Wang Denghong

Rutiles in eclogite from the Sulu UHPM Terrane: A preliminary study

In recent years more than 40 rutile-bearing eclogite ore bodies have been discovered among the thousands of eclogite bodies in the Sulu Utra-High Pressure Metamorphic (UHPM) terrene. Rock-and ore-cores obtained by the Chinese Continental Scientific Drilling (CCSD) Project revealed the presence of several hundred meters of rutile-bearing eclogites. This paper presents a preliminary petrographic, trace element, and Pb isotope study of rutile ores in eclogite. Rutiles occur as inclusions, intergranular infillings, remnant replacements, and hydrothermal infillings in the host rocks. The ore minerals define four stages of rutile mineralization and metamorphic evolution in the eclogites. Electron microprobe (EMP) trace element analysis of three rutile specimens show that different occurrences of eclogite also have different trace element compositions in rutile. These compositional differences may reflect different source rocks for the eclogites. Peak metamorphic temperatures were calculated using the Zr geothermometer in rutile. The Pb isotopic compositions of rutile obtained by step-fuse analysis of single grains of rutile did not fall on one growth line, but show similar variation between different samples. This implies that the Pb isotopic compositions of rutile may have been disturbed during its growth. This variation could be used to trace the growth history of the rutile, and further to trace the process of continental subduction- exhumation.

Lead isotopic composition of rutiles from the Chinese continental scientific drill (CCSD) hole and its genetic significance for the superlarge rutile deposit in Maobei, Jiangsu Province

The central orogenic belt in China, which extends from the Kunlun Mountains in the west to the coast in the east, has experienced a complex tectonic evolution. Based on the Chinese Continental Scientific Drill (CCSD) Hole, this paper reports that the Pb isotopic composition of rutiles selected from surface, from 350m depth and from 500m depth in core are variable, with high content of radiogenic Pb at the middle and later stages of the step-by-step leaching process. This suggests that the rutile-bearing eclogites might have experienced two times of subduction and exhumation.

Preliminary study on the Chinese continental mineralization system

China is enriched in mineral resources. How to systematically deduce the regularity of mineralization in order to serve for prospecting is the main purpose of this paper. The Chinese continental mineralization system (CCMS) can be referred to as the whole group of mineral deposits located in the present continent of China and their genetically related geological factors. The CCMS consists of 214 minerogenic series of 11 geological periods from Early Archean to Cenozoic, including at least 978 patterns of representative mineral deposits. The CCMS is the final result of mineralization formed through the whole evolution history of Chinese continental crust.