The A-level Geology Field Trip saw Upper Sixth students enjoy a fascinating 5-days in Anglesey. We visited numerous locations from our base in the village of Llangaffo.
Day One
On Thursday, we visited Lligwy Beach. We studied Devonian age (approximately 410 Million years old = 410My) sediments deposited in broad floodplains, when the climate was very arid. We then moved to the south side of the bay to study flash flood conglomerates of early Carboniferous age. These rested on older fossiliferous limestones containing ancient corals and brachiopods (approx. 350My). We ended the day with a brief stop to explore Din Lligwy. Here we saw the remains of a small, fortified ancient settlement dating back to the 4th century CE.
Day Two
Friday was spent visiting south east Anglesey. We studied igneous, dolerite dykes that have cut through ancient, Precambrian rocks, known as “Gwna schist”. These were intruded as the Atlantic Ocean began to open over 100 million years ago. The second stop of the day was Lleiniog. Here we studied glacial deposits formed during the last ice age, namely boulder clay (glacial till) resting upon older fluvio-glacial meltwater sediments formed during an earlier ice advance.
Day Three
On Saturday we headed to Newborough Forest, to take part in the local Parkrun! Harry Flanagan set off like a rocket, quickly opening up a lead that Dr Dolding was not able to close over the final kilometre. Have warmed up with the run, the group walked to nearby Llanddwyn Island to study ancient pillow lavas and volcanic agglomerates that formed on a mid ocean ridge over 600 million years ago. At the lighthouse at the tip of the island, outcrops of Gwna Melange were seen – a fabulous mix of jumbled pillow lava, and metamorphosed sandstone / limestone blocks that had tumbled down into a deep ocean trench at a plate margin. The group also undertook an analysis of crystal sizes in the dolerite dykes that cut these rocks.
Thank you Dr Dolding & Mrs Otero
