Heat and Chemical Exchange During the Early Stages of Backarc Rifting in a Polar Region: Hydrothermal Activity in Bransfield Strait, Antarctica

极地弧后裂谷早期阶段的热和化学交换：南极洲布兰斯菲尔德海峡的热液活动

• 批准号: 9725972
• 负责人: Gary Klinkhammer
• 金额: $ 18.34万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-06-01 至 2001-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9725972&HistoricalAwards=false
• 关键词: Heat; Chemical; Exchange; During; Early

NSF FORM 1358 (1/94) This award, provided by the Office of Polar Programs of the National Science Foundation, supports research to investigate hydrothermal venting in Bransfield Strait, between the South Shetland Islands and the Antarctic Peninsula. Previous exploratory work in the Strait identified several sites where hot hydrothermal fluids emanate from the sea floor. These discoveries were made using an instrument package specially designed to detect and map the thermal and chemical anomalies that hydrothermal activity imparts on the overlying water column. Hydrothermal sites in the Strait range in water depth from 200 to 1300 meters and occur on the volcanic outcrops that periodically protrude through the sediment cover along the strike of the rift zone. These sites are alligned with the caldera at Deception Island which has active hot springs. These are the first submarine hydrothermal sites discovered in Antarctica and as such represent unique research opportunities. This project will return to the Strait to further map and sample these areas. There are several compelling reasons to believe that further exploration of vent systems in the Bransfield will yield exciting new information: (1) Bransfield Strait is a back-arc rift system and it is likely that the vent fluids and mineral deposits associated with venting in this setting are unlike anything sampled so far from submarine vents. (2) Preliminary evidence suggests that venting in the Bransfield occurs in two different volcanic substrates: andesite and rhyolite. This situation provides a natural laboratory for investigating the effects of substrate chemistry on vent fluid composition. (3) Bransfield Strait is isolated from the system of mid-ocean ridges and has a relatively short history of rifting (approximately 4 my). So, while the region straddles the Atlantic and Pacific, vent biota in the Strait may well have a distinct genealogy. Biochemical information on vent species in the Bransfield will add to our knowledge of the dispersal of life in the deep ocean. In the past such discoveries have led to the identification of new species and the isolation of previously unknown biochemical compounds. (4) The fire and ice environments of hydrothermal sites in the Bransfield may prove to be the closest analog for primordial environments on Earth and extraterrestrial bodies. The Bransfield Strait is one of the most productive areas of the world's oceans and lies close to the Antarctic continent, far removed from the mid-ocean ridge system. The combination of organic-rich sediment and heat produced by volcanism in this back- arc setting creates a situation conducive to unusual fluids, unique vent biota, and exotic hydrothermal deposits. Collaborative awards: OPP 9725972 and OPP 9813450

NSF表格1358（1/94）由国家科学基金会极地计划办公室提供的该奖项支持研究研究布兰斯菲尔德海峡，南设得兰群岛和南极半岛之间的水热通风。 以前在海峡的探索性工作确定了几个地点，热热热流体从海底发出。 这些发现是使用专门设计的仪器包进行的，以检测和绘制热热活动在上覆的水柱上赋予的热和化学异常。 海峡的水热范围从200到1300米处的水深度范围内，并发生在火山露头上，这些露头会定期通过裂谷区罢工的沉积物覆盖物伸出。 这些地点在具有活跃温泉的欺骗岛上与火山口配置。 这些是在南极洲发现的第一个海底热液遗址，因此代表了独特的研究机会。 该项目将返回海峡以进一步映射并采样这些区域。 有几个令人信服的理由相信，布兰斯菲尔德（Bransfield）中的通风系统进一步探索将产生令人兴奋的新信息：（1）布兰斯菲尔德海峡（Bransfield STRAIT设置与远离潜艇通风口的任何采样不同。 （2）初步证据表明，布兰斯菲尔德的排气发生在两种不同的火山底物中：安山岩和流纹岩。 这种情况提供了一个自然实验室，用于研究底物化学对排气液组成的影响。 （3）布兰斯菲尔德海峡与中山脊的系统隔离，并具有相对较短的裂谷历史（大约4个）。 因此，尽管该地区跨越了大西洋和太平洋地区，但海峡中的排气生物群可能具有独特的家谱。 关于布兰斯菲尔德（Bransfield）中排气物种的生化信息将增加我们对深海生命分散的了解。 过去，这种发现导致了新物种的鉴定以及以前未知的生化化合物的隔离。 （4）Bransfield中热液位点的火和冰环境可能被证明是地球和外星物体原始环境的最接近的类似物。 布兰斯菲尔德海峡（Bransfield Strait）是世界海洋中最有生产力的地区之一，靠近南极大陆，距离海洋中部山脊系统很远。 在这种背弧环境中火山作用产生的有机富集的沉积物和热量的结合创造了有利于异常流体，独特的排气生物群和异国情调的热液沉积物的情况。 协作奖：OPP 9725972和OPP 9813450