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1.
Runnymede has large samples of Neolithic and Late Bronze Age animal bones, with contrasting preservation conditions in both periods. The bone evidence has been used to interpret the formation of the site deposits. There are few articulated bones, and no joins were found in butchered bone, indicating that the area studied did not contain primary refuse. Various aspects of bone alteration have been analysed: (i) the proportion of bones with very good surface preservation was high in the in situ Neolithic excavation units and the basal Bronze Age midden, but bones in the upper units were mostly eroded. These units are reworked flood deposits. The greater degree of fragmentation of the bone in the reworked units has been quantified, using a system of recording the ‘zones’ present on each bone, which allows calculation of the fraction present. It is also demonstrated that the reworked units contain a lower proportion of identified bones and a higher proportion of teeth and iaws than the units with well-preserved bone, (ii) Quantification of canid gnawing shows, unexpectedly, that more was recorded on well-preserved bone. Thus recognition of gnawing depends on bone condition. This also confirms that most of the erosion of the bone surface is a post-depositional phenomenon. The sequence of activities is therefore interpreted as follows: meat was cooked and consumed, and the bones discarded for the dogs. At a later stage, larger bones were picked up and thrown away in the river or midden. Some ethnographic examples of periodic cleaning of farming settlements are cited.  相似文献   
2.
Oxygen is a key parameter in the degradation of archaeological material, but little is known of its dynamics in situ. In this study, 10 optical oxygen sensors placed in a 2 m deep test pit in the cultural deposits at Bryggen in Bergen have monitored oxygen concentrations every half hour for more than a year. It is shown that there is a significant spatial and temporal variation in the oxygen concentration, which is correlated to measured soil characteristics, precipitation, soil water content and degradation of organic material. In these deposits oxygen typically occurs when the air content of the soil exceeds 10–15% vol, while oxygen dissolved in infiltrating rainwater is of less importance for the supply of oxygen in the unsaturated zone.  相似文献   
3.
The Trèves zinc–lead deposit is one of several Mississippi Valley‐type (MVT) deposits in the Cévennes region of southern France. Fluid inclusion studies show that the ore was deposited at temperatures between approximately 80 and 150°C from a brine that derived its salinity mainly from the evaporation of seawater past halite saturation. Lead isotope studies suggest that the metals were extracted from local basement rocks. Sulfur isotope data and studies of organic matter indicate that the reduced sulfur in the ores was derived from the reduction of Mesozoic marine sulfate by thermochemical sulfate reduction or bacterially mediated processes at a different time or place from ore deposition. The large range of δ34S values determined for the minerals in the deposit (12.2–19.2‰ for barite, 3.8–13.8‰ for sphalerite and galena, and 8.7 to ?21.2‰ for pyrite), are best explained by the mixing of fluids containing different sources of sulfur. Geochemical reaction path calculations, based on quantitative fluid inclusion data and constrained by field observations, were used to evaluate possible precipitation mechanisms. The most important precipitation mechanism was probably the mixing of fluids containing different metal and reduced sulfur contents. Cooling, dilution, and changes in pH of the ore fluid probably played a minor role in the precipitation of ores. The optimum results that produced the most metal sulfide deposition with the least amount of fluid was the mixing of a fluid containing low amounts of reduced sulfur with a sulfur‐rich, metal poor fluid. In this scenario, large amounts of sphalerite and galena are precipitated, together with smaller quantities of pyrite precipitated and dolomite dissolved. The relative amounts of metal precipitated and dolomite dissolved in this scenario agree with field observations that show only minor dolomite dissolution during ore deposition. The modeling results demonstrate the important control of the reduced sulfur concentration on the Zn and Pb transport capacity of the ore fluid and the volumes of fluid required to form the deposit. The studies of the Trèves ores provide insights into the ore‐forming processes of a typical MVT deposit in the Cévennes region. However, the extent to which these processes can be extrapolated to other MVT deposits in the Cévennes region is problematic. Nevertheless, the evidence for the extensive migration of fluids in the basement and sedimentary cover rocks in the Cévennes region suggests that the ore forming processes for the Trèves deposit must be considered equally viable possibilities for the numerous fault‐controlled and mineralogically similar MVT deposits in the Cévennes region.  相似文献   
4.
The first occurrence of immiscibility in magmas appears to be most important in the magmatic–hydrothermal transition, and thus studies of magmatic immiscibility should be primarily directed towards recognition of coexisting silicate melt and essentially non-silicate liquids and fluids (aqueous, carbonic and sulphide). However, immiscible phase separation during decompression, cooling and crystallization of magmas is an inherently fugitive phenomenon. The only remaining evidence of this process and the closest approximation of natural immiscible magmatic liquids and vapours can be provided by melt and fluid inclusions trapped in silicate glasses and magmatic phenocrysts. Such inclusions are often used as a natural experimental laboratory to model the process of exsolution and the compositions of volatile-rich phases from a wide range of terrestrial magmas. In this paper several examples from recent research on melt and fluid inclusions are used to demonstrate the significance of naturally occurring immiscibility in understanding some large-scale magma chamber processes, such as degassing and partitioning of metals.  相似文献   
5.
This study examines the remains of an agricultural complex found in the Yavneh coastal dunefield, central Israel. Known as a plot-and-berm agroecosystem, the complex consisted of earthworks in a crisscross pattern of sand berms and sunken agricultural plots that were used for groundwater harvesting. The plots, which provided easy access to the high groundwater table and the berms around them, are overlaid by a gray sand unit covered by pottery sherds and artifacts. This gray sand is more fertile than the underlying sand, suggesting refuse enrichment. Artifactual similarity of the finds to those of inland (Tel) Yavneh suggests that Yavneh was the main source for the refuse additive. Based on artifacts and OSL ages it seems that this agroecosystem was active during the 10th to early 12th centuries a.d. The agroecosystem demonstrates an early example of an Early Islamic agrotechnological attempt in marginal and sandy regions of the Mediterranean basin.  相似文献   
6.
Two spinicaudatan species, Triglypta eedemtensis Li sp. nov. and Dundgobiestheria mandalgobiensis Li gen. et sp. nov., are described on the basis of scanning electron microscopy (SEM) imaging of newly collected specimens from paper-thin laminated black shale of the Eedemt Formation exposed at the Eedemt locality in the Khootiin Khotgor coal mine region of Dundgobi Province in southeast Mongolia. Triglypta eedemtensis is ornamented mainly with puncta and a punctate fine reticulum; radial lirae occur only on two or three growth bands near the venter. The small spinicaudatan Triglypta is a common component of the Middle Jurassic Euestheria ziliujingensis fauna and Sinokontikia fauna, and is a typical taxon in the Middle Jurassic lacustrine sequences of northern Hebei and the Junggar and Turpan basins of the Xinjiang Autonomous District of China; however, it does not occur in stratigraphically higher units elsewhere. Therefore, the age of the Eedemt Formation should be considered Middle Jurassic rather than Early Cretaceous. The Eedemt Formation is much older than the Early Cretaceous Shinekhudag Formation in the Shine Khudag area of southeast Mongolia.  相似文献   
7.
Abstract

In recent years systematic archeochemical investigations in the medieval town of Trondheim have provided the heritage management authorities with a rich and complex set of data concerning the status and condition of the cultural deposits in the anthropogenic material. The collected data raises important questions for the long-time management of in situ preservation for archaeological material in non-saturated zones. In this paper we present the standardized scientific methods used in these archeochemical investiga- tions. We examine the results from several sites in the town and discuss the challenges facing modern heritage management in its efforts to protect a complex body of archaeological material in the non-saturated zone. We show that sediments with a thickness of 1–2 m have low levels of moisture and organic matter, and most of the inorganic parameters analysed are found in oxidized form with low preservations. The 2–3 m thick anthropogenic sediments showed better preservation conditions.  相似文献   
8.
Nonlinear time domain site response analysis is used to capture the soil hysteretic response and nonlinearity due to medium and large ground motions. Soil damping is captured primarily through the hysteretic energy dissipating response. Viscous damp-ing, using the Rayleigh damping formulation, is often added to represent damping at very small strains where many soil models are primarily linear. The Rayleigh damping formulation results in frequency dependent damping, in contrast to experiments that show that the damping of soil is mostly frequency independent. Artificially high damp-ing is introduced outside a limited frequency range that filters high frequency ground motion. The extended Rayleigh damping formulation is introduced to reduce the over-damping at high frequencies. The formulation reduces the filtering of high frequency motion content when examining the motion Fourier spectrum. With appropriate choice of frequency range, both formulations provide a similar response when represented by the 5% damped elastic response spectrum.

The proposed formulations used in non-linear site response analysis show that the equivalent linear frequency domain solution commonly used to approximate non-linear site response underestimates surface ground motion within a period range relevant to engineering applications. A new guideline is provided for the use of the proposed formulations in non-linear site response analysis.  相似文献   
9.
考古学次生堆积的研究与探索   总被引:4,自引:1,他引:3  
高蒙河  陈淳 《华夏考古》2001,1(2):94-101
一、问题的提出 随着当代考古学的目标从器物描述扩展到对人类行为的信息提炼,对考古遗址中文化堆积改造和遗址形成过程的了解,便成为田野工作的一项重要方面。虽然,对过去社会文化和人类活动的了解取决于考古学家对遗址的仔细发掘和采样,但是发掘和采样在多大程度上反映了历史的真实面貌,则是一个很大的未知数。因为,考古遗址从形成开始,不但受到人类活动的改造,而且在使用时和废弃后的漫长岁月里,还会被堆积后的自然和人类动力破坏得面目全非。所以,如果要科学地认识考古学文化,仔细分辨人类和自然对考古遗址的改造和扰动就必…  相似文献   
10.
Formation processes are generally considered as a negative factor for behavioral inference in archaeology. The concept of formation processes, however, can potentially be far more useful for behavioral inference in archaeology than simply identifying spurious variability in the archaeological record. Physical traces left by cultural formation processes convey a certain kind of behavioral information which may not be otherwise available. Variables related to site occupation, such as the occupation span, the number of occupation episodes, and the location of activities, can be inferred from characteristics of refuse deposits, or refuse structure.  相似文献   
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