Accumulation by dispossession and hazardscape production in post-corporate gold mining in Itogon,Philippines

This study investigates the experience of a gold mining community two decades after corporate mining activities ceased and were replaced by informal subcontract small-scale mining in Itogon, Philippines. Drawing on David Harvey’s accumulation by dispossession and Daanish Mustafa’s hazardscape, we consider the lasting effects, from 1903, of dispossession upon the establishment of the first commercial mines in the Philippines as experienced by traditional miners in Itogon. Despite the closure of mining operations, mineral lands remain privately owned, resulting in the persistence of legal land dispossession among local small-scale gold miners. Mining activities still continue as small-scale miners are able to access abandoned mines through subcontract mining. Subcontract mining has changed the source of capital that funds mining activities from mining corporation to rent-seeking small-scale mining financiers, but the new economic relations still benefit from the capitalist logic of low natural resources and labour value. We argue that the production of hazardscapes is a consequence of accumulation by dispossession through (1) processes of expropriation of mineral lands and the consequent creation of free labour among local miners; (2) the externalisation environmental cost as an accumulation strategy that results in the production of socionatural hazards; and (3) exploitation of those who labour and who are made to work in precarious work environment while contributing to the production of hazardscapes.     

一批流散海外的吐蕃文物的初步考察

吐蕃文物曾通过不同途径流散于海外,主要包括金银器与织锦。从中反映出吐蕃作为七世纪以来兴起于青藏高原的强大政治集团与唐、粟特、萨珊波斯等都有着密切的文化联系,并已形成具有自身特色的金银器制作风格;以对兽纹为主题的织锦是吐蕃人最为喜好的"番锦"之一,有可能为粟特锦,也有可能为包含粟特锦、波斯锦等中亚风格在内的"胡锦"。吐蕃银器上的纹饰更是多见于吐善时期的装饰性图案当中,并且影响到以后的藏族艺术。     

Pre-Hispanic gold pieces of an enigmatic archaeological finding in Medellín,Colombia: A glance at an archaeometric analysis

The study analysed pre-Hispanic gold objects found within a surprising archaeological finding of a structure that likely served as a funeral pyre in Medellín, Colombia. ¹⁴C analyses of the site's organic materials dated the structure to the fifth century ce . The metal objects were subjected to X-ray diffraction (XRD), energy-dispersive X-ray fluorescence (EDXRF), scanning electron microscopy-energy dispersive X-ray (SEM-EDX), density measurement by the Archimedes method, and metallographic analysis. The measurements by EDXRF and SEM-EDX showed that the pieces were composed mostly gold and silver. The XRD results indicated that the microstructure of the objects corresponded to a single phase of gold and silver. The images obtained by the metallographic microscope showed equiaxial grains with some twins, a structure consistent with annealed metals. The different colours observed correspond to different grain orientations. Pre-Hispanic objects from a second archaeological site in the municipality of Amalfi (Department of Antioquia) were also analysed for comparative purposes. The results showed that the gold objects were not subjected to any alloying process, but were instead manipulated in their original form (native gold). The shape of the objects and their microstructural results suggested that the pieces were manufactured by casting, mechanical deformation and then annealing.     

新疆山普拉墓地出土金线结构形貌与材质特征研究

山普拉墓地出土的珍贵纺织品与新疆其他古墓葬群出土的纺织品一样,是研究世界古代纺织史、丝绸之路物质文化交流的重要标本,承载着人类社会发展极其重要的历史、文化、科技价值。为研究古代纺织品的用金技术,以新疆和田洛浦县山普拉墓地出土金线为研究对象,借助光学显微镜和扫描电镜对金线的形貌进行显微观察,以揭示金线及其芯线的结构特征,获取了金线相关几何尺寸等信息。同时结合能谱仪分析,对金线的成分进行检测,获得了金线合金中各元素的比例。本研究结果可为中国古代纺织品的用金技术研究提供科学依据,并且期冀通过今后逐步积累的大量金线分析数据能够揭示出中国较早时期纺织品用金技术的起源及其发展脉络。     

Monitoring fluid chemistry in iron oxide–copper–gold‐related metasomatic processes,eastern Mt Isa Block,Australia

Most researchers in the Proterozoic eastern Mt Isa Block, NW Queensland, Australia, favour magmatic fluid and salt sources for sodic‐(calcic) alteration and iron oxide–copper–gold mineralization. Here we compare spatial, mineralogic and stable isotope data from regional alteration assemblages with magmatic and magmatic‐hydrothermal interface rocks in order to track chemical and isotopic variations in fluid composition away from inferred fluid sources. Tightly clustered δ¹⁸O values for magnetite, quartz, feldspar and actinolite for igneous‐hosted samples reflect high temperature equilibration in the magmatic‐hydrothermal environment. In contrast, these minerals record predominantly higher δ¹⁸O values in regional alteration and Cu–Au mineralization. This dichotomy reflects partial equilibration with isotopically heavier wallrocks and slightly lower temperatures. Increases in Si concentrations of metasomatic amphiboles relative to igneous amphiboles in part reflect cooling of metasomatic fluids away from igneous rocks. Variations in X_Mg for metasomatic amphiboles indicate local wallrock controls on amphibole chemistry, while variations in X_Cl/X_OH ratios for amphiboles (at constant X_Mg) indicate variable aH₂O/aHCl ratios for metasomatic fluids. Biotite geochemistry also reflects cooling and both increases and decreases in aH₂O/aHCl for fluids away from plutonic rocks. Decreased aH₂O/aHCl ratios for metasomatic fluids reflect in part scavenging of chlorine out of meta‐evaporite sequences, although this process requires already saline fluids. Local increases in aH₂O/aHCl ratios, as well as local decreases in δ¹⁸O values for some minerals (most notably haematite and epithermal‐textured quartz), may indicate ingress of low salinity, low δ¹⁸O fluids of possible meteoric origin late in the hydrothermal history of the region. Taken together, our observations are most consistent with predominantly magmatic sources for metasomatic fluids in the eastern Mt Isa Block, but record chemical and isotopic variations along fluid flow paths that may be important in explaining some of the diversity in alteration and mineralization styles in the district.     

Fluid flow in shear zones: insights from the geometry and evolution of ore bodies at Renco gold mine,Zimbabwe

The geometry of mineral deposits can give insights into fluid flow in shear zones. Lode gold ore bodies at Renco Mine, in the Limpopo Belt, Zimbabwe, occur as siliceous breccias and mylonites within amphibolite facies shear zones that dip either gently or steeply. The two sets of ore bodies formed synchronously from hydrothermal fluids. The ore bodies are oblate, but have well‐defined long axes. Larger ore bodies are more oblate. High‐grade gold ore shoots have long axes that plunge down dip; this direction is perpendicular to the long axes of the low‐grade ore bodies. The centres of the high‐grade ore bodies align within the low‐grade ore bodies along strike in both gently and steeply dipping groups. The range of sizes and shapes of the ore bodies are interpreted as a growth sequence. Geometrical models are proposed for the gently and steeply dipping ore bodies, in which individual ore bodies grow with long axes plunging down dip, and merge to form larger, more oblate ore bodies. The models show that when three or more ore bodies coalesce, the long axis of the merged ore body is perpendicular to the component ore bodies, and that ore bodies in the deposit may have a range of shapes due to both growth of individual ore bodies, and their coalescence. The long axes of the high‐grade ore bodies are parallel to the shear directions of both the gently and steeply dipping dip slip shear zones, which were the directions of greatest permeability and fluid flow. The larger, lower grade bodies, which may have formed by coalescence, are elongate perpendicular to these directions.     

寿县李三孤堆楚器的研究与探索

本文介绍了李三孤堆楚墓所出青铜器的流散和收藏慵况,回顾了自20世纪30年代初至今学者们对这批楚器的研究历程及成果,并从铭文释读、器物形制、器群主人及其埋葬环境几方面分别阐述了各家之说,最后通过回顾和分析总结出目前这一研究中存在的问题,提出了深入进行这一研究的重要意义,并指出了今后的研究方向。     

云阳县马粪沱墓出土战国晚期汉代青铜器的分析研究

通过对云阳马粪沱墓出土战国晚期——汉代铜器标本的电镜扫描和金像分析,结合考古学背景,我们进行一些研究。     

青海卡约文化出土的金器

卡约文化是分布在青海地区青铜时代的考古学文化,除发现陶、石、骨、角、牙、料器等类文物外,还发现了一批主要用于装饰的金器。这批金器从制作到用途,反映了青藏高原东北部古羌民族的重要文化特色。作为我国目前发现的最早黄金制品之一,卡约文化金器代表的是这一时段金属冶炼和制作技术的水平,也为我们探讨黄金的原始功用提供了重要线索。     

Pyrite–sulfosalt reactions and semimetal fractionation in the Chinkuashih,Taiwan, copper–gold deposit: a 1 Ma paleo‐fumarole

The mineralized fracture system that underlay paleo‐fumarole field at Chinkuashih, Taiwan has been exposed by copper–gold mining to depths of about 550 m below the paleo‐surface. Its mineralogy and systematic variations in metal and semimetal (Fe, Cu, As, Sb, Bi, Hg, Cd, Sn, Zn, Pb, Se, Te, Au, Ag) concentrations provide insights into the chemical responses of a magmatic‐vapor phase as it expands through fracture arrays to the surface and discharges as fumaroles associated with more extensive solfatara. At Chinkuashih, following initial sealing of the fractures by silica‐alunite alteration, brittle failure reestablished discharge from an underlying reservoir of magmatic vapor. Crystalline pyrite was deposited first in the fractures and was succeeded and replaced by ‘enargite’ (Cu₃(As,Sb)S₄) as sulfosalt encrustations (‘sublimate’) on fracture surfaces and in extensional cracks. Subsequent recrystallization resulted in complex exsolution intergrowths with antimony fractionation to the evolving crystal–vapor interface. Heavy metal fractionation between sulfosalt and vapor enriched the vapor phase in heavy metals that subsequently precipitated as complex Bi–Hg–Sn sulfosalts in discrete areas (paleo‐fumaroles) close to the paleo‐surface in a manner analogous to modern‐day fumaroles on active volcanoes such as Vulcano, Italy. As in similar paleo‐fumaroles (e.g., El Indio, Chile and Lepanto, Philippines), the most characteristic reaction sequence is the partial replacement of the early pyrite by enargite and Fe‐tennantite. It is proposed that this reaction tracks the decrease in the pressure of the underlying magmatic‐vapor reservoir because of the sustained discharge of vapor to the surface.