden Basin beds are dominated byhighly silicified quartz arenite and sublithic arenite, with minor recessive laminated shale and siltstone that are likely to predominate incovered areas. Neoproterozoic to Cambrian sedimentary rocks of the Murraba Basin are inferred to underlie cover in the northeast of theProject area.A series of intrusive rocks are suggested by the aerial magnetics within the Project area, however, no outcropping examples are observed.Mafic to intermediate intrusive rocks have been intercepted in historical drilling. Only limited amounts of outcropping Proterozoic rocks exist,as the landscape is dominated by extensive Tertiary aeolian sand cover (Figure 4). Morris et al. (2018) argue this cover is thin, generally lessthan 10 m, and more likely 1-3 m thick, due to the occurrence of ferruginous lag, variably ferruginized bedrock fragments and isolatedpatches of ferricrete and calcrete, and is supported by the results of exploration drilling and single-station passive seismic data.The Neoproterozoic to Cambrian succession is deformed by open folds, with more intense deformation adjacent to fault zones. The age ofthis deformation is poorly constrained, but may have taken place during the Petermann or Alice Springs Orogenies. These folds arenorthwest- to southwest-trending as a result of regional warping during younger deformation, possibly involving north–south shortening.

    Updating this image from the previous post shows how important this change might be. Also the need for a window through the Hidden Basin beds so that there is limited cover through which exploration needs to penetrate. For ENR this likely means a considerable depth as their application tenements are definitely overlain by HBB and/or Murraba basin sediments.
    https://hotcopper.com.au/data/attachments/6175/6175909-8d27a68d4f9dfa18a04ecc14420409dc.jpg


    Previous Exploration
    A summary of historical exploration conducted within the Project area and surrounds is outlined below. A desktop literature survey includinga review of all available reports was completed during the 2017-2018 reporting period (Haines, 2018d).Very little previous work has occurred over the Project area. This is largely due to extensive aeolian cover and resultant lack of outcrop. Aninability to obtain a land access agreement with the traditional landowners also impeded exploration, such as for CRA Exploration in the early1990s who relinquished their tenements after four years of negotiations. The remote location and consequent expense required to completeexploration in this area are also likely contributing factors.
    Following the completion of a regional airborne geophysical survey in 1982 by the Bureau of Mineral Resources, BHP conducted anexploration program over the northern area of the current Project in search of diamondiferous kimberlites. Anomalism over four areas wasfollowed up with a targeted ground magnetics survey and RAB drilling to bedrock. RAB drilling also occurred on a fifth prospect with acombined 283 metres being drilled over 21 holes. BHP concluded the magnetic anomalies were probably caused by intermediate to basicrocks with no kimberlitic affinities. Within the drilling rocks recorded include metaquartzite, volcanics and pyroxenite with quartz veining,strong silica, jaspilite and hematite alteration also noted.
    In 2015 the Geological Survey of Western Australia completed a regolith geochemical survey over the Ngururrpa native title area thatincludes the Project area. The results of this survey showed that despite extensive cover meaningful results could be obtained fromconventional soil sampling in this region. A peak gold concentration of 63ppb was recorded although this was northeast of the Project area.


    Getting BHP's 1983 drilling onto a map is challenging with the work below schematic though hopefully adequate.
    https://hotcopper.com.au/data/attachments/6175/6175930-009f19bb5783d0dbec6bce6325cf0d0b.jpg

    Detail of BHP shallow drilling
    Partial legend applicable to all.
    https://hotcopper.com.au/data/attachments/6175/6175972-5079cab46139133d922ff68784b8f1dc.jpg

    https://hotcopper.com.au/data/attachments/6175/6175976-4a3b00f884bd029671efea389c737f0b.jpg

    https://hotcopper.com.au/data/attachments/6175/6175982-ac52cd3844f92f3eb652268b72d71c6c.jpg

    https://hotcopper.com.au/data/attachments/6176/6176004-1bd273ea99898f76136b06e3dc9f987f.jpg
    Deepest hole 20m for these 4 sites. Most appear to have entered bedrock that is shown as logged. Subsequent petrography confirmed mafic lithologies but also some diorite.
    What age are these lithologies? If basement of 1500+My then interesting structural setting. Unlikely to be mafic intrusions into HBB if 1000My date is reasonable. That would likely mean the intrusions are younger though does not preclude multiple carbonatite events related to such intrusions.

    Newmont's aircore results are summarised in the open file above. HBB sediments not drilled through and no Au to explain soil anomaly. Tough area to explore then and still will be. Newmont access goes over multiple sand dunes - obviously cleared to do so but may not be the norm.


 
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