Friday, June 23, 2006

Archaeology Paperwork

Even archaeologists have lots of forms to fill in. They are collecting information about the past, and it's more important than the treasures they find. So I have spent today measuring the distance from the sides of the trench to a baseline, so that we can make a plan of the trench. Then measure and plot the features of the trench, which for some reason are called 'contexts' in Britain, though not in Australia where our professional archaeologist comes from. We have to draw sections, too, which involves measuring down from a level line to draw pits, stone courses and the like.

Each hole, wall, or drain has to have a context form filled in, describing it in very close detail (texture and colour of earth, percentage of pebbles for example) with a separate form for the earth we dig out of it. Then out with the theodolite to get the depths of the features. Taking photographs of the cleaned surface comes before all this. After all this, we have finished with the carefully preserved features and we dig them up to see what's underneath, and therefore almost certainly older. 'Almost certainly' is the archaeologist's favourite phrase. The newspapers prefer 'Indiana Jones', 'Lara Croft' or even 'Tony Robinson'.

Post holes, properly called 'post pits' were the main dish today. To put up a simple structure, from ancient times to today, we dig a hole and put a post in the ground. Well, I say 'we' but I'm afraid that doesn't include me personally. Then we put something hardish round it, cement these days but formerly clay, and jump up and down on it if it's clay, so that the post stands up straight for a long time. Then put a corrugated iron or thatch roof on it. When the roof has rusted or rotted, and the posts have rotted away (if you have a fence you know how quickly that happens), the hole fills up with stuff which looks different from the surrounding earth, even when you have just excavated three feet of later ash and cobblestones from over the top. That's how we can find a post hole.

Dig away half of the discoloured patch to see a section of what the earth is like in the hole. There will be the loose earth on top which the hole digger levelled the soil with, or has fallen into the hole later. Under that the compacted clay that was used to hold up the post. If you are really lucky, there will be a round or square area of loose stuff at the bottom called the 'pipe' which represents the smaller hole where the post itself fitted in.

I hope I'm getting some of this right, guys! I'm back there again next Tuesday, unless they tell me to go away and never darken their robbed threshhold stone pit again. By then, the hard work of digging up a hard concrete-like surface should have been done by the weekend volunteers, and the students who put in lots of hard work between rollups. I did wonder why archaeologists seem more likely to smoke than avaerage, but I have realised that, being an outdoor occupation, it is likely to attract smokers.

No comments: