Field Trip: Sully Island & Lavernock Point

Leader: Professor Maurice Tucker, University of Bristol & BGS

Entry Fee

Members: Free

Visitors: £3.00

Date and Time



Sully, Penarth CF64 5UG

Field Trip Description

The Triassic rocks near Sully and Penarth (50 miles west of Bristol), near Cardiff, were deposited around the edge of a lake or inland sea in which the Mercia Mudstone/ Keuper Marl was deposited. The Trias overlies the Carboniferous limestone which locally created hills and cliffs around the lake; wave-cut shore-platforms and wave-notches were cut into the limestone cliffs, and screes of Carb Lst debris were formed, locally reworked into beach gravel breccias. A range of shoreline limestones was developed – with stromatolites, ripples, tepees, birdseyes, and these are interbedded with soils (calcretes) and evaporites, mostly gypsum-anhydrite, since replaced by dolomite and quartz. Dinosaur footprints are also present in the muddy marginal lacustrine sediments.

The day is dependent on the tides and we shall visit Swanbridge, Sully Island, Bendrick Rock and Lavernock Point.

Travel arrangements:

We will travel in private cars for this excursion and hopefully car-sharing can be arranged.

Meeting point will be the public car-park at Swanbridge, near the Captain’s Wife pub (postcode CF64 5UG), opposite Sully Island.

Travel via the M4 to junction 33, then head south towards Barry on the A4232, A4050, A4231 and B4267 through Sully to Swanbridge. AA Route planner suggests 1 hr 30 mins and ~65 miles from Bath.

Rendezvous at 10.30 am.

Location Map

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Important Notice: Bath Geological Society Insurance

Each person attending a field meeting does so on the understanding that he/she attends at his/her own risk. The Bath Geological Society has Public Liability Insurance Cover for field and indoor meetings, but Personal Accident Cover and Personal Liability Cover remain the responsibility and personal choice of the participant.

There may be an element of appropriate cover included in house insurance or in travel insurance: although Bath Geological Society activities are not particularly dangerous members are advised to check whether exclusions apply to activities in which they plan to participate in case they wish to arrange further cover. An annual travel insurance may be the best solution for any member who regularly attends field events: this again is a matter of choice.

Please note however that all members participating in overseas events will be required to have travel insurance for the duration of the event: this is so that participants are covered for Medical, Repatriation and Personal Liability expenses. The Personal Accident element remains the personal choice of the member and again members are advised to check exclusions so that they can make an informed decision about the cover they want.