Explosive subaqueous eruptions: edifices and deposits

这项为期四年的研究经费题为“爆炸性水下喷发：建筑物和沉积物”，是一项关于古代水下喷发及其火山的过程导向研究。本研究的适用部分将利用观测到的火山碎屑沉积组织来确定可能存在的多金属火山块状硫化物沉积，这些多金属火山块状硫化物沉积是古代水下火山固有的。研究区包括魁北克省阿比提比绿岩带的太古代（约2.7 Ga）布莱克河群、安大略省瓦比贡省2.9 Ga陡岩区和新西兰南岛第三纪Oamaru火山杂岩。主要重点是识别和表征原生水下火山碎屑岩，并将其与改造后的同类岩区分开。所研究的喷发类型是大到中等体积的火山碎屑流和沉降物沉积，通常与火山口有关，火山口是火山崩塌结构，以及小体积的喷泉和由火山渣和火山碎屑锥产生的苏尔特采亚火山喷发。这些火山大厦发生在水下的事实使我们能够更好地了解水下爆炸的形成和分布。主要的输运过程是泥沙重力流，其中周围介质水起着突出的作用。三种常见的爆炸产物是火山碎屑流、跌落和涌浪，后者在水下可能不可能发生。学生将直接从该研究项目中获得资助，该研究项目包括一篇博士论文和两篇硕士论文。学生们将使用基本的测绘技术，同时也使用详细的相分析，在每年1-3个月的时间里，在野外识别各种岩石层。学生津贴和实地后勤是本研究项目的主要费用。

The four-year research grant entitled "Explosive subaqueous eruptions: edifices and deposits" is a process-oriented study concerning ancient subaqueous eruptions and their volcanoes. The applicable part of the study will use the observed pyroclastic deposit organization to vector possible polymetalic volcanic massive sulfide deposits that are inherent to ancient subaqueous volcanoes. The study areas include the Archean (ca. 2.7 Ga) Blake River Group of the Abitibi greenstone belt, Quebec, the 2.9 Ga Steep Rocks area  Wabigoon Subprovince, Ontario, and the Tertiary Oamaru volcanic complex, South Island, New Zealand. Major emphasis is placed on identifying and characterizing primary subaqueous pyroclastic rocks and differentiating them form their reworked counterparts. The type of eruptions studied are large- to moderate-volume pyroclastic flows and fallout deposits commonly associated with calderas, which are volcanic collapse structures, and small-volume fountaining and Surtseyan eruptions emanating from cinder and pyroclastic cones. The fact that these volcanic edifices occur under water allow us to better understand how subaqueous explosions form and distribute. The principal transport process is that of sediment gravity flows, in which the surrounding medium water plays a prominent role. The three prevalent types of explosive products are pyroclastic flow, fall and surge, with the latter probably not possible in the subaqueous realm. The students will be directly funded from this research project, which consists of one PhD and two MSc-level theses. Students will use basic mapping techniques but also use detailed facies analysis to identify the various rocks suites over a period of 1-3 months per year in the field. The student stipendium and field logistics represent the major costs of this research project.