The Zhongshan Station of China is located in the Larsemann Hills, East Antarctica. Low pressure granulite facies gneisses together with late granites are outcroped in the region. Three biotite samples from a garnet se...The Zhongshan Station of China is located in the Larsemann Hills, East Antarctica. Low pressure granulite facies gneisses together with late granites are outcroped in the region. Three biotite samples from a garnet segregation, a syenogranite and a granite-pegmetite were measured with 40Ar/39Ar incremental heating technique. Biotites from the garnet segregation give an 40Ar/39Ar plateau age of 504±1Ma. Biotites from the syenogranite yield an 40Ar/39Ar plateau age of 494 ±1 Ma. Biotites from the granite-pegmatite give an 40 Ar/39 Ar plateay age of 486±1Ma. They verify 500 Ma thermal event called 'Pan African event' by previous K-Ar and Rb-Sr data. They are cooling ages of the biotites when the paleogeotherm of the area droped to the K-Ar closure temperature for biotite.展开更多
基金This project is supported by National Natural Science Foudation of ChinaState Antarctic Committee of China
文摘The Zhongshan Station of China is located in the Larsemann Hills, East Antarctica. Low pressure granulite facies gneisses together with late granites are outcroped in the region. Three biotite samples from a garnet segregation, a syenogranite and a granite-pegmetite were measured with 40Ar/39Ar incremental heating technique. Biotites from the garnet segregation give an 40Ar/39Ar plateau age of 504±1Ma. Biotites from the syenogranite yield an 40Ar/39Ar plateau age of 494 ±1 Ma. Biotites from the granite-pegmatite give an 40 Ar/39 Ar plateay age of 486±1Ma. They verify 500 Ma thermal event called 'Pan African event' by previous K-Ar and Rb-Sr data. They are cooling ages of the biotites when the paleogeotherm of the area droped to the K-Ar closure temperature for biotite.
