ENTANGLED MEMORY: TOWARD A THIRD WAVE IN MEMORY STUDIES

This essay takes up the call for a “third phase” in memory studies and makes theoretical and methodological suggestions for its further development. Starting from an understanding of memory that centers on memory's temporality, its relation to language, and its quality as a social action, the essay puts forward the concept of “entangled memory.” On a theoretical level, it brings to the fore the entangledness of acts of remembering. In a synchronic perspective, memory's entangledness is presented as twofold. Every act of remembering inscribes an individual in multiple social frames. This polyphony entails the simultaneous existence of concurrent interpretations of the past. In a diachronic perspective, memory is entangled in the dynamic relation between single acts of remembering and changing mnemonic patterns. Memory scholars therefore uncover boundless cross‐referential configurations. Wishing to enhance the dialogue between the theoretical and the empirical parts of memory studies, we propose four devices that serve as a heuristic in the study of memory's entanglement: chronology against time, conflict, generations, and self‐reflexivity. Current debates on European memory permit us to explore the possible benefits that the concept of entangled memory carries for memory studies.     

明代辽东中层行政管理区划的形成——以辽东苑马寺卿兼职兵备事为线索

辽东是明代边疆防御体系中的重要地区。由于各种历史地理因素所限,明代辽东地方行政实行军事化的卫所制管理,以一个都司管理25个实土卫,一度形成了行政管理幅度过大、难以实行有效管理的局面。因此在嘉靖年间,辽东全境被划分成6个行政地理单元分别管理,同时从"军管型政区"向"文管型政区"转变,将相邻各系统文官都纳入当地管理体制,连朝廷派驻辽东管理马政的苑马寺卿和行太仆寺卿也各领一道辖境,处理地方军政事务,从而使辽东形成了事实上的三级行政区划。这种增加行政管理层级、缩小管理幅度、实行军事管理与文官监督相结合的处理方式,体现了明代地方行政管理中因地制宜的思路,同时也反映出明代辽东边疆经略中的许多问题。     

ON THE RESOLUTION OF H/V MEASUREMENTS TO DETERMINE SEDIMENT THICKNESS,A CASE STUDY ACROSS A NORMAL FAULT IN THE LOWER RHINE EMBAYMENT,GERMANY

In recent years, H/V measurements have been increasingly used to map the thickness of sediment fill in sedimentary basins in the context of seismic hazard assessment. This parameter is believed to be an important proxy for the site effects in sedimentary basins (e.g. in the Los Angeles basin). Here we present the results of a test using this approach across an active normal fault in a structurally well known situation. Measurements on a 50 km long profile with 1 km station spacing clearly show a change in the frequency of the fundamental peak of H/V ratios with increasing thickness of the sediment layer in the eastern part of the Lower Rhine Embayment. Subsequently, a section of 10 km length across the Erft-Sprung system, a normal fault with ca. 750 m vertical offset, was measured with a station distance of 100 m. Frequencies of the first and second peaks and the first trough in the H/V spectra are used in a simple resonance model to estimate depths of the bedrock. While the frequency of the first peak shows a large scatter for sediment depths larger than ca. 500 m, the frequency of the first trough follows the changing thickness of the sediments across the fault. The lateral resolution is in the range of the station distance of 100 m. A power law for the depth dependence of the S-wave velocity derived from down hole measurements in an earlier study [Budny, 1984] and power laws inverted from dispersion analysis of micro array measurements [Scherbaum et aL, 2002] agree with the results from the H/V ratios of this study.     

一件淮北市东汉“木侠纻”耳杯的测试分析

考古出土的漆器中,除木胎之外,有自铭“革园”的皮革与麻布为胎的漆器,有自称为“布”“绪”“纻”的麻布胎漆器,有自铭“布缯”的麻布和缯帛(一种丝织物)为胎的漆器,以及麻布夹贴于木胎之上的“木侠纻”漆器。作为夹纻胎漆器其中的一种类型,“木侠纻”漆器与“布胎”漆器在制作工艺上是否不同,二者之间是否存在技术演变关系的问题值得深入探讨。 本工作以2011年10月淮北市出土的一件东汉时期的耳杯为例,采用超景深视频显微镜、X射线衍射仪(XRD)、傅里叶红外光谱仪(FTIR)、扫描电子显微镜与能谱仪(SEM-EDS)等测试手段进行研究,深入了解汉代“木侠纻”漆器的工艺特点。显微结构观察发现在器物木胎与外层漆灰之间有着清晰的织物平纹组织结构,织物层的厚度仅占整体厚度的11.4%,远低于同尺寸“布胎”耳杯织物层所占的比例(后者一般在50%以上)。成分测试分析结果显示,髹漆材料为传统的中国大漆,红色漆膜呈色颜料为朱砂,织物材质可能为苎麻纤维,漆灰成分为SiO₂、NaAlSi₃O₈和Ca₈H₂(PO₄)₆H₂O等常见物质。上述研究结果说明,比较汉代“木侠纻”漆器工艺与“布胎”漆器,在髹漆材料、呈色颜料以及漆灰中矿物质成分等方面并无区别,仅在织物层的厚度所占胎体尺寸比例等方面有着明显差异。同时,本研究中发现“仅在木胎一侧贴附麻布”的做法与文献记载的“两麻布夹贴于木胎之上的木侠纻”工艺并不完全一致。 文章首次采用科技手段从制作材料、髹漆工艺等方面揭示了汉代“木侠纻”制作技术。事实上,从厚木胎斫制到薄木卷制成型,再到以布为胎,胎骨的变化见证了古代漆器水平的进化历程。从考古出土的漆卮、樽可以发现,薄木卷制而成的器型在两端的连接处仅依靠生漆或其他材料,其本身的结构并不牢固。古代漆工们为了防止木胎开裂,在接口处的木胎之上粘贴织物。这种借助于植物纤维的拉力增强木胎牢固性的技术即为“木侠纻”。当然,“木侠纻”工艺是否直接催生了“布胎”漆器还有待进一步讨论,但至少从传统手工业技术发展的规律可以进一步窥探两种工艺之间的借鉴或启示。时至今日,这种工艺在今天的家具、屏风制作中依然广泛使用。     

Potential of palaeofluid analysis for understanding oil charge history

Fluid inclusion data, particularly the distribution of hydrocarbon fluid inclusions and their chemistry, can provide insights into oil charge in a petroleum-prospective region. Examples from the UK Atlantic margin show how we can understand thermal regime, timing and chemistry of oil charge. Data from the UK Atlantic margin based on fluid inclusion temperature profiles shows anomalously high temperatures which are highest at the top of the Triassic–Eocene sequence. This is interpreted as a product of hot fluid flow, probably reflecting hydrothermal activity related to intrusion of sills at depth. The preservation of high temperatures also implies rapid migration from depth through fracture systems. Ar–Ar analysis of oil-bearing K-feldspar cements, and petrographic studies of oil inclusion distribution help delimit timing and migration pathways for the hot fluid charge and later fluid migration events. Coupled with compositional data for oils measured destructively (organic geochemistry) or non-destructively (fluorescence), these approaches allow the development of oil charge histories based on real data rather than theoretical modelling.     

Palaeolithic engravings and sedimentary environments in the Côa River Valley (Portugal): implications for the detection,interpretation and dating of open-air rock art

The pre-Magdalenian phase of the Côa River Valley open-air rock art is mostly distributed at the boundary between the rocky valley slopes and the floodplain that correspond to the most favourable geomorphological setting for the preservation of pecked and deeply superposed engravings of the most famous artistic phase of the area. The natural vertical panels of the engraved art located at this geomorphological interface have suffered weathering during two cold events of the Lateglacial. They were buried by several colluvial and alluvial deposits. The reconstruction of the sedimentary and archaeological context of the CôaRiver Valley engraving permits a better assessment of the preservation processes and interpretation of Palaeolithic open-air rock art.     

1. INTRODUCTION: MULTIPLE TIMES AND THE WORK OF SYNCHRONIZATION

In this essay, which introduces the History and Theory forum on Multiple Temporalities, I want to discuss how the existence of a plurality or a multiplicity of times has been conceptualized in the historiographical tradition, partly by entering into a dialogue with recent writers, historians, philosophers, sociologists, anthropologists, and literary scholars, partly by returning to the eighteenth century, to the origin of “the modern regime of historicity” (Hartog). In these theoretical and historical investigations I aim to do two things: on the one hand, to explore and discuss different ways of conceptualizing multiple times, in terms of nonsynchronicities, layers of time, or natural and historical times; on the other hand, to trace how these multiple times have been compared, unified, and adapted by means of elaborate conceptual and material practices that I here call “practices of synchronization.” From the eighteenth century onward, these synchronizing practices, inspired by, but by no means reducible to, chronology have given rise to homogeneous, linear, and teleological time, often identified as modern time per se, or simply referred to as “progress.” In focusing on the practices of synchronization, however, I want to show how this regime of temporality during its entire existence, but especially at the moment of its emergence in the eighteenth century and at the present moment of its possible collapse, has been challenged by other times, other temporalities, slower, faster, with other rhythms, other successions of events, other narratives, and so on.     

Effects of episodic fluid flow on hydrocarbon migration in the Newport‐Inglewood Fault Zone,Southern California

Fault permeability may vary through time due to tectonic deformations, transients in pore pressure and effective stress, and mineralization associated with water‐rock reactions. Time‐varying permeability will affect subsurface fluid migration rates and patterns of petroleum accumulation in densely faulted sedimentary basins such as those associated with the borderland basins of Southern California. This study explores the petroleum fluid dynamics of this migration. As a multiphase flow and petroleum migration case study on the role of faults, computational models for both episodic and continuous hydrocarbon migration are constructed to investigate large‐scale fluid flow and petroleum accumulation along a northern section of the Newport‐Inglewood fault zone in the Los Angeles basin, Southern California. The numerical code solves the governing equations for oil, water, and heat transport in heterogeneous and anisotropic geologic cross sections but neglects flow in the third dimension for practical applications. Our numerical results suggest that fault permeability and fluid pressure fluctuations are crucial factors for distributing hydrocarbon accumulations associated with fault zones, and they also play important roles in controlling the geologic timing for reservoir filling. Episodic flow appears to enhance hydrocarbon accumulation more strongly by enabling stepwise build‐up in oil saturation in adjacent sedimentary formations due to temporally high pore pressure and high permeability caused by periodic fault rupture. Under assumptions that fault permeability fluctuate within the range of 1–1000 millidarcys (10^?15–10^?12 m²) and fault pressures fluctuate within 10–80% of overpressure ratio, the estimated oil volume in the Inglewood oil field (approximately 450 million barrels oil equivalent) can be accumulated in about 24 000 years, assuming a seismically induced fluid flow event occurs every 2000 years. This episodic petroleum migration model could be more geologically important than a continuous‐flow model, when considering the observed patterns of hydrocarbons and seismically active tectonic setting of the Los Angeles basin.     

The stress regime of the Western Canadian Sedimentary Basin

All available information relevant to in situ stress orientations and magnitudes in the Western Canadian Sedimentary Basin (WCSB) were examined to provide a better understanding of how regional stress fields may affect geothermal development. The smallest principal stress is horizontal over most of the Western Canadian Sedimentary Basin, and it varies in magnitude across the region. Horizontal stress trajectories show that S_Hmax axes are generally aligned SW–NE. A total of 1643 measurements of microfracture and minifracture closure pressures, leak‐off pressures and fracture breakdown pressures have been harnessed to map S_Hmin gradients across the basin at depths of 156–500, 500–1000, 1000–4185 and 2000–4185 m. Vertical stress magnitudes, calculated in 91 wells, showed that at constant depth, S_V increases towards the Canadian Rocky Mountains. Resultant regional stress maps show consistent trends in orientation of stress axes. As a result, predictions can be made that propagation axes of subsurface hydraulic fractures will be dominantly SW–NE, except over the Peace River Arch area, where they will trend more towards SSW–NNE. Engineered geothermal systems in the WCSB can be optimised by drilling horizontal wells parallel to S_Hmin.     

Maintaining high fluid pressures in older sedimentary basins

High fluid pressures in old geologic basins, where the mechanisms that generate high fluid pressure have ceased to operate, pose the problem of how high fluid pressures are maintained through geologic time. Recent oil and gas exploration reveals that low permeability shales, the source beds for oil and gas, contain large quantities of gas that are now being exploited in many sedimentary basins in North America. No earlier analyses of how to maintain high fluid pressure in older sedimentary basins included a shale bed as a source of adsorbed gas; this is a new conceptual element that will fundamentally change the analysis. Such a large fluid source can compensate for a low rate of bleed off in a dynamic system. If the fluid source is large enough, as the gas within these shale source beds appears to be, there will no appreciable drop in pressure accompanying a low rate of leakage from the basin for long periods. For the dynamic school of basin analysts this may provide the missing piece in the puzzle, explaining how high fluid pressures are maintained for long periods of geologic time in a crust with finite, non-zero permeability. This is a hypothesis which needs to be tested by new basin analyses.