Development of the crust continental in the colision zone

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The indoor experiments for the ultra-high pressure (UHP) rocks from Dora Maira Massif, western Alps, and from Su-Lu region in the Shandong Peninsula, China, were carried out.Based on more than 600 thin section observation of the Dora Maira samples, a precise P-T-t path of the UHP rocks, especially P-T conditions of the climax UHP stage and a retrograde stage but under still higher pressure condition, were determined. A new amphibole group mineral, ferronyboeite was also identified as a retrograde phase of UHP rocks. The output of our geological and petrological studies were referred in two guide books of international meetings held in 1994 and 1995 in Italy.Our study in the Shandong Peninsular reveals following facts :1) The spatial distribution of the UHP rocks were determined in the Shandong Peninsular ; the area to the South of the Yantai-Qingdao-Wullian Fault.2) UHP evidence were found from various kind of lithotypes, e.g., garnet-lherzolite, marble and metagranite. The UHP metagranite in Shandong is the first example in the Asia, and the second in the world.3) Rb-Sr dating of the gneissose rocks indicates that the LP gneiss in the NW area of the Peninsular shows significantly older age (1800Ma) than the gneiss in the UHP area (700Ma). The latter age suggest the basement of the UHP area were correlated to the Yangtzi Craton.