John took the group to visit Mike Marshall, who is a professional preparator of fossils he finds along the coast, including ichthyosaurs and fish fossils for museums.     He explained how he selects potential specimens and then how he prepares them in his little workshop close to the coast.

His website is http://www.ycfossils.force9.co.uk

Julie and Alison are working on the programme for next year.     We have had many offers of speakers for evening talks so we can look forward to a great variety of subjects, on the geology of places such as Greenland, Jersey and Western Ireland, to the mass extinction at the Permo-Triassic boundary and the archaeological site at Myers Wood, near Kirkburton.

We are however, short of ideas for field trips, though a weekend in the lead-mining area of Alston, North Yorkshire, has been proposed.     Please let us know where you would like to explore and we will see what we can arrange.     Any suggestions to Julie or Alison, please.

Several members of the group enjoyed a sunny evening finding the finer points of sedimentary structures in the Lower Coal Measures, including steep dips in shales and gentle folds in sandstones, which are not usually found in the Huddersfield area.

Meet 9.30am at the car park of the Woodman Inn, Thunderbridge, (SE 189116) to share cars.     Bring a packed lunch and walking boots.     Ian will be taking us for short walks around Scissett, Shepley and New Mill to look at the Holme fault.

"Recognition of the Holme Fault as a surface structure has been a significant discovery of the recent BGS mapping.     It has a big influence on the scenery, the most obvious being the "saddle" of Rough Rock on the skyline at West Nab.

The fault was first inferred from gravity surveys, as a deep structure affecting both the basement and the overlying Carboniferous succession, and was later located on seismic profiles.     It was thought not to reach the surface, but recent mapping shows that it does; it can be traced for about 20 km in an east to west direction from High Hoyland via Denby Dale, New Mill and Holmfirth to the crest of the Pennines near West Nab.     The downthrow, up to 100m, is towards the north.

It is one of a series of faults that moved during the deposition of Carboniferous sediment.     In these circumstances more sediment accumulates on the downthrow side of a fault than on the upthrow side, and this helps to make the structure show up on seismic profiles.     The fault plane flattens off downwards and the strata on the downthrow side bend over towards it - the resulting geometry resembles that of a rotational landslip, though on a very much bigger scale.     The structure on the downthrow side is called a "rollover", and in the case of the Holme Fault it turned into a proper anticline during compression movements at the end of the Carboniferous, when the throw on the fault reversed direction.

This "hanging-wall anticline" is present just about everywhere along its length, and is the key to finding the surface position of the fault, as I hope to demonstrate in the field on the 16th May."
Ian Chisholm (formerly of BGS)