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

本文研究硫化物扩散的主要目的是：(A)利用放射性示踪技术和二次离子探针光谱法测量硫化物（闪锌矿、黄铁矿、黄铜矿和砂黄铁矿）中铁和硫的扩散系数，并从矿物物理和化学的角度解释硫化物的扩散机理；(B)了解天然矿石样品的矿物结构。在宽泛的温度范围内（400 ~ 900℃）进行了大量的硫化物扩散加热实验。对闪锌矿中铁和硫的扩散速率进行了精确测量。然而，其他硫化物如黄铁矿、黄铜矿和毒砂的扩散实验由于原子从晶体表面蒸发产生的粗糙度而不能成功地获得良好的扩散曲线。铁和硫在闪锌矿中的扩散机制已汇编成一篇论文，并已提交给《经济地质杂志》。本文的第二个研究目的是对某些黑岩矿床矿石的各种结构进行定量分析。对东北地区黑子型和矽卡岩型矿床进行了地质调查和取样。研究了硫化物矿石的结构和组成分带，阐明了矿石的形成机制和沉积条件。此外，本文还利用相同的织构分析技术对以下主题进行了研究。Togawa安山岩熔岩中囊泡形态与分布、Yano-shokozan叶蜡岩矿床中叶蜡岩晶体大小变化、Tsukinuno底长石矿床中方英石形成动力学方面、Odessa铁陨石微织构形成过程。这些主题发表在研究论文中。从黑岩成矿作用和热液蚀变作用的角度对某些中新世玄武岩的囊泡形态和分布进行了初步研究。

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.