Geochronological and geochemical constraints on the heat source of thermal activity in the Rausu geothermal field, Shiretoko Peninsula, Hokkaido, Japan.
|
Accession number;02A0639373
|
| Title;Geochronological and geochemical constraints on the heat source of thermal activity in the Rausu geothermal field, Shiretoko Peninsula, Hokkaido, Japan. |
| Author;
GOTO Y
(Tohoku Univ., Sendai, Jpn)
KONO T
(Tohoku Univ., Sendai, Jpn)
TSUCHIYA N
(Iwate Univ., Morioka, Jpn)
|
Journal Title;J Mineral Petrol Sci
|
Journal Code:G0150B
|
ISSN:1345-6296
|
|
VOL.97;NO.3;PAGE.79-84(2002)
|
| Figure&Table&Reference;FIG.2, TBL.3, REF.28 |
| Pub. Country;Japan |
| Language;English |
| Abstract;The Rausu geothermal field is situated in the middle part of the Shiretoko Peninsula, east Hokkaido, Japan. It has been classified into "A-type" (characterized by high temperature/depth ratio) in terms of its Geothermal Activity Index. The geology of the area consists of Tertiary volcaniclastic rocks, a hornblende dacite intrusion and overlying Tertiary to Quaternary lavas. The dacite is 63wt.% SiO2 and belongs to the calc-alkaline suite. The solidus and subsolidus temperatures of the dacite magma, calculated from mineral equilibrium, are 830.DEG.C. and 741.DEG.C., respectively. The K-Ar age obtained from hornblende phenocryst is 3.0.+-.0.8Ma. The geological, geochronological and petrological data suggest that the heat source of the Rausu geothermal field is a long-lived, high-temperature granodioritic pluton existing beneath the intrusion. It is suggested that the thermal activity is caused by the upwelling of high-temperature fluids related to the pluton, through fracture networks within or around the intrusion. (author abst.) |
|
|
|
Related Articles;
|
|
|
