地熱系に関与する起源水の地球化学的分類とその意義 [in Japanese] Geochemical classification of source waters relating to geothermal system [in Japanese]
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"Source water" is defined as the independent water which exists of rather stable composition and in comparatively large amount. It has been formed under individually specific environment. Geothermal model is well illustrated by arrangement of the source waters which are defined as to reveal their formation situations, viz., their formation mechanisms and formed positions. Source water itself is made up of sources materials. The source materials considered are, rock, meteoric water, sea water, magmatic water, volcanic gas, fumarolic gas, etc. A great number sets of various combinations of the source materials may produce many kinds of source waters. Too many kinds of source waters mere cause confusion, however, in case constructing geothermal model. In order to avoid such undesired confusion simplified modeling is recommended by adopting less number of source waters as possible. Following 11 source waters are hence thought adequate; deep thermal water, ocean related thermal water, geothermal vaguely related water, volcanic themal fluid, high temperature steam heated water, low temperature steam heated water, alteration zone related water, deep seated warm water, sea water, low temperature metamorphic sea water and meteoric water. Their decisive criteria mainly on compositional characteristics are listed in the source water classification table. An algorism was thought out to select the appropriate souce water for the source water we have got to know through geochemical analysis. The principle of the algorism is score counting for the source water on the basis of the criteria in the source water classification table. This scoring algorism made it possible to select the adequate fundamental source water for individual interpreted source water as sufficient geochemically. The individual source waters occupy specified underground position and those spacial settlements are also limited concerning to mutual aquifer connenction and continuity. Thus geothermal model can be appropriately shown taking acount of source waters occuring in the area and of those mutual relation.
Chikyukagaku 26(2), 63-82, 1993
The Geochemical Society of Japan