Mud Brick Metaphysics and the Preservation of Earthen Ruins

In the conservation of built heritage, earthen ruins rank as one of, if not the most, intractable of problems to be confronted. Lacking the very architectural devices originally in place to combat and control weathering, earthen ruins face rapid deterioration without constant remedial and preventive conservation. Often it is the enormous mass of many ancient earthen ruins that explain their persistence; however, even these will collapse over time from differential erosion, or eventually stabilize as formless lumps. The impossible demands of simultaneously preserving architectural form and fabric (materiality) challenge the archaeologist and conservation professional who attempt to manage both for temporary and permanent display.     

Assessment of Construction Techniques and Material Usage in İzmir Rural Houses

The domestic architecture in the rural villages of ?zmir comprises a unique built environment with their masonry wall textures, semi-open sofas, round tiled-hipped roofs, and chimneys, and represents an important part of the cultural and architectural heritage. This assessment is mainly based on field observations that focus on the architectural and structural layout of intact, damaged, and destroyed houses. During field observation and the analysis of data certain plan typologies and relationships between the geological formations of the region and choice of materials and construction techniques were observed. While load-bearing masonry and timber skeleton systems are common, extensive use of timber laces, stone, and fired or adobe brick masonry with mud mortar and timber frames infilled with masonry materials were frequently seen. Generally, round timber elements such as wall plates, laces, lintels, posts, and frames of flooring systems are used. Architectural degenerations in authentic houses, defective details and partially due to the earthquake-prone nature of the region seismicity have been evaluated. An overall approach for the preservation and sustainability of this heritage is suggested.     

Real‐time mud gas logging and sampling during drilling

Continuous mud gas loggings during drilling as well as offline mud gas sampling are standard procedures in oil and gas operations, where they are used to test reservoir rocks for hydrocarbons while drilling. Our research group has developed real‐time mud gas monitoring techniques for scientific drilling in non‐hydrocarbon formations mainly to sample and study the composition of crustal gases. We describe in detail this technique and provide examples for the evaluation of the continuous gas logs, which are not always easy to interpret. Hydrocarbons, helium, radon and with limitations carbon dioxide and hydrogen are the most suitable gases for the detection of fluid‐bearing horizons, shear zones, open fractures, sections of enhanced permeability and permafrost methane hydrate occurrences. Off‐site isotope studies on mud gas samples helped reveal the origin and evolution of deep‐seated crustal fluids.     

War-stained: British Combatants and Uniforms, 1914–18

Historians have long recognized the role of military uniforms in marking the transformation of civilians into servicemen. However, this was not a simple transition, completed the moment individuals put on service dress shortly after enlistment. Rather, the process of transformation continued throughout servicemen’s lives in the military, reflecting changed circumstances that might include a move to a different war theatre, promotion, or illness and injury. Focusing on the experiences of British soldiers during the First World War, this article explores the meanings of uniforms as servicemen were transformed from raw recruits into experienced combatants. It questions the extent to which the stained and worn uniforms that seemed the inevitable outcome of front line duty were seen as consistent with the manly heroism expected of soldiers, paying attention not only to the army authorities’ insistence on ‘spit and polish’, but especially to combatants’ perceptions of the effect of dirt on their own identities and sense of self. Thus, this article argues, the transformation into combatants involved potentially dangerous and degrading encounters with dirt and vermin, but also the development of strategies — centred on bodies and on uniforms — that sought to counter the threat of long-term harm and pollution.     

The geological methane budget at Continental Margins and its influence on climate change

Geological methane, generated by microbial decay and the thermogenic breakdown of organic matter, migrates towards the surface (seabed) to be trapped in reservoirs, sequestered by gas hydrates or escape through natural gas seeps or mud volcanoes (via ebullition). The total annual geological contribution to the atmosphere is estimated as 16–40 Terragrammes (Tg) methane; much of this natural flux is ‘fossil’ in origin. Emissions are affected by surface conditions (particularly the extent of ice sheets and permafrost), eustatic sea‐level and ocean bottom‐water temperatures. However, the different reservoirs and pathways are affected in different ways. Consequently, geological sources provide both positive and negative feedback to global warming and global cooling. Gas hydrates are not the only geological contributors to feedback. It is suggested that, together, these geological sources and reservoirs influence the direction and speed of global climate change, and constrain the extremes of climate.     

Hydrogeochemical dynamics affecting steam‐heated pools at El Chichón Crater (Chiapas – Mexico)

El Chichón is an active volcano located in the north‐western Chiapas, southern Mexico. The crater hosts a lake, a spring, named Soap Pool, emerging from the underlying volcanic aquifer and several mud pools/hot springs on the internal flanks of the crater which strongly interact with the current fumarolic system (steam‐heated pools). Some of these pools, the crater lake and a cold spring emerging from the 1982 pumice deposits, have been sampled and analysed. Water–volcanic gas interactions determine the heating (43–99°C) and acidification (pH 2–4) of the springs, mainly by H₂S oxidation. Significantly, in the study area, a significant NH₃ partial pressure has been also detected. Such a geochemically aggressive environment enhances alteration of the rock in situ and strongly increases the mineralization of the waters (and therefore their electrical conductivity). Two different mineralization systems were detected for the crater waters: the soap pool‐lake (Na⁺/Cl^? = 0.4, Na/Mg>10) and the crater mud pools (Na⁺/Cl^? > 10, Na/Mg < 4). A deep boiling, Na⁺‐K⁺‐Cl^?‐rich water reservoir generally influences the Soap Pool‐lake, while the mud pool is mainly dominated by water‐gas–rock interactions. In the latter case, conductivity of sampled water is directly proportional to the presence of reactive gases in solution. Therefore, chemical evolution proceeds through neutralization due to both rock alteration and bacterial oxidation of ammonium to nitrate. The chemical compositions show that El Chichón aqueous fluids, within the crater, interact with gases fed by a geothermal reservoir, without clear additions of deep magmatic fluids. This new geochemical dataset, together with previously published data, can be used as a base line with which to follow‐up the activity of this deadly volcano.     

Hydrothermal monitoring in a quiescent volcanic arc: Cascade Range,northwestern United States

Ongoing (1996–present) volcanic unrest near South Sister, Oregon, is accompanied by a striking set of hydrothermal anomalies, including elevated temperatures, elevated major ion concentrations, and ³He/⁴He ratios as large as 8.6 R_A in slightly thermal springs. These observations prompted the US Geological Survey to begin a systematic hydrothermal‐monitoring effort encompassing 25 sites and 10 of the highest‐risk volcanoes in the Cascade volcanic arc, from Mount Baker near the Canadian border to Lassen Peak in northern California. A concerted effort was made to develop hourly, multiyear records of temperature and/or hydrothermal solute flux, suitable for retrospective comparison with other continuous geophysical monitoring data. Targets included summit fumarole groups and springs/streams that show clear evidence of magmatic influence in the form of high ³He/⁴He ratios and/or anomalous fluxes of magmatic CO₂ or heat. As of 2009–2012, summit fumarole temperatures in the Cascade Range were generally near or below the local pure water boiling point; the maximum observed superheat was <2.5°C at Mount Baker. Variability in ground temperature records from the summit fumarole sites is temperature‐dependent, with the hottest sites tending to show less variability. Seasonal variability in the hydrothermal solute flux from magmatically influenced springs varied from essentially undetectable to a factor of 5–10. This range of observed behavior owes mainly to the local climate regime, with strongly snowmelt‐influenced springs and streams exhibiting more variability. As of the end of the 2012 field season, there had been 87 occurrences of local seismic energy densities approximately ≥ 0.001 J/m³ during periods of hourly record. Hydrothermal responses to these small seismic stimuli were generally undetectable or ambiguous. Evaluation of multiyear to multidecadal trends indicates that whereas the hydrothermal system at Mount St. Helens is still fast‐evolving in response to the 1980–present eruptive cycle, there is no clear evidence of ongoing long‐term trends in hydrothermal activity at other Cascade Range volcanoes that have been active or restless during the past century (Baker, South Sister, and Lassen). Experience gained during the Cascade Range hydrothermal‐monitoring experiment informs ongoing efforts to capture entire unrest cycles at more active but generally less accessible volcanoes such as those in the Aleutian arc.     

Geophysical and geochemical evidence of large scale fluid flow within shallow sediments in the eastern Gulf of Mexico,offshore Louisiana

We analyse the fluid flow regime within sediments on the Eastern levee of the modern Mississippi Canyon using 3D seismic data and downhole logging data acquired at Sites U1322 and U1324 during the 2005 Integrated Ocean Drilling Program (IODP) Expedition 308 in the Gulf of Mexico. Sulphate and methane concentrations in pore water show that sulphate–methane transition zone, at 74 and 94 m below seafloor, are amongst the deepest ever found in a sedimentary basin. This is in part due to a basinward fluid flow in a buried turbiditic channel (Blue Unit, 1000 mbsf), which separates sedimentary compartments located below and above this unit, preventing normal upward methane flux to the seafloor. Overpressure in the lower compartment leads to episodic and focused fluid migration through deep conduits that bypass the upper compartment, forming mud volcanoes at the seabed. This may also favour seawater circulation and we interpret the deep sulphate–methane transition zones as a result of high downward sulphate fluxes coming from seawater that are about 5–10 times above those measured in other basins. The results show that geochemical reactions within shallow sediments are dominated by seawater downwelling in the Mars‐Ursa basin, compared to other basins in which the upward fluid flux is controlling methane‐related reactions. This has implications for the occurrence of gas hydrates in the subsurface and is evidence of the active connection between buried sediments and the water column.     

藏文大藏经金色经文成分及纸张微生物分析

藏文大藏经是翻译成藏文的印度佛教原典和佛教著述的总集,具有很高的历史价值、科学价值和艺术价值。本工作利用光学显微镜观察、扫描电子显微镜与能谱法、显微激光拉曼光谱法、高效液相色谱-质谱法、微生物分离纯化培养技术、分子生物学鉴定技术和高通量测序等方法分析了一件甘肃武威市博物馆藏书写金色经文的明清时期藏文大藏经样品和两件表面附有微生物的大藏经样品。分析结果表明:金色书写材料为金银铜合金颗粒,其中金(Au)含量72.8%～75.6%,银(Ag)含量22.8%～26.0%,铜(Cu)含量1.2%～1.6%,使用的金泥纯度不高;大藏经纸张用靛青染色,并以石墨涂覆表面;纸张的pH值在7.0～7.5之间,未酸化;纸张纤维间散布有大量真菌孢子,保存期间微生物繁殖生长的分泌物是纸张粘连的主要原因之一。纯化培养及分子鉴定结果表明大藏经表面绿色霉斑为烟曲霉(Aspergillus fumigatus),高通量测序结果显示附着在大藏经表面的微生物种类包括毛壳菌属(Chaetomium sp.)、曲霉属(Aspergillus sp.)、毛霉属(Mucor sp.)和白僵菌属(Beauveria sp.)等。研究结果可为大藏经保护材料和修复技术的选择提供信息与依据,也为其揭展和防霉材料筛选提供评估数据。