Electron Microscoplc and mineralogical studies on biologically induced metal ores and minerals

生物诱发金属矿石和矿物的电子显微镜和矿物学研究

基本信息

批准号：
08454155
负责人：
AKAI Junji
金额：
$ 5.06万
依托单位：
Faculty of Science, Niigata University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1998
项目状态：
已结题

项目摘要

It is interesting to investigate biologically Induced metal ore or rnineral phases. The processes have much impact to Earth'ssurf ace environments and also on Earth History. In this project, three major sub-themas were selected : that is, (1) Formation processes of biolocgically induced iron ore, such as Gunma lion Mine, (2) Old and recent stromatoilte structures and their characteristics, and (3) biogenic (magne to tactic bacterial) magnetite. One of the major results of these studies is about (1) on Gunma Iron mine. The following is the summary. Sedimentary iron ores From the Iron Mine were mine ralogically described .The Iron ore is composed of nanocrystalline goethite, well crystallized jarosite and very small amounts of strengite. Characteristiciron-ore types include thick-banded iron, thin-banded lion ore and fossil-aggregate ore rich in moss and/or leaves. Algal fossils are clearly preserved in the goethite bands in the thick-banded ore. Lattice imaging howed characteristic crystallographic orientations of the goethite nanocrystals. The thin- banded lion ores may probably formed by bacterial iron biominera1ization. The bandings may be attributed to biological or seasonal rhythms. Various products of biomineraIization are found in the present pH 2-3, Fe2^<2+>-and SO_4^<2-> rich streams ; Fe-P-(S) to Fe-S-(P) precipitates. Mosses and green algae are also collecting Fe precipitates in and around the cells. These ores are regarded as Biologicaly Induced lron Ore. (2) Mn stromatolite were found both from Japan (as recent hot springsediments), and from Australia precambrian strata. (3) The magnetite was mine ralogically and cryst allographically examined.

研究生物诱导的金属矿石或矿物相是很有趣的。这些过程对地球表面环境和地球历史都有很大影响。在该项目中，选择了三个主要分主题：即（1）生物诱发铁矿石的形成过程，例如群马狮子矿，（2）古老和现代叠层石结构及其特征，以及（3）生物成因（磁铁矿到战术细菌）磁铁矿。这些研究的主要成果之一是关于群马铁矿的（1）。以下是摘要。对来自铁矿的沉积铁矿石进行了矿山地质描述。铁矿石由纳米晶针铁矿、结晶良好的黄钾铁矾和极少量的红铁矿组成。典型的铁矿石类型包括厚带状铁矿石、细带状狮子矿石和富含苔藓和/或树叶的化石骨料矿石。厚带状矿石中的针铁矿带中清晰地保存有藻类化石。晶格成像显示了针铁矿纳米晶体的特征晶体取向。细带状狮子矿石可能是由细菌铁生物矿化作用形成的。这些条带可能归因于生物或季节节律。目前pH 2-3、富含Fe2^2+-和SO_4^<2->的水流中发现了各种生物矿化产物； Fe-P-(S) 至 Fe-S-(P) 沉淀。苔藓和绿藻也在细胞内和细胞周围收集铁沉淀物。这些矿石被认为是生物诱发的铁矿石。 (2) 锰叠层石既来自日本（作为新近的温泉沉积物），又来自澳大利亚前寒武纪地层。 (3)对磁铁矿进行了矿物学分析和晶体异位分析。