Dr. Ming Chen [Guangzhou Institute of Geochemistry]

Title:   The Xiuyan impact crater in China and evidence for an impact origin

Time:  10:00 – 11:00 AM, July 8, 2015, Wednesday

Place:  Conference room 201, Build 6, HPSTAR (Shanghai)

Host:   Jinfu Shu

Abstract:

The investigation of terrestrial impact craters began in 1970s in China and a lot of efforts have been made in this field. More than three decades have passed since the first impact crater in China became approved by the international scientific society. This first confirmed impact carter in China is the Xiuyan structure, which located in the Liaodong Peninsula in the northeastern China. It is a bowl-like crater of 1800m in diameter formed about 50 thousand years ago. A series of shock-metamorphic diagnostic evidence of minerals provide strong support for an impact origin of the crater. The found evidence includes shock-induced high-pressure minerals of coesite, TiO2-II and reidite, the planar deformation features of quartz and feldspars, and diaplectic glass of quartz and feldspars and so on. The Xiuyan crater is one of the impact structures with the most abundant shock-metamorphic phenomena of minerals around the world.

Biography of the Speaker:

Dr. Ming Chen (陈鸣) is currently a research professor in the Guangzhou Institute of Geochemistry, Chinese Academy of Sciences. He is a mineralogist and mainly engaging in the investigations of natural shock effects of minerals. He found several ultrahigh-pressure new minerals in shocked meteorites which could be predominating in the Earth’s mantle, which include xieite, tuite, lingunite and others. He reevaluated the pressure and temperature history of shock-induced high-pressure minerals in nature, which has finally resulted in well accepted new theory that the shock-induced high-pressure minerals in nature can be used as an approach for our understanding of mantle minerals. He is the finder of the first Chinese impact crater, for which China and the world has waited for decades.