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Date: | Mon, 3 Jul 2000 11:31:34 +1000 |
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>Hi
> Does anyone know of any articles that look at the movement of
>artifacts such as pieces of ceramics and bottle glass in a field that has
>been ploughed with modern farm equipment?
> The site dates to 1850-1890 and the adjoining field has some
>artifact clusters plus a few scattered pieces and l was wondering how much
>ploughing actually moves objects around.
Susan,
I know of no articles, but have had experience of the phenomena myself. In
paddocks in the Shepparton area, I have seen c1850 sites (abandoned for
more than 50 years) where material has been transported horizontally for up
to 150 metres. Three methods are apparent:-
1. stock trampling - items like whole bottles (generally modern) half or
smaller pieces of bricks and the like, are kicked around by stock and
rolled in the direction of the slope, or along stock paths. These tend to
be the longest travellers. Small and sharp artefacts can lodge in feet or
cling to hides, and be transported considerable distances, even between
paddocks.
2. movement across the plough line. - mouldboard ploughs expecially move
all artefacts (with the sod) between 20 and 60 centimetres with each pass
perpendicular to the direction of ploughing. Cumulative movement can be
calculated if you know the frequency and direction of ploughing. Some
ploughing techniques such as alternate lands where the plough runs one
direction then returns down the other side of the furrow, will move
artefacts away from a central line, but subsequent ploughing may reverse
this the next season - this is usually done to prevent uneven build up and
removal of soil from different parts of the paddock. However, slope can
effect the gross movement of soil in ploughing and you will often see a
cutting at the tip of a paddock and an embankment at the bottom.
3. movement in the direction of ploughing - the friction of the plough
through the soil (especially when ploughing down hill) tends to move the
artefacts in the direction of the plough. Again good farmers will reverse
direction to avoid unwanted soil transport. The type of soil has a major
effect here nd movement can be quite variable. I have returned to a
specific site before and after ploughing and noted individual artefacts
moved either not at all, or several metres in the same event. Artefacts
will also lodge on parts of the machinery to drop off somewhere else.
The overall effect of these different influences can result in a
distinctive pattern.
A difuse spread of certain artefacts types across the paddock
generally - including small ceramic/glass fragments, and rollable brick and
other pieces. Isolated concentrations may occur in areas where stock and
vehicle traffic is focussed, for example around trees, or at gates.
More concentrated speread of artefacts fanning out from the source
in the direction of travel of either stock or plough, tending to peter out
with distance. My experience is a 50 % reduction in density for every 3-4
metres from the point of origin.
Then of course there is the vertical transport of artefacts through the
soil - but this is a whole different kettle of fish.
If any one has alternative models, I like to hear the dialogue (preferably
on list)
Gary Vines
Melbourne's Living Museum of the West
P.O. BOX 60 Highpoint City, 3032
Victoria, Australia
ph. +61 3 93183544
fax. +61 3 93181039
email- [log in to unmask]
www.livingmuseum.org.au
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