(p. 417) Survey and Excavation
Preservation of the archaeological evidence depends on a myriad of tightly interwoven cultural and environmental factors, and this all the more true in wetland contexts. Since the majority of archaeological artefacts found in wetland contexts are made of organic material, even though they might be perfectly preserved, their physical composition (mainly wood and plant remains) makes them difficult to be identified as they become an integrated part of the surrounding matrix (e.g. peat). Part 3 takes into account the various innovative techniques to detect waterlogged organic remains, as well as the various excavation techniques to retrieve them.
Weller and Bauerochse (Chapter 24) discuss recent advances in the detection of organic materials within peat deposits. As standard GPR (ground-penetrating radar) methods often fail to identify water-saturated wooden object in peatlands, they suggest the recently developed SIP (spectral induced polarization) technique, which is able to distinguish between the various organic materials (peat, wood, etc.) according to their electrical properties. The identification of organic materials becomes even more difficult if they are buried in underwater sediments (e.g. at the bottom of seas, lakes, or rivers). In this case Plets (Chapter 25) suggests acoustic techniques as a possible remedy to the problem, especially when dealing with shallow waters.
Once the archaeological remains are identified, archaeologist have to face the challenging reality as to whether the site should be excavated of preserved (see also Part 5). Brunning's paper (Chapter 26) is a great interface between the two activities, offering a few examples of cultural heritage strategies to avoid irreparable mistakes made as a result of too hastily taken decisions.
(p. 418) However, if excavation is unavoidable, Chapters 27 and 28 will assist us to choose the most appropriate methods, according to the various wetland/waterlogged archaeological contexts. Bell (Chapter 27), for instance, discusses intertidal excavations, pointing out all the logistical problems that may arise when narrow tidal windows limit the access and permanence on site. Doran (Chapter 28) shows the complexity of highly waterlogged sites.