Secular fluctuations in reef ecosystems during the Middle Palaeozoic to earliest Mesozoic interval : integration of metazoan and microbial reefal changes

1.首先，本课题对扬子地台南缘沿着的二叠系、三叠系过渡层和下三叠统（Hindeodus parvus带）的岩相、沉积相和生物相进行了研究。主要结果如下：（1）详细的岩性和生物地层学证据表明，二叠系/三叠系界线是不整合的。（2）最低的三叠系以血栓岩的夹层为特征，表现出特征性的微观到宏观特征。无论研究的区域，在凝块岩中观结构和宏观结构的变化是常见的。（3）血栓形成的起始和终止在所测量的各个切片中显示出共同的模式。这种模式在以下几个方面特别明显：1）二叠纪/三叠纪地层接触的性质; 2）凝块岩结构和结构的变化; 3）凝块岩的产出方式，以及流动性。 关于我们 二、研究了北西南地区下泥盆统后生动物礁和微生物礁的成因，澳大利亚，阐明了微环境中的微生物的填充模式，在特定阶段的层孔菌生长。3.皱纹虫是古生代后生动物中最重要的类群之一，其生长可塑性与其无性繁殖的规律性和生长方式的灵活性有关，为了揭示中古生代至早中生代礁生态系统的真实性质，应特别注意个体后生动物和微生物之间的地球生物学相互关系，以及它们随时间的变化。上述一些结果已在学术期刊和日本地质学会、日本古生物学会等的会议上发表。少

1.Firstly, this research project has focused on lithofacies, depositional facies, and biofacies of Permian and Triassic transitional beds, as well as lowest Triassic (the Hindeodus parvus Zone) beds, along the southern periphery of the Yangtze Platform. Chief results are as follows :(1)The Permian/Triassic boundary is unconformable, based on detailed lithologic and biostratigraphic evidence.(2)The lowest Triassic is characterized by intercalations of thrombolites that exhibit characteristic microscopic to megascopic features. Irrespective of the region studied, variations in mesoscopic texture and macroscopic structure are common in thrombolites.(3)The initiation and cessation of thrombolite formation show a common pattern in the individual sections measured. This pattern is especially marked with respect to : 1)the nature of the Permian/Triassic stratigraphic contact ; 2)variations in texture and structure of thrombolites ; and 3)modes of occurrence of thrombolites, together with fluc … More tuations in ocean conditions after the end-Permian collapse of metazoan reef ecosystems.2.Secondly, the genesis of Lower Devonian metazoan and microbial reefs in N.S.W., Australia, was elucidated in terms of the infilling patterns of microbialites within microenvironments that were created during specific stages of stromatoporoid growth. Continuously modified cryptic spaces are utilized by a variety of microbial communities and their growth products.3.Thirdly, growth plasticity in the Rugosa, one of the most important Palaeozoic metazoan groups, was considered in relation to the regularity of asexual reproduction and the flexibility of growth modes.In order to decipher the true nature of reef ecosystems during the Middle Palaeozoic to earliest Mesozoic interval, special attention should be paid to the geobiological interrelationships between individual metazoans and microbes, as well as to their modifications through time.Some of the results noted above have been presented in academic journals and at meetings of the Geological Society of Japan, the Palaeontological Society of Japan, and others. Less