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Deep ore prospecting in central and eastern China is discussed in relation to the shortage of many mineral resources in the country. The differences between deep and shallow ore deposits are discussed and geological problems relating to prospecting for deep ore are considered including the integrity, depth of occurrence and three-dimensional structure of the metallogenic system, mineralisation zoning and criteria for locating deep ore deposits., Deep ore prospecting in central and eastern China is discussed in relation to the shortage of many mineral resources in the country. The differences between deep and shallow ore deposits are discussed and geological problems relating to prospecting for deep ore are considered including the integrity, depth of occurrence and three-dimensional structure of the metallogenic system, mineralisation zoning and criteria for locating deep ore deposits.

Six metallogenic domains are proposed on the basis of Chinese geotectonic evolution and regional lithospheric features. They are the Tien Shan-Xingmong, Tarim-North China, Qinling-Qilian-Kunlun, Yangtze, South China and Himalayan-Sanjiang domains, each of whose geological and ore-forming characteristics are described. The tectonic evolution and main metallogenic systems of the Precambrian, Early and Late Palaeozoic, Mesozoic and Cainozoic are also discussed and a number of metallogenic features are highlighted: the large proportion of Chinese mineral deposits found on palaeo-continental margins; the significant superimposed mineralisation; the concentration of large-scale mineralisation of crust-derived anatectic granites in certain spatial-temporal structures; the development of epithermal ore-forming systems; the clear role of structural controls; the complexity and diversity of gold mineralisation; the characteristic multiple-stage and heterogeneous nature of mineralisation; and the culmination of tectonic mineralisation on continental margins during the Mesozoic., Six metallogenic domains are proposed on the basis of Chinese geotectonic evolution and regional lithospheric features. They are the Tien Shan-Xingmong, Tarim-North China, Qinling-Qilian-Kunlun, Yangtze, South China and Himalayan-Sanjiang domains, each of whose geological and ore-forming characteristics are described. The tectonic evolution and main metallogenic systems of the Precambrian, Early and Late Palaeozoic, Mesozoic and Cainozoic are also discussed and a number of metallogenic features are highlighted: the large proportion of Chinese mineral deposits found on palaeo-continental margins; the significant superimposed mineralisation; the concentration of large-scale mineralisation of crust-derived anatectic granites in certain spatial-temporal structures; the development of epithermal ore-forming systems; the clear role of structural controls; the complexity and diversity of gold mineralisation; the characteristic multiple-stage and heterogeneous nature of mineralisation; and the culmination of tectonic mineralisation on continental margins during the Mesozoic.

The Erbutu Ni-Cu sulphide deposit is hosted in a small ultramafic intrusion located at the southern margin of the Central Asian orogenic belt, Inner Mongolia. This deposit is the first case of a magmatic sulphide deposit related to boninitic magmatism in an arc setting. The host intrusion is composed of orthopyroxenite and olivine orthopyroxenite. More than three quarters of the intrusion contains economic, disseminated sulphide mineralisation. SHRIMP U-Pb dating of zircons from the intrusion gives a crystallisation age of 294.2 +/-2.7 Ma, similar to the age of the Permian Tarim plume in northwest China. Olivine orthopyroxenite is characterised by olivine crystals with relatively high forsterite contents of 85-88 mol% and extremely low Ca contents of less than 250 ppm. Coexisting orthopyroxene crystals have clinoenstatite composition with enstatite from 86 to 88 mol%. Whole-rock data show characteristic enrichments of light REE relative to heavy REE, pronounced negative Nb-Ta anomalies, and moderately positive Hf anomaly. The 34-S isotope values of sulphide separates are 4-5 per mille, significantly higher than the typical mantle value (0 +/-2 per mille). The Hf isotope values of zircons are from -4 to -9. These data indicate that the parental magma was a boninite. Crustal contamination was involved during magma evolution and ore formation. (Authors.), The Erbutu Ni-Cu sulphide deposit is hosted in a small ultramafic intrusion located at the southern margin of the Central Asian orogenic belt, Inner Mongolia. This deposit is the first case of a magmatic sulphide deposit related to boninitic magmatism in an arc setting. The host intrusion is composed of orthopyroxenite and olivine orthopyroxenite. More than three quarters of the intrusion contains economic, disseminated sulphide mineralisation. SHRIMP U-Pb dating of zircons from the intrusion gives a crystallisation age of 294.2 +/-2.7 Ma, similar to the age of the Permian Tarim plume in northwest China. Olivine orthopyroxenite is characterised by olivine crystals with relatively high forsterite contents of 85-88 mol% and extremely low Ca contents of less than 250 ppm. Coexisting orthopyroxene crystals have clinoenstatite composition with enstatite from 86 to 88 mol%. Whole-rock data show characteristic enrichments of light REE relative to heavy REE, pronounced negative Nb-Ta anomalies, and moderately positive Hf anomaly. The 34-S isotope values of sulphide separates are 4-5 per mille, significantly higher than the typical mantle value (0 +/-2 per mille). The Hf isotope values of zircons are from -4 to -9. These data indicate that the parental magma was a boninite. Crustal contamination was involved during magma evolution and ore formation. (Authors.)

The quartz keratophyric rocks are seen in the same horizons as sulphur, zinc, lead and copper as well as siderite, or even as intercalations in siderite beds. The relationship between keratophyres and orebodies, together with the geological characteristics of the deposit and the geological-structural settings of mineralisation, suggest that the Dongshengmiao deposit was formed in an environment of Middle Proterozoic submarine volcanic activity., The quartz keratophyric rocks are seen in the same horizons as sulphur, zinc, lead and copper as well as siderite, or even as intercalations in siderite beds. The relationship between keratophyres and orebodies, together with the geological characteristics of the deposit and the geological-structural settings of mineralisation, suggest that the Dongshengmiao deposit was formed in an environment of Middle Proterozoic submarine volcanic activity.