ANNUAL DOSE CONVERSION FACTORS FOR TL AND ESR DATING

Revised values based on ICRP publication No. 38 are given, together with energy release values for individual members of the three radioactive series. There is an increase of 5% in the pre-radon beta component of the thorium series and a decrease from 4.8% to 3.7% in the percentage of the combined uranium series gamma component which is pre-radon in the uranium-238 series.     

安以轩在这里，与精灵约会

传说,这里是精灵居住的岛屿,宁静而神秘,让人无法抵挡的美景和弥漫在空气中的气息是精灵赐予这个岛宝贵的财富。跨越了换日线,经过长途的飞行,我4fJgl本期明星安以轩一起来到了这个美丽的地方。这里,就是库克群岛。     

DATING THE CONSTRUCTION OF EARLY LATE WOODLAND EARTHEN MONUMENTS AT THE JACKSON LANDING SITE IN COASTAL MISSISSIPPI

Abstract

Middle Woodland and early Late Woodland monuments generally have been interpreted as ceremonial spaces that integrated communities both within and among regions. This article presents information on the early Late Woodland component at the Jackson Landing site, a large site with a platform mound and semicircular earthwork, located on the Mississippi Gulf Coast. Earlier research is synthesized with more recent investigations of the mound to argue that the site’s monuments were built during the early Late Woodland period between approximately A.D. 400 to 700. Determining when Jackson Landing’s monuments were built is important because their construction provides a temporal baseline for regional and, perhaps, interregional social integration along the central Gulf Coast.     

MAGNETIZATION DATING AT A MEDIEVAL MONASTERY (TUPHOLME,LINCOLNSHIRE)*

Tupholme Abbey, founded by c. 1166, was constructed of limestone masonry, some of which was reoriented at several times through its history. The limestone progressively acquired a ‘soft’, time-dependent magnetization in the earth's magnetic field—viscous remanent mag-netization (VRM)—that acts like a clock. Although VRM is normally disregarded by geologists because of its ephemeral nature, this remanence is acquired and persists over time-scales that are useful to archaeologists. Successive VRMs were initiated, at different ages of stabilization of the masonry, thus yielding a chronometric curve that allows us to determine, at least relatively, when masonry was installed.     

DATING THE BRONZE AGE IN SPAIN

Summary. How can archaeologists combine and use C14 determinations when they have irregular recalibrated dates? This question is solved by an example with six determinations from the Bronze Age settlement of El Castillo in the mountains of eastern Spain. For the first time we can date precisely the end of the Eneolithic to 2150–2110 BC, and the start of a Bronze Age expansion stage by 1960 BC. Each has a distinctive material culture; that of the Bronze Age stage is linked closely to the climax of the Motillas in La Mancha, and more distantly to El Argar in SE Spain.     

THERMOLUMINESCENCE DATING: RADIOACTIVITY IN QUARTZ

Alpha activities measured for four quartz extracts indicate that, in some samples, the alpha dose-rate to the quartz due to radioactivity within the quartz can be significant. Uranium mapping of the quartz by neutroninduced fission tracks shows that the radioactivity is not homogeneously distributed.     

国内外旅游解说研究进展

旅游解说是旅游景区服务设施的重要组成部分,但相关研究滞后于实践发展。基于国内外关于旅游解说文献资料的整理分析,认为现有的研究集中于概念辨析、解说媒介、案例规划设计、解说系统评估、新兴旅游方式解说、多学科理论引入等方面。同时从研究内容、研究理论、数据来源、分析方法方面对比了国内外旅游解说研究的异同。最后提出国内旅游解说未来重点的研究内容,以及在研究方法上可借鉴国际研究,采用更多定量定性方法结合使研究成果更加丰富。     

ALPHA-RECOIL TRACKS IN ARCHAEOLOGICAL CERAMIC DATING

Among the manifestations of radioactive decay which can be etched to optical visibility on the surface of mica are tracks from nuclei recoiling from alpha emission, called ‘alpha-recoil tracks’. If, beforeetching, the mica is heated to temperatures of the order of 600°C, all evidence of these tracks is annealed from muscovite mica in a few minutes. Alpha activity observed on mica from pot sherds, from stones surrounding fire places, from fire pits, and fired daub may constitute an alpha-recoil track clock which started at the moment of the last firing of the artifacts.     

RESEARCH IN PROGRESS IN SCANDINAVIA

The authors quantitatively analyze the effect of railroad construction on agricultural land values in the often overlooked, agriculturally oriented, trans-Mississippi West. This region is unique in American history in that, at the end of the nineteenth century, the railroad itself preceded widespread settlement. Using a hedonic model, they show that railroad transport increased agricultural land values in this region by more than 20 percent, which had a larger impact than recent studies have found for other regions. Moreover, the authors found that the addition of a railroad to a county significantly increased its growth in land values. This finding is contrary to that of existing studies. Finally, the authors show statistically that the railroad and land values were not endogenously determined, lending credibility to the causality of the results presented in their hedonic and growth models. These results indicate a valuable alternative approach to use in the historical analysis of transportation infrastructure and its impact on land prices.     

AN ATTEMPT AT DATING THE SWANSCOMBE SKULL BONES USING NON-DESTRUCTIVE GAMMA-RAY COUNTING

A low-background germanium spectrometer was used to measure the gamma-ray spectra of the three parts of the Swanscombe skull. Detailed studies of the method showed that it was possible to make accurate measurements of the content of ²²⁶ Ra and ²³¹ Pa but less accurate ones of ²³⁸U and ²³⁵U. Results from the three samples were inconsistent, showing that their exposure to radioactive ground water must have been very different, although they were found close together. The uncertainty in the ratio of ²³⁴U to ²³⁸U in the ground water and the lack of knowledge of the time at which the bones acquired the uranium also prevented the deduction of any reliable dates for these specimens.     

RADIOCARBON DATING: REVOLUTIONS IN UNDERSTANDING*

Radiocarbon dating has undergone a number of ‘revolutions’ in the past 50 years. This is in part because it is a field in continuous development, but perhaps more because of its profound impact on archaeology and the nature of interdisciplinary research. In order to understand the use of radiocarbon as a dating tool, it is necessary to understand the life cycle of radiocarbon, from its production in the upper atmosphere, through its sequestration in reservoirs and samples and its final decay. Different elements in this life cycle lead to complications, or subtleties that need to be understood if we wish to develop high‐resolution chronologies. Most of the changes that have influenced radiocarbon dating are revolutions in understanding of the natural world in disparate academic disciplines. More than ever, it is necessary for users of radiocarbon to understand and engage with the science that underlies the method.