• Before you can get planning permission for a road or new building, you must make sure there is no evidence on the site that will be lost forever. This is called rescue archaeology. Before the M3 motorway was built in Co. Meath, a total of 126 sites between Clonee and Kells were excavated.
• Sometimes archaeological sites are discovered purely by accident. For example, a farmer ploughing a field might find something and report it, leading to a full investigation of the site. That is exactly how the Ardagh Chalice (see page 41) was found!
Rescue archaeology in Co. Meath ahead of the construction of the M3 motorway How evidence is preserved
Evidence such as bodies and artefacts can be preserved for thousands of years if the conditions are right. As a general rule: when both air and moisture are present, things decay rapidly.
However, the extreme heat of deserts, for instance, dries out objects quickly and this can prevent decay, preserving them. When bodies are buried in airtight coffins or sealed tombs – or completely covered in volcanic ash, as occurred in Pompeii (see chapter 5) – the airless conditions can slow decay and preserve objects. European peat bogs preserve bodies extremely well, due to the combination of cold, acidic water and airlessness below the water level.
CHECKPOINT!
1. Define the term excavate in your own words. 2. Define the term aerial photograph in your own words. 3. List five ways that archaeologists find sites to excavate. 4. List three ways that evidence can be preserved.
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I can explain how archaeologists find sites to excavate and how evidence is preserved.
