Annotated record of the detailed examination of Mn deposits from CNAV Endeavour in 1967 to 1968 over the Bowie Seamount area

Bowie Seamount, a submerged volcano situated off the west coast of Canada at 53° 18; N, 135° 39' W, has a relief of 10,000 ft. and comes to within 100 ft. of the ocean surface. It is made up of a series of intersecting ridges which together give the mountain an overall northeast - southwest elongation. It appears to be a combination central and fissure type volcano which has been built up over a system of intersecting fractures in the oceanic crust. Two terraces form the flattened summit of the volcano at approximate depths of 45 and 130 fathoms. These are thought to be the remains of platforms produced by combined wave erosion and shallow-water vulcanism during late Quaternary time when sea level was lower than it is today. The last phase of volcanic activity on the summit occurred after the formation of the upper terrace no more than 18,000 years ago. Samples dredged from the upper half of the volcano include: pillow fragments, fragments of non-pillowed flows, pillow breccias, bombs, tuffs, ash, and unsorted tephra. The rocks are mainly alkali olivine basalts, accompanied by rare andesites which, presumably, were derived by differentiation of the basaltic magma. Feldspathic and gabbroic inclusions, many of which appear to be cumulates, are common in the basalt. Ice-rafted rocks are rare on the summit of Bowie Seampunt but are common on its nearest neighbour - Hodgkins Seamount. A ferro-manganese deposit, apparently over 1 million years old, that exists on the summit of Hodgkins Seamount, suggests that this peak is relatively much older than the summit area of Bowie Seamount. Palagonite appears to form as the initial phase of weathering of glassy basalts in the area of study but the products of more advanced weathering are montraorillonite and zeolites. Rock fragments that have been rounded by chemical weathering are common.

鲍伊海山（Bowie Seamount）是一座坐落于加拿大太平洋西海岸外、坐标为北纬53°18′、西经135°39′的水下火山（submerged volcano），其地形高差达10000英尺，最浅处距洋面仅100英尺。该海山由一系列相互交汇的海岭组成，整体呈北东-南西向延伸，属于中心式与裂隙式复合火山，形成于洋壳内一组相互交汇的断裂系统之上。海山的平顶火山口由两处阶地构成，大致分别位于45英寻和130英寻的深度处。研究认为，这两处阶地是晚第四纪时期（当时海平面低于现今）海浪侵蚀与浅水环境火山活动共同塑造的平台遗迹。海山顶部的最后一期火山活动发生在上层阶地形成之后，距今不超过18000年。从海山上半部分拖网采集的样本包括：枕状熔岩碎块、非枕状熔岩流碎块、枕状角砾岩、火山弹、凝灰岩、火山灰以及未分选火山碎屑。该区域岩石以碱性橄榄玄武岩为主，伴生少量安山岩，推测由玄武质岩浆分异作用形成。玄武岩中常见长英质与辉长质包体，其中多数为堆晶岩。鲍伊海山顶部的冰筏运岩较为罕见，但在其最近的邻海山——霍奇金斯海山（Hodgkins Seamount）上则较为常见。霍奇金斯海山顶部存在一处形成年代至少超过100万年的铁锰沉积，这表明该海山的顶部区域比鲍伊海山的顶部区域古老得多。在本研究区域内，橙玄玻璃（palagonite）似乎是玻璃质玄武岩风化的初始产物，而进一步风化的产物为蒙脱石（原文疑似笔误为montraorillonite）与沸石（zeolites）。经化学风化作用磨圆的岩石碎块在此区域较为常见。