Geochemistry of ferromanganese deposits from the Wombat Plateau@en

Ferromanganese crusts, nodules, and ferromanganese-rich sediments were recovered on the Wombat Plateau, northwest Australian continental margin, by dredging during Bureau of Mineral Resources cruise 56 of Rig Seismic and by drilling during ODP Leg 122 of JOWES Resolution. We report here the chemistry and mineralogy of the ferromanganese crusts, nodules, and associated ferromanganese-rich sediments. The ferromanganese deposits from the ODP sites are up to 40 cm thick and probably formed in Late Cretaceous to Eocene times. Those from outcrops usually formed in several phases, and their age is unconstrained except that the substrates are Mesozoic. The samples were recovered from present-day water depths of 2000-4600 m, on the Wombat Plateau adjacent to the Argo Abyssal Plain. […]本研究涉及的铁锰结壳（Ferromanganese crusts）、铁锰结核（nodules）及富铁锰沉积物（ferromanganese-rich sediments），采自澳大利亚西北大陆边缘的袋熊高原（Wombat Plateau）：其中部分样品通过搭载于瑞格地震号（Rig Seismic）的澳大利亚矿产资源局（Bureau of Mineral Resources）第56航次的拖网作业获取，其余样品则由JOWES Resolution号执行的大洋钻探计划（Ocean Drilling Program，ODP）第122航次的钻探作业获得。本文报道了上述铁锰结壳、结核以及伴生富铁锰沉积物的地球化学与矿物学特征。大洋钻探计划各站位所获铁锰矿床厚度可达40厘米，其形成时代大致为晚白垩世至始新世。露头样品的形成通常经历多期次地质作用，仅可知其赋存基质为中生代地层，具体形成年龄尚未得到限定。所有样品均采自袋熊高原毗邻阿尔戈深海平原（Argo Abyssal Plain）的区域，现今水深介于2000~4600米之间。[…]