A Chinese trilogy
When a deposit is one of China’s largest, it must be big, which is why we bring you not one, but three ore-some samples to highlight ore mineralization at China’s Jinding deposit – the country’s largest source of zinc (Zn).
…Jinding all the way. Oh what fun it is to …
The Jinding deposit is located within the Lanping Basin, Yunnan Province, China. The formation of the deposit and the diversity of its minerals are attributed to the interaction of two fluid systems. One fluid came from great depths beneath the basin and was the main carrier of metals. The other fluid occurred within the basin providing the sulphur that was essential for the formation of the ore minerals at Jinding. When these two fluids mixed, minerals containing zinc (Zn), lead (Pb), silver (Ag), copper (Cu), cobalt (Co), and cadmium (Cd) were deposited.
Jinding’s ores
Photograph A shows a breccia sample composed of limestone fragments of different composition, shape, size and orientation, which result from the breakage of the country rock during faulting. The cavities are filled with rock flour, carbonate cement and the zinc bearing mineral zincite (ZnO).
Photograph B shows a fine-grained layered rock composed mainly of milky yellow sphalerite (ZnS) with white zincite (ZnO). The golden coloured mineral at the base of the sample is the copper bearing mineral, chalcopyrite (CuFeS2). The small vertical and oblique joints and veinlets indicate the deformation of this impermeable rock after its formation.
Photograph C shows a kidney shaped (botroidal) mass of a dark mixture of fine crystalline sphalerite (ZnS) and galena (PbS) with yellow crusts of cadmium bearing smithsonite (Zn,CdCO3). Here the toxic element cadmium is associated with the base metals zinc and lead. This association has to be considered in the exploitation of the deposit to prevent contamination down the river.
We have the Museum’s Scientific Associates Dr Baruch Spiro and Dr Chris Halls to thank for bringing us these samples.
Visit window nineteen and window twenty to read of more samples collected while on fieldwork.
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…Jinding all the way. Oh what fun it is to …
The Jinding deposit is located within the Lanping Basin, Yunnan Province, China. The formation of the deposit and the diversity of its minerals are attributed to the interaction of two fluid systems. One fluid came from great depths beneath the basin and was the main carrier of metals. The other fluid occurred within the basin providing the sulphur that was essential for the formation of the ore minerals at Jinding. When these two fluids mixed, minerals containing zinc (Zn), lead (Pb), silver (Ag), copper (Cu), cobalt (Co), and cadmium (Cd) were deposited.
Jinding’s ores
Photograph A shows a breccia sample composed of limestone fragments of different composition, shape, size and orientation, which result from the breakage of the country rock during faulting. The cavities are filled with rock flour, carbonate cement and the zinc bearing mineral zincite (ZnO).
Photograph B shows a fine-grained layered rock composed mainly of milky yellow sphalerite (ZnS) with white zincite (ZnO). The golden coloured mineral at the base of the sample is the copper bearing mineral, chalcopyrite (CuFeS2). The small vertical and oblique joints and veinlets indicate the deformation of this impermeable rock after its formation.
Photograph C shows a kidney shaped (botroidal) mass of a dark mixture of fine crystalline sphalerite (ZnS) and galena (PbS) with yellow crusts of cadmium bearing smithsonite (Zn,CdCO3). Here the toxic element cadmium is associated with the base metals zinc and lead. This association has to be considered in the exploitation of the deposit to prevent contamination down the river.
We have the Museum’s Scientific Associates Dr Baruch Spiro and Dr Chris Halls to thank for bringing us these samples.
Visit window nineteen and window twenty to read of more samples collected while on fieldwork.
< Back to calendar