Experimental research on atomic diffusion in sulfide minerals and its applications to formational precesses of ore textures.

硫化物矿物中原子扩散实验研究及其在矿石结构形成过程中的应用

基本信息

批准号：
02453046
负责人：
MIZUTA Toshio
金额：
$ 4.1万
依托单位：
AKITA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1992
项目状态：
已结题

项目摘要

The main purposes of this study on sulfide diffusion are as follows: (A) measurements of iron and sulfur diffusivities in sulfides (sphalerite,pyrite,chalcopyrite,and aresenopyrite) by radio-tracer techniques and secondary ion microprobe spectrometry and interpretation on diffusion mechanism of sulfides from the viewpoints of mineral physics and chemistry,(B) understanding of mineralogical textures in natural ore specimens.Large number of heating experiments for sulfide diffusion were carried out in wide range of temperatures(400- 900ﾟC). Iron and sulfur diffusion rates in sphalerite were measured precisely. However, the diffusion experiments for other sulfides such as pyrite, chalcopyrite, and arsenopyrite were not successful to obtain good diffusion profiles because of roughness by evaporation of atoms from crystal surfaces. Iron and sulfur diffusion mechanisms in sphalerite were compiled in a paper and are submitted to the Journal of Economic Geology. For the second aim of this study, various kinds of textures in ores from some kuroko deposits are quantitatively analyzed. Geological surveys and sampling were carried out for ore deposits of Kuroko and skarn-types in Tohoku district. Ore textures and compositional zonation in sulfide ores are investigated to clarify the formational mechanisms of ores and depositional conditions. Furthermore, following topics are studied by the same texture analysis technique. Morphology and distribution of vesicles in the Togawa andesite lava, size variation of pyrophyllite crystals in the Yano-shokozan pyrophyllite deposits,Kinetic aspects of cristobalite formation in the Tsukinuno benthonite deposit,formational processes of microtextures in the Odessa iron meteorite. These topics were published in research papers. Preliminary results are obtained for morphology and distribution of vesicles in some Miocene basalts from the standpoints of kuroko mineralization and hydrothermal alteration processes.

本次硫化物扩散研究的主要目的如下：（A）通过放射性示踪技术和二次离子探针光谱技术测量硫化物（闪锌矿、黄铁矿、黄铜矿和砂黄铁矿）中铁和硫的扩散系数，并解释硫化物的扩散机制。从矿物物理和化学的角度认识硫化物，(B)了解天然矿石标本中的矿物结构。大量加热硫化物扩散实验在较宽的温度范围（400-900℃）下进行，铁和硫在闪锌矿中的扩散速率得到了精确测量。然而，其他硫化物如黄铁矿、黄铜矿和毒砂的扩散实验并不成功。由于闪锌矿中原子的蒸发而产生粗糙度，从而获得良好的扩散曲线，该论文汇编并提交了该论文。本研究的第二个目的是对东北地区的黑子矿床和矽卡岩型矿床进行地质调查和取样。研究了硫化物矿石的结构和成分分带，以阐明矿石的形成机制和沉积条件。此外，通过相同的结构分析技术研究了以下主题。十川安山岩熔岩中的囊泡、Yano-shokozan 叶腊石矿床中叶蜡石晶体的尺寸变化、Tsukinuno 膨润土矿床中方英石形成的动力学方面、Odessa 铁陨石中微结构的形成过程这些主题已发表在研究论文中。获得了一些中新世玄武岩中囊泡的形态和分布的结果黑子矿化和热液蚀变过程的立场。