南沙群岛海域汞量地球化学异常分析

概述在南沙群岛海域开展海上汞量地球化学调查与异常分析的主要成果。从1989至1994年的5个航次中，完成了11655km测线和1790个站的表层海水和海面大气中汞量现场测定。在圈定的19个汞量异常中，推断有9个与下伏油气储层有关，另有7个为断裂带的反映，还有3个可能指示海底存在天然气水合物或深水油气藏。调查结果表明，汞量测量是一种有效的海上油气资源和地质调查手段，能为南沙油气资源远景评价和大型断裂构造调查提供重要的地球化学依据。

MERCURY GEOCHEMICAL ANOMALIES IN NANSHA ISLANDS SEA AREA

The paper summarizes major resultS from mercury geochemical inveshgations in the Nansha Islands sea area in 1989-1994. Mercury contents in surface seawater and sea-surface air were determined in situ at 1790 stations along 11655 Km survey lines on 5 cruises. A total of 19 mercury anomalies were identified,among which 9 are correlated with oil / gas reservoirs at depth, 7 with fault belts. 3anomalies found in lower slope are possibly indicative of the existence of methane gas hydrate or hydrocarbon accumulations in deep-water areas. The results demonstrate that the mercury determination may be an effective tool in offshore oil / gas exploration and geological investigation, as it can provide important geochemical evidences for hydrocarbon accumulations and large-scaled faults.