The River Swale is a river in Yorkshire, England and a major tributary of the River Ure, which itself becomes the River Ouse, emptying into the North Sea via the Humber Estuary. The river bed is a sedimentary rock composed largely of the minerals calcite abnd aragonite, which are different crystal forms of calcium carbonate, if you look closely the rockbed here contains skeletal fragments of marine organisms.
There are three distinct geological areas in Upper and Mid Swaledale. the upper reaches of the river flow over Carboniferous, Permian and Triassic rock, all of which are atop a layer of Lower Paleozoic beds. These rocks are rich in minerals and metalliferous sulfide ores such as Galena, Sphalerite, Chalcopyrite and Bravoite. There are also deposits of Fluorite, Barite, Witherite, Calcite, Dolomite and Barytocalcite.
Over time rivers can cut through bedrock. Rivers flowing over soft sedimentary rocks can cut deep gorges and canyons. Geoligists call river deposits alluvium. Waterfalls form when the river flows over an area with layers of harder and softer rocks. Soft rocks are quickly worn away while harder rocks resist erosion. The resistant layers form a lip which the water cascades over as you can see in front of you.
Questions:
1. Explain what the horizontal slabs of the riverbed are made from?
2. Describe the shape of the of the rocks that make up the waterfall and why they are this shape?
3. Look across the waterfall to the opposite side of the river, there is a outcrop, explain what this outcrop is made up from?
4. Estimate the height of this outcrop?
Please email your answer, and photos are always welcome.