Archaeological materials deterioration

Further to monitoring the environment itself, modem materials placed on a site can serve as analogues to the types of archaeological material found. In this way their deterioration can be regularly monitored in order to better understand the processes. Furthermore, these materials serve as a proxy indicator of the environment, and can potentially serve as a warning should the environment... 

In situ preservation is a form of preventive conservation, but absolute preservation in situ is not achievable. All sites are dynamic and deterioration of archaeological materials will continue, albeit at slow, and often imperceptible rates. However, environmental conditions favourable to the preservation of archaeological sites, and artefacts, can be assured by a three pronged sequence of environmental monitoring, study of the deterioration of analogous modern materials placed on a site, and the state of preservation of artefacts themselves. 

A rchaeological excavations at pre-Columbian sites have yielded espe-cially rich collections of textile artifacts. These materials often reveal information of considerable anthropological and art historical significance. The difficulties of restoration, maintenance, and exhibition for archaeological textiles are well known to conservators and art historians (1). These materials are frequently recovered in a severe state of deterioration ranging from dangerous embrittlement to extreme friability. The... 

This chapter is an overview of the wide variety of archaeological studies conducted by chemists. From the earliest stone artifacts to the artistic manuscripts and textiles of the more recent past, the studies presented in this volume show the wide range of materials that have been studied by chemical techniques. The field keeps expanding as chemists help provide information valuable in the interpretation of archaeological sites and artifacts. Besides helping to detect fraudulent artifacts and artistic objects in museum collections, chemists have studied the physicochemical deterioration processes that destroy the monuments and objects of the past. Thus, the role of chemists is more than just discovery of the past it includes investigation that may help preserve the artifacts for future generations to enjoy and study. 

Whereas ceramics are polycrystalline materials, consisting of several phases (discrete chemical compounds), glass consists of a three-dimensional network with short-range order. For both, deterioration can occur early due to daily use or much later during exposure in museums, or due to aggressive soil environments for archaeological objects or due to weathering of architectural elements. 

Surely a few thought about the material, the wood, now archaeological wood about the physical and chemical state of the wood and the task of conserving this waterlogged wood about how the unique burial environment, through some fluke, allowed this wood to evade the natural cycle of deterioration for 333 years and about the secrets hidden in the wood, such as information about its age and the environment in which it lived, secrets revealed in its unique growth patterns. 

I am sure that the most overpowering emotions stemmed from the feeling that this ship is a link to human society of a different century. Attractive as the social aspect is, the topic of this book is wood, archaeological wood. We see the Wasa as a heritage and research object, as a cultural and environmental informant. More basically, it is deteriorated material that we have retrieved from a specific environment. The ship must now be preserved in the new environment in which we have placed it. 

Over the years attitudes toward objects or finds have changed. In the past, archaeological excavations were done for looting and for curiosity. Today such projects are undertaken with scientific discipline to obtain accurate information about human material culture and interrelationship with the environment. Sophisticated scientific techniques are used to extract this information, and legislation is in place to protect archaeological sites and objects. Conservation is now a standard procedure to prevent the object s deterioration after excavation and potentially to preserve it for posterity. 

Some dry archaeological wood may be riddled by insect activity and require consolidation. Hillman and Florian (24) have described a sandwich type of deterioration of boards of a bentwood box. The boards are virtually a sandwich of paper-thin outer surfaces between which the wood is completely riddled with lyctid beetle galleries and tunnels filled with frass. This porous material is easily, consolidated. 

Analytical investigations also focus on new ways of protecting susceptible materials that have not yet shown signs of degradation. The continued efforts to replicate archaeological artifacts and antiques and subject them to accelerated deterioration experiments provide useful results in the development of new treatments. Much can be learned from understanding how compositions deteriorate due to their inherent incompatibility or instability to external agents. 

Concrete and stone are the most widely used materials in construction and infrastructures. Biodeterioration of these materials has important economic consequences, especially when replacement or repair of infrastructures such as bridges or municipal sewer systems is involved (Biczok 1968 Diercks et al. 1991 Ford 1993 Mansfeld et al. 1990 Sand and Bock 1984 Sand etal. 1983,1987,1991 Yao and Li 1995). In addition, biodeterioration plays an important role in deterioration of stone in historic buildings, monuments, and archaeological sites (Arino et al. 1997 Bianchi et al. 1980 Bock et al. 1989 ... 

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