This EarthCache will bring you to a unique site where rare dinosaur footprints have been preserved.

The natural forces on Earth are very powerful and as a result it is very difficult to find long-lasting evidence of habitation and passage due to the many forms of erosion. 
Due to these forces, it is astonishing that humanity has found as much evidence of ancient animals as they have done.
Dinosaurs existed approximately 243 - 65 million years ago and the preservation of their bodies only occurred under very precise conditions making fossils such a rare and valuable find.

The Fossilisation Process

The field of fossilisation is extremely complex. The main criteria is that after death, as the remains of plants and animals decay, they must be covered in sediment such as sand or mud very quickly, to help preserve them.

The evidence left behind by animals, such as burrows or tracks, is called a trace fossil, also known as an ichnofossil. It is a fossil record of biological activity by lifeforms but not the preserved remains of the organism itself.

For tracks to be preserved, once again which is extremely rare, the prints need to be made in wet sand or silt, usually on the shore of a lake. The prints then need to be buried gently under silt where they are then preserved and permitted to harden and mineralize.

Types of Rock

Geologists, and especially palaeontologists, can use the evidence found in rocks to determine the environment in which a fossil was deposited, or to deduce how the crystals in a metamorphic or igneous rock were formed.  There are 3 main types of rock.

1 – Igneous rocks

These form when molten rock, known as ‘magma’, cools. As a general rule, the slower it cools, the larger the crystals found within it, and vice versa.

2 – Sedimentary rocks

These form when older rocks have been weathered and the residue deposited, usually in layers. Over time, these layers are then squashed by the weight of overlying material, slowly turning the sediments into sedimentary rocks.

3 – Metamorphic Rocks

These form when older rocks are buried deep within the Earth’s crust. Over millions of years they are heated and deformed so causing the original structure within the rock to crystallise or re-crystallise, depending on the original rock.
 

Keates Quarry Dinosaur Footprints

Millions of years ago dinosaurs walked here, and now it's your turn!

Scattered across the rock surface of this old quarry are fossilised dinosaur tracks. They were left by giant plant eaters called sauropods that walked here beside a shallow freshwater lagoon 145 million years ago.

Back then this landscape would have been very different. What we call Europe today was much closer to the tropics and Dorset was covered by coastal forests, swamps, lagoons and salt flats. In the sticky heat dinosaurs, pterosaurs and primitive crocodiles lived side by side. Over time layers of rock were laid down in those environments, trapping and burying the remains and traces of ancient life.

Millions of years later, when people arrived to quarry those layers for building stone, they discovered the fossils trapped within them.
There are over 100 tracks preserved here. They were probabably left by sauropods which could grow to around 26m long and weigh betwen 40 and 50 tons. There were many different types of sauropod dinosaur and as a group they included the largest animals that have ever walked the Earth.

In January 1997, Kevin Keates, whose family has quarried Purbeck stone for over 300 years, was working here, carefully excavating the layers of rock. Another local quarryman, Trev Haysom, noticed the shapes in the rock surface and identified them as dinosaur tracks. Today the National Trust looks after this site and Kevin Keates and his son continue to dig stone just across the fields to the north west. Quarrying is part of Purbeck's living heritage, and without the knowledge and interest of people like Kevin and Trev, these remarkable tracks would never have been discovered.

Scientists have given two different theories about how these tracks formed. The first is that they are 'primary' prints, made where the feet of the dinosaurs pressed into the surface of the lagoon's beach. The second theory is that they are 'transmitted' prints, made by the great weight of the dinosaur pressing down through layers of wet sediment.

Logging Tasks

As this is an earthcache, there is no physical container to find but you will need to answer the following questions. Some information is here on the site but you may also need to do some further research.  We suggest you bring a tape measure.

1. What is the approximate size of the largest footprints that you can see?

2. What type of dinosaur made them?

3. Can you explain why there may be so many footprints at this site?

4. Can you name the type of rock that the prints are preserved in?

5. (Optional)  Take a photograph showing yourself or your GPS device by the access point showing the "Dinosaur footprints" signpost. 

Send us the answers via e-mail or the Message Centre but you do not need to wait for our reply before logging the cache. We would only write to you if there is a problem with your answers.

Cache placed with the kind permission of the National Trust. 

Thanks also to the Jurassic Coast Trust who help with the maintenance of the site and have produced the interpretation board.

Access

The footprints can be easily accessed from the nearby Priest’s Way walking trail, which is located a short walk from the village of Worth Matravers, or from the Spyway National Trust Carpark (Signposted from Langton Matravers) : free to NT members otherwise charges apply. The site is owned and managed by the National Trust.  Access to the site is free, but we suggest you should only visit in daylight hours.