南极南设得兰群岛海域地质新进展:“海洋六号”南极科考初步成果  

New Geological Progress in Offshore Area of South Shetland Islands, Antarctic: Preliminary Results of R/V “Hai Yang Liu Hao” Expedition

作　　者：何高文[1] 付少英[1] 邓希光[1] 赵庆献[1] 王力峰[1] 王海峰[1] 关晓春[1] 刘胜旋[1] 庞云天[1] 陈玺[1] 柴祎[1] 罗贤虎[1] 朱本铎[1] 朱振华[1] 李强[1] 苏丕波[1] 何赵 吴聪[1] 黄宁[1] 何发光[1] 蓝明华 HE Gao-wen;FU Shao-ying;DENG Xi-guang;ZHAO Qing-xian;WANG Li-feng;HE Gao-wen;WANG Hai-feng;LIU Sheng-xuan;PANG Yun-tian;CHEN Xi;CHAI Yi;LUO Xian-hu;ZHU Ben-duo;ZHU Zhen-hua;LI Qiang;SU Pi-bo;HE Zhao;WU Cong;HUANG Ning;HE Fa-guang;LAN Ming-hua(Key Laboratory of Marine Mineral Resources,Ministry of Natural Resources,Guangzhou Marine Geological Survey,Guangzhou,Guangdong 510075)

机构地区：[1]自然资源部海底矿产资源重点实验室,广州海洋地质调查局,广东广州510075

出　　处：《地球学报》2018年第6期643-656,共14页Acta Geoscientica Sinica

基　　金：中国地质调查局海洋地质调查计划项目(编号:GZH201100303)资助。

摘　　要：2016—2017年跨年度执行的中国第33次南极科考"海洋六号"航次,首次获取了南极半岛南设得兰群岛北部海域、布兰斯菲尔德海峡以及欺骗岛三个区域的17 850 km^2范围内多波束全覆盖高精度水深数据,地形分辨率高于目前公开的国际数据。多道地震结果显示调查区多处存在天然气水合物地球物理标志BSR。地热测量热流值表明南设得兰群岛以北热流值与全球海洋热流值数据吻合,不存在明显异常,群岛以南热流值数据偏高。沉积物样品为典型的冰海沉积物,在南设得兰群岛与南设得兰海沟之间,沉积物以粉砂-砂为主,夹杂砾石,随水深增加,沉积物粒径变细;而在布兰斯菲尔德海区表层沉积物分布具有不对称性,海槽南部陆架-上陆坡以及海槽东北和相邻陆架,沉积物以砾石、砂质为主;海槽和下陆坡为粉砂质硅质软泥。沉积物顶空气样品现场测试结果表明,表层沉积物50 cm左右深度内的甲烷含量没有明显的差异性,但在岛坡深水区两个测站甲烷含量在270cm左右深度时都存在局部高异常,且两者总甲烷含量的变化趋势有一定的相似性,可能与水合物分解迁移有关。The 33rd China Antarctic Research Expedition R/V“Hai Yang Liu Hao”Cruise,which was implemented in 2016–2017,was the first to obtain the full coverage and high precision multi-beam echo sounding water depth data of the seabed in the north of the South Shetland Islands,the Bransfield Strait and the Deception Island in the Antarctic Peninsula,covering an area of 17 850 km2.Accurate topographic maps with higher terrain resolution than currently published data were obtained.The results of multi-channel seismic show that there are many natural gas hydrate geophysical markers BSR in the survey area.The geothermal heat flow value indicates that the heat flow value in the north of the South Shetland Islands is consistent with the global ocean heat flow data.There is no obvious anomaly,and the heat flux value data in the south of the archipelago are relatively high.Sediment samples are typical submarine glacial sediments between the South Shetland Islands and the South Shetland Trench.The sediments are dominated by silt-sand,mixed with gravel,and the sediment size becomes finer with increasing water depth.The distribution of surface sediments in the Bransfield Strait area is asymmetrical.On the southern shelf-upper slope of the trough and in the northeast and adjacent shelf of the trough,the sediments are mainly gravel and sandy,whereas the trough and the lower slope are silty siliceous ooze.The field test results of the headspace gases sample of sediments show that there is no significant difference in the methane content of surface sediments at the depth of about 50 cm below the seabed,but there are local high anomalies in the methane content of the two stations in the deep water area of the island slope at around 270 cm below the seabed.There is a certain similarity in the trend of total methane content,which may be caused by the decomposition and migration of hydrates.

关 键 词：南设得兰群岛 布兰斯菲尔德海峡 地质地球物理调查 “海洋六号”船 

分 类 号：P941.61[天文地球—自然地理学] P714.8