Archaeological excavation
In archaeology, excavation is the exposure, processing and recording of archaeological remains.[1] An excavation site or "dig" is the area being studied. These locations range from one to several areas at a time during a project and can be conducted over a few weeks to several years.
Excavation involves the recovery of several types of data from a site. This data includes artifacts (portable objects made or modified by humans), features (non-portable modifications to the site itself such as post molds, burials, and hearths), ecofacts (evidence of human activity through organic remains such as animal bones, pollen, or charcoal), and archaeological context (relationships among the other types of data).[2][3][4][5]
Before excavating, the presence or absence of archaeological remains can often be suggested by, non-intrusive remote sensing, such as ground-penetrating radar.[6] Basic information about the development of the site may be drawn from this work, but to understand finer details of a site, excavation via augering can be used.
During excavation, archaeologists often use stratigraphic excavation to remove phases of the site one layer at a time. This keeps the timeline of the material remains consistent with one another.[7] This is done usually though mechanical means where artifacts can be spot dated and the soil processed through methods such as mechanical sieving or water flotation. Afterwards, digital methods are then used record the excavation process and its results. Ideally, data from the excavation should suffice to reconstruct the site completely in three-dimensional space.
History[edit]
The first instance of archaeological excavation took place in the sixth century BC when Nabonidus, the king of Babylon, excavated a temple floor that was thousands of years old.[8] During early Roman periods, Julius Caesar's men looted bronze artifacts, and by the medieval period, Europeans had begun digging up pots that had partially emerged from erosion, and weapons that had turned up on farmlands.[8] Antiquarians excavated burial mounds in North America and North-West Europe, which sometimes involved destroying artifacts and their context, losing information about subjects from the past. Meticulous and methodical archaeological excavation took over from antiquarian barrow-digging around the early to mid-nineteenth century and is still being perfected today.[9][8]
The most dramatic change that occurred over time is the amount of recording and care taken to ensure preservation of artifacts and features. In the past, archaeological excavation involved random digging to unearth artifacts. Exact locations of artifacts were not recorded, and measurements were not taken. Modern archaeological excavation has evolved to include removal of thin layers of sediment sequentially and recording of measurements about artifacts' locations in a site.
Concepts[edit]
Site formation[edit]
Archaeological material tends to accumulate in events. A gardener swept a pile of soil into a corner, laid a gravel path or planted a bush in a hole. A builder built a wall and back-filled the trench. Years later, someone built a pigsty onto it and drained the pigsty into the nettle patch. Later still, the original wall blew over and so on. Each event, which may have taken a short or long time to accomplish, leaves a context. This layer cake of events is often referred to as the archaeological sequence or record. It is by analysis of this sequence or record that excavation is intended to permit interpretation, which should lead to discussion and understanding.
The prominent processual archaeologist Lewis Binford highlighted the fact that the archaeological evidence left at a site may not be entirely indicative of the historical events that actually took place there. Using an ethnoarchaeological comparison, he looked at how hunters amongst the Nunamiut Iñupiat of north central Alaska spent a great deal of time in a certain area simply waiting for prey to arrive there, and that during this period, they undertook other tasks to pass the time, such as the carving of various objects, including a wooden mould for a mask, a horn spoon and an ivory needle, as well as repairing a skin pouch and a pair of caribou skin socks. Binford notes that all of these activities would have left evidence in the archaeological record, but that none of them would provide evidence for the primary reason that the hunters were in the area; to wait for prey. As he remarked, waiting for animals to hunt "represented 24% of the total man-hours of activity recorded; yet there is no recognisable archaeological consequences of this behaviour. No tools left on the site were used, and there were no immediate material "byproducts" of the "primary" activity. All of the other activities conducted at the site were essentially boredom reducers."[12]