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

1.首先，研究了扬子地台南缘二叠系、三叠系过渡层及三叠系最低层(Hindeodus parvus带)的岩相、沉积相、生物相。主要结果如下：(1)根据详细的岩性和生物地层学证据，二叠系/三叠系界线是不整合的。(2)最低的三叠系以血栓岩夹层为特征，具有典型的微观到宏观特征。无论研究的区域如何，血栓形成的中观结构和宏观结构的变化是常见的。(3)血栓形成的开始和停止在所测量的个别切片上显示出共同的模式。这一模式在以下方面尤其明显：1)二叠系/三叠系地层接触的性质；2)血栓的结构和结构的变化；以及3)血栓的赋存方式，连同Fluc…2.第二，澳大利亚西北部下泥盆统后生动物和微生物礁的成因，是根据在层状孔生长的特定阶段形成的微环境中微生物岩的充填模式来阐明的。Rugosa是最重要的古生代后生动物类群之一，其生长可塑性与无性繁殖的规律性和生长方式的灵活性有关。为了破译中古生代至中生代早期珊瑚礁生态系统的真实性质，应特别注意单个后生动物与微生物之间的地质生物学相互关系以及它们随时间的变化。上述一些结果已发表在学术期刊上，并在日本地质学会、日本古生物学会等会议上发表。较少

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