| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1990: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1989: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Research Abstract |
I.Solitary corals were collected from the Permian of the Kitakami, Abukuma, Hida and Chugoku mountains. They occur mostly in limestone facies, followed by calcareous sandstone and shale facies. Yield from non-calcareous facies is extremely rare.
II.Coral producing horizons range from the earliest Permian to the late Permian. However, if we divide the Permian into 3 parts, the coral occurrence from the upper part is rare. This is also related to the result of facies control. Taking the stratigraphic succession in the Kitakami mountains as standard, the occurrence from the Sakamotozawa and Kanokura Formations and their equivalents is fairly rich ; whereas corals are rare in the Toyoma Formation. It has been so considered that the sedimentological environment shifted from shelf to slope facies in the Kitakami Mountains at around the Toyoma Time. Coral occurrence must have been influenced by this phenomenon, as stated above. Development of the Upper or Uppermost Permian is much restricted a
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lso in the other areas, where no corals were obtainable from the horizons concerned. Therefore coral assemblage near or at the Terminal Permian can not be investigated in Japan.
III.Stratigraphic distribution of detected solitary coral genera is : Lophophyllidium, Lophocarinophyllum, Duplocarinia, Amandophyllum, Yabeiphyllum, Laophyllum, Iranophyllum, Sakamotosawanella from the Sakamotozawa Formation and its equivalent formations : Cyathaxohia, Calophyllum, Verbeekiella, Lophophyllidium, Ufimia? and Iranophyllum from the Kanokura Formation and its equivalents : Only one sample from the Toyoma Formation.
IV.Viewed from dissepimented solitary rugose corals, both Tethyan and Boreal type forms are known to coexist in the Lower Sakamotozawa Formation. But later on until the kanokura Time only Tethyan corals occur. As to the so-called Cyathaxonia fauna no or little provinciality is detectable. Although Verbeekiella and Duplocarinia were originally described from Timor belonging to the Tethyan Realm, the rest is more or less cosmopolitan in nature.
V.Many well-preserved individuals were collected for Verbeekiella which contains 2 species : among them one is a new species. From the ontogenetical investigation of this new form, shortening of cardinal septum occurs from the early growth stage, thereby indicating a unique position of this group in the rugosan phylogeny. Plerophyllids are rare and not fully investigated. Less
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