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> travel > travel features > 2004 spring special | appeared in DIVER April 2004 | ||||||||
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2004 Spring Special Intro | The Ore stone | Hodge Close | Johnstone's Hole | Crab City | Bracklesham Bay Bracklesham Bay Sussex by Gavin Parsons |
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It's Tony Robinson's fault. Yes, that bloke who played Baldrick in Blackadder. If he didn't run around the country getting excited by holes in the ground, then I'd never have got interested in old stuff. And when I say old, I really mean old. Wrecks are one thing, but I'm talking so old that the objects have turned to stone. Fossils fascinate me. To hold something in your hand that hasn't been alive for millions of years, yet still looks like it did the day the creature died, is kind of bizarre. And when it is something quite recognisable as coming from a creature that still lives today, then my mind really gets messed up. Swim on a patch of shallow reef off the promontory of Selsey Bill and there's a good chance that you will find just that. Here, in a seam of sedimentary clay running off the South Downs, are deposits of the most common fossils on the planet - sharks' teeth. Quite strange, considering that sharks and other cartilaginous fish rarely survive in fossil form because they don't have any hard bones. Yet the teeth are the hardest, most robust part of a shark and are shed throughout their lives. For millions of years (and sharks and rays have seen the dinosaurs come and go) sharks' teeth and ray mandibles have been dropping to the seabed across the globe, and the fossilised forms are found all over the planet. There was a time when the tectonic plate on which the UK sits was in a much warmer part of the world and was covered by a shallow sea. In it swam various species of sharks which deposited their teeth, just as modern sharks do today. Go to any shark-feeding site, dig around in the sand and you have a good chance of uncovering a piece of elasmobranch dentistry. If you were alive several million years ago, you could have done the same thing over the seabed that today forms a part of southern England. The bizarre thing is that, even though the teeth-owners have long since departed, you still can. Sharks' teeth and ray mandible fossils litter the seabed of Bracklesham Bay, Sussex and the beginning of the dive season is the best time to make finds, as rough winter weather breaks up the seabed to expose fresh fossils. It is possible to find fossils by walking along the beach, or indeed anywhere around the shallow bay, but those finds tend to be open to a great deal of chance. For a more reliable source, you need to be directly over the clay seam where the fossils are buried. Because of this, I always dive with Wittering Divers, which knows which areas produce the best finds (though being in the right place doesn't mean you will always come back with fossils). The key to finding fossils is to have a keen eye. You need to know what you are looking for and be aware that the fossils don't necessarily lie flat on the seabed. They poke out of the clay at odd angles and are passed over as stones more often than not. The area, although shallow at around 5-9m deep, offers an interesting bottom topography of holes, shelves and undercuts where the clay has been eroded unevenly. Fish life isn't fantastic here, but when you have eyes glued to the mud, fish-watching becomes unnecessary. The dive boat leaves the beach at Bracklesham and motors into the shallow bay past the wreck buoy of the protected HMS Hazardous, and around onto the clay beds. With the anchor set, buddy pairs descend into the often-cloudy water. The visibility does improve in summer, but after winter storms the fine sediment and lack of current mean that you probably won't be able to see the surface, even this shallow. I tend to start searching at the base of the many overhangs, as the water movement often carries loose fossils into these sheltered spots. Gently, I fan away at the surface deposits, taking care not to stir up too much, as the sediment can take a while to settle. I look for black stones. In the fossilisation process, the original organic parts of the shark's tooth are replaced by minerals such as iron pyrites and silica. The tooth, therefore, loses its whiteness, and by the time it is considered a fossil (and is by definition made of rock) it has turned black or reddish-brown. Some teeth are tiny, about the size of a reef shark's, while others come from raggedtooth sharks, or close relations of theirs. Yet others are more triangular and serrated and appear to come from relatives of great whites. There is no apparent order to the finds, but the concentration of so many teeth has led palaeontologists to believe that the sea in which the sharks swam was shallow and dried up, or suddenly became too hostile for the sharks to survive in, so that great numbers died off over a very short period. When collecting, it's best to take a hard plastic container with you, as the fossils are still sharp and will puncture bags and possibly even put a hole in a BC. Also, be careful when handling them. There's no point getting bitten by a million-year-old shark! The fossil beds provide an unusual adventure and a step away from the usual wrecks and reefs that are the staple diet of most UK divers. Tony Robinson, I'm sure, would enjoy them as you will. Contact Wittering Divers on 01243 672031 or visit www.witteringdivers.co.uk. |
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 Wildlife you won't notice while you're hunting those fossils - a lobster in its hole  clay seabed worn down by sea movement  an array of shark's tooth fossils collected at Bracklesham Bay  a scallop rises from a patch of sand | |||||||
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Intro |
The Ore stone |
Hodge Close |
Johnstone's Hole |
Crab City |
Bracklesham Bay 
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