Abstract

The article discusses the preliminary results of plume and bottom sediment studies of the Trollveggen hydrothermal vent field based on data from cruise 68 of the R/V Akademik Mstislav Keldysh. The hydrothermal vent field is located east of the axial zone of the slow-spreading Mohn Ridge near the Jan Mayen hotspot at a depth of about 550 m (71°18′ N, Norwegian–Greenland Basin). The hydrothermal vent field plume was characterized by a weak distribution in the water column; temperature, density, and salinity anomalies; a moderate methane concentration; and a low concentration of suspended particulate matter near the bottom. The enrichment of bottom sediments in barium, strontium, and some sulfide-forming elements (zinc, lead, copper, and molybdenum) was shown. Two mineral assemblages of hydrothermally modified bottom sediments were revealed: pyrite and barite–marcasite. The temperature of hydrothermal fluids was established by thermal and cryometric studies of gas–liquid fluid inclusions in barite (128–260°С); the FeS–ZnS equilibrium diagram of sulfide minerals was also used (130–290°С). Our data were close to direct fluid temperature measurement data [28]. We compared the hydrothermal mineralization of the Trollveggen vent field and earlier studied fields of the Mid-Atlantic Ridge located near the Azores hotspot. As a result, we confirmed the influence of ocean depth and PT conditions on the formation of hydrothermal deposits.

中文翻译：

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大西洋中脊71°N处的热液矿物组合（初步结果）

摘要

本文根据来自R / V Akademik Mstislav Keldysh的第68航次的数据，讨论了Trollveggen热液喷口区羽状流和底部沉积物研究的初步结果。热液喷口场位于Jan Mayen热点附近，缓慢扩散的Mohn脊轴向区的东部，深度约550 m（挪威格陵兰盆地，北纬71°18′）。热液喷口场羽流的特征是在水柱中分布较弱。温度，密度和盐度异常；甲烷浓度适中；底部附近的悬浮颗粒物浓度低。显示了钡，锶和一些硫化物形成元素（锌，铅，铜和钼）中底部沉积物的富集。揭示了热液改性底部沉积物的两种矿物组合：黄铁矿和重晶石-镁铁矿。热液温度是通过对重晶石中气液流体包裹体的热学和低温学研究确定的（128-260°С）；还使用了硫化物矿物的FeS–ZnS平衡图（130–290°С）。我们的数据接近直接流体温度测量数据[28]。我们比较了Tr​​ollveggen喷口区的热液成矿作用和早先研究过位于亚速尔群岛热点附近的中大西洋海脊的热液成矿作用。结果，我们证实了海洋深度和PT条件对热液沉积物形成的影响。