Field and Desk Archaeology

Classification of Neolithic and Bronze Age Monuments

In order to use Geometry for Classification, we need to have very accurate plans or the ability to view Archaeology from directly above. In recent years, we can use Lidar Flyovers and Google Earth for this. This gives us a great advantage over previous generations of Archaeologists. At the same time, mathematical algorithms became generally available, which allow us to model Best Fit Lines, Circles and Ellipses. Exactly what we need for the study of Neolithic Geometry. It should be noted that there are many Classes of monuments where Geometry is no help, so these are outside of the scope of my work.

By using NRest, we are now in a position to study geometric forms with more clarity and accuracy than in the past. Sites should be assumed to be multi-period from the start and we should only attempt to deal with one period at a time. Sometimes the site will have been modified from an earlier design and sometimes they will be new-builds of a particular design. It is time to revisit Classification and put it on a sounder footing. If we can sensibly identify distinct variants and sub-variants, then it can only be helpful to any analyses. It will soon become clear that this work is neither comprehensive nor set in stone. It is and always will be, work in progress.

Current Geometric Classes

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  Circle - e.g. Stone Circle, Ring Cairn...

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  Flattened Circle - circle with one flattened segment on the perimeter

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  Ellipse - anything oval or even sub-oval, from the Latin ovum (egg), but not Egg-shaped.

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  Egg-shaped - true egg shape (Alexander Thom)
  
  

  Compound Ring - all other unclassifiable rings (Alexander Thom)

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  Class 1 Henge - circular bank with 1 entrance

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  Class 2 Henge - circular or irregular oval bank with 2 entrances

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• Class 3 Henge - circular bank with 4 diametrically opposed entrances
  
  

  Avebury Henge in its current form is no longer a Class 3 Henge (see below), but lies on the footprint of a Class 3 Henge as shown in this mock-up. 3 of the 4 Class 3 entrances are still in the correct position. The current fourth Northern entrance is slightly off true, but is in a modified section. Almost half of the Class 3 Henge circle is unmodified.

Revised Geometric Classes

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• Tri Flattened Circle - circle with 3 adjacent flattened segments on the perimeter. Moel Ty Uchaf was described by Aubrey Burl, The Stone Circles of Britain, Ireland and Brittany, Yale 2000, The Shape of the Ring, page 49 thus:
  

  It is as likely that they were the result of haphazard construction as of nice mathematics. The latter argument is supported by the shape of Moel ty Uchaf cairn in Merioneth in which the ring of touching kerbstones has flattened arcs at north-west, north-east and south-east.

  There is nothing haphazard - the intersections of the arcs lie on the Primary circle.

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  Ellipse - must be mathematical Ellipse. This can be assessed in NRest.

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  Egg-shaped - Alexander Thom lists 10, but some like Cairnpapple are not. Others are open to different interpretations. Burgh Hill is the alternative name for Allan Water - modelled as a Truncated Ellipse here. Not particularly coherent as a class.

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  Flattened Ellipses - I had put Flattened Ellipses down to later Iron Age modifications. However there does seem to be a pattern for Cumbrian Ellipses. The Flattening is aligned with the short axis.

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  Extended Ellipses - Park Beck is an example where the Ellipse has been Extended on the short axis to accentuate the Summer Solstice sunrise.

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  Truncated Ellipses - there is a growing body of evidence which suggests that Ellipses truncated on long axis may form a distinct class.

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  Class 2 Henge - now a strictly circular bank with 2 diametrically opposed entrances. This ties in with the other circular Henge Classes.

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• Clamshell Henges - no longer Class 2. They have 2 entrances, but are asymmetric. They form a large distinctive set. Some may have been previously been Class 2 Henges (Coupland and Broadlea). Represents a paradigm shift away from earlier symmetry. Coupland Henge was described by R.J.C. Atkinson, (1950) 'Four new henge monuments in Scotland and Northumberland', Proceedings of the Society of Antiquaries of Scotland, 84, 57-66 thus:

  It is noticeable that a line joining the centres of the entrance-gaps divides the monument asymmetrically; the same feature appears in the plans of other henge monuments of Class 2, notably Cairnpapple and Arbor Low.

Cumbrian Ellipses

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• There are a number of Ellipses, mainly in Cumbria, which seem to conform to the same pattern, labelled Class 1. To construct a Class 1 Ellipse, make a rope the same size as the major axis of the ellipse. Fold the rope in two and lay the folded rope straight on the ground in the orientation you want, in this case N-S. Put in 2 pegs at each end of the folded rope at pegging points P1 and P2. Find centre point C if required. Tie one end of the rope to P1 and the other to P2. Draw the rope tight against the fixed points P1 and P2, to create the vertex, V. Moving the vertex V around the centre, keeping the rope taut, defining the ellipse.The centre post can be used to align stones on opposing sides of the ellipse.

  
  

• The Cumbrian Class 1 Ellipses have all been Stone Ellipses, but Devil's Quoit in Oxfordshire is a Henge. Currently I am categorising Cumbrian ellipses.

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    Long Meg - SAA(FL / NS) / ST?

    Twelve Apostles - SAA(EW)

    Gamelands - SAA(FL)

    Glassonby - ST

    Studfold Gate

    Robin Green - Henge

  • Abbreviations

    ST: Axes intersect Stones on circumference

    SAA: Short Axis Alignment

    - FL: Flattened

    - EX: Extended

    - EW: East West

    - NS: North South

  • Cumbrian Henge Ellipses:
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  • Park Beck Henge - SAA(EX / Summer Solstice Sunrise)
  • Tongue House Henge - SAA(EX / EW / Cairn)
  • Millriggs Henge
  • Robin Green Henge
  • Druid Stones Henge - SAA(FL / EW / Tumulus)
  • Deepdale Beck Henge - SAA(EX / NS)