The composition of the continental crust

https://cyberleninka.org/article/n/352063.pdf

87Sr/86Sr, δ13C and δ18O evolution of Phanerozoic seawater

The second edition of The Biomarker Guide is a fully updated and expanded version of this essential reference. Now in two volumes, it provides a comprehensive account of the role that biomarker technology plays both in petroleum exploration and in understanding Earth history and processes. Biomarkers and Isotopes in the Environment and Human History details the origins of biomarkers and introduces basic chemical principles relevant to their study. It discusses analytical techniques, and applications of biomarkers to environmental and archaeological problems. The Biomarker Guide is an invaluable resource for geologists, petroleum geochemists, biogeochemists, environmental scientists and archaeologists.

The Biomarker Guide

Carbon isotope fractionation in plants

he efficiency of photosynthesis continues to interest biochemists, biologists, and plant physiologists. Scientists interested in CO2 uptake are concerned about the extent to which the uptake rate is limited by such factors as stomatal diffusion and the chemistry of the CO2 absorption process. The fractionation of carbon isotopes that occurs during photosynthesis is one of the most useful techniques for investigating the efficiency of CO2 uptake. Atmospheric carbon dioxide contains approximately 1.1% of the nonradioactive isotope carbon-13 and 98.9% of carbon-12. During photosynthesis, plants discriminate against C because of small differences in chemical and physical properties imparted by the difference in mass. This discrimination can be used to assign plants to various photosynthetic groups. The isotope fractionation also reflects limitations on photosynthetic efficiency imposed by the various diffusional and chemical components of CO2 uptake. When analyzed in detail, this fractionation provides information .about water use efficiency and indicates that different strategies are needed for improving wateruse efficiency in different kinds of plants. Isotope fractionation in simple physical and chemical processes is well understood and is commonly Current studies include

Carbon Isotopes in PhotosynthesisFractionation techniques may reveal new aspects of carbon dynamics in plants

Theoretical and Experimental Principles.- Isotope Fractionation Processes of Selected Elements.- Variations of Stable Isotope Ratios in Nature.

Jochen Hoefs

Papers

Stable isotope geochemistry

The nature of O18/O16 and C13/C12 secular trends in sedimentary carbonate rocks

Geochemie stabiler isotope