Dorset’s Jurassic Coast – Worbarrow to Abbotsbury
In the second part of his east-west journey along Dorset's World Heritage coastline, Colin Varndell takes a trip from Worbarrow to Abbotsbury
Published in April ’14
Worbarrow Tout is a conical mound of rock forming the easternmost point of Worbarrow Bay. The layers of rock within Worbarrow Tout were initially laid down horizontally, but now they stand almost erect, as testimony to the colossal power of the earth movements which moulded the Dorset landscape.
The sweeping vista of Worbarrow Bay is littered by the effects of erosion with avalanche type piles of debris sloping down from the cliff. On the beach lie many huge blocks of stone which have come to rest here as evidence of the continual process of erosion. On the cliff top above are the remains of an iron age hillfort, Flowers Barrow. But only about half of this once massive earthwork still exists, the remainder having been claimed by the forces of erosion. It is generally thought that when the hill fort was first constructed the coastline may have been as much as one mile further out into the channel.
Mupe Ledges and Rocks are further testament of how immense earth movements shunted and buckled the Dorset landscape. Slanting layers of stone form the almost vertical ledges, while Mupe Rocks sit at incredibly acute angles above sea level and have been responsible for many shipwrecks in the past.
Beyond here lies one of the most famous geological features in the world: the fantastic Lulworth Crumple as it is affectionately known to geologists. The crumple was formed when continental plates collided and thrust the layers of sedimentary rock vertically. The underlying clays here could not support the heavier rock and with time part of this collapsed to form the amazing ‘S’ shape which attracts thousands of visitors every year.
The highest point immediately west of Lulworth Cove is Dungy Head, with its layers of rock lying at approximately 45° angle to the sea. The magnificent view west from here takes in the impressive sweep of St Oswald’s Bay towards Man o’War Cove.
At the extreme south end of Man o’War Cove the layers of rock which were originally laid down as sediments, have been thrust upwards to stand vertically at a right angle to the sea. It is in these vertical layers of stone that the famous Durdle Door arch has been forged by the pounding of the waves.
The view west from Durdle Door is dominated by chalk, representing an immense phase of time in Dorset’s geological history. Chalk formed in a tropical sea and is made up of algae skeletons and has been estimated to have been laid down at the rate of one to six centimetres every 1000 years. Today, these chalk cliffs form some of Dorset’s most spectacular coastal landscapes.
Swyre Head is one of the most impressive chalk cliffs, and when viewing it from the Durdle Door viewpoint it is difficult to imagine the length of time it would have taken for the remains of tiny sea creatures to build up this massive height. It is also difficult to understand the sheer vastness of the chalk when we consider that many of the great hills of north Dorset were also formed in this way. Beyond Swyre Head the coast path is not for the faint hearted as it undulates severely between here and White Nothe. One walking guide describes this as ‘a walk to take your breath away in every sense of the word!’
Immediately west of Swyre Head lies Bat’s Head, protruding further into the English channel to provide far reaching views along the coast in both directions. The view west can only be described as a magnificent white landscape leading the eye to the chalk headland of White Nothe. The name of this promontory means ‘white nose’ and it is just beyond here that the chalk gives way to older rocks in the form of Kimmeridge Clay and Portland and Purbeck limestones.
The beach between Ringstead Bay and Osmington Mills is difficult to negotiate on foot because the pebbles are so large and also there are the huge stone nodules to negotiate. It is therefore easier to follow the coast path rather than the beach along this stretch. The fascinating nodules can be inspected with relative ease on the beach at Osmington Mills. These also occur at various other points along Dorset coast and are understood to be the fossil remains of animal burrows. They are strewn along the beach where they have tumbled from the cliffs as great pebbles or ‘doggers’ as they are known. These nodules formed after animal burrows in the soft, sandy rock were vacated and, acting as conduits for seeping fluids were filled with sand and soupy clays, ultimately becoming cemented in time. As the cliffs erode, so these ‘doggers’ roll out onto the beach. Between here and Bowleaze Cove, the cliffs are a rich, yellow ochre colour, scarred with great fissures transecting the escarpment, demonstrating the effects of continuous erosion by weather and water.
Weymouth owes its success to its low-lying situation and the sandy beach, both formed from the great rivers which carried the sand here as glaciers melted in the north of the country. Such vast surges of water carved and levelled the landscape here, dumping its payload as it fanned out into the bay.
In contrast to Weymouth, Portland remains a high plateau of rock extending five miles into the English Channel. This remarkable landform is the only landscape feature of its kind on the south coast. Such a southerly position has resulted in a unique environment, where very few frosts occur resulting in a mild climate. Certain species of flora and fauna thrive here, where elsewhere along the south coast they may not exist, or at least struggle to survive.
The island has defied the forces of erosion due to the hardness of the rock, which is the one attribute that makes Portland so special, the stone. It has been quarried here for centuries to the effect that man has changed the landscape of the island by digging massive craters, literally by hand for much of the time. The stones’ constitution is sufficiently dense to stand up to weathering (the main reason Portland has remained an island) but not too hard to resist dressing and carving. As a result, Portland stone has been used for many of London’s most iconic buildings.
To fully appreciate the size and extent of the Chesil Bank we first walk from the Ferrybridge centre, directly over the beach to the sea shore. At this point, the beach is some 240 metres wide and reaches a height of nearly fifteen metres. This huge beach or bank acts as a sea defence for the Fleet Lagoon. The Fleet is one of the best examples of a saltwater lagoon to be found in the world. From Ferrybridge the Chesil Bank continues to be an important sea defence for the causeway, linking Portland to the mainland. The Fleet lagoon stretches from Ferrybridge to Abbotsbury, home to the world famous swannery. The view eastwards from Abbotsbury Hill is one of the most magnificent in the whole of England as we look back along the Fleet lagoon towards Weymouth and Portland in the far distance. This impressive vista enchants the observer with its ever-changing response to the seasons. ◗
❱ The pictures for this piece were taken before the Dorset coastline was ravaged by the 2013/14 storms