3.4 Post Excavation Analysis

Throughout the excavation of a site, numerous samples will be taken. The number of these will vary depending on the goal of the excavation, as well as how much time and money is available. Ultimately though, each excavation will likely finish with a collection of:

• Archaeological finds, attributed to a specific context
• Soil samples taken from a specific feature and context
• Materials or samples set aside for dating methods

The latter of these will be discussed properly in Module 5. Archaeological Science, but post excavation analysis of finds and soil samples will be described below.

Finds are perhaps what people attribute most with archaeology. Pottery, bone, tools, jewellery. All of these are kinds of archaeological finds, excavated or discovered and preserved in order to understand, and share, the past. Finds are usually excavated on site and can originate in a number of different ways. In situ finds are considered to be intended to be there, this includes burials and refuse. A find is excavated in situ if it does not appear to have been disturbed in the time since it was deposited. A cemetery offers the best example of in situ finds – as all (or almost all) of the remains and grave goods placed there were done so deliberately. Secondary depositions refers to finds that were moved from their original location or placed without as much intentionality as in situ deposits. Admittedly the difference can be quite murky and up to interpretation. For example, if an iron age farmer throws a cattle bone over their shoulder and into a ditch after eating it is that a secondary deposit or in situ? It was hardly intentionally placed, but we also can’t make any particularly profound claims about it.

As you may have figured out by now, a lot of archaeology is murky and up for interpretation. It is due to this that we gain as much solid information as we can at every opportunity. Even with careful excavation, impeccable recording, and clear stratigraphy, we can only learn so much from a site. We may be able to tell from the kinds of ditches we excavate that a site was iron age – round houses and enclosure ditches are pretty compelling evidence – but that does not necessarily demonstrate how long a site was occupied for, the kinds of people who lived there, or how they engaged with the world around them. Finds can begin to fill these gaps. The first step after collecting finds, and making sure they remain associated with their features and context numbers, is cleaning them. This is a long, careful process, and the archaeologists have the honour of being the first people to have properly seen these finds in tens, hundreds, or thousands of years. It does not matter if you are cleaning a cow’s femur, a golden earring, or an ancient board game piece – every single find is valuable and telling about past society. Once cleaned, finds are sent to typological or material specialists, who can begin to unravel the story they tell. For example, an expert in iron age pottery can identify the likely purpose of different vessels, and may be able to explain which contexts were associated with what activity. Meanwhile, a zooarchaeologist may be able to uncover what animals were present at the site – did they keep many pigs, did they have pet dogs? All of these aspects are inaccessible without the archaeological finds to back them up, and enormous amounts of information would be lost without careful excavation and good record keeping.

Soil samples are taken throughout the excavation, usually targeting contexts and features of particular archaeological interest or uncertainty. There are numerous different types of soil samples such as bulk samples, core samples, and thin section samples. Of these, bulk samples are the most general purpose and will be discussed here. They are ideally collected during the excavation of a specific feature so that nothing can be introduced into the sample from outside - which could throw off analysis. The samples are usually around 20 cubic cm and ideally from a single context - often the lowest context in a features stratigraphy so that the oldest part of the feature is targeted. The samples, rather exciting, look like a box of soil. That’s because they are a box of soil. It’s how we use these samples that makes them so valuable.

One of the most common methods to use with bulk samples is flotation, where the soil is soaked and gently broken apart by stirring, before being poured through a set of sieves and gauzes. By carefully pouring off the water, anything from the soil that floats can be collected, dried, and analysed. Also, the sieve can catch tiny finds that may have escaped an excavator on site - countless gold beads will have been lost over the years thanks to a combination of factors like bad weather, lighting, and exhausted archaeologists who want to go home. Sieving soil samples gives us an extra chance to find any, admittedly uncommon, lost finds. The main materials that float from soil samples are ecofacts. Archaeobotanists can analyse these to gain an understanding of the natural and managed landscape around a site. For example, if every context sampled produces carbonised domestic barley grains it is extremely likely that barley was both cultivated and consumed at the site. Ecofacts are extremely valuable windows into the past, and careful post excavation allows us to understand sites in a way that would otherwise be impossible.

At an even deeper level, archaeological specialists called palynologists can use microscopes on specially prepared soil samples to investigate pollen at archaeological sites. This is enormously important, and can both directly reveal the floral makeup of a site and be used in broad statistical analysis to consider how a site changed over the years - with variation in pollen often mirroring climatic or cultural practices.

The archaeological process is not concluded with the post-excavation stage, but it is the end of the direct chain of events surrounding a site excavation. Over the course of this process we survey and prospect into a site, then excavate it to reveal the archaeology, then conduct further analysis on what we discover. Following this, even more analysis and interpretation can be conducted - often lasting years. The core of the excavation process, however, has been explained over the course of this module.