Cover Story：Principle slip zone (PSZ) of Wenchuan Earthquake in the core of Wenchaun earthquake Fault Scientific Drilling (WFSD). Comprehensive studies show that the PSZ is 100~200 μm in thickness, and locally forms graphite grains of nanometer size, which suggests that the slip mechanism of the fault is dominated by thermal pressure boost, and the strength of the fault is extremely low. The enrichment of graphite might be regarded as the mark of instantaneous frictional heating during the earthquake of the upper crust and could also serve as the evidence of the occurrence of a great earthquake, thus having important significance for the understanding of Wenchuan Earthquake and the judgement of paleoearthquakes. The research achievement led by Professor LI Hai-bing, Insti-tute of Geology, Chinese Academy of Geological Sciences, ranks the tenth among “Top Ten Geologi-cal Sci-tech Progresses of China Geological Sur-vey(CGS) and Chinese Academy of Geological Sciences(CAGS) in 2014”. For details, see page 257-269 of this issue. (Photo by LI Hai-bing)
