Geological Survey of Western Australia (GSWA)’s Post

The Temporal Distribution of the Host Rocks to Gold, the Archean Witwatersrand Basin, South Africa This new Open Access publication is by Neil Phillips, Julian Vearncombe, Dave Craw and Arthur Day The hosts to gold around the Witwatersrand Basin span over 400 my, through 14 km of stratigraphy in a variety of host rocks and in tectonic settings that include periods of rifting, thermal subsidence, foreland basin, flood basalt outpouring, graben development, and further thermal subsidence. A geological model that assumes placer processes to explain this diversity implies a super-long-lived and special source of the detrital gold, transport, and highly effective sorting processes over a time span of 400 my. There is no evidence of a special source and sorting over such a long time period. In the Phanerozoic, this would be equivalent to the special source and sorting processes operating continually over an equivalent period of geological time spanning from the Devonian up until the present day; this is as yet recognised nowhere else on the planet. With regard to the geological model that assumes a placer process, this is untenable because of these scientific shortcomings and its lack of success in exploration. Click on the below for read/download.

#ASXNews USGS confirm Mountain Pass and Colosseum zircons are “indistinguishable” Dateline Resources Limited is pleased to provide an update to rare earth studies being undertaken at the Colosseum Project in California. The studies follow on from previous mapping and sampling studies by the Company’s rare earth experts, Anthony Mariano PhD and Tony Mariano Jnr as well as geophysical modelling undertaken in late 2023. • USGS has undertaken zircon aging analysis for Colosseum and Mountain Pass. • The #REE concentrations and chondrite-normalised spectra for the “Colosseum zircons are indistinguishable from the Mountain Pass zircons”. • The Colosseum zircons have much lower U and Th (~20-50 ppm each) than Mountain Pass zircons (~100-800 ppm U, ~100-1,400 ppm Th). Commenting on the study, #DTR’s Managing Director, Stephen Baghdadi, stated: “The study by the USGS continues to add weight to the evidence that Colosseum has the potential to host a significant rare earth system with low uranium and thorium content. We have the right geology, the right timing and are in a known and proven rare earth district. “Whilst Dateline could have undertaken the age dating work on its own, its reassuring to have these results come from an independent US Federal agency. “The immediate focus is on drilling the gold deposit at Colosseum ahead of mine planning for underground mining and a mineral resource update, however we continue to progress planning and studies on the rare earth potential.” Full announcement: https://loom.ly/5PwAU0I #DatelineResources #rareearths #ASX

Can brittle and ductile deformation coexist during the remobilization of sulfide minerals? It appears that the dolomitic rock initially exhibited brittle deformation and fractured into smaller fragments. As a result, voids and cracks are created, and minerals have migrated there. Then came ductile deformation, which is characterised by elongated quartz grains, and sulphide remobilization may have occurred along the foliation planes. First picture: Sulfide minerals run parallel to the flattened and extended quartz fingers (ductily deformed) along the foliation planes. Second picture: Sulfide minerals cementing dolomitic fragments (brittle deformation) and recrystallized quartz fractions show signs of ductile deformation. Looking for some insightful advice from the more experienced members of the community. #geologist #geologyrocks #exploration #Exploration geologist

WHAT TYPE OF SOIL DOES GOLD OCCUR? The first soil type that comes to mind when gold is mentioned is 'black sand'. Although it cannot be said that there is definitely gold in the place where there is black sand, it is known that this soil type contains many minerals and heavy metals. Since gold is one of the heaviest metals, the soils most sought after by gold seekers are black sand. Soils containing volcanic ash and red soils, which are mostly seen in deserts, are also the lands that gold seekers often look for. Although gold can be found in many rock types, it is mostly found in quartz rocks. As important as this may seem, the quartz rocks are so abundant that more information is needed. Therefore, looking at quartz known as dirty or rotten will increase the probability of finding gold. In addition, brown or orange pieces in dirty quartz are a sign of being close to gold. One of the characteristics of dirty quartz is that it is brittle. Dirty quartz rocks can be easily broken with a hammer or shovel. When these rocks are broken, thin strips of pure gold can be reached. The points where different types of rocks come into contact are another sign that gold may be nearby. The pressure that arises when different rock types come together at a 90 degree angle and the high temperatures resulting from this pressure cause cracks in the rocks. Gold is also liquefied by being exposed to this heat and is pushed towards the surface. In this process, it may cool down gradually and appear in a solid form. Sources: https://lnkd.in/gSSSEwuA Attention to all geologist, exploration professional and those who interested in Gold, do come join us in our upcoming online workshop course Gold Exploration from Scratch! Register now and be the one in this adventurous workshop. Online Workshop Course: Gold Exploration from Scratch Date: April 27th, 2024 (Saturday) Time: 9.00 am – 5.00 pm Venue: Online Zoom Application Register now and book your seat! To register, click link below: https://lnkd.in/dG-ir8VC Don’t forget to register and join our workshop to gain more knowledge on gold exploration from scratch! #gex #academygex #jeoxplorer #geologist #theorytoreality #geophysical #geotechnical #siteinvestigation #training #workshop #skill #refreshknowledge #exchangeidea #goldmining #goldscratch

Trenching as an early exploration method is a time efficient and a low-cost method for mineral exploration. Following the removal of the overburden material and providing a clean face in the fairly fresh litho-unit is mapping the lithography and structural variations in the trench. Carefully mapping structures and alteration provides highly valuable details that give a preliminary idea of the field relationships and geologic structures. Assaying gold-related alteration patterns and structure can provide an insight into the potentiality of a prospect. This trench uncovered the width of mineralised zones and helped to identify the major structural trends. A wide zone of carbonates pointed towards a common occurrence of gold mineralization in the late stages of Neoproterozoic orogeny associated with sheared silica and carbonate rocks and Qz veins. #mining #geology #explorationandproduction #trenching #ore #goldmining