plow zone?

[laracrofty]

Hello BAJR,

I'm an Archaeologist and Project Manager for a professional archaeology firm in the southeastern US. I was speaking with some of my workmates this morning about the differences between European/UK and American archaeological recording methods. I've had training in both, and I see that both methods are appropriate for different data sets.

In Europe/UK as far as I know most people use some flavour of Single Context Planning, which focuses on stratigraphic relationships (vertical). Our site investigations tend to deal more with horizontal artifact distribution rather than vertical stratigraphic relationships, as the latter are very often destroyed in advance of our investigation. Logging agriculture is very common in the southeastern US, and results in extremely deep ridges and furrows, and pretty much destroys any vertical stratigraphy. We often work in deep plow zones which we excavate in arbitrary 10 cm levels.

I know that plowing happened/s in the UK and Europe, so how do you address it in your recording? Is it generally treated like any other context or is it written off due to disturbance? How would you approach documenting a site with no discernible vertical stratigraphy?

Would very much appreciate any insight into this that anyone can offer.

Thanks!
Alys

[1man1desk]

Most ploughing in the UK is in the region of 300mm (about 1 foot) depth, although it does vary quite a lot. Deeper ploughing does occur, for instance where potatoes are to be grown, and in some cases the soil is 'improved' through the practice of 'subsoiling' - both of these practices are far more destructive than normal ploughing.

For much of our prehistory and history, the construction of settlements, burials, field systems and other features has included a substantial component of negative features (pits, ditches, etc) that are cut into subsoil. At least part of these features often survives ploughing, and most of our archaeological excavations in land that has been ploughed focuses on these sub-surface features. This does give us a strong bias in our evidence, but it also does give us something meaty to get our teeth into.

Although such sites often appear to be made up of individual, isolated features cut into natural subsoil, it is still possible to take an approach based on vertical stratigraphy, within the individual features (e.g. multiple fills of a ditch) and where the features intersect.

Methods vary according to specific project needs, but in most archaeological excavations in ploughed areas the ploughsoil is taken off by machine, and hand-excavation focuses solely on the sub-surface features. Under some circumstances, more attention may be paid to archaeology in the ploughsoil, but this is the exception rather than the rule.

It is often the case that archaeological sites that whose non-portable remains have been completely ploughed away will either not be recognised, or will be recorded as 'just another artefact scatter'. However, for certain periods of our prehistory (e.g. the Mesolithic) or in some other circumstances, we find ourselves in a situation similar to the one you describe in the US, and in those cases we focus more on what is to be found in the ploughsoil.

One way in which ploughsoil archaeology is taken more seriously here is through the practice of 'fieldwalking', i.e. the inspection of ploughed surfaces to identify artefact scatters. This practice is used principally as a method of prospecting for the possible presence of plough-truncated archaeological sites consisting of features cut into the subsoil, as outlined above.

I have personal experience of the sort of archaeology affected by forestry agriculture that you describe, albeit in Scotland rather than the south-eastern US. We found that it was possible to identify and excavate archaeological remains (prehistoric burial mounds in this case) with full attention to vertical stratigraphy, within the spaces between the forestry furrows (which were over 1m wide and up to 1m deep, separated by around 3-5m).


1man1desk

to let, fully furnished

[BAJR Host]

Thanks one man... that susinctly sums it all up.

"No job worth doing was ever done on time or under budget.."
Khufu

[Oxbeast]

Good post 1man.
The only thing that I would add is that in the UK, the ploughing can become the archaeology. Depending on the type of work that you're doing, recording the earthworks of Medieval and Post Medieval ploughing is now standard practice.

http://en.wikipedia.org/wiki/Ridge_and_furrow

The relationships of other landscape features to the ridge and furrow can be key in relative dating: i.e. is this feature on top of or under the R&F? Unfortunately, most of the earthworks of the Medieval period have been ploughed out in the last 50 years. I suspect that you might find ridge and furrow in the US in places like NH and VT, where farms were abandoned as the west was opened up for settlement.

[m300572]

Parts of Britain (mainy upland areas) have been deep ploughed for forestry at well - huge swathes of the Southern Uplands and Highlands of Scotland, bits of Datmoor for example. Where survey was doine in advance it invariably turned up archaeology but very little of it was actually systematically surveyed.

Anoer destructive ploughing practice in British farming is de-stoning where the top 300mm of soil is passed through a seive to remove stones - mainly for growing root crpos where stones mar the perfection of the supermarket carrot - but the bulk of the stones is removed so the next ploughing goes a little deeper into the undisturbed sub plough layer.

Added to this every hectare of field loses a few tonnes of soil with the roots at harvest - again leading to deper penetration o the plough into undisturbed layers.

[laracrofty]

quote:Originally posted by m300572

Parts of Britain (mainy upland areas) have been deep ploughed for forestry at well - huge swathes of the Southern Uplands and Highlands of Scotland, bits of Datmoor for example. Where survey was doine in advance it invariably turned up archaeology but very little of it was actually systematically surveyed.

Anoer destructive ploughing practice in British farming is de-stoning where the top 300mm of soil is passed through a seive to remove stones - mainly for growing root crpos where stones mar the perfection of the supermarket carrot - but the bulk of the stones is removed so the next ploughing goes a little deeper into the undisturbed sub plough layer.

Added to this every hectare of field loses a few tonnes of soil with the roots at harvest - again leading to deper penetration o the plough into undisturbed layers.

Thanks for the comment. I hadn't heard of the sieving practise before. Unfortunately in the case of most early Historic occupations, the stratigraphy just isn't substantial enough to survive the disturbance by logging. It's taken me a while, actually, to get used to the differences in methodology because I was initially trained to use stratigraphy as my first point of information. At a lot of the sites I work on, there simply isn't any. This leads to the presence or not of artifacts being much more heavily weighted than I was originally comfortable with. One of the first things you learn as a student is that context is essential, but we don't have that level of resolution very often, so we have to go with horizontal artifact distribution. We get that by doing very close interval shovel tests (5m sometimes), and recording the artifacts.

I was uncomfortable with this for a long time, until I learned what you can do with distribution maps. I think in the year and a half I have been working in South Carolina I've worked on one site with actual stratigraphy. Occasionally we get sites with features that extend into the subsoil, but even that is rare. So it just requires a totally different approach. I'm going to be back in England for the summer though, on an anglo-saxon site, and it'll be so nice to be able to use a trowel again I can't wait

[BAJR Host]

a whs trowel I hope

As a matter of interest... do you think we (in the UK) are missing something by not looking closer at topsoil distribution.

"No job worth doing was ever done on time or under budget.."
Khufu

[Windbag]

Although I'm no geoarchaeologist, I suppose that the longer and more continuous agricultural exploitation of the land in parts of the UK compared to the US might, on average, have led to thicker topsoil and subsoil layers forming. I'm perfectly happy to stand corrected on that one though.

[laracrofty]

I have a WHS trowel, actually two. I've broken several marshaltowns on bricks and whatnot, but the WHS ones seem to last forever

I don't think it's a matter of missing things. I definitely default to the usual method of doing desk based research on the area, followed by fieldwork in light of the results of the desk based inquiry. I think in South Carolina the physical attributes we're working with have so often been compromised and placed in secondary contexts that we don't have other options. In cases where you have little or no history documentation, or you're dealing with ephemeral things such as short term native american settlements (manifesting as a few pot sherds and nothing else), then I think the close interval shovel test data can be really useful.

My workmate who is collaborating with me on my current project has been slowly winning me over in terms of the value of such data. When I was actually in the field doing the work I felt a little mercenary, but when my workmate showed me how to manipulate the data we'd gathered I was surprised at what was visible. You could see houses, outbuildings, different activity areas, different site phases. Those things were of course completely invisible when you were standing on the site itself. I'm certainly wary of turning any site into swiss cheese, as it were, but if you have a high level of disturbance I think it's a reasonable alternative. If I had to chose between the two obviously it's better/more fun to have intact stratigraphy to look at, but in a pinch this method works better than I'd originally thought it would.

[Dirty Dave Lincoln]

Hosty,when you say about looking at topsoil distribution I take it you mean about finds within it-either on the surface or throughout? i've known a few PO's who would prefer no finds were recovered from the topsoil once it has been machined out to the side of the trench,usually on the grounds that "they could have come from anywhere" which I find rediculous.Example: Trench 1 is opened and the topsoil is numbered 100 then any finds haven't come from "anywhere" but from the area of that trench and as such then locates them within the field.
Besides,refusing to pick up finds from the topsoil and you can often lose some of the best finds from the site.
Or am I just greedy in wanting to pick up everything? (it's mine,my precious!)