太平洋多金属结核中的锰矿物及其相变  

Manganese Minerals in Polymetallic Nodules of Pacific Ocean and Their Phase Transformation

作　　者：萧绪琦[1] 郭立鹤 刘新波[1] 

机构地区：[1]中国地质科学院矿床地质研究所,地质矿产部海洋地质研究所

出　　处：《岩石矿物学杂志》1997年第4期367-373,T002,共8页Acta Petrologica et Mineralogica

基　　金：国家"八五"重点攻关项目

摘　　要：从太平洋多金属结核中鉴定出的锰矿物有水羟锰矿、钙锰矿、水钠锰矿、布塞尔矿、布塞尔矿－锰钴土混层矿物及纤锌锰矿。锰矿物的分布特点是，太平洋中部ＣＰ区以水羟锰矿为主，钙锰矿次之；ＣＣ区以片状钙锰矿为主，水羟锰矿次之；东太平洋海盆以片状钙锰矿和布塞尔矿为主，水羟锰矿较少。通过锰矿物相变实验，探讨了水羟锰矿－钙锰矿、水钠锰矿－布塞尔矿、钙锰矿－布塞尔矿。Manganese mineral phases in polymetallic nodules from Pacific Basin have been studied by means of TEM, XRD and FTIR. Six mineral phases, viz. vernadite, todorokite, birnessite, buserite, buserite asbolite mixedlayer mineral and woodruffite, have been identified. Their morphological and microstructural features have been described. In Central Pacific Ocean, nodules in CP zone are rich in vernadite and, next, todorokite, whereas in CC zone the sheet todorokite is dominant, and vernadite comes second. Nodules from East Pacific basin are rich in lamellar todorokite and buserite, with minor vernadite. The IR spectroscopic study shows that condensed octahedral unite of MnO6 exist in the structure of vernadite, todorokite, birnessite, but the strength of Mn-O bond decreases gradually in order of todorokite, birnessite, vernadite. Relationships of the phase transformation among manganese minerals were inquired into. Phenomena of phase transformation between vernadite and todorokite and between layered buserite and vernadite were discovered. The result of heat treatment shows that up to 105℃ buseriteI may be transformed into birnessite owing to dewatering, and there is no phase transformation between todorokite and birnessite; up to 400℃ layered buserite may be transformed into vernadite, but there exists no structural change for fibrous todorokite with tunnel structure.

关 键 词：太平洋 多金属结构 锰矿物 相变 

分 类 号：P744.3[天文地球—海洋科学]