Petrologic and Geochemical Characteristics and Origin of Gusui Cherts,Guangdong Province,China

The characteristic structures of the Precambrian cherts from the Gusui section, Guangdong ,Chi-na, include bedded structure ,laminated structure ,massive structure and pseudobrecciated structure.The chert is characterized by consistently low abundance of TiO2,Al2O3 and most trace elements.Howevver ,it is enriched in Ba,As,Sb,Hg and Se.In Al-Fe-Mn ternary diagrams,it falls into the “hydrothermal field“ .Correspondence analysis and factor analysis show that many elements show up in the factor that represents the leaching of country rocks by hydrothermal solutions,and are the very characteristic element association fo the geochemically anomalous South China basement.Petrologic and geochemical evidence suggests a hydrothermal origin for the chert.The chert may have been formed in a Precambrian fift or an extension zone developed within the Yunkai marginal geosyncline, with a fault system linking it to an unknown heat source at depth.

Petrologic and geochemical characteristics and origin of Gusui cherts,Guangdong Province,China

The characteristic structures of the Precambrian cherts from the Gusui section, Guangdong, China, include bedded structure, laminated structure, massive structure and pseudobrecciated structure. The chert is characterized by consistently low abundance of TiO₂, Al₂O₃ and most trace elements. Howevver, it is enriched in Ba, As, Sb, Hg and Se. In Al-Fe-Mn ternary diagrams, it fells into the “hydrothermal field”. Correspondence analysis and factor analysis show that many elements show up in the factor that represents the leaching of country rocks by hydrothermal solutions, and are the very characteristic element association of the geochemically anomalous South China basement. Petrologic and geochemical evidence suggests a hydrothermal origin for the chert. The chert may have been formed in a Precambrian rift or an extension zone developed within the Yunkai marginal geosyncline. with a fault system linking it to an unknown heat source at depth. This project was jointly funded by the National Natural Science Foundation of China (49303041), the Open Laboratory of Ore Deposit Geochemistry, Chinese Academy of Sciences, and Canadian International Development Agency.