关键词: 天然气水合物, 成矿条件, 找矿标志, 南海

Abstract: Gas hydrate has become the focus of international interest over the past few years because of its abundance and its potential importance as (1) new energy resources,(2) controlling factor of global climatic change,and (3) trigger of sea floor instability.The South China Sea is one of marginal seas in the western Pacific.It is well known for their abundant oil and gas reserves,but only a little work has been done on gas hydrate. However, geological background, gas resource, temperature and pressure are good to form gas hydrate.Recently,the multichannel seismic profiles were rechecked and some bottom-simulating reflectors (BSR) as well as blanking zones were identified. Some high temperature anomalies above the sea surface were discovered from satellite thermal-infrared images,which is probable related to gas hydrate or gas seeps. Furthermore,high methane concentration of sediments and low chlorinity anomalies in interstitial water, which regarded to be indicators of gas hydrate,were also found from Site 1146,ODP leg-184.Moreover,the hydrocarbon anomalies and radioactive anomalies of shallow sediments were recognized.Therefore,it is quite probable that gas hydrates may occur in the South China Sea.

Key words: gas hydrate, background, indicators, the South China Sea