水みちとしての断層と節理 : 構造地質学から応用構造地質学へ  [in Japanese] Faults and joints as pathways of groundwater : From structural geology to applied structural geology  [in Japanese]

断層と節理は構造地質学の主要な研究対象であると同時に, 応用地質学の重要な研究対象でもある。しかし, 構造地質学は応用地質学の問題に積極的には答えていない。断層系・節理系や断層帯に関する構造地質学的研究成果に断層と節理が水みちとして「どのように機能するか」という新たな視点を加えることにより, 構造地質学は応用地質学に重要な知見を与えることができよう。物理探査を積極的に援用して断層と節理の3次元的特徴およびそれらの水みちとしての特徴を捉えることも重要である。露頭における断層系・節理系や破砕帯の特徴も, 水みちとして「どのように機能するか」を評価するために積極的に利用すべきである。断層と節理に関する構造地質学的研究は単にテクトニクスの解明という視点からだけではなく, 今後は水みちとしての断層と節理に関するナチュラルアナログとしての意義も大きい。水みちという視点からの新たなモデル化も緊急の課題である。

Faults and joints are one of the main subjects of structural geology. They are also important subjects of engineering geology. There are so many problems which may be not solved with out the study of faults and joints, concerning environments and natural disasters on the earth's surface or the safety and effectiveness of foundations for large-scale constructions. Until now, structural geology gives no sufficient answers for these problems in engineering geology. Amongst, "How faults and joints functionate as pathways of groundwater" is an important problem in engineering geology toward the 21th century, and structural geology should play its important role for this problem. There are so many studies in structural geology on fault/joint systems and fault zones. Structural geology should have an additional view point, "how faults and joints functionate as pathways of groundwater", and structural geology will be recognized as an essential field in the studies of underground environments and performances of basement rocks. Structural geology should use much geophysical methods for understanding the three-dimensional structures of faults and joints and their performances as pathways of groundwater. Knowledges on structural and geometrical features of faults and joints at outcrops are also inevitable for understanding the performances of faults and joints as pathways of groundwater. Structural geology has been studying the kinematic, dynamic, and tectonic aspects of faults and joints. These results of structural analyses should be recognized as natural analogues of performances of faults and joints in groundwater system. The modelling of faults and joints also gets an new view point from groundwater study.