石川縣鳳至郡町野町・南志見村・柳田村附近の地質
スポンサーリンク
概要
- 論文の詳細を見る
The Cenozoic strata in the areas of Machino-machi, Najimi-mura and Yanaida-mura, in Fugeshi-gun, Ishikawa Prefecture, are classified, on the basis of field observations, into the following formations, from lower to upper : Konosuyama volcanics : Comprised of andesite, basalt, dacite, agglomerates of andesite, basalt and dacite, and diorite., Part of the diorite is younger than the volcanics., Although the distribution of the various rock types has been mapped their stratigraphic sequence is not known., .,.,., (stratigraphic relation unceertain) .,.,., Toktunari formation : Comprised of pumiceous tuff and brecciated tuff with lenticular layers of tuffaceous sandstone, tuffaceous mudstone and conglomerate., Lignite seams and fossil shells are found in a few places., These rocks are intercalated between flows of andesite, basalt and dacite., .,.,., unconformity .,.,., Higashi-Innai formation : Comprised of mudstone, siltstone, sandstone and conglomerate in which lignite is intercalated., Fossils of Mollusca and Foraminifera are abundant., .,.,., Awagura formation and Iwakurayama rhyolite : The Awagura formation is comprised of finely stratified white or light green colored pumiceous tuff, brecciated tuff and sandy tuff., The Iwakurayama rhyolite eruption is responsible for the large quantities of tuff in the Awagura formation, and consequently, the eruption took place during deposition of the Awagura., .,.,., Najimi formation : Comprised of tuffaceous mudstone and tuffaceous siltstone, and locally contains pumice layers and laminated tuffaceous sandstone layers., Molluscan shells and sponge spicules occur throughout the formation., In the northern part of the areas, Radiolaria and Globigerina, are common and Conchocele is the outstanding megafossil., In the southern part of the areas, Foraminifera are abundant and Globigerina is also found., The occurrence of Globigerina suggests a free connection with the open sea., .,.,., unconformity .,.,., Okawa terrace deposits : Comprised of sand, gravel and clay in which fossils are absent., From fossil evidence, the Higashi-Innai formation, which has yielded Operculina, Miogypsina, Vicarya and others, is considered to be early Miocene in age., The Higashi-Innai formation contains rocks of marine and brackish-water facies as evidenced by fossils and lignite which contains sulphur., Among the geological structures of the district are several faults, and folding has occurred., Faults and fold axes trend east-west., The geological age of the folding and faults is considered post-Miocene and pre-Okawa time.,
- 日本地質学会の論文
- 1954-04-25