Laminae and their origin in microbialites: macro-scale information in micro-scale structure

2014 Fiscal Year Final Research Report

• Project/Area Number: 25610151
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Stratigraphy/Paleontology
• Research Institution: Osaka City University
• Principal Investigator: EZAKI Yoichi 大阪市立大学, 大学院理学研究科, 教授 (60221115)
• Co-Investigator(Kenkyū-buntansha): GOTO Shinsuke 大阪市立大学, 大学院理学研究科, 准教授 (70347483)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: 微生物岩 / ストロマトライト / ラミナ / バクテリア / 鉱物

Outline of Final Research Achievements

Laminae, which are a characteristic feature of stromatolites, vary in their origin according to the time in geological history and depositional environment. The microbes responsible for stromatolite growth include not only oxygenic photosynthetic bacteria, but also anoxygenic photosynthetic bacteria and chemosynthetic bacteria, thereby facilitating the precipitation of minerals such as calcium carbonate. In addition to mineral precipitation, the dissolution of minerals and the development of destructive textures (e.g., micritisation) through endolithic activity contribute to laminae formation via complex interactions. The periodicity of laminae indicates different time cycles. Specific accumulation patterns of laminae (e.g., the conical stromatolite growth form that is unique to Conophyton) possibly provided a defense against intense (ultraviolet) light during the Precambrian.

Free Research Field

層位・古生物学