• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Describe the characteristics of chalk and the land forms typical of chalk areas

Extracts from this document...

Introduction

Describe the characteristics of chalk and the landforms typical of chalk areas Chalk is a soft white or whitish form of limestone, composed of the remains of small marine organisms. It formed after the shells and skeletons of these organisms were deposited in a thick layer on the sea bottom. Chemically, chalk is almost pure calcium carbonate with traces of other minerals. It ranges in hardness and texture from very soft porous varieties to harder close-grained types. ...read more.

Middle

This is the reason why distinctive rolling hills and vales are common in chalk scenery areas. Chalk scenery is also closely associated with the development of escarpments or cuestas which have steep scarp slopes and gentle dip slopes. However these features are more a product of erosion than of weathering. As with all limestone scenery, there is little surface drainage on chalk. Dry valleys are common features, and the size of these suggests different climatic conditions in earlier times. ...read more.

Conclusion

* The freezing of water in rock pores during glacial periods caused the chalk to become impermeable and allowed surface drainage to develop. Later, as temperatures rose and ice melted, the chalk once again became permeable causing the surface streams to disappear, leaving dry valleys behind. * The streams and their valleys developed on an overlying layer of impermeable rock. This layer was removed by a combination of weathering and erosion, resulting in the valleys being gradually superimposed on the underlying permeable chalk. * Surface drainage developed during periods of significantly higher rainfall than at present. When the rainfall decreased the water-table dropped, leaving behind dry valleys. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Rocks & Weathering section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Rocks & Weathering essays

  1. Free essay

    Outline the major landforms associated with Periglacial landscapes and discuss their formation.

    These are areas of rock and soil that are constantly active moving and changing shape on the slopes of the Periglacial environment. Another process affecting the topography of the land was that of nivation. Nivation is a process that sees the snowfall venture into the warmer climate.

  2. Determining the paleoenviroment and tectonic history of a small area (Cocklawburn Beach)

    I have used this photo to show bed 21-23 as it is clearer Bed 22: This coal layer has formed very close to another coal layer, which shows that the area stayed as a swampy land for a long time.

  1. 'I think that sedimentary stones will be more affected by weathering than igneous stones.' ...

    - On the one hand I think that the 'thumb' method of grading the stones was very effective because it meant that in Granite rocks, for example, that have less obvious visual flaws, I could grade them more decisively. However, on the other hand, the rock grading scheme was not

  2. Find out why there is no Carboniferous Limestone visible around the Somerset area.

    The maps will be used to find the relative thickness of the Rocks in Somerset on the levels and in the Mendips to illustrate a big hole in the carboniferous section in Somerset. Having looked at the maps, I have seen that there are different scales in the graphs.

  1. Construct two Graphic Log Sections, one on the eastern exposure (ST 3375 6645) and ...

    Banding shows differing layers in texture of colour. 9 Limestone Corals, bivalves and slikenslides. This limestone was probably formed in relatively shallow water as a reef. The evidence for this is, the fossils that are found within it, corals and bivalves. Slickensides happen when the surface of the rock has become polished or striated from the grinding or sliding motion of an adjacent rock mass.

  2. To What Extent Does Limestone Give Rise To Distinctive Land Forms.

    Massive Limestone from the Carboniferous Period (Of, belonging to, or denoting a geologic division of the Paleozoic Era following the Devonian and preceding the Permian, including the Mississippian Period and the Pennsylvanian Period and characterized, especially in the Pennsylvanian, by swamp formation and deposition of plant remains later hardened into coal.)

  1. In this Essay I will inform you of the social, economic and environmental advantages/ ...

    which since Calcium is one of the highest metals in the reactivity series can be formed very fast, because of its vast quantities cheaply, and in mass production. Because its about the most highest reactive metal that's also in vast quantities it forms glass that's a very unreactive stable bonded

  2. Compare and Contrast the Weathering Found in an Area of Limestone Country with that ...

    This matter produces humic acids as it decomposes that are considered important in promoting carbonation because the weathering of rock under soil appears more active than where bare rock is exposed. In Ingleborough in the Yorkshire Dales National Park, there are many specific limestone features.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work