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Zechstein Field Trip
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Leader: |
Bernard Cooper (Horus Petroleum) |
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Date: |
5-6 September 2009 |
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Logistics: |
The cost of the field trip includes 2 nights Bed and Breakfast accommodation at The Best Western Sea Hotel, South Shields, located on the sea front for Friday 5 September and Saturday 6 September. Full English breakfast will be included but evening meals will not be included, so you will just need to pay for lunches and any other personal expenses. Transport will be provided for the trip. You will just need to make your own way to the hotel in South Shields www.seahotel.co.uk |
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Cost: |
£220 per person |
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To Book: |
This fieldtrip will be based in South Shields and will visit both coastal cliff sections and onshore exposures. The Zechstein succession, including the three carbonates, is magnificently exposed and was mapped in considerable detail by the late D.B.Smith of the British Geological Survey. The Yorkshire Geological Society hosted a series of lectures on the European Zechstein at the BGS, Keyworth on March 21st 2009 as a tribute to D.B.Smith.
The emphasis will be on correlating the outcrops with the Southern North Sea Zechstein succession. The main differences are that the thick offshore evaporate sequences are represented onshore by thin solution residues and brecciation of the overlying carbonates due to collapse.
The fieldtrip will commence at Frenchman’s Bay where the Yellow Sands Formation (Rotliegendes) are overlain by the Z1 Marl Slate Formation (Kupferschiefer) and Z1 Raisby Formation (Zechsteinkalk). The thin overlying residue of the Z1 Hartlepool Anhydrite Formation (Werranhydrit) is overlain by the highly brecciated Z2 Concretionary Limestone Formation (Stinkdolomit). The Z1 and Z2 carbonates will be examined in some detail at Trow Point.
Spectacular onshore outcrops overlooking the river Wear at Claxheugh Rock and the associated Ford Quarry in Sunderland show the Yellow Sands and Marl Slates overlain by the Z1 Raisby Formation and the Z1 Ford Formation (Werradolomit) shelf edge reef. The massive bryozoan / algal reef core can be studied at Claxheugh Rock and both reef core and backreef facies in Ford Quarry. The details of the reef core can also be seen in the next location at Tunstall Hills, also in Sunderland.
Cliff exposures at Marsden Bay exhibit the upper non – brecciated facies of the Z2 Concretionary Limestone. These carbonates exhibit sapropelic laminates, graded turbidites and slump deposits typical of deposition in a mid slope environment. The next cliff exposure, to the north of Seaham, exposes the lateral shallow water equivalent of the Z2 Concretionary Limestones, the Z2 Roker Dolomite Formation (Hauptdolomit). These dolomites were originally deposited as oolitic limestones exhibiting a range of shallow water sedimentary structures.
At Seaham Harbour the Z2 Roker Dolomite is overlain by the strongly contorted residue of dolomitic clays and limestones which is all that is left of the Z2 Forden Evaporite Formation (Basalanhydrit and Stassfurt Halite). This is overlain by the carbonates of the Z3 Seaham Formation which consists of some 30m of calcite mudstones characterised by the presence of the alga Calcinema and discontinuous layers of calcite concretions and coarsely crystalline limestones resulting from dedolomitization. The top of the formation is characterised by algal stromatolites.
NB: For safety reasons a maximum of 15 places are available. If you are interested in attending please contact julie@pesgb.org.uk
Registered charity number 1085619
