扬子崆岭新太古代壳-幔地球化学特征及其与华北克拉通-大别造山带的对比

认识华北与扬子克拉通太古宙时期是否属同一岩石圈块体以及大别造山带的归属对研究中国大陆早期演化历史具有重要地质意义．对新太古代斜长角闪岩和ＴＴＧ片麻岩组合样品系统的元素和同位素地球化学研究结果表明，新太古代扬子崆岭与华北陆块存在岩石圈地幔性质上的明显差异，其ＴＴＧ片麻岩的岩浆形成环境与条件也区别显著．湖北大别杂岩在一系列地球化学特征上表现出与扬子崆岭不同的特殊性，而与扬子北缘后河杂岩地球化学特征相似．崆岭斜长角闪岩、ＴＴＧ片麻岩和华北ＴＴＧ片麻岩的Ｕ，Ｔｈ元素组成特征符合其Ｐｂ同位素填图成果，但华北斜长角闪岩Ｕ，Ｔｈ元素组成特点与其Ｐｂ同位素填图成果不一致

GEOCHEMICAL FEATURES OF NEOARCHEAN CONTINENTAL CRUST AND MANTLE IN CHINA: CORRELATION AMONG YANGTZE KONGLING, NORTH CHINA CRATON AND DABIE OROGENIC BELT

The following two questions should first be clarified in this paper: Did the Yangtze and North China cratons share a same lithosphere in the Archean? What does the Dabie orogenic belt belong to? The clarification of these two questions is very significant for our understanding of the early evolution of China continental blocks. A systematic geochemical study of elements and isotopes in the sample series of the Neoarchean amphibolite and TTG gneiss shows that notable differences arise in the mantle property of the lithosphere between the Neoarchean Yangtze Kongling and the North China continental terrain. In addition, the magmatic formation and condition of the TTG gneiss are also distinctive. The Dabie complex in Hubei Province differs from that in Yangtze Kongling in terms of geochemistry, but resembles that in Houhe, northern margin of the Yangtze craton. The geochemical compositions of U and Th both in the Kongling amphibolite, TTG gneisses and in the North China TTG gneiss coincide with the actual results of isotopic mapping of lead. However, the geochemical compositions of U and Th in the North China amphibolite differ from the actual results of isotopic mapping of lead.