CAJ | 학술논문

海水中的氦同位素能对海底热液活动进行有效示踪。本文对在西南印度洋49°~56°E洋脊段采集的5条CTD拖曳剖面共14件深水样品进行了氦氖同位素分析。通过分析水体中存在的氦同位素异常,探讨调查区热液异常的特征和热液羽状流的分布。分析表明,5条CTD剖面均存在δ3 H e异常,其中CTD7-2(位置：37.927°S、49.412°E,水深2140 m,离底高度100 m)的δ3He 值最大,达到49.2%。根据δ3He分布特征,认为调查区内存在至少6处热液羽状流,其中37.927°S、49.412°E以西数千米范围内可能存在海底热液喷口。
해수중적양동위소능대해저열액활동진행유효시종。본문대재서남인도양49°~56°E양척단채집적5조CTD타예부면공14건심수양품진행료양내동위소분석。통과분석수체중존재적양동위소이상,탐토조사구열액이상적특정화열액우상류적분포。분석표명,5조CTD부면균존재δ3 H e이상,기중CTD7-2(위치：37.927°S、49.412°E,수심2140 m,리저고도100 m)적δ3He 치최대,체도49.2%。근거δ3He분포특정,인위조사구내존재지소6처열액우상류,기중37.927°S、49.412°E이서수천미범위내가능존재해저열액분구。
The helium isotope anomaly in the seawater is a good indicator of the hydrothermal activity in the sea-floor.During DY115-21 cruise Leg 7,five CTD Toyo profiles were deployed between 49°E and 56°E on the Southwest Indian Ridge and 1 4 seawater samples were collected for helium and neon isotope analysis.In this pa-per,we examine the helium isotope anomalies in the water column and discuss the distribution of the hydrothermal plumes in the investigated area.Our results show that all of the five CTD profiles exhibit distinctδ3 He anomalies. Sample CTD7-2 which was sampled at 37.927°S,49.412°E in the water depth of 2 140 m (100 m above the sea-floor)exhibited the largestδ3 He anomaly of 49.2%.According to the distribution pattern ofδ3 He,it is suggested that there may existed at least 6 hydrothermal plumes in the investigated area,and one active hydrothermal venting site probably lies within a few kilometers west of 37.927°S,49.412°E.