Geological note: Igneous and sedimentary rocks dredged from the northern Macquarie Ridge, Southern Ocean

Altered basalt, dolerite and gabbro have been dredged from a previously unsampled portion of the Macquarie Ridge (47o-48° S), using the commercial fishing vessel Amaltal Explorer. These rocks are petrographically and geochemically similar to mafic-ultramafic volcanic and plutonic suites of MORB-like petrological affinity, collected along the ridge between 49° and 58° S by previous investigators. The northernmost part of the Macquarie Ridge (Puysegur Bank) is thus geologically related to the rest of the ridge, even though it is bathymetrically part of the New Zealand continental shelf. Sedimentary rocks dredged from 47o-48° S were derived from both oceanic Macquarie Ridge and continental New Zealand sources. There is no evidence of subduction-related magmatism along any part of the Macquarie Ridge.

研究团队通过商业渔船“阿玛塔尔探索者号（Amaltal Explorer）”，于麦夸里海岭（Macquarie Ridge）南纬47°-48°的此前未被采样的区域拖采获得了蚀变玄武岩、辉绿岩与辉长岩。这些岩石在岩石学与地球化学特征上，与此前研究者在该海岭南纬49°-58°区段采集的、具有洋中脊玄武岩（Mid-Ocean Ridge Basalt, MORB）类岩石学亲缘性的镁铁质-超镁铁质火山-深成岩组合高度相似。尽管麦夸里海岭最北端的普伊塞格海台（Puysegur Bank）在水深地形上隶属于新西兰大陆架，但从地质学视角来看，其与该海岭其余区段存在成因联系。从南纬47°-48°区域拖采得到的沉积岩，其物源同时涵盖大洋环境的麦夸里海岭与大陆环境的新西兰源区。目前尚无证据显示麦夸里海岭的任何区段存在与俯冲作用相关的岩浆活动。