1988 Fiscal Year Final Research Report Summary
International Correlation of Japanese Non-marineCretaceous Bivalve Faunas
| Project/Area Number |
62540604
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Stratigraphy/Paleontology
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| Research Institution | Kumamoto University
National Museum of Nature and Science,Tokyo |
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Principal Investigator |
TAMURA Minoru Professor, Faculty of Education, 教育学部, 教授 (40040018)
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| Project Period (FY) |
1987 – 1988
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| Keywords | Cretaceous non-marine bivalve faunas / Tetori group / Kitadani alternation / Trigonioides / Nippononaia / Pseudohyria |
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| Research Abstract |
Japanese non-marine Cretaceous alternating with marine one occupies the most important position for correlation between Asiatic continental Cretaceous and inter-national marine Cretaceous. As itoshiro subgroup, Tetori group is considered as the most important one among Japanese non-marine Cretaceous, I conducted field survey Itoshiro subgroup and the related formations of Tetori group for collecting bivalve fossils and for obtaining bivalve succession in these two years. The effects are as follows.
1) I newly collected pseudohyria matsumotoi, Nippononaia tetoriensis from Kitadani alternation in katsuyama area, which has been included in Akaiwa subbroup, together with Trigonioides tetoriensis, Plicatounio naktongensis and Nagdongia soni.
2) The observation of the hinge structure of Trigonioides specimens from Kitadani alternation shows that the Trigonioides specimens belong to Wakinoa. Considering above facts together with the effects already reported, Kuwajima alternation, Itoshiro subgroup and such related formations as Izuki and Okurodani formations are safely correlated with Kitadani alternation each other. Further. the bivalve assemblage of Kitadani alternation is safely correlated with the ones from Yeohwadong formation to the Lowest part of Dongmyeong formation, Nagdong subgroup, korea.
Non-marine Cretaceous in China yields rich non-marine Cretaceous bivalves in-cluding many new species and occupies important position for the study. However, pre-cise and safe information for understanding these new species is difficult in the present time, because of difficulty of obtaining fossil specimens. So correlation with Chinese Cretaceous was not conducted this time.
Besides the T.P.N. fossils already stated, sprcimens of Isognomon, Sphaerioides and "Sphaerium" were collected by my study this time. These will be important for Correlation not only in the Japanese non-marine Cretaceous but also in continental Cretaceous as those in China and other continental areas.
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