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

How limestone formed.

Extracts from this document...


How limestone formed? Most limestones in our part of the world formed in shallow seas that covered our area hundreds of millions of years ago. Other names for limestone We use the scientific name "limestone" for this rock, but it is also known by many other names: When limestone is crushed into gravel and used for building roads or making concrete, it's often called an aggregate. Here are some ways to classify limestone (by grouping it with similar types of rocks): Geologists have a catch-all term that includes both limestone and dolostone. They call them carbonate rocks. Limestone is a sedimentary rock. How to recognize limestone Limestone is mostly light to dark gray in color. Its grains can be mud-sized, so that the rock looks dull, or they can be sand-sized or larger bits of broken shell or other limey material. You can scratch limestone into white powder with a nail or knife. (See more about the scratch test.) Limestone is made mostly of the mineral calcite, so it bubbles gently when you put a drop of white vinegar on it. ...read more.


Using the sharp point of the nail, try to scratch the surface of your rock. If the nail digs in and scratches off a line of powdered rock, then the nail is harder than the rock. In this case, the nail scratched off a line of powdered white limestone. If the nail does not scratch off any powdered rock, then the rock is harder than the nail. In this case, some of the nail rubbed off on the rock! This left a line of silvery metal on the white chert. (This happens pretty often when you try to scratch hard, light-colored rocks.) James Hutton (1727-1797), the eminent 18th century gentleman farmer and founder of modern geoscience, authored the concept of the rock cycle, which depicts the interrelationships between igneous, sedimentary, and metamorphic rocks. The upper part of the earth (mantle, crust and surface) can be envisioned as a giant recycling machine; matter that makes up rocks is neither created nor destroyed, but is redistributed and transformed from one rock type to another. ...read more.


igneous rocks form at sea floor spreading ridges. Fluid intrusion of these rocks, both during and after formation, results in some low grade metamorphism. As the rocks cool, and more magma is introduced from below, the plate is forced away from the spreading ridge, and acquires a sediment cover. As shown in the figure, in this case, the plate is eventually subducted under a continental plate. In the trench of the subduction zone, at relatively shallow depths, high pressure - low-high temperature metamorphism of the plate and its sediment cover occur. 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. This melt is either driven to the surface as volcanic eruptions, or crystallizes at depth to form plutonic igneous rocks. Sedimentary rocks form from the weathering, erosion, transport and deposition of arc material onto the continental platform and shelf. ...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. Compare and Contrast the Weathering Found in an Area of Limestone Country with that ...

    Limestone pavements contain a large number of features that make them easily recognisable. The surface is made up of clints and grykes that are widened by the weathering process of carbonation. The clints are not porous and therefore are not weathered as fast, but the grykes allow water to penetrate

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

    iron oxide, and magnesium oxide, which is burned together in a kiln and finely pulverised and used as an ingredient of mortar and concrete, which sets really dry and hard for good foundational support of large buildings. It is essential for the production of cement because it makes up almost

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

    Also I would have made another test on both Pen Y Fan and Cock marsh to compare the differences about a week later. This would show which footpath is eroding quicker. Overall I would have more photos that I took on the fieldwork trip, but my camera broke during the study, luckily I still have some photos.

  2. Soil is a product of its natural environment and the ways in which humans ...

    If a farmer doesn't leave the field fallow for a year, the crops take up the nutrients from the soil, and as the vegetation is removed at harvest, the vegetation isn't allowed to decay and thus add nutrients back to the soil.

  1. Dovedale - Limestone rocks.

    Unusual fauna that develop in this light deficient environment range from bacteria, crustaceans, spiders, fish and small mammals. These ecosystems are very sensitive to change. Changes in water percolation and airflow can significantly alter these stable environments effecting both life forms and the rates of bedrock dissolution.

  2. Sedimentary Rocks

    better preserved, such as the shells and bones, and these have to be extracted carefully form the materials around them. You would expect to find fossils in igneous rocks because they are formed from molten mixed up magma. Fossils would not survive in such conditions.

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

    find the energy of the transport medium at the time of deposition, this card will also to be used to checked the sorting of the rock, which will show the rate of deposition. I will look for any fossils in the rock, as they will help to show if there

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

    Reasons for Studying a Graveyard: I have chosen to study a graveyard because: - There are all three rock types: igneous, sedimentary and metamorphic. - It is relatively easy to see the stones, whereas if I were to study a cliff, for instance, it would be hard to study the middle of the cliff.

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