Electron probe microanalysis study on processes of low-temperature oxidation of titanomagnetite |
| |
| Authors: | Takatoshi Akimoto Hajimu Kinoshita Toshio Furuta |
| |
| Institution: | 1. Department of Earth Sciences, Chiba University, Chiba 260 Japan;2. Ocean Research Institute, University of Tokyo, Nakano, Tokyo 164 Japan |
| |
| Abstract: | Partially oxidized titanomagnetite grains in various kinds of volcanic rocks were investigated by electron probe microanalyzer (EPMA) in order to clarify the process of oxidation at low temperature. The following results were obtained by the present investigation: (1) Primary composition of titanomagnetite is homogeneous in individual grains, although variation in composition among different grains is observed on each thin section. (2) Migration of Fe cations during low-temperature oxidation is clearly seen in all oxidized grains. Some other constituent cations are also bleached and consequently the relative content of the remaining cations becomes large. (3) The detailed internal structures of titanomagnetite grains are observed as backscattered electron images (BEI) with an electronprobe microanalyzer, and it seems likely that the structures depend upon the degree of low-temperature oxidation. (4) The chemical and physical properties of oxidized titanomagnetites imply that low-temperature oxidation is not a simple process but a complex one. Such an oxidation process is correlatable to both the mobility of cation and the oxidation condition such as a circulation of some active hydrothermal materials at low temperature. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
