Scottish Landform Example 40: The Buchan Gravels Formation: A Remnant Deposit of a Palaeo-landscape

Abstract

The Buchan Gravels Formation (BGF) takes the form of a series of gravel deposits of intriguing age and origin in North-East Scotland. The BGF is divided into two geographically-distinct groups, the Windy Hills Gravel Member (WHGM) and the Buchan Ridge Gravel Member (BRGM). The WHGM occurs in central Buchan, and is predominantly composed of quartzite gravels considered to have been deposited by eastwardly-flowing rivers. In contrast the BRGM is found in eastern Buchan, and is composed largely of flint-rich gravels, the precise origins of which are still under debate. Both gravel members are of considerable age, judging by the number of rotted clasts they contain. In addition, both presently occupy high ground, despite seeming to have originated as water-lain deposits. Although of unknown age, the BGF members provide evidence of topographic inversion since their deposition, and quite possibly preglacial age.     

石质文物表面憎水性化学保护的副作用研究

根据最小干预和不影响文物原貌的原则,使用表面化学防护和化学加固等保护材料被认为是保护石质文物的有效方法。目前,已试用于石质文物表面保护的化学材料主要是有机硅等有机化合物。这些有机材料能起到一定的防水和加固作用,但是也潜在不少问题,一些可能的危害目前还没有引起人们足够的重视。本工作以通用有机硅类防水加固剂为表面保护材料,以砂岩、凝灰岩、白云岩、大理岩和花岗岩为保护对象,模拟各种破坏因素,包括干湿循环、盐结晶、冻融和加热等的作用和联合作用,研究了表面化学处理后岩石样品在模拟环境中的变化情况,发现破坏现象严重。其中,化学保护剂在石材表层产生的亲水/憎水界面导致石材受某些应力的加速破坏是重要原因。上述研究结果提示,在石质文物的保护中应慎重使用憎水性表面化学保护剂。     

化学保护的副作用及其对策的探索性研究:(Ⅰ)多层化学保护

化学防护和化学加固是目前保护土、石、砖等材质的不可移动文物的常用方法.所用化学材料主要是有机硅等憎水性有机化合物.这些材料能起到一定的防水和加固作用,但也存在不少问题,有的导致了更严重的破坏.其中,憎水性保护层的起壳剥落是最常见的破坏现象,特别当环境干湿循环频繁,文物本体或地下可溶性盐含量较高的情况下,憎水性化学保护层很容易从文物本体上起壳剥落,造成文物的加速腐蚀破坏.为了减小此类破坏的危害程度,本工作探讨了化学保护剂在混合使用和多层配合使用条件下的防护和加固效果.结果发现,以憎水性较弱的化学材料做基底渗透,以憎水性较强的化学材料做表而保护,由此构成的多层保护措施可以降低化学保护层起壳剥落的危害.其主要原因是,多层保护形成的憎水梯度分散了吸湿膨胀形成的界面拉应力,也缓解了盐结晶析出产生的膨胀应力.     

霉蚀皮质文物的保护

皮质物属于吸湿性较强的一种物品,当保存环境中温湿度大大超过皮质品的安全相对温湿度临界线时,就特别容易生霉。严重时会造成大面积霉腐。如果反复的霉蚀劣化,不仅会致使皮质失去光泽,强度、弹性下降,而且逐渐使皮质皱裂、老化,甚至腐烂。     

The relative effects of core surface morphology on flake shape and other attributes

It is long been thought that many flake attributes, including both size and shape, are largely due to the morphology of a core’s flaking surface, yet this has never been tested under strictly controlled conditions. Using molded glass cores with surface morphologies that highly resemble prehistoric ones, this experiment demonstrates that while core surface morphology does exhibit some influence on flake size and shape, a high degree of variation in flakes produced with the same core surface morphology shows that the effects of other independent variables, such as exterior platform angle and platform depth, have an even stronger effect. A major implication of these results is that current approaches to reconstruct prehistoric knapping strategies are overlooking significant sources of variation.     

Bone surface modifications in zooarchaeology

Cutmarks made by stone tools, conchoidal flake scars from hammerstone percussion, carnivore tooth marks, striations from sedimentary abrasion, and other surface modifications on bones from archaeological sites constitute a crucial body of evidence for investigating the role of human behaviors and of nonhuman taphonomic processes in site formation. This paper describes the various kinds of bone surface modifications produced by humans and by nonhuman processes and assesses the current status of bone surface modification studies with regard to such issues as the need for greater analytical standardization, the selection of instruments for examining bone specimens, tactics for identifying the origins of marks on bones, and strategies for inferring human behaviors.     

The ‘invisible’ hearths: a contribution to the discernment of Mesolithic non-structured surface hearths

In the cover sand area of the NW European plain very little is known about fireplaces within Mesolithic settlement areas. Yet the frequent occurrence of burnt ecofacts (hazelnut shells and bone) and artefacts (flint and quartzite) clearly indicates the presence of (surface) hearths on nearly every campsite. Most of these hearths are non-structured and are thus barely visible in the soil. Furthermore in most spatial studies minimal effort has been made to locate these ‘invisible’ hearths as accurately as possible. This paper discusses the potential and modalities of detailed spatial analysis of burnt artefacts and ecofacts, using recently obtained archaeological and experimental evidences. It is concluded that such an analysis can offer interesting insights into the dynamics of Mesolithic hearths.     

云冈石窟石质文物表面污染物清洗效果检测技术实验

云冈石窟长年暴露于自然界风化环境中,以及近些年来,周围煤矿的开采带来的环境污染,极大地影响及危害云冈石窟石雕艺术品的价值及保存,影响云冈石雕文物的有效寿命.为此,通过对云冈石窟三种典型的污染物、粉尘、烟熏及表面结垢进行清洗实验,并采用色差仪、显微视频成像仪及三维形貌仪对清洗效果进行检测,特别的是三维形貌对加固样品和空白样品的形貌变化比较分析,得出样品的显微形态及表面粗糙度数据,对文物的“最少人为干预”和“不改变文物原状”原则的评价给予了支持,为石质文物清洗效果评估提供了新的方法.     

PMTA对青铜表面保护作用

研究了1-苯基-5-巯基四氮唑(PMTA)对青铜的缓蚀性能。经盐水浸泡试验和电化学测试证明,用 PMTA 处理过的青铜片抗 Cl~-腐蚀性能较好。电子能谱分析(AES 和 XPS)表明 PMTA 与青铜合金元素配位较大,因此推测 Cu_2O、SnO_2、PbO 等相互作用而形成复杂的络合物膜起了保护作用。     

Variation in surface morphology of a Miocene hemicytherid ostracode

The development of the shell and patterns of reticulation in the middle Miocene ostracodes Hermanites glyphica and Quasibradleya are explored in relation to the development of macro-reticulation (primary) and micro-reticulation (secondary), and the effects of aggradation and degradation on surface morphology. Microreticulation is shown to be genetically controlled, not polymorphic or environmentally controlled, whereas aggradation and degradation are shown to vary continuously. Some relationships between ostracode morphology and intraspecific variation, environmentally-cued polymorphism and the phenomena of aggradation and degradation are discussed.     

The correlation of surface and subsurface artifacts: A test case from Late and Terminal Classic Popola,Yucatan, Mexico

Abstract

Surface collections are commonly used by archaeologists to sample artifact assemblages, but the correlation of surface and subsurface artifacts is not fully understood. Cultural, taphonomic, and research-design factors that can affect the relationship of surface and subsurface deposits are reviewed and the correlation of surface and subsurface deposits is tested statistically with data from the site of Popola, Yucatan, Mexico, a Late and Terminal Classic period (a.d. 600–1100) village in the northern Maya lowlands. This study suggests that surface artifact density is not correlated with subsurface artifact density. Large-scale surface collections can characterize the overall assemblage of a site, but not any small area in particular. In shallow bioturbated soils there is no significant variation between surface and subsurface assemblages at any depth. Surface artifacts may be used to identify the presence of subsurface artifacts, but should not be used to suggest their absence.     

The 2-day wave in the middle atmosphere as simulated in a general circulation model extending from the surface to 100 km

The 2-day wave observed in the mesosphere and lower thermosphere has been reproduced in a general circulation model of the atmosphere run for fixed January conditions. The wave was confined to the summer hemisphere between 50 and 100 km, and was most strongly evident in the meridional velocity where it caused a reversal in the direction of this wind approximately every 24 h. Similar but smaller fluctuations could be detected in the zonal wind and temperature. The synoptic distributions from the model confirm that the 2-day wave is a zonal wave number 3 phenomenon and that it progresses westwards. These distributions have maximum amplitudes occurring at higher latitudes than observed, probably owing to the mean wind intensity in the model summer hemisphere being slightly underestimated. Quite marked interactions occurred between the high latitude and tropical features of the synoptic meridional velocity distribution as the wave progressed. The wave had a very small phase variation with altitude, and, except for a region near 70 km, exhibited hardly any sign of baroclinic activity. The formulation of the model eliminates atmospheric tides or orography as forcing agents responsible for the excitation of the 2-day wave.     

松烟和油烟的表面化学性质研究

作为制墨发展史中绝对主流的两种墨品松烟墨和油烟墨,其使用性能的差异往往和它们的物理结构和化学性质直接相关。因此有必要对制墨原料的物理和化学性质进行准确测定。为此,对其原料松烟和油烟的主要组成、颗粒结构和分散状态进行研究的基础上,联合采用Zeta电势测定、X射线光电子能谱(XPS)、程序升温脱附与质谱联用(TPD-MS)、热重(TG)和傅里叶变换红外(FTIR)等不同表征方法,对两种烟料的表面化学性质进行了定性、定量分析。结果表明,松烟和油烟不仅在颗粒尺寸、石墨化程度、比表面等方面有所不同;更重要的是它们在表面电荷、表面基团的种类、分布、相对含量等方面也存在较大的差异。并进一步从黑度、色度、光泽、渗透、层次和稳定性等方面,讨论了松烟和油烟的物理和化学特性与用墨性能之间的关系。希望可以更好地明确制墨原料的物理化学性质,并进一步与制墨工艺、墨的品质相关联,从而指导制墨工艺的改进提高。研究结果可为制墨工艺、墨的使用、鉴别和保存提供科学的依据。     

汉代陶俑彩绘颜料表征分析

为了建立汉代彩绘工艺、彩绘颜料等方面的数据库,为跨地域横向对比研究及彩俑的中长期保护和博物馆展出提供科学依据,本研究利用MINLTA CR-300色度仪、X—Rite Spectrodensitometer密度仪、XTL系列显微镜分析方法,对汉代陶俑彩绘6种颜料层61个样品的色度数据和5件陶俑残片颜料密度值的分布范围和表面显微结构信息特征进行了系统的分析测试。在大量色度数据的收集分析基础上,构建球体色度容差评估模型。球体色度容差评估结果表明,黑色样品保存较为完好,橙红色色度腐蚀现象严重,橙红色陶俑样品较其他样品分布均匀。颜料密度分析表明,橙红色陶俑腿残片保存状况相对较好,表面的颜料层较均匀且致密。显微分析发现,5％B72乙醇体系对表面颜料加固中,B72加固剂的分散性好,颜料表面无明显变化,在陶俑彩绘颜料保护过程中,B72-乙醇体系是可以选择的。     

Diurnal,semi-diurnal and terdiurnal Hough components of surface pressure

Diurnal and semi-diurnal Hough components of surface pressure are evaluated by classical tidal theory for previously presented profiles of water vapour and ozone heating. Values are compared with the observational results of Haurwitz and Cowley (1973) and show significant discrepancies which are considered to indicate the need for additional heating to be identified. The present calculations are in satisfactory agreement with those for semi-diurnal modes evaluated by Walterscheid et al. (1980).Profiles of terdiurnal heating due respectively to ozone and water vapour absorption of solar radiation are calculated for the (3,3,3) to (3,3,6) Hough modes and corresponding surface pressure oscillations are evaluated by classical tidal theory. Comparisons are made with earlier evaluations and with observationally derived results. The calculated solstitial (3, 3, 4) mode, which is the mode of the largest surface pressure amplitude, shows good agreement in phase with observation but underpredicts observed amplitudes by about 36% in contrast to earlier evaluations which were based on a now unacceptable basic temperature profile.     

Hair surface and mechanical properties of Copt mummies from Antinopolis

In the late nineteenth century, excavations were conducted in the necropolis of the site of Antinopolis, a city founded in 130 CE. Over sixty Copt mummies, out of the thousands of graves excavated, were brought to France in the early twentieth century. Unlike mummies of the Pharaonic era, no specific study has been conducted on the mummies of the Christian era. To identify these techniques of mummification and their state of preservation, the Louvre museum has conducted a multidisciplinary study on thirty-nine mummies located throughout France.In this work, we studied the surface topography and the mechanical properties of the hair from eleven mummies.To qualify the hair wear, 3D topography of their surface has been measured with an interferometer of vertical resolution 2 nm and an analysed surface of 20 × 84 μm. The results show that, for most of the hair samples, the cuticle has completely disappeared and the cortex appears very porous. However, for a few of the hair samples, the scales are perfectly regular like those of healthy hair, which is probably due to the mummification techniques used.The mechanical properties of the hair were determined using a three-point bending mechanical test.The results show that the mechanical hair properties are not correlated with the surface morphology of the cuticle.     

汉陶俑彩绘颜料表面特征分析

利用色度仪、反射密度计和显微分析技术,对汉代陶俑彩绘颜料进行了综合研究。测定了各种颜料层的色度、密度和颜料表相的显微结构信息,获得各种颜料的色度分布范围,表征出彩绘颜料层的密度和风化状况,关联分析了颜料密度与颜料特征之间的关系,构建了球体色度容差评估模型,为颜料层表面的色泽评价提供定量化评价,为陶俑彩绘颜料保存时间尺度的评估提供分析数据,为陶俑彩绘的科学保护提供科学依据。