| Co-Investigator(Kenkyū-buntansha) |
TOMITA Katsutoshi Faculty of Science, Kyoto University, 理学部, 講師 (70025352)
BANNO Shohei Faculty of Science, Kyoto University, 理学部, 教授 (30019468)
MORIMOTO Nobuo Faculty of Science, Kyoto University, 理学部, 教授 (10029829)
|
|---|
| Budget Amount *help |
¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1985: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1984: ¥1,100,000 (Direct Cost: ¥1,100,000)
|
|---|
| Research Abstract |
In this research project, the following three studies concerning with reacation processes of metamorphic minerals were carried out.
(1) Construction of hydrothermal equipment: A hydrothermal equipment was specia-ly designed and constracted to carry out experiments up to 900゜C and 1 kb.
(2) Determination of diffusion constant of silica in supercritical water: The most important factor of reaction kinetics in metamorphism and metasomatism is a diffusion constant of silica in supercritcal water. The diffusion constants was measured using the hydrothermal equipment constructed in (1). The experiments were done on the system; SiO_2 - Mg(OH)_2, SiO_2 - MgO, SiO_2 - Ca(OH)_2, SiO_2 - CaO, SiO_2 - CaCO_3. The amounts of reaction products were incleased linearly with the root of duration time. Based on this relationship, the diffusion constant were calculated as follows; D = Do.exp([-(E+PV^*)]/RT), Do = 0.55(+0.57, -0.28) cm^2/sec, E = 48(<plus-minus>5) kj/mol., V^*= 81<plus-minus>12) cm^3/mol., where R and T are gas constant and temperature, respectively.
(3) Appearence of high-temperature form of cordierite in metamorphic rock: Cordierite is major phase of metamorphic rocks and has two polymorphs, high- and low-temperature forms. While no reports were there on occurrence of the high-temperature forms in metamorphic rock, sector trilling of cordierite transformed from the high-temperature form was found in the present study. Furthermore, based on appearence of the sector trilling, the contact metamorphic rock can be classfied into two zones with cordierite. Stability field of the high-temperature form was also studied using the hydrothermal equipment of (1). The stability field is wider than those reviously reported and the high-form is stable even at 700゜C.
|
