Excavation methods
Excavation in Area H in 2007. B. Wells.
Archaeological excavation remains the main method of exploration of the Sanctuary of Poseidon. Excavation produces the data that can be further analyzed using the kind of methods described below. The method of excavation, however, is not always the same. Different methods or strategies are applied depending for instance on the goal of the investigation in a particular trench, or on previous knowledge of the stratigraphy in the area to be excavated.
Part of the graphical documentation of the stratigraphy in Area D1a in 2004. E. Savini.
Until 2005 we mainly investigated buildings already excavated in 1894. Relatively small trenches were therefore opened up in areas, which had been left untouched by the previous excavators, or where the sequence of architectural features seemed unclear. As the 1894 excavation had focused on uncovering the foundations of the buildings, results were reached especially in the interiors of the same buildings, where the dirt floors were found largely untouched.
Since 2007 we work in areas where no previous excavation has taken place as far as we know. Our aim is to investigate architectural structures or buildings detected in geophysical surveys in 2004 and 2006. The strategy now is to uncover as much as possible of the buildings before excavating to any particular depth. Archaeological excavation as such is a destructive method of investigation, and should–according to our philosophy–only be conducted in areas where the best possible results can be expected. Where to excavate to a greater depth is easier to decide once we know the extent of a building or a structure and may be able to have educated guesses of its function.
Section of Archaic cistern. E. Savini.The excavation is conducted stratum by stratum. A stratum can be defined as a deposition of dirt or soil created by nature (such as landslide or erosion) or by man (such as terrace fill or a dirt floor) at a certain point in time. Some strata were created at one instance (for example a terrace fill); others have accumulated over time as a result of human activity at the site. Artifacts and other remains found in a stratum help us date and define the activities at the site. Documenting where artifacts are found is therefore essential in our excavation as in any excavation.
Strata can be extensive and are therefore not suitable as the basic documentation unit. They are therefore divided in smaller units, which we have chosen to call Blocks. The Blocks are oriented north to south in accordance with a matrix or master grid of the whole site, and vary in size according to the type of stratum they are part of. The surface and bottom of every Block is measured with a total station in order to enable us to create three-dimensional representations of them.
Vertical photography in Area H. B. Wells.
In some cases vertical photography is used to document a Block. The photographs, taken either manually or by using a huge tripod, add texture to the surface of the Blocks thus enhancing the amount of the information. A number of reference marks visible in the photographs are measured with the total station. Then the images are processed in a GIS environment in the computer where they are rectified and placed in their right position. Our final goal is to be able to create a three-dimensional representation of any cultural layers removed from the site and thus ensure that as little as possible of the information gets lost.
The Blocks are also the basic units in a geographical data base, where all information on the character of the soil, the particulars of the artifacts as well as the nature of the organic remains is collected. Geographical Information Systems, and in particular the software package ArcGIS, is used as a tool for data management, mapping, analysis and display of the spatial information.
AP
