If the ground water is used up then the bog becomes dependant upon precipitation. Since sphagnum moss cells can store water, the water table of the bog can rise above surrounding ground-water table. Living raised bogs can spread rapidly under the right circumstances. Bog peat typically contains abundant micro and macro-scopic fossils and pollen and provides the raw data for regional palaeoecological studies.
Introduction[ edit ] Excavation initially involves the removal of any topsoil overburden by machine. This material may be examined by metal detector for stray finds but unless the site has remained untouched since its abandonment there is invariably a layer of modern material on the surface of limited archaeological interest.
In rural areas, any features are often visible beneath the surface as opposed to urban areas where there may be thick layers of human deposits and only the uppermost contexts will be initially visible and definable through isolation from other contexts. A strategy for sampling the contexts and features is formulated which may involve total excavation of each feature or only portions.
It is preferred goal of excavation to remove all archaeological deposits and features in the reverse order they were created and construct a Harris matrix as a chronological record or "sequence" of the site.
This Harris matrix is used for interpretation and combining contexts into ever larger units of understanding. This stratigraphic removal of the site is crucial for understanding the chronology of events on site. It is perhaps easier to think of this as "archaeological deposits should leave the site in the reverse order they arrived".
A grid is usually set up, dividing the site into 5 m squares to better aid the positioning of the features and contexts on the overall site plan.
This grid is usually tied into a national geomatic database such as the Ordnance Survey in the UK. In urban archaeology this grid becomes invaluable for implementing single context recording. Single context recording system[ edit ] Single context recording was developed in the s by the museum of London as well as earlier in Winchester and York and has become the de facto recording system in many parts of the world and is especially suited to the complexities of deep urban archaeology and the process of Stratification.
Depending on time constraints and importance contexts may also be photographed, but in this case a grouping of contexts and their associations are the purpose of the photography. Finds from each context are bagged and labeled with their context number and site code for later cross reference work carried out post-excavation.
The height above sea level of pertinent points on a context, such as the top and bottom of a wall are taken and added to plans sections and context sheets. Heights are recorded with a dumpy level or total station by relation to the site temporary benchmark abbr.
Samples of deposits from contexts are sometimes also taken, for later environmental analysis or for scientific dating. Stratigraphic excavation in practice[ edit ] Slumped top fill revealing edges of a Saxon sunken featured building Best practice of stratigraphic excavation in its basic sense involves a cyclical process of cleaning or "troweling back" the surface of the site and isolating contexts and edges which are definable in their entirety or part as either Discrete discernible "edges" that form an enclosed area completely visible in plan and therefore stratigraphically later than the surrounding surface or Discrete, discernible "edges" that are formed by being completely separated from the surrounding surface as in 1 and have boundaries dictated by the limit of excavation.
Following this preliminary process of defining the context, the context is then assessed in relation to the wider understanding of the site, for considerations of reduction of the site in phases, and then removed and recorded by various methods.
Often, owing to practical considerations or error, the process of defining the edges of contexts is not followed and contexts are removed out of sequence and un-stratigraphically.
This is called "digging out of phase". It is not good practice.
After removing a context or if practical a set of contexts such as the case would be for features, the "isolate and dig" procedure is repeated until no man made remains are left on site and the site is reduced to natural. Physical methodology of excavation[ edit ] The process of excavation is achieved in many ways depending on the nature of the deposits to be removed and time constraints.
In the main, deposits are lifted by trowel and mattock and shovelled or carried from the site by wheel barrow and bucket. The use of many other tools including fine trowels such as the plaster's leaf trowel and brushes of various grades are used on delicate items such as human bone and decayed timber.
When removing material from the archaeological record some basic guidelines are often observed. Work from the known to the unknown.
This means that, if one is unsure of the stratigraphic boundaries of the material in question, the removal of material should start from an area where the sequence is better understood rather than less.
Work from the top to the bottom. As well as working from the known to the unknown, also as far as possible, remove material at the physically highest level in the context and work towards the lowest.
This is best practice because loose spoil will not then fall onto and contaminate the surface being worked on. In this way blurring detail that might have been instructive to the excavator is avoided.
In archaeology, we use our eyes. Excavation of contexts correctly often relies on detailed observations of minute differences. If in doubt, bash it out. This rather cavalier-sounding maxim is a concise way of expressing the need to progress. There is always more to be done on a site, than there is time in which to do it.
At times the next feature or context to be removed in the sequence is not clear even to an experienced archaeologist. When it is not possible to proceed in an ideal manner, the excavation must be continued in a more arbitrary way, with temporary sections, until discernible stratigraphy is again encountered.
An area of the site is reduced leaving arbitrary, temporary sections as a form of stratigraphic control to provide early warning of "digging out of phase". If the arbitrary area for excavation is wisely chosen, the sequence should be revealed and excavation can return to a truly stratigraphic method.- Archaeology is a continuously evolving field where there is a constant stream of new branches and excavation methods.
Due to the influx of new technologies and innovations in recent decades, archaeologists have been able to excavate previously inaccessible areas. Database of FREE Archaeology essays - We have thousands of free essays across a wide range of subject areas.
Sample Archaeology essays! In this essay, I have chosen to analyse human osteology in forensic and archaeological studies, covering certain techniques and methods which are involved and also going through different time scales in which explains how forensics and archaeology itself has rapidly progressed over the period of time.
Archaeology Essays – Archaeological Excavation Can archeological digging of sites non under immediate menace of development or eroding be justified morally?
Explore the pros and cons of research (as opposed to deliver and salve) digging and non-destructive archeological research methods utilizing specific illustrations. Archaeology Essays – Archaeological Excavation Can archeological digging of sites non under immediate menace of development or eroding be justified morally?
Explore the pros and cons of research (as opposed to deliver and salve) digging and non-destructive archeological research methods utilizing specific illustrations.
Archaeology is the scientific study of past human culture and behavior from the origins of humans to the present. Archaeology studies past human behavior through the examination of material remains of previous human societies/5(15).