| Project/Area Number |
09640561
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Petrology/Mineralogy/Science of ore deposit
|
|---|
| Research Institution | HOKKAIDO UNIVERSITY |
|---|
Principal Investigator |
MATSUEDA Hiroharu Hokkaido Univ.The Hokkaido Univ. Mareum ; Pro., 総合博物館, 教授 (20108921)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
ISHIYAMA Daigo Akita Univ.Fac. of Eng.Res., Asso.Pro., 工学資源学部, 助教授 (30193361)
|
|---|
| Project Period (FY) |
1997 – 1999
|
| Project Status |
Completed (Fiscal Year 1999)
|
| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 1999: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1998: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1997: ¥2,400,000 (Direct Cost: ¥2,400,000)
|
|---|
| Keywords | Epithermal / Au-Ag mineraligation / Acid-sulfate alteration / Time-spatial analysis / Fluid inclusion / Stable isotope / K-Ar age / 浅熱水性金鉱床 / 高硫化型金鉱化作用 / 低硫化型金鉱化作用 / 新大豊鉱床 / 中越鉱床 / 勢多鉱床 / 大峠鉱床 / 浅熱水性金銀鉱床 / 硫黄同位体比 / 赤石鉱山 / 小樽赤岩 |
|---|
| Research Abstract |
On the genesis and formation process of the epithermal Au-Ag deposits related to young volcanic activities in the island arc geologic environ- ment, it is investigated to clarify the formation environment and con- centration process of the elements from the viewpoints of ore geology, geochemistry and petrology based on the field and laboratory works. Basic experiments are also conducted in order to improve and obtain high accuracy in chemical analyses.
Both low- and high-sulfidation types of gold mineralizations in epi- and meso-thermal conditions are investigated on their assemblages of ore and alteration minerals to determine the physicochemical conditions and time-spatial relationships of the both types. Study fields are also extended to the same types in northeast Japan and Indonesia to make comparative study.
As a concluding remarks, it is clarified that the high-sulfidation type gold mineralization is stongly affected by the magmatic fluids, but the low-sulfidations is by meteoric water. The former is prior to the latter and is located closer to the intrusive rock. Both types of gold mineralizations are strongly related to the magmatic acitivity, and the originated high temperature fluids dissolving various metals in the style of sulfide complexes might have effectively precipitated them due to the boiling by pressure decrease and/or mixing with meteoric water to cause cooling, oxidation or dilution in shallow environment.
|
