sources. This suggests that the oldest group of meteorites is more closely related to one another than they are to the younger meteorites that are derived from less incompatible-element-depleted sources. Closed-system fractional crystallization of this suite of meteorites is modeled with the MELTS algorithm using the bulk composition of Yamato 980459 as a parent. These models reproduce many of the major element and mineralogical variations observed in the suite. In 2 addition, the rare-earth element systematics of these meteorites are reproduced by fractional crystallization using the proportions of phases and extents of crystallization that are calculated by MELTS. The combined effects of source composition and fractional crystallization are therefore likely to account for the major element, trace element, and isotopic diversity of all shergottites.Thus, assimilation of a martian crustal component is not required to explain the geochemical diversity of the shergottites.
A critical review of the conceptual and practical evolution of forensic anthropology during the last two decades serves to identify two key external factors and four tightly inter-related internal methodological advances that have significantly affected the discipline. These key developments have not only altered the current practice of forensic anthropology, but also its goals, objectives, scope, and definition. The development of DNA analysis techniques served to undermine the classic role of forensic anthropology as a field almost exclusively focused on victim identification. The introduction of the Daubert criteria in the courtroom presentation of scientific testimony accompanied the development of new human comparative samples and tools for data analysis and sharing, resulting in a vastly enhanced role for quantitative methods in human skeletal analysis. Additionally, new questions asked of forensic anthropologists, beyond identity, required sound scientific bases and expanded the scope of the field. This environment favored the incipient development of the interrelated fields of forensic taphonomy, forensic archaeology, and forensic trauma analysis, fields concerned with the reconstruction of events surrounding death. Far from representing the mere addition of new methodological techniques, these disciplines (especially, forensic taphonomy) provide forensic anthropology with a new conceptual framework, which is broader, deeper, and more solidly entrenched in the natural sciences. It is argued that this new framework represents a true paradigm shift, as it modifies not only the way in which classic forensic anthropological questions are answered, but also the goals and tasks of It has been two decades since the publication in these pages of an influential article by Mehmet Yas ar Is can (Is can, 1988) discussing the then current and future state of forensic anthropology. In that article, Is can reviewed the key trends and landmarks in the development of forensic anthropology during the 1970s and 1980s, highlighting the main problems potentially threatening the future development of the field. Much of the article is devoted to a rather comprehensive review of developments in the construction of the basic biological profile from skeletal tissues (age, sex, stature). Very little discussion was devoted to the relevance of crime scene evidence, and there was no discussion relative to estimates of postmortem interval and reconstructions of events surrounding the death. Clearly, issues beyond the laboratory-derived observations of the bones themselves were not considered to fall under the purview of what a forensic anthropologist did at that point in time. Is can did stress the need for research aimed specifically at forensic anthropology applications, which at the time were hampered by inappropriate sample materials and strategies, poor analytical standards, and the lack of specific training of forensic anthropology practitioners. He indicated that the common source of many of the problems within forensic...
Abstract— The induced thermoluminescence (TL) properties of 16 CV and CV‐related chondrites, four CK chondrites and Renazzo (CR2) have been measured in order to investigate their metamorphic history. The petrographic, mineralogical and bulk compositional differences among the CV chondrites indicate that the TL sensitivity of the ∼130 °C TL peak is reflecting the abundance of ordered feldspar, especially in chondrule mesostasis, which in turn reflects parent‐body metamorphism. The TL properties of 18 samples of homogenized Allende powder heated at a variety of times and temperatures, and cathodoluminescence mosaics of Axtell and Coolidge, showed results consistent with this conclusion. Five refractory inclusions from Allende, and separates from those inclusions, were also examined and yielded trends reflecting variations in mineralogy indicative of high peak temperatures (either metamorphic or igneous) and fairly rapid cooling. The CK chondrites are unique among metamorphosed chondrites in showing no detectable induced TL, which is consistent with literature data that suggests very unusual feldspar in these meteorites. Using TL sensitivity and several mineral systems and allowing for the differences in the oxidized and reduced subgroups, the CV and CV‐related meteorites can be divided into petrologic types analogous to those of the ordinary and CO type 3 chondrites. Axtell, Kaba, Leoville, Bali, Arch and ALHA81003 are type 3.0–3.1, while ALH84018, Efremovka, Grosnaja, Allende and Vigarano are type 3.2–3.3 and Coolidge and Loongana 001 are type 3.8. Mokoia is probably a breccia with regions ranging in petrologic type from 3.0 to 3.2. Renazzo often plots at the end of the reduced and oxidized CV chondrite trends, even when those trends diverge, suggesting that in many respects it resembles the unmetamorphosed precursors of the CV chondrites. The low‐petrographic types and low‐TL peak temperatures of all samples, including the CV3.8 chondrites, indicates metamorphism in the stability field of low feldspar (i.e., <800 °C) and a metamorphic history similar to that of the CO chondrites but unlike that of the ordinary chondrites.
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