Margin

This was taken as a documentary picture, without any thought or design, except trying to get as good an image as possible of the weird circle at the bottom centre. But I really like it; I think the the colour of the wet ironstone in bright sun is stunning. Everything white embedded in the stone is a 160 million-year-old, Jurassic fossil - though fossilised what, I have no idea. Now it is sitting on 21st century plastic, made from the remains of plankton that have sunk to the bottom of an ancient ocean and decayed anaerobically - possibly around the same time (within 50 million years, or do). The rock is supposed to hide the plastic and make the pond more pleasing on the eye

The cyclops are obviously still thriving, and still keeping down the algae - marine algae probably also contributed to the oil that generated the plastic. The long green leaves are Stratiotes aloides - 'water soldiers' - a rather mysterious and ancient water plant, native to UK, that floats freely in the water, trailing long roots. It precipitates calcium carbonate (limestone) on its surface in winter, making it denser and causing it to sink, only to float up again in the spring. Ancient, but not as old as the ironstone or the oil

Our clever biologist friend says the circle of jelly, that was stuck on the side wall of the pond, is probably water snail eggs. I hope so. I tried to introduce snails from our neighbour's pond, but I could barely see them and have not seen any in the water since. It provides a useful focal point for the picture