Spring Programme - 6 July 2013

Significant Glacial and Post-glacial phenomena in north-east Yorkshire.

Peter C. Robinson with Brian Walker, Forest District Advisor & Brian Hicks, Forest District Ecologist

Meet at 9:15 am at West Ayton Forge Valley Inn Car Park (SE986846).

This is a physically very easy excursion. Walking is limited and there are few slopes to negotiate. However walking boots are advised. Field notes will be provided for each site visited. Please be prepared to arrange to share seats in cars when we meet at Forge Valley Inn Car Park. Cars may be left at Forge Valley Inn Car Park until the end of the excursion. Liquid refreshment and food are available at the Forge Valley Inn – expect to be back here between 13:00 and 13:45 pm. Sandwiches can also be purchased from the Spar Stores and the local fish and chip shop should be open for those who wish, otherwise bring a packed lunch. Hard hats and reflective safety jackets are necessary for Hanson’s Quarry - these will be provided by the Quarry Manager. At the Quarry the leader will place the safety of the group into the authority of the Quarry Manager. All members of the group are required to follow his instructions and guidance. It is essential that the group keep together with the Quarry Manager. At 16.00 p.m. we will conclude the excursion and depart Hanson’s Quarry.

The field excursion will inspect:

  1. Harwood Dale Moor S.S.S.I. (SE 961991) - Interglacial Palaeosols (fossil soils) resembling plinthite (iron -rich, humus -poor mixture of clay with quartz and other minerals) characteristic of tropical clay soils.
  2. Broxa Forest - Prof. Dimbleby's Polygons formed during the Devensian Glacial Period where the soils shrank into polygons during freeze/thaw action to leave fissures that later filled with fine wind blown soil that subsequently gave rise to a suite of plants restricted to the soil filled polygons and different from plants of the surrounding soils.
  3. The Seivegill sub-arial meltwater channel and sink holes in Forge Valley.
  4. The sand and gravel deposits with a wide suite of glacial erratics at Hanson's Sand and Gravel Quarry Wykeham.