Rotunda Geology Group Field Trips 2015

Rotunda Geology Group Summer Field Programme
2015

For all field outings participants should wear stout footwear and clothing suitable for wet weather conditions and rucksacks to keep hands free when walking. Hard hats are required for quarry and cliff base visits where advised below. Please Note: RGG will not be able to provide hard hats for members – please bring your own.

Yorkshire Geology Month. May.
Several walks and talks are available, including this programme and local trips to Bempton and Flamborough. For latest updates please see www.yorksgeolsoc.org.uk

Saturday 30th May 2015 What can we learn from the Chalk of the Wolds
Leader: Derek Gobbett
This is a low intensity field trip, mainly by car, to investigate the classic exposures of chalk in the Wolds.
Meet at 9:45 am at the Staxton Hill car park [TA009778] where we will organise the transport using as few cars as possible because roadside parking is limited near the pits to be viewed. We will visit four Chalk pits using cars to travel from one pit to the next and the total amount of walking will be limited to little more than 1 km. At lunch time we will be in Weaverthorpe where there is a standard grade pub, The Star, and a posh pub, The Bluebell. Members have the choice of a pub lunch or a packed lunch on the ‘green’.

Health and Safety: The main concerns here is the proximity of roads and the need for roadside parking and the risk of falling rock from these old and crumbly chalk quarries. Please bring hard hats. There are bee hives to be avoided in one quarry, Masons Pit at Weaverthorpe.

As well as demonstrating the classic Chalk exposures Derek will outline some of the basic geological processes involved in sedimentation, lithification and deformation. The formation of bedding, jointing and the overprint of diagenesis and structural deformation as well as fossil preservation will be discussed. The four quarries to be inspected are:

1. Gills Farm Pit south of Thixendale [SE 846593] c.500m from the road
2. Mason’s Pit, Weaverthorpe [SE 973709] c. 80m from the road
3. Parish Pit, Langtoft [TA 012659] c.40m from the road
4. Foxholes “Quarry” (TA 013736] c. 30m from the road.

Sunday 5th July 2015 Of Fossils and Fracking (Saltwick Bay and Whitby East)
Leader: Liam Herringshaw (University of Durham)
This excursion will use the Whitby Mudstone Formation to introduce some of the new thinking being applied to shales, their composition, origins, and geomechanical properties. Many long-held hypotheses about shales are being challenged, and the Whitby mudstones are playing a key role in this work. We will discuss the applicability of these Jurassic shales to the understanding of shale systems more broadly.
Meet at 10:30 am at the Car Park at Whitby Abbey (YO22 4JT). We will walk from Whitby Abbey along the Cleveland Way to Saltwick, descending to the beach there. We will then walk along the coast, returning to the car park via Whitby itself. We will finish by 4 pm. Please bring a packed lunch and drinks. Toilet facilities are available at the Saltwick Caravan Park cafe.
Clothing and safety: Stout footwear and waterproof clothing are essential. Hard hats will also be required – please provide your own. The descent down to the beach at Saltwick is steep, as is the return up to the Abbey car park at Whitby; members may wish to bring a walking pole or stick to assist them.
Access to the section is tide-controlled, and the headlands at Saltwick Nab and Whitby East can only be crossed safely a couple of hours either side of low tide, which is at 13:20. The mudstones are also slippery, especially when wet, and the cliffs are vulnerable to rock falls.
The organic-rich Early Jurassic mudstones of the Yorkshire Coast have been of economic and scientific interest for centuries, but are the subject of new research as a result of the growing interest in unconventional hydrocarbons. This excursion will focus on the highlights of the Lower and Middle Jurassic succession exposed between Saltwick Bay and Whitby. This coastal section provides particularly good exposures of the Lower Jurassic Whitby Mudstone Formation. At low tide, the upper part of the famous Jet Rock is exposed at Saltwick Nab, and then the walk towards Whitby provides exposures of the succeeding Bituminous Shales, Hard Shales and Alum Shales, all exposed in a gentle syncline. At the mid-point of the section, the folding brings the Middle Jurassic Dogger Formation down to beach level. The overlying Saltwick Formation is also well-exposed.

Saturday 1st August Filey Bay: the Speeton Clay, Chalk and glacial tills
Leader: Pete Rawson

This excursion will focus on the type locality of the Lower Cretaceous Speeton Clay, which is exposed along the south-eastern part of Filey Bay.

Meet at 10 am on the beach opposite the foot of the path leading down from the Reighton Sands holiday camp to the shore. To reach the camp, turn off the A165 coast road towards Reighton village, and immediately north of the village is a minor road leading to Reighton Gap and the Reighton Sands camp. There are two car parks at the camp but if these are full, there is a small parking area (TA 128757) on the cliff-top at Reighton Gap and parking at the side of the road nearby. It is best then to walk back into the holiday camp. If you arrive late, walk SE along the sands (i.e. towards the chalk cliffs) until you spot the party!
Clothing and safety: stout footwear (but not wellington boots) and waterproof clothing are necessary; the clay cliffs can be very slippery when wet. Hard hats are useful but not essential. Note: there are no toilet facilities. Low tide is at 11:45, high tide at 17:47.
Geology: The Speeton Clay sequence represents almost the whole of Early Cretaceous time and provides a fascinating glimpse of life in a marginal marine basin of the Boreal Realm. The clays crop out in low cliffs which are prone to landslipping and marine erosion, so the degree of exposure changes constantly. In 1889 G. W. Lamplugh divided the sequence into four main units, the A (top) to D (bottom) beds, based on the belemnite faunas. This provided the key to unravelling the details of the section. The excursion will concentrate on the stratigraphy and fossil fauna. Whatever the degree of exposure on our visit, we can guarantee that you will find some of the typical belemnites!
We will also be able to examine a wide range of erratic rocks, including some with Carboniferous corals, washed onto the beach from the adjacent tills.
If time allows we will also walk further along the shore to look at the Hunstanton Chalk Formation (‘Red Chalk’) and the lowest beds of the Chalk Group.
This excursion is suitable for beginners. The total walking distance is about 3 km, or 4 if we walk as far as the Chalk. It is mainly along the shore, with a cliff path at the beginning and end of the excursion.
Lunch: Bring a packed lunch to eat on the beach.

Saturday 5th September 2015 Jurassic Plants and Ores at Hasty Bank and Cold Moor
Leaders: Chris Hill and Steve Livera

This is a ‘twice in a lifetime’ opportunity to visit a fully exposed section of the world famous Jurassic plant fossil SSSI at Hasty Bank. The exposure trench will be filled in after this trip. Collecting will be possible and is encouraged although limited to already loose material.
The total walking distance will be approximately 6 km and involve a total ascent of 150m spaced through the day. Please bring a packed lunch. There are no toilet facilities on this trip.
Meet at 10.30 am in the Clay Bank car park by the junction of the B1257 and the minor road to Ingleby Greenhow, at NZ 572 036 [Explorer OL26 1:25,000]. We expect to finish by 17:00 at the latest.
Health and Safety. The road by the car park is extremely busy and dangerous and will be crossed with care. Trip hazards are many because of slippery roots and the uneven ground on the Forestry bridleway and Cleveland Way, and there are concealed drops in places. It is essential to keep to the path. Members will be asked to stay out of the ironstone adits as the roofs are crumbling badly. Hard hats are required as are stout walking boots because of the risk of turned ankles when walking along some steep slopes. Walking poles may help. If you bring a hammer please use eye protection at the ironstones. The Plant Bed exposure is on a steep slope with a dangerous deep slit trench which must be avoided and approached only as directed.
Route and overview. We will walk along the bridleway to Cold Moor outlining the Lower to Middle Jurassic transition and its marked lateral variation. Whilst the Cold Moor sequence was fully marine, Hasty Bank is of interest because it exposes some of the earliest beds of the advancing shoreline and subsequent terrestrial deposits at the shorefront of the Ravenscar Group. We will investigate the Dogger Formation ironstone adits on Cold Moor and the Dogger at the Wainstones, as well as the extensive jet mines in the area and the Hasty Bank plant bed. The ironstones are very fossiliferous and the spoil heaps provide good collecting opportunities. The Hasty Bank plant bed is the most intensively studied plant fossil locality in the World. Discovered in 1927, it has yielded a fascinating diversity and abundance of plants and even a few animals including recently the first records of insects from the Yorkshire Jurassic. Notable plants include the ancient marattialean fern Angiopteris [Guanyin’s Cushion], widespread in the tropics today and a descendant of Carboniferous tree ferns. There are also missing links amongst the present day families of Cycads and the only substantial record of the genus Cycas between its origin in the Permian of China and the bizarre ‘living fossils’ which still survive today. At the base of the Ravenscar Group freshwater depositional environments replaced underlying marine ones in a sporadic manner, including intertidal environments with trace fossils and trees such as the probable mangrove Pachypteris papillosa, abundant enough for the leaves of this ancient seed fern to form a paper coal.

18-20 September – Yorkshire Fossil Festival Weekend, Scarborough
Scarborough Museums Trust, supported by the Palaeontological Association, will once again be holding a Fossil Festival in and around the Rotunda Museum and also on the nearby beach. Several universities will be involved along with local and regional societies and groups. The RGG will be playing an important supporting role and in due course we will be seeking volunteers.
See www.scarboroughmuseumstrust.org.uk or ring 01723 353665 for details.

For further information about the Rotunda Geology Group please contact
Sue Rawson: suerawson@yahoo.co.uk