Preview

PDF 1996-Rao-Compar...pdf | Download (407kB) Available under University of Tasmania Standard License. | Preview

Abstract

Modern bryozoan skeletal mineralogy varies with seawater temperature: polar Antarctic bryozoans are mainly low-Mg calcite, whereas temperate Tasmanian bryozoans are predominantly high-Mg calcite with variable amounts of aragonite. Bivalve molluscs from both polar and temperate regions are mainly aragonite with variable amounts of low-Mg calcite. The o180 and o13C isotope fields of polar skeletons are clearly separated from the temperate fields, due to differences in seawater temperatures, levels of o13C in seawater and the circulation of seawater masses. 0180 values of bryozoa, benthic foraminifera and bivalve molluscs give near-equilibrium seawater temperatures. Small differences in 0180 and o13C values between skeletons are due to their variable growth rates. Meltwater effects are small (7%) in the polar Antarctic Sea and high (<25%) in the shallow Arctic Sea because ice sheets do not melt in the Antarctic region, whereas significant melting of ice sheets occurs in summer in the Arctic regions. Skeletal carbonate mineralogy and 0180 and o13C variations can be used in the recognition of ancient, non-tropical carbonate skeletons and carbonate rocks.

Item Type:	Article
Authors/Creators:	Rao, CP and Amini, ZZ and Franklin, DC
Keywords:	Royal Society of Tasmania, RST, Van Diemens Land, natural history, science, ecology, taxonomy, botany, zoology, geology, geography, papers & proceedings, Australia, UTAS Library
Journal or Publication Title:	Papers and Proceedings of the Royal Society of Tasmania
ISSN:	0080-4703
DOI / ID Number:	https://doi.org/10.26749/rstpp.130.2.87
Collections:	Royal Society Collection > Papers & Proceedings of the Royal Society of Tasmania
Additional Information:	Copyright Royal Society of Tasmania
Item Statistics:	View statistics for this item

Actions (login required)

Item Control Page