Primitive carbonaceous chondrites contain a large array of organic compounds dominated by insoluble organic matter (IOM). A striking feature of this IOM is the systematic enrichment in deuterium compared with the solar hydrogen reservoir. This enrichment has been taken as a sign of low-temperature ion-molecule or gas-grain reactions. However, the extent to which Solar System processes, especial...

The process of monoisotopic mass determination, i.e., nomination of the correct peak of an isotopically resolved group of peptide peaks as a monoisotopic peak, requires prior information about the isotopic distribution of the peptide. This points immediately to the difficulty of monoisotopic mass determination, whereas a single mass spectrum does not contain information about the atomic composi...

Isotopic variation of food stuffs propagates through trophic systems. But, this variation is dampened in each trophic step, due to buffering effects of metabolic and storage pools. Thus, understanding of isotopic variation in trophic systems requires knowledge of isotopic turnover. In animals, turnover is usually quantified in diet-switch experiments in controlled conditions. Such experiments u...

The stable isotopic composition of drinking water, diet, and atmospheric oxygen influence the isotopic composition of body water ((2)H/(1)H, (18)O/(16)O expressed as δ(2) H and δ(18)O). In turn, body water influences the isotopic composition of organic matter in tissues, such as hair and teeth, which are often used to reconstruct historical dietary and movement patterns of animals and humans. H...

Of the elements strictly synthesized in stars, oxygen is by far the most abundantly produced. We review the nucleosynthesis and Galactic chemical evolution of this important element. We then review its isotopic composition in presolar grains recovered from primitive meteorites and from interplanetary dust particles. As we describe, knowledge of these isotopic compositions provide important cons...

available online at http://meteoritics.org 667 © Meteoritical Society, 2004. Printed in USA. Determining the possible building blocks of the Earth and Mars Thomas H. BURBINE1* and Kevin M. O’BRIEN2 1Laboratory for Extraterrestrial Physics, NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA 211152 Wallingsford Road, Los Alamitos, California 90720, USA *Corresponding author. E-mail:...

Introduction: The Moon is generally thought to have formed from a circumterrestrial disk generated by the impact of a Mars-sized body onto a nearly-formed Earth [1]. The gravitational energy released in such an event is sufficent to completely melt and partially vaporize the Earth and lunar-forming material. This fluid phase of the evolution is not well understood, but may have delayed lunar ac...