Soil marks are differences in
soil colour as a result of underlying archaeological
features. They can be seen when a
plough
A plough or ( US) plow (both pronounced ) is a farm tool for loosening or turning the soil before sowing seed or planting. Ploughs were traditionally drawn by oxen and horses but modern ploughs are drawn by tractors. A plough may have a wooden ...
ed-out
earthwork has left hard dry material of a former bank and damper wetter material from a former ditch. They can also occur when a feature has cut through the top soil to reveal underlying chalk. Soil marks typically become visible in ploughed or harrowed fields, usually where there are restricted periods before the crops grow.
Appearance
The most obvious and occurring trace of soil marks is a difference in color relative to the rest of soil. Depending on the local
geology
Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth ...
, the soil marks can show up as dark against a light background or vice versa. The color of the soil is very important in determining whether or not
organic or burnt deposits happened over the soil, producing a black or red colored soil. This allows
archaeologist
Archaeology or archeology is the study of human activity through the recovery and analysis of material culture. The archaeological record consists of Artifact (archaeology), artifacts, architecture, biofact (archaeology), biofacts or ecofacts, ...
s to understand the purpose of the
artefacts found in the vicinity of the soil mark and can indicate whether or not fire was used.
Occurrence
Archaeology that involves plough-damaged field systems,
burial mounds
A tumulus (: tumuli) is a mound of earth and stones raised over a grave or graves. Tumuli are also known as barrows, burial mounds, mounds, howes, or in Siberia and Central Asia as ''kurgans'', and may be found throughout much of the world. ...
,
Roman villa
A Roman villa was typically a farmhouse or country house in the territory of the Roman Republic and the Roman Empire, sometimes reaching extravagant proportions.
Nevertheless, the term "Roman villa" generally covers buildings with the common ...
s or former sites usually produce soil marks. The soil marks gives the archaeologists an idea of where the structures were built or where the soil was damaged and for what reason. For instance, indicating a dried-up river channel (known as a
palaeochannel), which may subsequently reveal rich waterlogged archaeological deposits in its lower layers, or an area of slightly higher ground above winter flood level on an
alluvial floodplain, which may be very hard to detect from the ground but which has attracted settlement for thousands of years.
See also
*
Crop mark
Notes
Methods in archaeology
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