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

The Earths Crust.

Extracts from this document...


Sedimentary Rock Sedimentary rocks are layers of dirt, sand or little pieces of rock that are compressed very tight to form a single rock. Sedimentary rocks are formed somewhere where there is loose bits of sand, dirt or little pieces of rock. It needs an area of pressure where the rock can be compressed, like a very deep ocean which will force the rock down. The dirt falls on the bottom of the sea bed and slowly accumulates layer after layer, while the pressure from the ocean compresses it. Only sedimentary rocks contain fossils. Metamorphic rocks and igneous rocks have been through too much heat to have any fossils left in them. Fossils are very useful to identify the age of the rock, because they can be compared to known ages. Sandstone is an example of sedimentary rock. This is formed from sand and it looks like sand. The rock looks like sand squashed very tightly together. There are two different types red sandstone and yellow sandstone. Limestone is formed from sea shells. Mostly formed with calcium carbonate, which is grey or white coloured. ...read more.


Then again the metamorphic rock can either rise to the surface or descend further where it will become magma. When magma reaches the surface it cools and becomes igneous rock, extrusive rock comes straight out of the volcano, but intrusive rock sets below as a big bump below the surface. When all of the rock reaches the surface, the weathering will begin to gradually wear down the rock and it will be carried of to the sea. The process then starts again at the beginning. Weathering/Water cycle Weathering is the process in which rocks are broken up and worn down. There are three types: Physical weathering which is caused by the ice in the cracks of rocks. This is where rain water floods into the cracks in the rocks, and when the temperature drops below zero the water turns into ice, as the water freezes the expansion pushes the rock apart. This happens repeatidly until the rock is pushed apart enough for a piece to break off. Chemical weathering is caused by acid rain onto limestone. All rain is a very weak acid, so very slowly it will dissolve the limestone. Biological weathering which is caused by plant roots in the cracks of rocks. ...read more.


These magnetic stripes were only discovered in the 1960's. Plate Boundaries. Plate boundaries are between tectonic plates, they're usually trouble like volcanoes and earthquakes there are three different ways that plates interact: Colliding, separating and sliding past each other. Oceanic and continental plates sliding past each other. The oceanic plate is always forced underneath the continental plate. This is called a subduction zone. As the oceanic crust is pushed down it melts and pressure builds up due to all the melting rock. This molten rock finds its way to the surface and volcanoes form. There are also earthquakes as the two plates slowly grind past each other. A deep trench forms on top of the ocean floor where the oceanic plate is being forced down. The continental crust crumples and folds forming mountains at the coast. When two continental plates collide and meet head on. Any sediment layers lying between the two continent masses get squeezed between them. These sediment layers inevitably start crumbling and folding and soon form into big mountains. The Himalayan Mountains are an example of this. Sea floor spreading. When tectonic plates move apart, magma rises up to fill the gap and produces new crust made of basalt. The mid-atalnatic ridge runs the whole length of the atlantic and actually cuts thorugh the middle The Earths Crust Page 1 ...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. Determining the paleoenviroment and tectonic history of a small area (Cocklawburn Beach)

    are any special environmental conditions in the area during that time of disposition. I will also use evidence of any sedimentary structures to determine the environment of deposition. I will also examine the colour of the rocks to try and determine the mineral and oxygen content, as this can be

  2. I am trying to find out how footpath erosion on Pen Y Fan which ...

    However, if I were to do it again I think there would be some additions and some changes that I would make. In the backround information section I would try to find out more about Cock Marsh. In the data presentation section I would have tried to include more different graphs.

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

    Figure 4: Swallow holes and their formation Shake holes, also called Dolines, are surface depressions in a limestone area with dense joints and bedding planes. They can be formed in two separate ways. Firstly, limestone may often be covered in boulder clay two or three metres thick.

  2. Rock types.

    The may have really tiny crystals. * Contact metamorphism - recrystallization of pre-existing rocks due to high temperatures and pressures. This can happen when in igneous intrusion bakes surrounding rocks and may cause them to recrystallize. Also, when the sedimentary rock, mudstone, is changed by contact metamorphism, it first produces slate (low grade metamorphism), then schist and then gneiss (high grade metamorphism).

  1. James Hutton (1727-1797), the eminent 18th century gentleman farmer and founder of modern geoscience, ...

    As the plate travels deeper, high temperature conditions cause partial melting of the crustal slab. Fluid intrusion plays a key role in partial melting. As the partial melt rises, and intrudes into the continental plate, the surrounding country rock is contact metamorphosed at high temperature conditions.

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

    How Does the limestone industry benefit glass production and manufacturing? Calcium Oxide, a product formed from the decomposition of Calcium Carbonate) is cheap and plentiful and can be applied to sand( sodium dioxide)and heated strongly to form Calcium Silicate(Common Glass)

  1. Classification of Igneous rocks.

    Chemistry composition= Chemical composition of igneous rocks is the most distinguishing feature. * The composition usually reflects the composition of the magma, and thus provides information on the source of the rock. * The chemical composition of the magma determines the minerals that will crystallize and their proportions.

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

    Some had been eroded and weathered away making it difficult to recognise them How we collected our fieldwork data is shown in the table below. Analysis and Conclusions Location 1 Eastern Exposure, Middle Hope (ST 3375 6645) Rock Unit Rock Type/ Colour/ Grain size Sedimentary Structures/ Fossils/ Other Explanation on

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