郑韩故城出土青铜器的矿料来源初步分析

基于富集在铜料中而保留其母矿信息的元素可以用于示踪青铜器的矿料来源,为了解郑韩故城青铜器的矿料来源,利用ICP-AES方法对郑韩故城出土东周时期青铜器的微量元素进行了检测。结果显示,21个青铜器样品微量元素特征具有相对一致性,推测可能具有相同的原料来源。与小双桥遗址出土青铜器的微量元素特征进行对比,二者存在明显的差异,说明从商代中期到春秋战国时期,这一地区的原料来源发生了改变。研究结果可为研究东周时期这一地区铜业发展状况提供线索。     

Changes in chemical composition caused by water–rock interactions across a strike‐slip fault zone: case study of the Atera Fault,Central Japan

In some cases, water–rock interactions in fault zones can affect radionuclide migration. Here, we analyzed the chemical compositions of well‐exposed fault rocks from the strike‐slip Atera Fault, Central Japan, in order to understand the variability and behavior of major and selected trace elements. The fault zone has a 1.2‐m‐wide, smectite‐rich fault core and paired damage zones that developed within welded tuff on one side of the core and within granite on the other side. The 30‐cm‐wide, kaolinite‐rich fault gouge is developed in granite cataclasite, and it shows indications of the latest fault activity, while the 1.2‐m‐wide fault core appears to be older. Hydrogen and oxygen isotope ratios in the clay‐rich fault gouges, and carbon and oxygen isotope ratios in carbonates indicate that the two major clay‐rich zones formed in bedrock near the surface, consistent with observed deformation structures. Based on chemical analyses, we identified (1) a slight depletion in SiO₂, Na₂O, K₂O, and light rare earth elements at the edges of the 1.2‐m‐wide fault core, (2) a clear depletion in SiO₂, Na₂O, K₂O, and all rare earth elements except Eu in the 30‐cm‐wide fault gouge, and (3) an increase in CaO, MnO, and heavy rare earth elements across the entire 1.2‐m‐wide fault core. Findings (1) and (2) reflect water–rock interactions in the 1.2‐m‐wide fault core and in the 30‐cm‐wide fault gouge that resulted in the formation of smectite and kaolinite. Finding (3) reflects carbonate precipitation caused by the addition of basalt fragments from a nearby site to the 1.2‐m‐wide fault core during faulting, and subsequent sorption reactions of heavy rare earth elements via processes such as complexation with the carbonates.     

Sediments exposed to high temperatures: reconstructing pyrotechnological processes in Late Bronze and Iron Age Strata at Tel Dor (Israel)

Many of the sediments analysed from Tel Dor (Israel) show structural alterations indicating that they were exposed to high temperatures. This observation is consistent with the abundant evidence for use of pyrotechnology from the earliest exposed Middle Bronze Age strata through the Roman period. Such structurally altered sediments may well represent one of the more widespread and durable records of pyrotechnology, and as such could be invaluable for reconstructing past human activities. The specific aims of this research are therefore to develop the means for identifying local sediments that were altered by different pyrotechnological activities and to elucidate the varying circumstances whereby sediments were exposed to high temperatures in a Late Bronze and Iron Age 1 section.     

微量元素示踪古代青铜器铜矿料来源的可行性

目前,微量元素示踪法在青铜器矿料来源研究中的应用不尽人意。为此,模拟熔铸青铜器,对它们的微量元素作多元统计分析,旨在探讨利用微量元素探索古代青铜器铜矿料来源的可行性。分析表明：若舍弃冶炼后富集亍炉渣中的亲石亲铁元素,而仅选取富集于铜料中的亲铜元素及一些凡具有亲铜性,又具有亲铁性元素的成分数据,则通过多元统计分析,能较好地区别不同产地的铜矿料。     

Responses of South African Agate and Chalcedony When Heated Experimentally,and the Broader Implications for Heated Archaeological Minerals

Here we present a database of responses by South African agate and chalcedony to heat treatment. This will assist analyses of heated stone tools not only in South African archaeological sites, but wherever heated agate and chalcedony pieces were knapped. The minerals are abundant worldwide. To replicate potential heating methods during the Stone Age we placed some minerals in a wood fire, some under coals, and others were buried in sediments beneath fires. Thermal responses include lustrous flaked surfaces, pot lid fractures, semi-circular internal fractures, rough internal surfaces, and crazing. Aerobic heating is implied by pot lid fractures. To explain the thermal responses we analyzed the minerals using X-ray fluorescence, Raman spectroscopy, and carbon and sulfur analyses. Our chalcedony contains more water and impurities than agate, making it more vulnerable to thermal damage. Our method of combining field experiments with chemical analyses has global applications even though we expect that mineral components of agate and chalcedony will vary slightly in different parts of the world.     

Weakening processes in thrust faults: insights from the Monte Perdido thrust fault (southern Pyrenees,Spain)

The Monte Perdido thrust fault (southern Pyrenees) consists of a 6‐m‐thick interval of intensely deformed clay‐bearing rocks. The fault zone is affected by a pervasive pressure solution seam and numerous shear surfaces. Calcite extensional‐shear veins are present along the shear surfaces. The angular relationships between the two structures indicate that shear surfaces developed at a high angle (70°) to the local principal maximum stress axis σ₁. Two main stages of deformation are present. The first stage corresponds to the development of calcite shear veins by a combination of shear surface reactivation and extensional mode I rupture. The second stage of deformation corresponds to chlorite precipitation along the previously reactivated shear surfaces. The pore fluid factor λ computed for the two deformation episodes indicates high fluid pressures during the Monte Perdido thrust activity. During the first stage of deformation, the reactivation of the shear surface was facilitated by a suprahydrostatic fluid pressure with a pore fluid factor λ equal to 0.89. For the second stage, the fluid pressure remained still high (with a λ value ranging between 0.77 and 0.84) even with the presence of weak chlorite along the shear surfaces. Furthermore, evidence of hydrostatic fluid pressure during calcite cement precipitation supports that incremental shear surface reactivations are correlated with cyclic fluid pressure fluctuations consistent with a fault‐valve model.     

Chinese engagement in Southeast Asian energy and mineral resources: motivations and outlook

Abstract

The energy and mineral resource base of Southeast Asia is relatively modest by international standards. Nevertheless, Chinese energy and mining companies have been investing heavily in the region over recent years, in comparison with multinational companies and state-backed companies from other Asian countries. This paper applies a framework derived from the field of business studies to analyze why the scale of China’s engagement in Southeast Asia has become so great and how the motivations vary between the different energy and resource industries. The motivations for these activities reflect a mix of corporate and state objectives. Corporate objectives include securing energy or resource supply chains, increasing or diversifying their asset base, and enhancing their profits or market share. The motivations of the government range from straightforward support of the companies for the purpose of industrial strategy and security of resource supply, to development assistance and regional strategic positioning. The different motivations of the oil and gas, hydropower, and mining industries arise from the particular character of each market, both within China and globally. Southeast Asia has the twin advantages of geographic and apparent cultural proximity to China. Nevertheless, inexperience and a desire to catch up with their international peers have resulted in companies applying low social and environmental standards in some high profile projects. The subsequent disputes, together with the current low level of resource prices, may constrain the further growth of Chinese investment in the near future.     

Infant taphonomy

In almost all living creatures, in Primates as well as in seventeenth–eighteenth century human populations, a high infant mortality is the rule; therefore, the scarcity of children's bones in cemeteries is suspicious from a demographic point of view. Though possible in some cases, sociological causes appear less important than the peculiar behaviour of infants' bones in the tomb. This paper examines the physico-chemical properties of infants' bones and their consequences for the preservation of archaeological samples; it proposes a new way of approaching distributions at death in the past. © 1997 John Wiley & Sons, Ltd     

Permeability of the Mercia Mudstone: suitability as caprock to carbon capture and storage sites

The Upper Triassic Mercia Mudstone is the caprock to potential carbon capture and storage (CCS) sites in porous and permeable Lower Triassic Sherwood Sandstone reservoirs and aquifers in the UK (primarily offshore). This study presents direct measurements of vertical (k_v) and horizontal (k_h) permeability of core samples from the Mercia Mudstone across a range of effective stress conditions to test their caprock quality and to assess how they will respond to changing effective stress conditions that may occur during CO₂ injection and storage. The Mercia samples analysed were either clay‐rich (muddy) siltstones or relatively clean siltstones cemented by carbonate and gypsum. Porosity is fairly uniform (between 7.4 and 10.7%). Porosity is low either due to abundant depositional illite or abundant diagenetic carbonate and gypsum cements. Permeability values are as low as 10^?20 m² (10nD), and therefore, the Mercia has high sealing capacity. These rocks have similar horizontal and vertical permeabilities with the highest k_h/k_v ratio of 2.03 but an upscaled k_h/k_v ratio is 39, using the arithmetic mean of k_h and the harmonic mean of k_v. Permeability is inversely related to the illite clay content; the most clay‐rich (illite‐rich) samples represent very good caprock quality; the cleaner Mercia Mudstone samples, with pore‐filling carbonate and gypsum cements, represent fair to good caprock quality. Pressure sensitivity of permeability increases with increasing clay mineral content. As pore pressure increases during CO₂ injection, the permeability of the most clay‐rich rocks will increase more than carbonate‐ and gypsum‐rich rocks, thus decreasing permeability heterogeneity. The best quality Mercia Mudstone caprock is probably not geochemically sensitive to CO₂ injection as illite, the cause of the lowest permeability, is relatively stable in the presence of CO₂–water mixtures.     

Killing the goose that laid the golden egg? Australia's resource policy regime in comparative perspective

A common criticism of the minerals resource rent tax (MRRT) was that it would ‘kill the goose that laid the golden egg’ for the Australian economy. Mining companies, their industry associations, and the Liberal–National Coalition all argued the MRRT would reduce Australia's attractiveness for mining investment, and lead to ‘capital flight’ as resource firms shifted towards lower-taxing competitors. To evaluate this claim, it is necessary to compare Australia's resource policy regime – including, but not limited to, its taxation elements – against those of its principal competitors. This article undertakes such an evaluation by comparing Australian resource policies with those of nine of its major mineral and energy competitor countries. This survey reveals that Australia's comparatively high mining tax rates are partially offset by its ‘non-interventionist’ approach to resource policy, and that it has retained good rankings on international political risk surveys. There is some evidence of short-term market response to the mining tax, but there is little evidence of sustained capital flight occurring due to the MRRT. These data collectively suggest that the MRRT did not significantly undermine Australia's attractiveness for international mining investment, despite widespread perceptions to the contrary.