Search results
Results from the WOW.Com Content Network
Cliffs are usually composed of rock that is resistant to weathering and erosion. The sedimentary rocks that are most likely to form cliffs include sandstone , limestone , chalk , and dolomite . Igneous rocks such as granite and basalt also often form cliffs.
Since the flint is clearly more weathering- and erosion-resistant than the limestone, it collects on the beach of the chalk cliff and is transported to neighboring areas of the coast by waves and currents during storms and deposited there.
Chalk is a soft, white, porous, sedimentary carbonate rock.It is a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of microscopic plankton that had settled to the sea floor.
The products of chalk weathering are dissolved in rainwater and are transported in stream flow. Chalk streams transport little suspended material (unlike most rivers), but are considered "mineral-rich" due to the dissolved calcium and carbonate ions. The surface water of chalk streams is commonly described as "gin clear".
Such erosion landscapes are known as karsts. Limestone is less resistant to erosion than most igneous rocks, but more resistant than most other sedimentary rocks. It is therefore usually associated with hills and downland, and occurs in regions with other sedimentary rocks, typically clays. [85] [86]
Thermal stress weathering is an important mechanism in deserts, where there is a large diurnal temperature range, hot in the day and cold at night. [14] As a result, thermal stress weathering is sometimes called insolation weathering, but this is misleading. Thermal stress weathering can be caused by any large change of temperature, and not ...
The chalk outcrop at Flamborough Head in the north produces a headland relatively resistant to coastal erosion whilst the coastline south of this at such places as Mappleton and Hornsea with their soft glacial deposits are vulnerable.
Geological resistance is a measure of how well minerals resist erosive factors, and is based primarily on hardness, chemical reactivity and cohesion. [1] The more hardness, less reactivity and more cohesion a mineral has, the less susceptible it is to erosion.