(Table VII, page 92) Elemental chemical analyses of post volcanic deposits recovered from Hudson-70, Phase VII cruise (CNAV Endeavour)

The Dellwood Seamount Area, an area of approximately 10,000 square km., about 185 km. west of the northern tip of Vancouver Island is located at or near the northernmost end of the Juan de Fuca plate. The main purpose of the study was to test the hypothesis that the Dellwood Knolls mark the site of a short spreading segment connected to the Explorer Spreading Segment at one end by a transform fault trending along the southwestern slope of Paul Revere Ridge; and meeting the Queen Charlotte right lateral transform fault at the other end. An analysis of more than 950 km. of continuous seismic reflection profiles, in conjunction with other geophysical data, shows that (i) the Revere -Dellwood fault zone is a dextral transform fault zone connecting the Explorer and Dellwood spreading segments. (ii) The Queen Charlotte transform fault dies out at the southeastern end of the Scott Channel near the northeastern end of the Dellwood Spreading Segment. (iii) In the channel between the Dellwood Knolls (one of two possible locations of the Dellwood Spreading Segment), the sediments and volcanic basement are cut by normal faults, a feature which is characteristic of spreading centres with median valleys. The heat flow in this channel and in the Revere - Dellwood fault zone is high. (iv) The lower continental slope sediments west of Queen Charlotte Sound is faulted and crumpled and may be the northerly extension of the Scott Islands fault, zone and a site of slow contemporaneous or recently ceased subduction. The deformation of the thick turbidite sequence in the Winona Basin may also be due to subduction. Basalt from the area is chemically intermediate between tholeiitic and alkalic types. That from the Northwest Dellwood Knolls, however, is least differentiated and less than 1 myr. old in contrast to basalt from the sediment-draped Southeast Dellwood Knolls, the latter basalt having Mn-coating up to 50 mm. thick and is thus relatively old. This suggests that spreading may be occurring at the Northwest Dellwood Knolls and not in the channel between the knolls. The texture of basalts from the Dellwood Seamount Range vary depending on size of pillow and depth below pillow surface, but the mineralogy is essentially similar. An unusual rock probably best described as a plagio-clase-olivine basalt porphyry was also recovered from the Dellwood Seamount Range. Non-volcanic rocks recovered include glacial erratics, an authigenic sandstone comprising glacial fragments in an iron-rich cement, a laminated limonitic sediment and manganese nodules. The Dellwood Spreading Segment may have originated by left lateral transcurrent offset from the Explorer Spreading Segment, the offset caused by a change in the direction of motion of the Juan de Fuca plate.

戴尔伍德海山区（Dellwood Seamount Area）面积约10000平方千米，地处温哥华岛北端以西约185千米处，位于胡安·德·富卡板块（Juan de Fuca plate）的最北端或其邻近区域。
本研究的核心目的为验证下述假说：戴尔伍德海丘（Dellwood Knolls）代表一处短扩张段（spreading segment）的赋存位置，该扩张段一端通过沿保罗·里维尔海岭（Paul Revere Ridge）西南坡展布的转换断层（transform fault）与探险家扩张段（Explorer Spreading Segment）相连，另一端则与夏洛特皇后右旋转换断层（Queen Charlotte right lateral transform fault）相接。
研究团队对超过950千米的连续地震反射剖面（continuous seismic reflection profiles）及其他地球物理数据开展综合分析后，得到如下结论：
(1) 里维尔-戴尔伍德断层带为连接探险家扩张段与戴尔伍德扩张段的右旋转换断层带（dextral transform fault zone）；
(2) 夏洛特皇后转换断层终止于戴尔伍德扩张段东北端附近的斯科特海峡（Scott Channel）东南端；
(3) 在戴尔伍德海丘（戴尔伍德扩张段的两处可能赋存位置之一）之间的海峡中，沉积物与火山基底被正断层（normal fault）切割，该特征为发育中央谷的扩张中心的典型标志，该海峡及里维尔-戴尔伍德断层带的热流（heat flow）值较高；
(4) 夏洛特皇后湾（Queen Charlotte Sound）以西的大陆坡下部沉积物发生断层作用与褶皱变形，可能为斯科特群岛断层带（Scott Islands fault zone）的北向延伸区域，同时也是缓慢同期俯冲或近期停止俯冲的发生位点，威诺纳盆地（Winona Basin）内厚层浊积岩序列（turbidite sequence）的变形也可能由俯冲作用（subduction）所致。
该区域产出的玄武岩（basalt）在化学成分上介于拉斑玄武岩（tholeiitic）与碱性玄武岩（alkalic）之间。但西北戴尔伍德海丘的玄武岩分异程度最低，且形成年代不足1百万年（myr）；与之相对，被沉积物覆盖的东南戴尔伍德海丘的玄武岩带有厚度可达50毫米的锰涂层（Mn-coating），因此相对古老。这表明扩张作用可能发生在西北戴尔伍德海丘，而非海丘之间的海峡区域。
戴尔伍德海山链（Dellwood Seamount Range）产出的玄武岩的结构随枕状体尺寸及枕面下深度的差异而变化，但矿物学特征基本一致。研究团队还从该海山链中采集到一种罕见岩石，其最适宜的分类为斜长石-橄榄石玄武岩斑岩。
采集到的非火山岩包括冰川漂砾（glacial erratics）、以富铁胶结物包裹冰川碎屑形成的自生砂岩（authigenic sandstone）、纹层状褐铁矿沉积物（laminated limonitic sediment）以及锰结核（manganese nodules）。
戴尔伍德扩张段可能起源于探险家扩张段的左旋走滑偏移（left lateral transcurrent offset），该偏移由胡安·德·富卡板块运动方向的改变所引发。