东太平洋海盆内多金属结核中的铁矿物

东太平洋海盆内多金属结核中的铁矿物萧绪琦郭立鹤（中国地质科学院矿床地质研究所，北京１０００３７）１前言早在五十年代人们就已注意到，大洋多金属结核含铁量较高，由于结核中矿物颗粒细小，结晶程度低，使得铁矿物的确定很困难，通常称之为铁的氧化物和氢氧化物。在...

Ferruginous Minerals in Polymetallic nodules from the East Pacific Basin

Ferruginous minerals in polymetallic nodules from the East Pacific basin were studied by means of transmission electron microscope (TEM). Nine species of ferruginous minerals were identified in the nodules, namely ferocyhyte, akagancite, goethite, ferrihydrite, hematite, magnetite, maghemite, chromite and the hisingerite-like mineral. Both feroxyhyte and vernadite assume curled fibrous aggregates under TEM. It is considered that part of Fe 3 converted nonbiologically from Fe 2 in the ooze is trapped and then precipitates as feroxyhyte with vernadite during the deposition of Mn 4 . Goethite is too small to be recognized even under TEM. It was for the first time that ferrihydrite was discovered in oceanic nodules. The fact that the electron diffraction pattern of ferrihydrite contains the electron diffraction of goethite suggests the reciprocity between them. Hisingerite-like mineral which mainly consists of Si and Fe has been discovered both in polymetallic nodules and in sediments. This mineral was previously considered to be a mixture of ferruginous minerals and silicates. As samples of this mineral from various places are similar to hisingerite in structure, TEM morphological features and chemical composition, the authors believe that it is an independent mineral instead of a mixture, and hence temporarily name it hisingerite-like mineral.