This study uses high precision silicon isotopic measurements to understand events that occurred during the earliest stages of formation of the terrestrial planets. The isotopic compositions of diverse materials such as chondrites, lunar rocks and asteroidal basalts can shed light on the homogeneity of the solar nebula, metal-silicate differentiation on planetary bodies, and terrestrial moon formation.
Where there is water, there can be life. Improving our understanding of how life, as we know it, arose uniquely in our solar system on Earth depends critically on our understanding of the history of water in the solar system. Better characterizing the sources of water to the Earth-Moon system is crucial in constraining this history and motivated the experiments described in this dissertation. The oxygen isotopic composition of water in lunar samples in addition to meteorites from Mars and several asteroids, which have delivered significant material to the Earth-Moon system, were characterized. The ordinary chondrite (OC) samples, Bjurböle matrix, Bjurböle chondrules, and ALHA77216, contain 17O-enriched water with, [delta]17O up to 1.5%, released by high temperature heating. Water liberated from the carbonaceous chondrite (CC), Murchison, by heating to high temperatures (≤1000°C) possess [delta]17O approaching -1.5%. Low-temperature fractions of water from these OC and CC samples is mass-dependently fractionated ([delta]17O [approximately equal to]0%). The eucrite, PCA 91006 releases water upon heating to 50-350°C with [delta]17O [approximately equal to]1% and 600-1000°C with as low as -11%. The martian meteorite, NWA 7034, contains water with an average [delta]17O = 0.32%. The lunar samples analyzed (10049, 10057, 10060, 12021, 12039, 14163, 14305, 79035) possess water with average [delta]17O = 0.18%. The oxygen isotopic composition of a whole rock sample of a carbonaceous chondrite (CC) meteorite, Sutter's Mill, was also measured, and possesses [delta]17O = -1.8%. The 1[sigma] error on these [delta]17O values is 0.011%. These results reveal that delivery of water by OCs and CCs could account for almost all of the lunar water isotopic compositions measured. Complementary studies measuring the isotopic composition of ozone (O3), an important precursor to water, formed in experiments performed under analogous conditions to those that existed early in the formation of the solar system were also conducted. Additionally, experiments characterizing the isotopic composition of O2 involved in ion-molecule reactions which dominate molecule-formation processes occurring in cold regions of interstellar molecular clouds were also conducted. These complementary studies help define and explain the isotopic composition of oxygen-bearing reservoirs, especially water, in the present-day inner solar system.
The book starts with an introduction on silicon isotopes and related analytical methods, and explains the mechanisms of silicon isotope fractionation. Silicon isotope distributions in lithosphere, hydrosphere and biosphere are shown based on results from field studies, and silicon isotope relevance for applications are presented.
This volume of the EMU Notes in Mineralogy is one of the outcomes of a school in planetary mineralogy that was held in Glasgow, Scotland, in 2014. The school was inspired by the recent advances in our understanding of the nature and evolution of our Solar System that have come from the missions to study and sample asteroids and comets, and the very successful Mars orbiters and landers. At the same time our horizons have expanded greatly with the discovery of extrasolar protoplanetary disks, planets and planetary systems by space telescopes. The continued success of such telescopic and robotic exploration requires a supply of highly skilled people and so one of the goals of the Glasgow school was to help build a community of early-career planetary scientists and space engineers.
Chondrules are spherical silicate grains which formed from protoplanetary disk material, and as such provide an important record of the conditions of the Solar System in pre-planetary times. Chondrules are a major constituent in chondritic meteorites, however despite being recognised for over 200 years, their origins remain enigmatic. This comprehensive review describes state-of-the-art research into chondrules, bringing together leading cosmochemists and astrophysicists to review the properties of chondrules and their possible formation mechanisms based on careful observations of their chemistry, mineralogy, petrology and isotopic composition. Current and upcoming space missions returning material from chondritic asteroids and cometary bodies has invigorated research in this field, leading to new models and observations, and providing new insight into the conditions and timescales of the solar protoplanetary disk. Presenting the most recent advances, this book is an invaluable reference for researchers and graduate students interested in meteorites, asteroids, planetary accretion and solar system dynamics.
The development of multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) makes it possible to precisely measure non-traditional stable isotopes. This volume reviews the current status of non-traditional isotope geochemistry from analytical, theoretical, and experimental approaches to analysis of natural samples. In particular, important applications to cosmochemistry, high-temperature geochemistry, low-temperature geochemistry, and geobiology are discussed. This volume provides the most comprehensive review on non-traditional isotope geochemistry for students and researchers who are interested in both the theory and applications of non-traditional stable isotope geochemistry.
Though largely inaccessible, the geochemistry of Earth's mantle and core can be examined through a wide variety of approaches. Volume 2 focuses first on "remote" sensing using evidence from cosmochemical, seismic, petrologic and geochemical approaches. Mantle composition is then examined in detail through descriptions of mantle samples brought to Earth's surface through tectonic, volcanic, and volatile-outgassing processes. The volume concludes with examination of processes that modify the composition of the mantle and core including an early magma ocean, partial melting, element partitioning between minerals and melts, and physical mixing caused by plate subduction, mantle convection and mass exchange between mantle and core. Reprinted individual volume from the acclaimed Treatise on Geochemistry, (10 Volume Set, ISBN 0-08-043751-6, published in 2003) Comprehensive and authoritative scope and focus Reviews from renowned scientists across a range of subjects, providing both overviews and new data, supplemented by extensive bibliographies Extensive illustrations and examples from the field
A comprehensive guide to carbon inside Earth - its quantities, movements, forms, origins, changes over time and impact on planetary processes. This title is also available as Open Access on Cambridge Core.
