|Posted on July 6, 2014 at 11:50 AM|
The pit at Kings Dyke contains lots of spoil dumps- but mounds of clay which the diggers have piled up while excavating. Looking thoroughly (I hope you like getting muddy, because the best way to look closely is on hands and knees) you'll find all kinds of interesting bits and bobs in the spoil heaps, such as fish scales, sharks teeth (there are over 15 different sharks recorded from the Oxford clay), bivalves, Ammonite fragments, bits of belemnite guards, and the occasional bone fragment. These will probably have come from a skeleton that was once present, but was distubed during the diggers' excavating, and bits of the skeleton may have ended up on the spoil heap. Conversely, they may have been preserved as just isolated fragments- perhaps the animal they came from was preyed on and dismembered by predators in the water column, and as they fed, the easily removed bits like the limbs and flippers, sank to the seabed where they were preserved.
On the pit floor, you'll see large greyish concretions. Take the time to walk about, and check a few out. They often contain intact fishes and large marine reptile bones. You'll need a geological hammer, though, as they can be tough to crack.
When bone fragments from Oxford clay are exposed to the elements for a short time (be it a few days or weeks) they gain a sort- of, yellowish tinge.
Keep these tips in mind- I've found them useful before, and I'm sure you will. So let'shope we find some good fossils on saturday!:D