From a White Desert to the Largest World Deposit of Lithium: Symbolic Meanings and Materialities of the Uyuni Salt Flat in Bolivia

The Uyuni salt flat (Salar de Uyuni) in Bolivia possesses the largest lithium deposit in the world. Over the past 40 years, this location has been commodified and radically transformed. This paper examines how a landscape, understood from its material attributes and qualities, shapes and is shaped by social relations unfolding in a process of commodification and mining expansion. Based on primary qualitative data, the paper explores two elements: (1) how the symbolic meaning of this landscape has changed over time for the surrounding indigenous communities; and (2) how the different materialities of the salt flat as landscape, as ulexite and as lithium allow understanding of the drivers of socio‐environmental change and conflict in this region. The paper argues that social relations and governance frameworks are interlinked with changing symbolic meanings and the different materialities of the Uyuni salt flat.     

Empathy at Knifepoint: The Dangers of Research and Lite Pedagogies for Social Justice Movements

In this paper, I discuss the ways I have fallen short as a participatory geographer and activist both in my teaching and research practices. I use three critical moments in the development of our PAR collective in Colombia to push debates in geography on participatory research and pedagogy further through reflection on my struggles in the streets and in the university. Additionally, I connect these experiences and previous discussions in participatory geographies with Orlando Fals Borda's discussion of sentipensar (a concept that engages feeling and thinking simultaneously). I draw attention to the Latin American origins of PAR philosophy by placing Fals Borda into dialogue with the protagonists of our social movement in Colombia including human rights activists, homeless drug users and sex workers. In a general sense, this paper is an examination of the challenges I have faced in the contact zones of PAR inside and outside the classroom.     

董其昌《山水》册与《董范合参图》轴辨伪

上海博物馆藏董其昌《山水》册(共十开),为天启四年(1624)元旦所作,实并非董氏真迹。据考,该年四月董其昌才抵京。同时,该册对题均节录自董氏及明清书画著录著作与晚清文学笔记中,其第二开对题,与故宫博物院藏董氏癸酉(1633)夏五所作《董范合参图》轴题跋相同。再考《山水》册笔法,嫩弱飘浮,墨色平淡,与典型的董其昌风格相差甚远,更无其生拙秀逸之气;而《董范合参图》轴,用笔亦尖劲细碎,全幅墨气滞涩,艺术水准远不及故宫博物院藏董氏十二年前所作《仿古山水图》册,亦无法企及董氏卒前一年所作的《关山雪霁图》卷。可见,《山水》册和《董范合参图》轴非董氏本家之作。     

The “Blind” State: Government Quest for Formalization and Conflict with Small‐Scale Miners in the Peruvian Amazon

The Peruvian government is attempting to implement a formalization plan to deal with the chaotic expansion of small‐scale mining activities in the Amazon. However, this plan has been contested, delayed and halted by local miners. Why exactly has it been so hard for the government to enforce a formalization plan in Madre de Dios? This article aims to answer this question by analysing both government efforts to establish control over the region and the challenges it faces in enforcing its formalization plan. It is argued that current resistance to and conflict over the formalization process in Madre de Dios reveals a state governance problem due to the region having been historically governed as a zone for exploitation rather than for social and economic development. Similarly, the analysis highlights the absence of major corporations through which the state can establish a basis for governance, as in other parts of the country.     

Modelling the Lost City hydrothermal field: influence of topography and permeability structure

The Lost City hydrothermal field (LCHF) is hosted in serpentinite at the crest of the Atlantis Massif, an oceanic core complex close to the mid‐Atlantic Ridge. It is remarkable for its longevity and for venting low‐temperature (40–91°C) alkaline fluids rich in hydrogen and methane. IODP Hole U1309D, 5 km north of the LCHF, penetrated 1415 m of gabbroic rocks and contains a near‐conductive thermal gradient close to 100°C km^?1. This is remarkable so close to an active hydrothermal field. We present hydrothermal modelling using a topographic profile through the vent field and IODP site U1309. Long‐lived circulation with vent temperatures similar to the LCHF can be sustained at moderate permeabilities of 10^?14 to 10^?15 m² with a basal heatflow of 0.22 W m^?2. Seafloor topography is an important control, with vents tending to form and remain in higher topography. Models with a uniform permeability throughout the Massif cannot simultaneously maintain circulation at the LCHF and the near‐conductive gradient in the borehole, where permeabilities <10^?16 m² are required. A steeply dipping permeability discontinuity between the LCHF and the drill hole is required to stabilize venting at the summit of the massif by creating a lateral conductive boundary layer. The discontinuity needs to be close to the vent site, supporting previous inferences that high permeability is most likely produced by faulting related to the transform fault. Rapid increases in modelled fluid temperatures with depth beneath the vent agree with previous estimates of reaction temperature based on geochemical modelling.     

Numerical model of pore‐pressure diffusion associated with the initiation of the 2010–2011 Guy–Greenbrier,Arkansas earthquakes

We model pore‐pressure diffusion caused by pressurized waste‐fluid injection at two nearby wells and then compare the buildup of pressure with the observed initiation and migration of earthquakes during the early part of the 2010–2011 Guy–Greenbrier earthquake swarm. Pore‐pressure diffusion is calculated using MODFLOW 2005 that allows the actual injection histories (volume/day) at the two wells to diffuse through a fractured and faulted 3D aquifer system representing the eastern Arkoma basin. The aquifer system is calibrated using the observed water‐level recovery following well shut‐in at three wells. We estimate that the hydraulic conductivities of the Boone Formation and Arbuckle Group are 2.2 × 10^?2 and 2.03 × 10^?3 m day^?1, respectively, with a hydraulic conductivity of 1.92 × 10^?2 m day^?1 in the Hunton Group when considering 1.72 × 10^?3 m day^?1 in the Chattanooga Shale. Based on the simulated pressure field, injection near the relatively conductive Enders and Guy–Greenbrier faults (that hydraulically connect the Arbuckle Group with the underlying basement) permits pressure diffusion into the crystalline basement, but the effective radius of influence is limited in depth by the vertical anisotropy of the hydraulic diffusivity. Comparing spatial/temporal changes in the simulated pore‐pressure field to the observed seismicity suggests that minimum pore‐pressure changes of approximately 0.009 and 0.035 MPa are sufficient to initiate seismic activity within the basement and sedimentary sections of the Guy–Greenbrier fault, respectively. Further, the migration of a second front of seismicity appears to follow the approximately 0.012 MPa and 0.055 MPa pore‐pressure fronts within the basement and sedimentary sections, respectively.     

A NEW DATE FOR THE NEANDERTHALS FROM EL SIDRÓN CAVE (ASTURIAS,NORTHERN SPAIN)*

Torres et al. (2010 ) published a series of radiocarbon, AAR, ESR and OSL dates from the site of El Sidrón, northern Spain, which is notable for the discovery of the partial remains of 12 Neanderthals. Whilst the non‐radiocarbon methods suggested an age beyond 32 600–46 300 years, direct radiocarbon dates on the human fossils were inconsistent, ranging between 10 000 and 50 000 bp . This study uses the ultrafiltration pre‐treatment protocol to obtain a date of 48 400 ± 3200 bp (OxA‐21 776) on a bone fragment and confirm the antiquity of the Neanderthal assemblage. Moreover, it demonstrates the comparability of the ultrafiltration and ninhydrin bone radiocarbon pre‐treatment protocols, and highlights the need for appropriate screening methods where valuable collections with poor biomolecular preservation are sampled for collagen extraction.     

Notes & News

Abstract

This paper examines the British Museum unpublished records related to an Early Bronze (EB) Age pithos burial uncovered a century ago in the Inner Town at Carchemish. The grave, cursorily cited and variously dated (Chalcolithic, EB or even LBA) in the final reports, was described in some detail by Hogarth and Thompson; a precise dating is, however, possible today thanks to the information of paramount importance given by T. E. Lawrence who identified and took a picture of the associated finds, which was recently rediscovered in the Carchemish Archives. The pithos can be now ascribed to the third quarter of the third millennium BC and helps to confirm the recent theory according to which the Inner Town of Carchemish, with its massive earthen rampart, had already developed at the time of the second urbanisation in Syria and upper Mesopotamia.     

The Squatters' Movement in Europe: A Durable Struggle for Social Autonomy in Urban Politics

Squatting empty properties for living or to develop public activities has lasted in European cities for more than three decades. Although local and national contexts differ significantly, there are also some general trends and patterns that deserve careful attention. When squatting occasionally appears in public debates, controversy is generated and many gaps open between academic, social and political perceptions. In this article I use evidence from several European cities to argue that the squatters' movement has produced an original impact in urban politics. The main feature of this impact has been to generate a relatively wide autonomous and mainly non‐institutional mode of citizen participation, protest and self‐management. How has this been possible? Which are the specific contributions made by this urban movement? These are questions that both scholars and activists continuously claim to be relevant, so that this research attempts to offer some general answers based on detailed comparisons and experiences.     

Latest developments in rock art recording: towards an integral documentation of Levantine rock art sites combining 2D and 3D recording techniques

This paper presents a further step in the integral documentation of prehistoric rock art, combining 2D and 3D digital recording techniques. Image processing and digital enhancement techniques are an invaluable aid to obtain high quality and accurate 2D recordings, especially when working with faint motifs or complex superimpositions. But what constitutes a real breakthrough is the possibility of combining 2D digital tracings with metric 3D models, providing a whole set of metric outputs that improve our understanding of the motifs in their context and, at the same time, can be used to deliver accurate metric reproductions.