04111 Geologypanelfinala/W
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Although the rock at the far This site is unique. The Permian Magnesian Limestone left of the cliff face looks rocks here are seen nowhere else in Britain. 255 million the geology of ‘new’, this is due to years ago, where you are standing was the shoreline of a mechanical quarrying. shallow tropical sea surrounded by desert, much like the The brown earth deposits above the limestone are present day Arabian Gulf. The sea, called the Zechstein glacial drift deposited in the Sea, covered low-lying areas of last Ice Age some 20,000 what later became northern years ago, and are 255 Europe. At the time 'Britain' Quarry Moor million years younger than the limestone beneath! was on the eastern edge of a been dissolved by water movement through the rock, super-continent and lay just leaving underground hollows that cause the land above to north of the equator. It's hard collapse creating subsidence holes in and around Ripon. to imagine, standing here Lewis Carroll may well have seen these holes and possibly surrounded by vegetation, that used them for his ideas in Alice in Wonderland. during this time Europe was On the River Ure at Ripon Parks, gypsum in the Permian marls hot and dry, much like the has been exposed and can be seen in the spectacular banks. Sahara today. The shore was very flat with algal mats covering much of the area between low and high water. The high temperatures Keep a look out for wrens. evaporated the water leaving gypsum deposits, especially (above) Cross The Magnesian Limestone, which forms a The limestone cliff face and nearest to the high water mark, to create a 'gypsum marsh'. section of the marked ridge running from Bedale to undergrowth are an ideal deposits on This is preserved as the teepee like structures in the Knaresborough passing to the west of Ripon, feeding ground for one of the Zechstein Britain’s smallest birds. contorted rocks to your right. The wavy algal mats are Sea shoreline. was quarried for Ripon's earlier buildings; it preserved in the lower rocks to your left. No animal fossils (right) Looking can be seen in boundary walls and the lighter have been found in these rocks formed at the mineral-rich out over the coloured parts of Ripon Cathedral. When the gypsum marsh waters edge. The diagram (above right) shows a section and algal mat Zechstein Sea dried up, gypsum was deposited through the shoreline deposits, and the illustration (far towards the in the marls and limestones that lie right) shows how the coast would have looked. lagoon. underneath Ripon. Some of the gypsum has In the Cambrian period GEOLOGICAL TIME LINE mya : millions of years ago Time of Magnesian Limestone rock formation Britain lay close to the Supported through the Defra Aggregates Levy Sustainability Fund south pole. We moved slowly northwards and during the Permian Period, when the rocks of Quarry Moor were formed, Britain lay just north of the equator. (01423) 887943. figurehead Designed by Stephen Huxley. Illustrations by.