open access

https://hdl.handle.net/2115/38432

Seawater Chemistry, Biomineralization and the Fossil Record of Calcareous Organisms

英語

Hardgrounds

2008

21st Century COE for Neo-Science of Natural History, Hokkaido University

Origin and Evolution of Natural Diversity : Proceedings of the International Symposium, The Origin and Evolution of Natural Diversity, held from 1-5 October 2007 in Sapporo, Japan

21-29

International Symposium, "The Origin and Evolution of Natural Diversity". 1–5 October 2007. Sapporo, Japan.

Oscillations in seawater chemistry have characterized at least the last 600 million years of earth history. Three phases of aragonite seas have been separated by two of calcite seas, the former due to high molar ratios of Mg/Ca in seawater and the latter to low ratios. During aragonite seas, inorganic marine cements and ooids are aragonitic, whereas during calcite seas they are calcitic. Recent interest has focused on the effects of this cyclical change in seawater chemistry on biomineralization, as well as on taphonomy (including diagenesis) and hence fossil preservation. Although there is a need for rigorous testing of hypotheses, data on the geological distributions of aragonite and calcite skeletons among marine invertebrates lends variable support to links between seawater chemistry and: (1) de-novo evolution of calcite vs aragonite skeletons, (2) switchovers in mineralogy during subsequent clade evolution, (3) the relative success of clades using calcite or aragonite as biominerals, and (4) the development of hardgrounds with associated sclerobiont communities.

会議発表論文

Version of Record

BA85842508