| Project/Area Number |
03454029
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Stratigraphy/Paleontology
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| Research Institution | University of Tsukuba |
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Principal Investigator |
IGO Hisayoshi Institute of Geoscience, University of Tsukuba, Professor, 地球科学系, 教授 (20015572)
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| Co-Investigator(Kenkyū-buntansha) |
ADACHI Shuko Institute of Geoscience, University of Tsukuba, Assistant, 地球科学系, 助手 (80182997)
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| Project Period (FY) |
1991 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 1993: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1992: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1991: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Keywords | Triassic / Smaller Foraminifer / Mesozoic / Microbiostratigraphy / 微化石層序学 / 有孔虫 |
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| Research Abstract |
Previous to our present research, Triassic foraminifers have not yet been studied in Japan. We tried to collect many Triassic smaller foraminifers from carbonate rocks exposed in various areas in Japan. As the result, we discovered many specimens of Triassic foraminifers from carbonate rocks exposed in Menashidomari, Hidaka mountains, and Kamiiso (Hokkaido), Ashio Mountains, Okutama area and other areas of the Kanto Mountains, Akasaka Limestone and other limestones in the Mino-Hida Mountains, the Taho and Kamura Limestones of Shikoku and Kyushu, and other small unnamed carbonate rock blocks elsewhere in Outer Zone of Japan. Our collections also contain many Triassic carbonate rocks of southern Thailand and northwestern Malaysia. Some materials were collected from the Pacific Side of North America.
These specimens are thin-sectioned in preferred orientation and/or recovered as isolated specimens by acetic acid and hydrofluoric acid treatment and paleontologically studied. These indoor works are not completed but rapidly progressing. We checked most of the previously described Triassic foraminifers which were introduced mainly in European countries including Switzerland, Austria, Italy, and Burgaria. The examined specimens attain 486 species and synoptically listed for our future paleontological investigation.
Up to date, we already discriminated about 50 species of Triassic foraminifersfrom the Schytian to Rhaetian. Some primitive type of ammodiscusid species are found even in dolomitic limestone of the Lower Triassic. The species and genera of Involutinidae and Ophthalminiinae are abundant and diversified in the Middle to Upper Triassic. Evolutional tendency of Triassic foraminifers show similar pattern with that of scleractinian corals and sponges.
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