The Group's aim is to identify, survey, protect and promote geological and geomorphological sites in the former County of Avon - the modern unitary authorities of Bath and North East Somerset, Bristol, North Somerset and South Gloucestershire. RIGS are selected for their educational, research, historical and aesthetic value.

Friday, 19 February 2016

Aust Pylon and Talus Works

With the pylon at Aust coming up close to its 50th anniversary it is time that National Grid and Trant Engineering Limited give the concrete pillars it is stood upon some major renovation. As part of these works, that will continue throughout 2016, the concrete causeway that leads from the old ferry crossing down to the pylon will be in constant use. 

Over many years soil and clay have accumulated at the base of the adjacent cliffs forming a huge bank pushing against the causeway. It was time for the bank to be removed. 

During the first two weeks of February I was on site with a watching brief both for water birds using the foreshore and for fossils as the bank (talus) was removed and laid out across the beach. Two dumper trucks and two diggers were involved in transporting the soil and clay down to the beach. It was laid in two long rows along the beach enabling me to look through it. 

Although there was some rock amongst the talus it was mainly slabs of shelly limestone rock that revealed some lovely bivalve fossils but nothing more. However, time on the beach did give me the chance to find plenty of Rhaetic bonerock – mostly containing the usual mix of tiny teeth, coprolites and fish scales. A few boulders revealed larger bone and shark spines. 

I will be transferring the finds to Bristol Museum & Art Gallery – hand size pieces will be used as handling objects for learning activities. The bank itself has been cut back three metres and to a 45 degree angle. This will help reduce the pressure of future soil and clay building up against the road.  The recent high tides have been washing through the talus and cleaning up any remaining slabs of limestone. 

Ed Drewitt. Thanks also to Joe Keating and Dave Marshall from the School of Earth Sciences, University of Bristol, who covered a day each.

                                                    Talus being cleared at Aust

                                                       Fossil shells at Aust

                                                          Bonerock at Aust

                                                       Shark spine at Aust

                                                Fossilised bone at Aust

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