Study on evolution of Carboniferous-Permian-Triassic reef-building organisms and paleoenvironment of Panthalassan Ocean

石炭纪-二叠纪-三叠纪造礁生物演化与泛海洋古环境研究

• 批准号: 10640450
• 负责人: SANO Hiroyoshi
• 金额: $ 1.92万
• 依托单位: KYUSHU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10640450/
• 关键词: seamount-type limestone; reef-building organism; cyanobacteria; 海山型炭石灰岩; 海山型石灰岩

Special interest of this research project is in the significant rock-forming role of calci-microbes mainly of cyanobacteria and sessile foraminifers, both of which are usually small-sized and inconspicuous in the field and under the microscope. Microbialites and related organosedimentary structures were described as well as the paleontological characters and stratigraphic distribution of the calci-microbes. Chosen for study are Carboniferous-Permian Akiyoshi and Omi Limestones, Permian Funabuseyama Limestone, Triassic Konose Limestone, and a few other limestone-units. All the examined limestone units were formed as oceanic sediments of seamount top-capping buildups in an open-ocean setting of the Panthalassan Ocean. Rocks are at present exposed as large-sized isolated masses within Permian and Jurassic accretionary complexes of southwest Japan. More than 300 pieces of thin-sections, including extra-sized ones, were prepared from rock-samples, most of which are biostratigraphically cont … More rolledThe careful microscopic examination leads the author to a conclusion that calci-microbes greatly contributed to the Carboniferous, Permian, and Triassic shallow-marine carbonate sedimentation at the top of Panthalassan seamounts. Through this research project, diverse types of microbialites and related organosedimentary structures were recognized in all the examined limestone units. As well, several problematic microbes of uncertain taxonomic affinity were found out in several limestone units. The sedimentological properties of the microbialites and related structures and paleontological characters of calci-microbes were in separate described.Among many important results of the project, to be stressed is the occurrence of diverse microbialites in Lower-Middle Carboniferous and Upper Triassic rocks. This was unexpected, for the rocks of these ages are know to be characterized by the predominance of reef limestones formed by large-sized metazoans. This finding implies that calci-microbes acted as stratigraphically widespread and significant rock-forming biotas. Less

本研究项目特别感兴趣的是钙微生物的重要造岩作用，主要是蓝藻菌和无根有孔虫，这两种微生物在野外和显微镜下通常是小而不明显的。描述了微生物岩及其相关的有机沉积构造，以及钙微生物的古生物学特征和地层分布。研究选择石炭纪-二叠纪秋吉和尾尾石灰岩，二叠纪船井山石灰岩，三叠纪科诺斯石灰岩和其他一些石灰岩单元。所有被检查的石灰岩单元都是在泛海的开放海洋环境中形成的海山顶盖堆积的海洋沉积物。目前，在日本西南部的二叠纪和侏罗纪增生杂岩中，岩石以大型孤立体暴露。作者从岩石样品中制备了包括特大薄片在内的300多片薄片，这些薄片大多具有生物地层学意义。通过仔细的显微镜检查，作者得出结论：钙微生物对Panthalassan海山顶部石炭系、二叠纪和三叠纪浅海碳酸盐沉积起了重要作用。通过本项目的研究，在所有研究的灰岩单元中都发现了不同类型的微生物岩和相关的有机沉积构造。此外，在几个石灰岩单元中还发现了一些分类亲和性不确定的问题微生物。分别描述了微生物岩的沉积学特征和钙微生物的相关结构及古生物学特征。在该项目的许多重要成果中，值得强调的是下-中石炭统和上三叠统岩石中多种微生物岩的赋存。这是出乎意料的，因为这些年代的岩石的特点是由大型后生动物形成的礁灰岩占主导地位。这一发现表明，钙微生物在地层上广泛存在，是重要的造岩生物群。少

项目成果

Sano,H.: "Facies interpretation of Middle Carboniferous to Lower Permian Pope succession limestone of Cache Creek Group, Fort St.James, central British Columbia"Canadian Journal of Earth Science. (in press). (2001)

Sano, H.：“不列颠哥伦比亚省中部圣詹姆斯堡 Cache Creek 群中石炭纪到下二叠纪 Pope 演替石灰岩的相解释”《加拿大地球科学杂志》。

Sano,H.: "Facies interpretation of Middle Carboniferous to Lower Permian Popesuccession limestone of Cache Creek Group, Fort St.James, central British Columbia"Canadian Journal of Earth Science. (in press). (2001)

Sano, H.：“不列颠哥伦比亚省中部圣詹姆斯堡 Cache Creek 群中石炭纪到下二叠统教皇继承石灰岩的相解释”《加拿大地球科学杂志》。

佐野弘好: "美濃-丹波-足尾テレーンの石炭〜ジュラ系海洋性岩石"地質学論集. 55号. 123-144 (2000)

Hiroyoshi Sano：“Mino-Tamba-Ashio 地体的煤侏罗纪海相岩石”地质评论第 55 期。123-144 (2000)。

H.Sano: "Carboniferous-Permian-Triassic oceanic rocks of Mino-Tamba-Ashio terrane, southwest Japan"Mem.Geol.Soc.Japan. No.55. 123-144

H.Sano：“日本西南部美浓-丹波-足尾地体的石炭纪-二叠纪-三叠纪海洋岩石”Mem.Geol.Soc.Japan。

H.Sano: "Facies interpretation of Middle Carboniferous to Lower Permian Pope succession limestone of Cache Creek Group, Fort St James, central British Columbia"Canadian Journal of Earth Science. (in press).

H.Sano：“不列颠哥伦比亚省中部圣詹姆斯堡 Cache Creek 群中石炭纪到下二叠纪 Pope 演替石灰岩的相解释”《加拿大地球科学杂志》。