Thesis (Ph. D.)--University of Washington, 1995. / Vita. Includes bibliographical references (leaves [233]-240).

Thesis (Ph. D.)--University of Chicago, 1921. / "Private edition, distributed by the University of Chicago libraries." Part II, by Herbert N. McCoy and Leo Finkelstein.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1963. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves [153]-173).

Thesis (Ph. D.)--University of Washington, 1986. / Vita. Bibliography: leaves [192]-199.

This bachelor thesis consists of two parts. The first part consists of a review of the theoretical background. It starts off with a shorter review on theories of the history of the early Solar System, from protostellar evolution to grain agglomeration. This is then followed by a brief summary of different kinds of meteorites, what their origins might be and the radiometric dating techniques used to determine their ages. The second part of the thesis consists of an investigation of the possible forming times of the early planetesimals by computer simulation. These planetesimals can later become the parent bodies for iron-rich meteorites. Factors studied are ambient temperature and the abundance of the short-lived radioactive isotope 26Al in the forming nebula. The study found that the parent bodies of iron meteorites had to accrete within the first few million years after the earliest solids in the Solar System, the CAI. It also found that changes in the studied boundary conditions did extend this period, but not further than around 2.8Myrs compared to the standard 2.1Myrs. This data compares well to other, similar, studies. / Denna kandidatuppsats består av två delar. Först sammanfattas teorier om hur solsystemet tros ha formats, från hur solens närområde kan ha sett ut till hur de första himlakroppsembryona kan ha börjat formas. Detta följs av en kortare sammanfattning av olika typer av meteoriter och var de kan ha kommit från. Dessutom sammanfattas några tekniker som används för att bestämma åldern på dessa meteoriter. Huvuddelen av uppsatsen består av en undersökning av hur och när de kroppar järnrika meteoriter kommer från kan ha bildats med hjälp av en datorsimulering, och hur olika parametrar såsom temperatur och mängd radioaktiva isotoper kan ha påverkat denna tid. Undersökningen kom fram till att himlakropparna måste ha bildats snart, inom ca 2 Mår, efter de tidigaste kända delarna av vårt solsystem, CAI. Förändringar i de undersökta parametrarna kunde ändra denna tid något, men inte till senare än ca 2.8 Mår efter CAI. Detta stämmer väl med andra, liknande, studier.

This study used Raman spectral analysis to characterise the structural order of carbon in three carbonaceous chondrites and twelve achondrites. The achondrites analysed were a group of carbon-rich meteorites, known as ureilites. These meteorites are composed primarily of olivine and pyroxene and have igneous textures but contain noble gases and primitive oxygen isotopes which appear to contradict their high temperature origin, which has led to the group being described as “enigmatic” by some authors. This study used Raman spectral analysis to show that ureilite carbon is heterogeneous, even at the micrometer scale, and is derived from more than one source. In order to better understand the processes involved in ureilite formation, terrestrial analogues containing carbonaceous material with similar spectral characteristics to the meteorites were identified. Analysis of terrestrial samples showed that the sedimentary carbon can be incorporated into igneous rocks with little structural change, suggesting that the same may be true for carbonaceous material in ureilites. Although the terrestrial carbon is biogenic in origin, it is structurally similar to pre-biotic organic matter found in meteorites. Carbon can be used as an effective tracer for geological events, such as melting and heating, which appear to be ubiquitous in planetary evolution. This study concluded that carbon is a primary component of melts on the ureilite parent body (UPB) and that impact processes have increased the heterogeneity of ureilite carbonaceous material. Carbon is likely to have been remobilised by later impact events, explaining the lack of correlation between carbon content and isotopic values with other geochemical parameters. Spectral analysis suggested that most of the carbon in ureilites is derived from primitive material.

Thesis (Ph. D.)--Open University.

Thesis (Ph.D.)--McMaster University (Canada), 1994. / Source: Dissertation Abstracts International, Volume: 56-08, Section: B, page: 4197. Adviser: D. M. Shaw.

Undergraduate honors paper--Mount Holyoke College, 2006. Dept. of Astronomy. / Includes bibliographical references (42-44 leaves ).

The measurement of meteorite physical properties (i.e. density, porosity, magnetic susceptibility) supplements detailed chemical and isotopic analyses for small samples (thin sections or ~300 mg portions) by providing whole-rock data for samples massing in the tens of grams. With the advent of fast, non-destructive and non-contaminating measurement techniques including helium ideal-gas pycnometry for grain density, the Archimedean ―glass bead‖ method for bulk density and (with grain density) porosity, and the use of low-field magnetometry for magnetic susceptibility, all of which rely on compact and portable equipment, this has enabled a comprehensive survey of these physical properties for a wide variety of meteorites. This dissertation reports on the results of that survey, which spanned seven major museum and university meteorite collections as well as the Vatican collection. Bulk and grain densities, porosities and magnetic susceptibilities are reported for 1228 stones from 664 separate meteorites, including several rare meteorite types that are underrepresented in previous studies. Summarized here are data for chondrites (carbonaceous, ordinary and enstatite) and stony achondrites. Several new findings have resulted from this study. From the use of a ―weathering modulus‖ based on grain density and magnetic susceptibility to quantify weathering in finds, it is observed that the degree of weathering of ordinary chondrites is dependent on their initial porosity, which becomes reduced to less than ~8% for all finds, but for enstatite chondrites iii weathering actually increases porosity. Grain density and magnetic susceptibility, which have been shown to distinguish H, L and LL ordinary chondrites, also may distinguish shergottites, nakhlites and chassignites from each other, but the two groups of enstatite chondrites (EH and EL) remain indistinguishable in these properties. H chondrite finds exhibit a slight negative trend in porosity with increasing petrographic type, and all chondrite falls together exhibit a pronounced negative trend in porosity spanning all petrographic types. The overall trend corresponds roughly to a positive trend in porosities with respect to both degree of oxidation and percentage of matrix. It also corresponds to the macroporosities of analogous asteroids. These traits constrain models of conditions in the solar nebula and the formation of chondrite parentbody precursors.