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   PID: hpt/lnx 1.9.0-cur 2019-01-08   
   TID: hpt/lnx 1.9.0-cur 2019-01-08   
    South Africa, India and Australia shared similar volcanic activity 3.5   
   billion years ago    
    Ancient volcanism dating back to 3.5 billion years ago are common to   
   Archaean cratons of South Africa, India, and Australia    
      
     Date:   
         June 8, 2023   
     Source:   
         University of the Witwatersrand   
     Summary:   
         The Daitari greenstone belt shares a similar geologic make-up   
         when compared to the greenstones exposed in the Barberton and   
         Nondweni areas of South Africa and those from the Pilbara Craton   
         of north-western Australia.   
      
      
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   FULL STORY   
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   Cratons are pieces of ancient continents that formed several billions of   
   years ago. Their study provides a window as to how processes within and on   
   the surface of Earth operated in the past. Cratons preserve relics of our   
   young Earth as they host a variety of rock assemblages such as greenstones   
   and granites. Greenstones are rock assemblages that primarily comprise of   
   sub- marine volcanic rocks with minor sedimentary rocks. They are the best   
   archives to study early Earth surface processes. A new study published in   
   Precambrian Research by a team of researchers, led by Dr Jaganmoy Jodder   
   of the University of the Witwatersrand's Evolutionary Studies Institute   
   shows that the Singhbhum Craton in India hosts remarkably well preserved   
   volcanic and sedimentary rocks as old as 3.5 billion years, and that it   
   has similar geologic history to parts of South Africa and Australia.   
      
   The team that included researchers from the University of the   
   Witwatersrand (Wits University), University of Johannesburg (UJ) and   
   Chinese Academy of Sciences, Beijing, examined volcanic and sedimentary   
   rocks from the Daitari greenstone belt in the Singhbhum Craton of India   
   that were formed approximately 3.5 billion years ago. Jodder and his   
   co-workers conducted detailed field-based studies and precise Uranium-Lead   
   (U-Pb) radiometric-age dating to evaluate the geology of the ancient   
   greenstone rocks. Based on their study, the researchers established   
   key geological timelines that illustrate the tectonic evolution of the   
   Daitari greenstones.   
      
   "The Daitari greenstone belt shares a similar geologic make-up when   
   compared to the greenstones exposed in the Barberton and Nondweni areas   
   of South Africa and those from the Pilbara Craton of north-western   
   Australia," says Jodder.   
      
   Sub-marine volcanic eruptions were common between 3.5 and 3.3   
   billion-years- ago, which are largely preserved as pillowed lava within   
   the greenstones of the Singhbhum, Kaapvaal and Pilbara cratons. More   
   importantly the style of volcanism decoded from the silicic rocks provide   
   evidence for explosive sub- marine to sub-aerial settings.   
      
   "Following silicic volcanism, sedimentary rocks that comprise sub-marine   
   turbidity current deposits formed upon drowning of the volcanic vent. This   
   provided us with an age estimate for the sub-marine sedimentary rocks   
   that got deposited approximately 3.5 billion years ago, which was based   
   on precise detrital U-Pb zircon data."  Studies of ancient greenstones   
   are important not only to understand the diverse volcanic processes but   
   well-preserved greenstones preserve minor sedimentary rocks that formed   
   under sub-marine settings.   
      
   "These volcano-sedimentary rocks provide clues related to habitable   
   environments on the young Earth and can be regarded as time capsules   
   to help us better understand the evolutionary tale of the planet in its   
   early stages," says Jodder.   
      
   Jodder and the team of researchers propose that these ancient continents   
   may have been subjected to geologically similar processes 3.5 billion   
   years ago.   
      
   "However, we are not certain about their palaeo-geographic   
   positioning. And thus, cannot validate that they once formed part of a   
   supercontinent," says Jodder.   
      
   "The current research has led to a broader understanding of the ancient   
   volcano-sedimentary rocks exposed in the Daitari area in India. This   
   study resulted in unique recognition of felsic magmatic processes that   
   are common to the Archaean cratons of India, South Africa and Australia   
   respectively during the Palaeoarchaean times. It opens up newer avenues   
   for research on early Earth processes," says Jodder.   
      
       * RELATED_TOPICS   
             o Earth_&_Climate   
                   # Geology # Volcanoes # Natural_Disasters # Geography   
             o Fossils_&_Ruins   
                   # Origin_of_Life # Fossils # Ancient_Civilizations #   
                   Human_Evolution   
       * RELATED_TERMS   
             o Gondwana o Geology_of_the_Capitol_Reef_area o Ancient_Egypt   
             o Mountain o Parallel_evolution o Geology_of_the_Alps o   
             Homo_heidelbergensis o Engineering_geology   
      
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   Story Source: Materials provided by University_of_the_Witwatersrand. Note:   
   Content may be edited for style and length.   
      
      
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   Journal Reference:   
      1. Jaganmoy Jodder, Axel Hofmann, Hangqiang Xie, Marlina A. Elburg,   
      Allan   
         Wilson. Geochronology of the Daitari Greenstone Belt, Singhbhum   
         Craton, India. Precambrian Research, 2023; 388: 106997 DOI:   
         10.1016/ j.precamres.2023.106997   
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   Link to news story:   
   https://www.sciencedaily.com/releases/2023/06/230608120950.htm   
      
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