The grey limestone that makes up most of the two-mile long hump was laid down in early Carboniferous times, around 400 million years ago. These marine sediments (which reach a maximum thickness of 3000 feet at the Mendip Hills nearby) comprise the dead skeletons and shells of many different groups of invertebrates.
Corals are the most common type of fossil you will find along this coast, the most likely ones you will see are Zaphrentis species, which are cone-like corals and are found in many of the rocks, often in excellent condition. You might also see traces of the rugose coral (Dibunophyllum species) and brachipods (mostly Spirifer trigonalis). Crinoids can often be found but these are in most cases worn with the inside structure only visible. Bryozoans and fossil Algae make beautiful patterns on some of the rocks and Bivalves can also be found along much of the coastline at Middle Hope, Swallow Cliff and Sand Point, in the cliffs and large rocks on the foreshore.
The fossils are simply lying in the rocks but because this place is a SSSI you should only photograph them. If you did try to extract them, you would almost certainly destroy the fossil because the rocks are extremely hard.
Midway along the northern edge of the peninsula at a spot called Middle Hope are the remains of a raised beach deposit and a wave-cut platform which are evidence that the sea level was once much higher in these parts.
The main reason Geology students come here, however, is that in the coves below there are several outcrops of basaltic lava and this is one of the few places where igneous rock is interleaved between layers of sedimentary limestone.
The co-ordinates put you at Swallow Cove close to one of these unconformities. You may see veins of quartz running through the more resistant limestone rock and, if you look very closely, small fossil remains which are not easy to remove. Close to where you are standing is a discontinuity between these beds and the igneous rock which has a clearly visible crystalline structure.
TO LOG THIS EARTHCACHE you can claim a find so long as you e mail me to say what colour and type of rock you think is visible at the base of the limestone at this point. It's a type that has not been mentioned so far and you might have to use a bit of an internet search on periods close to the Carboniferous. I will get back to you asap to let you know if you are correct. If you can post a photo of yourself and your GPS with the Bristol Channel in view that would be great too
For more photos and geology see the good internet site at www.severnichthys.co.uk/geology07.htm or some of the Weston-super-Mare sites.
As well as the geology, there are lovely views of the islands of Flatholm and Steepholm from this Earthcache and, although the highest point is only 48 metres, there is some interesting scrambling to reach the very end of the peninsula. Its short grassland is a favourite haunt of swallows, skylarks and many butterflies which live off the colourful, limestone-loving flowers and the insect life.