North Duffield Conservation and Local History Society

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Formation of Group

Following the discovery of a piece of Roman pottery in a residents garden , a request was made to the Rural Archaeologist, Linda Smith, at North Yorkshire County Council, Northallerton, for the cropmark transitions for the village and surrounding areas..

Cropmarks,  are indications in the pattern of crop-growth or  colour. If there is a structure underneath the soil and invisible on the surface, it will cause a depletion of nutrients and lack of moisture causing the crops to be stunted. If there is a dyke or ditch underneath the surface, over millennia it will have filled with vegetable matter that retains moisture and  is nutrient-rich making the crop grow higher. The natural soil will encourage a crop growth in the mid-range. The varying crop heights will be visible in aerial photography as a 3D snapshot of what is invisible to the naked eye. Particularly, in dry weather, crops over structures may be lighter in colour and darker over ditches. There may also be indications known as 'soil marks' in particularly dry weather, again likely to be lighter over structures.(See image 'Cropmarks' in Archive)

The brown lines on the image are the cropmarks. The ones to the North of village include what appear to be Iron Age roundhouse bases, boundaries and ancient field-systems. The hatched areas are fields where  tell-tale ridge-and-furrow indicates early Medieval ploughing practices. Processes were put in place to begin an evaluation of the cropmarks and advice sought on interpretation of those cropmarks.

Not long after this evaluation commenced, AND was approached by Dr Mark Whyman of York Archaeological Trust(YAT) who had identified North Duffield as an ideal place to investigate why cropmarks appear on one soil-type but seldom, if ever on two other types of the ' Twenty Five Foot Drift', all of which were present over a small area East of North Duffield. The Twenty Five Foot Drift is an area laid down at the end of the last great ice age 12,000 years ago  when the Vale of York was inundated by meltwater laden with sediments unable to escape into the sea due to glaciers and landmasses surrounding the Vale.  A huge lake was formed called in modern times, Lake Humber and a thick layer of silt and sediment was formed that makes the Vale such a fertile place to this day. In addition, the Lower Derwent valley has been a seasonally inundated flood-plain for millennia bringing further sediments from the North York Moors. North Duffield sits on the Western edge of the Lower Derwent Valley and North Duffield Ings and Carrs are a National Nature Reserve due to their importance for biodiversity and an extremely rare resource.

The soil-types referred to are: sands and gravels, clays and silts and alluvium.

Cropmarks frequently appear on the former but seldom, if ever, on the other two. Why is that? Are there no features to be shown or are there features there but those two soil-types do not promote cropmarks? These are questions we hope to answer.

It was decided to form AND as a separate group within the History and Conservation Society and so a logo was devised and a Contact List of interested people was created. Dr's Mark Whyman and Jon Kenny of YAT visited the village hall in 2009 and addressed a meeting of AND when the proposed archaeological investigation was outlined.

As a result, a programme of field-walking was commenced to collate information of possible archaeological sites and a geophysical survey of the village green, using a Resistivity meter, following a training session, to try to understand a 'lump' on the green. This revealed some unusual features which were scheduled for investigation. (For Resistivity Record see Resources).