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Lead isotopes have been widely applied in geochemical exploration and evaluation of ore deposits, as well as in ascertaining the age of mineralization and the source of ore fluids. Long-term practice showed that the method of lead isotope targeting is somewhat efficient for macroscopic evaluation of forecasting areas, but not powerful enough for forecasting concealed orebodies. As the contents of U and the variation of U/Pb ratio sharply decrease with depth in the lithosphere, U-Th-Pb isotopic differentiation must have occurred during the crust-mantle evolution. Lead isotopic ratios show a wide variation range, varying in the front of mineralization and shallow-derived ores, but maintaining very stable in the major orebody and being usually close to the average isotopic composition of the crust and mantle of the continent block from which the ores were derived. Therefore, the lead isotopic composition can serve as a measure for identifying the position of mineralization. The lead isotope geochemistry was applied to the exploration and evaluation of the Baoban gold deposits of Hainan Province, China. The analytical results of ore veins and adjacent rocks showed that there is a correlation between the lead isotope data and the position of orebody. Based on the experience from the Baoban gold deposits and other ore deposits in Yunnan Province, an exploration principle has been established, that is, positive anomalies of lead isotope eigenvectors for prospecting deep-seated orebodies and negative anomalies of eigenvectors for enlarging lateral exploration surrounding the known deposit. The ore beds in the Erjia and Beiniu mining districts should be assigned to the deep part of the orebody and those in the Tuwaishan mining district should be the shallow part, so ore beds corresponding to those in the Erjia and Beiniu mining districts may be found in the Tuwaishan mining district.

The chronological data obtained by a variety of dating methods have confirmed that the sodium enriched metavolcanite series in the area of the Longbohe copper deposit at Jinping, Yunnan Province, was formed during the Proterozoic (its Pb−Pb isochron age=1595±75 Ma), corresponding to the Dahongshan Group sodium enriched metavolcanites. The Sm−Nd isochron age of 1336±46Ma should represent the time at which this series of volcanic rocks experienced spilitization in response to sodium metasomatism, equivalent to the time of sedimentation of the Ailaoshan Group and Yashan Group rocks. The Rb−Sr ages of the volcanic rocks and the Pb−Pb ages of copper ores have recorded the events of strong dynamic metamorphism and of strong reworking-metallogenesis of copper during the Jinningian period. Similarities in forming age, rock assemblage and isotopic characteristics between the sodium enriched metavolcanite series and the Dahongshan Group sodium enriched metavolcanite series have provided new clues to the exploration of the Dahongshan-type copper deposits in this area.

In this paper the Pb-Pb isochron method was used to determine the isotopic ages of the Luoxue Formation dolomites (1716 ±56 Ma), the Heishan Formation carbonaceous slates ( 1607 ±128 Ma) of the middle sub-group of the Kunyang Group and the Dayingpan Formation carbonaceous slates (1258 ±70Ma) of the upper sub-group of the Kunyang Group. The age of the middle sub-group of the Kunyang Group is about 1800 – 1600 Ma, belonging to the Late Paleo-Proterozoic, and that of the Dayingpan Formation in the upper sub-group of the Kunyang Group is about 1200 – 1300 Ma, belonging to the Middle Proterozoic. In addition, the Pb isotope chemical exploration techniques were used to study systematically the Pb isotopic compositions of rocks and ores across the No. 14 vein in the middle segment of the No. 1 pit of the Tangdan copper deposit and the result showed that the Pb isotope V1 values are negatively correlated with the copper contents. It is the first trial to use the systematic section method to conduct Pb isotope chemical exploration.

Based on the geological and geochemical information about migmatites, the following lines of evidence have been proposed for discriminating the anatectic leucosome in the Dabieshan Complex: (1) its width is larger than that derived from the subsolidus genesis, cutting across regional foliation, thus giving rise to complicated folds and wider selvages; (2) it is composed of melanic and accessory minerals in addition to quartz and feldspars; (3) the significant difference in anorthites of plagioclase between paleosome and leucosome; (4) temperature and pressure (P/T) conditions revealed by the mineral compositions and assemblages are over those for the onset of anatexis; and (5) it is enriched in the major elements (e.g. Al2O3, Fe2O3 and TiO2) and immobile and incompatible elements (e.g. LREE, Th, Hf and Zr). Finally, by combining the geological and geochemical features with the statistical data for the spatial distribution of minerals and mass-balance in the migmatites, it is concluded that anatexis is the cardinal mechanism of migmatization in the Dabieshan Complex.

Widely developed in the Dabie complex are various disequilibrium textures which provide direct evidence for the evolution of metamorphism and late-stage uplifting history. The typical mineral assemblage in the Opx-Gt-Pl-Bi gneiss in Huangtuling, Luotian County, Hubei Province, is Opx(I) + Gt + Pl(I) + Bi(I) + Q. The corona composed of cordierite and orthopyroxene (II) growing around garnets in the granulite makes it clear that there occurred the following metamorphic reaction: Gt + Q→ Cd + Opx(II). It is estimated that the granulite-forming temperature (T) and pressure (P) are 857–998°C and 1.18–1.23 GPa, respectively, and the corona was formed under the following conditions: T =829–911°C and P = 0.53–0.59 GPa. The above results indicate that there occurred a rapid and nearly adiabatic uplifting event and a decompressional metamorphism in the Dabie complex after the formation of granulite. As compared with the granulites worldwidely distributed in 90 locations (Harley, 1989), the Huangtuling granulite should belong to the high-pressure type, which represents the composition of the crust at a depth of more than 40 kilometers.