Record of Meso-and Paleozoic environmental change and biotic evolution in calci-microbial sedimnent

这项研究计划的部分成果已发表在相关期刊上，并在许多会议上发表。主要成果总结如下：1.在日本浅海碳酸盐岩单元的许多地层中都发现了以蓝藻为主的钙质微生物，而且在加拿大西部的中国南部，通过野外和显微镜研究，确认了它们在志留纪到第四纪(最近)的年龄范围。2.钙质微生物在广泛的浅海碳酸盐岩相中被识别，并在不同的环境中作为重要的沉积物生产者和沉积稳定剂和礁体的粘结剂。3.钙微生物的繁荣，特别是在后生生物礁构造物的几个衰退期(如二叠纪-三叠纪界线段，晚石炭世长而恶劣的冰库气候)，并在这些环境破坏时期发挥了重要的造岩生物群作用。4.从多个地质时代的浅海碳酸盐沉积中报道了不同类型的钙微生物礁相和相关的有机沉积结构。这些微生物沉积被认为与海底胶结物一起建立了小尺度的礁相地貌高点。我们的结果表明，需要用地球化学方法来更全面和定量地描绘与钙质微生物繁盛有关的环境因素(温度、盐度、大气CO_2气压、海平面波动等)的时间变化。我们研究项目的一些研究人员已经开始了针对这一目标的研究。

Part of results of this research program have been published in relevant journals and presented at many conferences and meetings. Major results are summarized as follows ;1.Highly diverse calci-microbes, mainly of cyanobacteria, were recognized at many stratigraphic levels of shallow-marine carbonate units in Japan, but also in South China, western Canada, Ws confirmed their occurrence ranges in age from Silurian to Quaternary(Recent) through the field and microscopic examination.2.Calci-microbes were recognized in a wide range of shallow-marine carbonate facies, and occurs as significant sediment-producer in varied environments and sediment-stabilizer and -binder of reefal fades.3.Calci-microbes flourished especially in several geologic periods of decline and demise of metazoan reef-builders(e.g., Permo-Triassic boundary interval, Late Carboniferous prolonged and severe icehouse climate) and played a significant role as rock-forming biotas in these environment-devastated periods.4.Various types of calci-microbial reefal facies and related organo-sedimentary structures were reported from shallow-marine carbonate sediments of many geologic ages. These microbial sediments are considered as having built up small-scale topographic highs of reefa facies, along with submarine cements.Our results suggest that geochemical approaches needed in order to more thoroughly and quantitatively delineate temporal changes of environmental factors(temperatures, salinity, atmospheric CO_2 pressure, sea-level fluctuation, etc) in relation to flourish of calci-microbes. Some investigators of our research project have already begun hew researches with this aim.