The Construction Process of the Angkor Monuments Elucidated by the Magnetic Susceptibility of Sandstone*

The Angkor monuments in Cambodia are mainly constructed of grey to yellowish‐brown sandstones. No differences in the constituent minerals and in the chemical composition of the sandstones have been confirmed among the monuments. However, we have found their magnetic susceptibility a useful parameter by which to distinguish them. The principal monuments of Angkor Wat, Ta Prohm, Preah Khan, Banteay Kdei and Bayon, constructed from the Angkor Wat period to the Bayon period (from the beginning of the 12th century to the beginning of the 13th century ad ), were investigated in detail using a portable magnetic susceptibility meter. We succeeded in dividing the periods of construction into stages. This elucidated the enlargement process of the monuments and correlated their construction stages.     

Consideration on the construction process and the sandstone quarries during the Angkor period based on the magnetic susceptibility

Detailed magnetic susceptibility measurement was conducted on the sandstones used for the Angkor monuments constructed in the period spanning the Preah Ko and Angkor Wat styles, and the construction process of the buildings and quarries of the sandstones was considered. Combined with the previous study on the sandstones of the Bayon style [Uchida, E., Cunin, O., Shimoda, I., Suda, C., Nakagawa, T., 2003. The construction process of the Angkor monuments elucidated by the magnetic susceptibility of sandstone, Archaeometry 45, 221–232], the magnetic susceptibility measurement revealed that there were 7 sandstone quarries corresponding to Stages I, II, III, IVa, V, VII and VIIIb during the Angkor period. The sandstones used for the monuments belonging to Stage I show average magnetic susceptibility values ranging from 1.1 to 2.3 × 10⁻³ SI units. In the Bakheng style period (Stage II), the average magnetic susceptibility of the supplied sandstones decreased gradually from around 10 to 1 × 10⁻³ SI units over time. The magnetic susceptibility range of the sandstones used for the monuments of Stage III was from 2.3 to 3.0 × 10⁻³ SI units. In the early Angkor Wat style period (IVb), the average magnetic susceptibility of the supplied sandstones increased over time, reflecting the supply of the sandstones from two different quarries, that is, the quarry corresponding to the Khleang and Baphuon style monuments (Stage IVa), with low average magnetic susceptibilities of 1.1 to 2.4 × 10⁻³ SI units, and the quarry corresponding to the main Angkor Wat style monuments (Stage V), with high average magnetic susceptibilities ranging from 2.8 to more than 4.3 × 10⁻³ SI units. The sandstones of Stage VII show low average magnetic susceptibility around 1 × 10⁻³ SI unit. The sandstones of Stage VId is a mixture of sandstones of Stages V and those of Stage VII. The sandstones with high magnetic susceptibilities are found in the monuments belonging to Stage VIIIb, reflecting the supply from the new sandstone quarry.     

Quarries and transportation routes of Angkor monument sandstone blocks

Sandstone blocks are the main construction materials used in the Angkor monuments in Cambodia. However, a thorough study of the quarries has not yet been carried out. We conducted a field investigation of sandstone quarries from the Angkor period at the southeastern foot of Mt. Kulen, which is approximately 35 km northeast of the Angkor monuments. As a result, we discovered more than 50 sandstone quarries. On the basis of the measurements of magnetic susceptibilities and thicknesses (step heights), we found that they were quarried at different times. These four quarrying areas were identified as the quarries D to G inferred by Uchida et al. (2007). In addition we investigated a canal that was identified on satellite images, connecting quarry sites at the foot of Mt. Kulen to the Angkor monuments. The field investigation suggests a high probability that the canal was used for the transportation of sandstone blocks from Mt. Kulen.     

A Reconsideration of the Construction Period of the Cruciform Terraces and the Elevated Causeways in the Angkor Monuments,Based on the Magnetic Susceptibility of the Sandstone Blocks*

In this paper, the construction period of the cruciform terraces with columns and the elevated causeways in the Angkor monuments of Cambodia is reconsidered, based on the results of our investigation of magnetic susceptibility and other characteristics of sandstone blocks. From an art‐historical point of view, they are generally considered as modifications in the post‐Bayon style period—the period during the reign of Jayavarman VIII (1243–95 ce ) or later. However, from a lithological point of view, the average magnetic susceptibilities of the sandstone blocks in the cruciform terraces with columns and the elevated causeways are consistent with the rest of the monument. In addition, the characteristics of the sandstone blocks in the cruciform terraces, such as their shape, the orientation of the bedding plane and the stacking method, suggest that they were constructed in the same period as the rest of the monument.     

PROVENANCE OF THE SANDSTONE USED IN THE CONSTRUCTION OF THE KHMER MONUMENTS IN THAILAND

We investigated the sandstone used in the construction of the Khmer monuments situated upon and around the Khorat Plateau in north‐east Thailand in order to clarify the provenance. The sandstones of the 22 investigated Khmer monuments can be classified into three groups. The sandstone of Group 1 is lithic and is derived mainly from the Khok Kruat Formation. This group includes the sandstone used at Phimai, Phnom Wan, Muang Khaek etc. The sandstone of Group 2 is siliceous and can be subdivided into three further groups. The sandstone of Group 2 is considered to have been derived from the Phu Phan, Phra Wihan or Sao Khua Formations. The sandstone used at Muang Tam, Phnom Rung, Sdok Kok Thom, Preah Vihear (Khao Phra Wihan), Narai Jaeng Waeng etc. belongs to Group 2. The sandstone of Group 3 is feldspathic and is correlated with the grey to yellowish‐brown sandstone that is commonly used in the Angkor monuments in Cambodia. This sandstone is used at Wat Phu and Hong Nang Sida in Laos. The above results reveal that the choice of sandstone used for the Khmer monuments, including the Angkor monuments, was dictated by the surrounding geology.     

STUDY ON THE PIGMENTS IN THE CRUCIFORM GALLERY OF ANGKOR WAT,CAMBODIA

In the cruciform gallery of Angkor Wat in Cambodia, red, orange, white and black pigments were widely painted on the surfaces of pillars, walls and friezes. The application sequence of the pigments is different from area to area. The following substances were confirmed from the pigments: hematite (laterite), minium, calcium oxalate hydrates (whewellite and weddellite), Pb–Cl compounds (cotunnite, laurionite and blixite), calcium phosphates (whitlockite), gypsum, hydrocerussite, calcite, anglesite, lead dioxide, azurite and carbon black. The orange pigment (minium) underlies the red pigment (hematite). The former may have been applied at the time of the foundation (the Angkor Wat style period), and the latter in the Bayon style period or later, but mainly before the early 17th century of the current era.     

Salt weathering of sandstone at the Angkor monuments,Cambodia: identification of the origins of salts using sulfur and strontium isotopes

The Angkor monuments in northwestern Cambodia, which are primarily made of sandstone, are suffering from deterioration due to salt weathering. In order to elucidate the sources of the salts and salt weathering process, this paper analyzed bulk chemical compositions and S (sulfur) and Sr (strontium) isotopic ratios for the salts and surrounding environmental materials. At places where bats inhabit the structures, various kinds of sulfate and phosphate salts are formed on the surface of the sandstone. The results of the analysis demonstrate that the S and P (phosphorus) components in the salts are primarily derived from bat guano. Moreover, Ca (calcium), which is the major element in the salts, is suggested to be derived from both bat guano and the sandstone. The isotopic data strongly suggests that bat guano is related to salt weathering. Removal of these animal excrements is essential for future conservation of these monuments. On the other hand, exfoliation of sandstone commonly occurs due to crystallization of calcite (CaCO₃) on platform surfaces of pyramid-type monuments. A large amount of Ca in calcite is suggested to be derived from calcite cement of the building sandstone.     

Bigberry Camp,Harbledown, Kent

Despite containing one of the largest stone and timber circles in Britain, the Late Neolithic monument complex at Stanton Drew, Somerset, has seen surprisingly little archaeological work. This paper presents the results of new fieldwork, which included excavation around a recently discovered recumbent stone, test-pitting on the floodplain of the River Chew and fieldwalking close to the monuments. The excavations revealed that the recumbent stone had been deliberately buried in the medieval period and also uncovered other archaeology of this date. The test-pitting exposed thick deposits of alluvium and from this it is argued that the landscape has changed dramatically since the monuments were constructed. The fieldwalking revealed a relatively low density of lithics which may indicate that activities around the monuments were carefully controlled. Also considered is the siting of the Stanton Drew monuments and their intimate relationship with the River Chew.     

Forty-Fourth Annual Congress,Liverpool, 1887

Abstract

The limestone quarried on Ham Hill near Yeovil in Somerset is very distinctive and readily identifiable. It was used extensively throughout the medieval period for a great variety of purposes. Whole buildings were constructed using it from floor to roof and it was also employed for decorative work and sculpture. A large group of church monuments was carved in Ham Hill stone, especially effigies and cross slabs. Monument production can be appreciated in the context of a much larger industry and analysis of the figures has revealed that the clients were predominantly the local gentry. Consequently, there are significantly more male civilian and female effigies than are typically found elsewhere, such as in Devon and Yorkshire. There is evidence of an awareness of the products from other stone centres in the south-west, which the carvers of Ham Hill stone were willing to imitate in order to satisfy customer requirements.     

Serpent Mound: Still Built by the Adena,and Still Rebuilt During the Fort Ancient Period

Radiocarbon dates from the base of Serpent Mound in Ohio demonstrate that it was built 2,100–2,300 years ago during the Adena period but was subsequently rebuilt or repaired about 900 years ago during the Fort Ancient period. We describe the basis for supporting the chronology of this building sequence, why it is the best and most complete explanation from the data at hand, and discuss the errors and misconceptions that critics of it have put forth. Our interest is in establishing a chronology of mound construction in order to address questions about cultural continuity/discontinuity, appropriation, and reuse of cultural monuments and religious/political symbols. We also plead that researchers jointly collect new data from Serpent Mound to end the back-and-forth questioning of chronological context and research competence.     

Recent Excavations at the Cluniac Priory of St. Mary,Thetford, Norfolk

RUMNEY CASTLE, a small ringwork historically part of the marcher lordship of Gwynll?g, was situated above a steep natural scarp overlooking the R. Rhymney. First mentioned in A.D. 1184–85, the castle guarded the W. boundary of the lordship and the river crossing. The defences consisted of a ditch and clay rampart constructed around three sides of the site. Initially incorporated into the defences along the fourth side was a large timber building and possibly a palisade. The entrance was originally defended by a large timber gate tower, later superseded by a smaller timber structure. Following this, the defences were strengthened with the widening of the rampart and the construction of a small tower or keep alongside the entrance. Several phases of timber building, including two large halls, were arranged around a courtyard. During a later period the entrance was relocated and a stone gate tower constructed.

During the second half of the 13th century the site was converted for use as a manorial centre. The rampart was levelled, the interior of the site infilled, and a range of buildings constructed along the edges of the mound. A well-sealed coin hoard of c. A.D. 1288–89 discovered in a destruction deposit provides a terminus post quem for the abandonment of the site.     

Palaeoenvironments, the archaeological record and cereal pollen detection at Clickimin, Shetland, Scotland

The Loch of Clickimin, Shetland, is well known for its broch and associated monuments supposedly of the Bronze and Iron Ages, although the former date is disputed. Pollen, diatom and sedimentological investigations permit fresh insights into the landscape and economic impacts of those who constructed the monuments, reveal that the environs of the site experienced environmental change from Neolithic times onward and provide the first Holocene radiocarbon dates from the immediate locality. The broch-building period witnessed a continuation of pre-existing pastoral husbandry for which heather burning may have exacerbated the natural spread of blanket peat. Initially, no evidence was adduced for local arable activity in the present investigation, and this was thought to be consistent possibly with the low numbers of excavated querns and the absence of cereal macrofossil finds when compared with other Shetland broch sites. The application of ‘rapid scanning’ techniques, however, led to the discovery of a consistent cereal-type pollen representation from Bronze Age times onwards. The discrepancies between the palaeoenvironmental evidence and the environmental and palaeoeconomic inferences made by the excavator of the site are explored. Evidence is presented that both supports and contradicts previous assumptions surrounding an important archaeological site.     

Moisture content measurement and surface water absorption test in the inner gallery of Bayon for the conservation of the bas-relief

The bas-relief carved on the sandstone wall in the central part of the inner gallery of Bayon in the Angkor monuments, Cambodia, has been severely damaged mainly due to calcite crystallization. In order to confirm the mechanism of salt weathering and help determine conservation measures for the bas-relief, measurements of the annual change in the moisture content in the bas-relief were conducted. We found that water supplied from the platform behind the bas-relief is the cause of calcite crystallization. It is therefore indispensable for the conservation of the bas-relief to prevent the water permeating from the inside of the platform behind it. As precipitated calcite from the water block pores near the surface of the sandstone, the surface water absorption test is a useful method to evaluate the degree of the salt weathering.     

Organizational principles of Khirigsuur monuments in the lower Egiin Gol valley,Mongolia

Khirigsuurs are the largest and most common archaeological monuments of the Mongolian Steppe in the Bronze Age and Early Iron Age, a critical time for the spread of nomadic pastoralism and the emergence of a new social order during the Bronze Age in Inner Asia. Using data from a full coverage regional survey of the Lower Egiin Gol valley, this paper presents a system for studying the defining ground level features of Khirigsuurs to discover structural categories, organize sites, compare Khirigsuur monuments across regions and explore activities that may have gone on around the Khirigsuurs themselves as they were built and used. The primary methods used are a study of monumental scale and a typology of additive parts from which complex and comparable types emerge. Elaborate Khirigsuurs illustrate the use of Khirigsuurs as small monuments, stages for group activities, and are the persistent backdrop for social transformations during the spread of nomadic pastoralism. I suggest that the Khirigsuurs of the Lower Egiin Gol are monuments constructed with relatively regular frequency, by a consistently sized group, and used for group oriented activities rather than the memorialization of an elite. This is consistent with something one might see as part of a regular yearly nomadic round.     

Differentiating Khmer Stoneware Production: An NAA pilot study from Siem Reap Province,Cambodia

We report analytical results for stoneware samples from four excavated Angkor‐period kilns in the Greater Angkor area. Previous work has suggested that establishing distinct chemical signatures for kiln complexes in this region is problematic. The current study highlights the effectiveness of neutron activation analysis (NAA) for differentiating the products of Angkorian kiln complexes; it also confirms the viability of a larger‐scale research programme to understand the relationship between Khmer stoneware production and patterns of distribution across the wider Angkorian territory. Evidence of ceramics excavated at kiln sites but produced elsewhere highlights the complexity of consumption patterns during the Angkorian period.     

Region, culture and society: understanding antiquity from the field

Approaches to the finds, monuments and settlements of past and present landscapes in different parts of Europe, and the contributions of their regional archaeological traditions, are briefly evaluated from a historical perspective. The point of departure is the work of the Dane, Ole Worm, in the early seventeenth century, on the whole of Denmark and Norway. Worm pioneered systematic large-scale topographical recording of monuments, and so provided data for the earliest archaeological distribution maps. Another Dane, N.F.S. Sehested, in the mid-eighteenth century, led the development of intensive small-scale regional studies. In conclusion, the methods of large scale active survey (e.g. in the Mediterranean) are reconsidered, and the particular role of Communist Eastern Europe in pioneering early large-scale excavation is emphasized.     

Urbanism and Residential Patterning in Angkor

The Khmer Empire (9th–15th centuries a.d.), centered on the Greater Angkor region, was the most extensive political entity in the history of mainland Southeast Asia. Stone temples constructed by Angkorian kings and elites were widely assumed to have been loci of ritual as well as habitation, though the latter has been poorly documented archaeologically. In this paper, we present the results of two field seasons of excavation at the temple site of Ta Prohm. Using LiDAR data to focus our excavations, we offer evidence for residential occupation within the temple enclosure from before the 11th century a.d. until the 14th century. A comparison with previous work exploring habitation areas within the Angkor Wat temple enclosure highlights similarities and differences between the two temples. We argue that temple habitation was a key component of the Angkorian urban system and that investigating this unique form of urbanism expands current comparative research on the diversity of ancient cities.     

TIMBER MONUMENTS,LANDSCAPE ANDTHE ENVIRONMENT IN THE NITH VALLEY,DUMFRIES AND GALLOWAY

This paper considers the impact of landscape and environment upon monuments built during the Neolithic period. Taking a group of timber monuments of Neolithic date in the Nith Valley region, Dumfries and Galloway, it examines their relationship to the topography and environment and seeks to explain their uniquely linear nature, a feature of timber monuments built in this region. It discusses the importance of incorporating plough‐levelled sites into landscape approaches to monuments, the potential impact of vegetation upon visibility patterns, and the value of considering the immediate locations of monuments, arguing that monuments built upon a heightened awareness of landscape topography, arising out of a long‐term relationship with place.     

Gravity-wave motions in the mesosphere and lower thermosphere observed at Mawson,Antarctica

We present the results of MF radar observations of mean winds and waves in the height range 78–108 km at Mawson (67°S, 63°E), Antarctica. The measurements were made in the period from 1984 to 1990. Climatologies of the prevailing zonal and meridional circulations made with a 12-day time resolution show that the mean circulation remained relatively stable over the 6 yr of observation. Climatologies of gravity-wave motions in the 1–24 h period range were also generated. These reveal that the r.m.s. amplitudes of horizontal wave motions near the mesopause (~90 km) are about 30 m s⁻¹, and that there is some anisotropy in the motions, especially at heights below 90 km. Meridional amplitudes are larger than zonal amplitudes, which suggests a preference for wave propagation in the north-south direction. Comparisons with MST radar wind observations made near the summer solstice at Poker Flat, Alaska (65°N) and at Andøya, Norway (69°N) show similarities with the Mawson observations, but the wave amplitudes and mean motions are larger in magnitude at the northern sites. This suggests hemispheric differences in wave activity that require further study.     

Conservation of the sacred at Angkor Wat: further reflections on living heritage

Abstract

This article reflects on and complements the paper 'Conservation of a “living heritage site”: a contradiction in terms? A case study of Angkor World Heritage Site', published by Keiko Miura Conservation and Management of Archaeological Sites, 7(1), (2005) 3–18. It develops further the notion of conserving sacred heritage in the light of a case study of Angkor Wat within the World Heritage site. Heritage management is always a balance between preserving different values – historic, aesthetic, use, spiritual, etc. Each of these categories of value has its own set of needs which are often not fully compatible with one another. Heritage management originally stemmed from the desire to protect the aesthetic and historic values of tangible heritage. Yet an over-emphasis on preserving these values alone is not tenable in a 'living heritage site'. At Angkor Wat it causes spiritual degradation and secularization. Highlighting instances in which this phenomenon has been apparent, this article suggests a way forward.