|
|||||||||||||||||||||||||||||||||||||||||||||||||
Introduction
Durlston Bay is much less publicised for its fossils than many other locations along the Dorset coast, despite yielding some very good specimens over the years. Good finds are reliant on recent cliff falls, at which time visitors to the area can hope to find a range of fossils. It's worth noting that this is not a family destination, aside from the heightened risk of cliff falls, the type and volume of fossils is more suited to experienced fossil hunters.
(Left) Parking is available in the surrounding roads. (Right) Access to the beach is made beneath the Coast Guard tower.
Local roads on the hill-top provide plenty of parking and easy access to the coast. Follow the public footpath down the grassy hill until you reach the Coast Guard tower at Peveril Point, from here it's possible to climb over the rocks to the foreshore.
The Geology of Durlston Bay
Durlston Bay represents a transition between the Jurassic and the Cretaceous periods. During this time a large lagoon stretched along the coast; on the land were large numbers of dinosaurs and mammals, and in the shallow waters were crocodiles, sharks, fish and turtles.
Detailed stratigraphy of Durlston Bay in 2007, adapted from Dr Ian West's stratigraphic diagram www.soton.ac.uk.
The close proximity of the land and sea gave rise to brackish water (saltier than fresh water, but not as salty as seawater), this is evidenced by concentrations of the freshwater pondsnail Viviparus, interspersed with the salt water mollusc Corbula. Much of this page is dedicated to the fossils found within the Upper Purbeck Beds, which date from approximately 140 million years ago.
Where to look for fossils?
Fossils can be found from the moment you step on to the beach and continue for several hundred meters to the south. Because many of the fossils are small it's necessary to pay close attention to the rock surfaces for even the slightest sign of a fossil within.
During our recent visit a large portion of the cliff had collapsed only a few days earlier, depositing a large volume of fresh material on the beach; therefore it's worth mentioning that the abundance portrayed by the following photos is not representative of the typical conditions.
(Left) Roy takes a moment to familiarise himself with the surroundings! (Right) A recent cliff collapse deposits fresh Upper Purbeck rock on the foreshore.
(Left) Fragments of the Upper Purbeck Beds; packed with fossils. (Right) Close-up of the fossil bearing rock.
Occasionally fossil rich sections of the 'Upper Purbeck Beds' are deposited on the beach; these are known to contain some truly excellent bones and teeth. Experienced fossil hunters will be able to identify these fragments by the concentration of small pieces of fossil wood, bones, shells etc. Breaking these rocks apart is a tough job, but persistence may pay off. Although this technique is recommended, we'd ask inexperienced visitors to avoid hacking apart the foreshore sporadically!
On his website, Dr Ian West describes the Upper Purbeck as representing "...the marginal deposits of a lake with pond snails, freshwater bivalves and ostracods, where plant debris and remains of fish and crocodiles were washed into the shallow marginal areas." For further reading please visit www.soton.ac.uk.
For more information about the features and processes controlling coastal fossil collecting locations click here.
What fossils might you find?
The most commonly found fossils are teeth belonging to fish and crocodiles, although the latter is significantly less abundant. Other finds include bivalves, fragments of turtle carapace, crocodile scutes and isolated fish bones.
(Left) A concentration of small bivalves. (Right) A small tooth, presumably belonging to a Hybodus shark.
(Left) A splendid crocodile tooth - Goniopholis? (Right) Close-up.
(Left) A partly damaged root of a crocodile tooth - Goniopholis? (Right) Close-up.
(Left) A small crocodile tooth - Goniopholis? (Right) Close-up.
(Left) A fragment of turtle shell. (Right) A large fragment of turtle carapace.
(Right) A fragment of a shark's fin-spine - Hybodus. (Right) An isolated fish skull bone.
(Left) A boulder surface containing dozens of tiny fish teeth - Lepidotes. (Right) Close-up.
(Left) A fragment of crocodile scute. (Right) A second fragment of crocodile scute.
Protecting your finds
It's important to spend some time considering the best way to protect your finds onsite, in transit, on display and in storage. Prior to your visit, consider the equipment and accessories you're likely to need, as these will differ depending on the type of rock, terrain and prevailing weather conditions.
(Left) Fossil wrapped in newspaper, ready for transport. (Right) A small compartment box containing cotton wool is ideal for separating delicate specimens.
When you discover a fossil, examine the surrounding matrix (rock) and consider how best to remove the specimen without breaking it; patience and consideration are key. The aim of extraction is to remove the specimen with some of the matrix attached, as this will provide added protection during transit and future handling; sometimes breaks are unavoidable, but with care you should be able to extract most specimens intact. In the event of breakage, carefully gather all the pieces together, as in most cases repairs can be made at a later time...continued.
|
|||||||||||||||||||||||||||||||||||||||||||||||||
