LANDFORMS

Waht is a lanform?

A landform is a feature on the surface of a terrain, natural landforms usually form and change very gradually; some can take millions of years:

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UNDERWATER: COASTAL:
1- mid-ocean ridge 1- cape 6-river mouth
2- abyssal plain 2- gulf 7- cliff
3- oceanic trench 3- bay 8- island
4- continental slope 4- peninsula 9- coast
5- continental shelf 5- delta

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RELATED TO RELATED TO
HIGH ALTITUDE: LOW ALTITUDE:
1-mountain 1- plain
2-mountain range 2- flood plain
3- mountain system 3- coastal plain
4- glacier 4- valley
5- plateau 5- fluvial valley
6- (hill) 6- depression
7- (hill)

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1- mid-ocean ridge: an underwater mountain in the middle of the ocean.

2- abyssal plain: an area of flat seafloor at a depth of 4.000 meters

3- oceanic trench: large depression on the seafloor near a continent.

4- continental slope: a steep slope which separates the end of the continental shelf from the oceanic floor.

5-continental shelf: sloping plain which joins the continents to the seabed, it is part of the continental

crust but it is beneath the sea water.

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6- cape: a large piece of land sticking out into the sea.

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7- gulf: large area of sea between two capes.

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8- bay: is smaller than gulf and the entrance is more closed off.

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9- peninsula: area of land almost completely surrounded by sea, it is only connected to the mainland by a narrow strip of land.

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10- Delta: a body of sediment deposited at the mouth of a river.

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11- cliff: a high, steep area of rock which suddenly meets the sea.

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12- island: is a piece of land surrounded by sea.

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13- coast: land close to the sea.

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14- mountain: natural elevation of land very high.

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15- mountain range: part of a mountain system.

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16- mountain system: group of mountains that are related.

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17- glacier: create U-shaped valleys

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18- plateau: flat landform that is elevated above the sea level

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19- hill: natural elevation not very high

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20- plain: flat land near a river or near the coast.

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21- valley: depression between upland areas, like mountains. Are always formed by the force of water, either as a liquid or solid

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22- fluvial valley: has V-shape

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23- depression: area of land that is lower than the area around it.

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THE MOST IMPORTANT LANDFORMS ON EACH CONTINENTS:

Mountains, plateaus and plains.

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GEOLOGICAL STAGES:The Earth’s surface is constantly changing. During these changes and evolution, we can identify different geological stages.

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• Precambrian time (4500 to 542 mya). The first
mountain ranges formed. Erosion destroyed them.

• Palaeozoic Era (542 to 250 mya). New mountain
ranges composed of hard materials formed.

• Mesozoic Era (250 to 65 mya). The sea covered dry
land and there was intense sedimentation.
• Cenozoic Era (66 mya) is divided into three Periods:
– Paleogene Period (66 to 23 mya). Tectonic plate
movement and alpine orogeny occurred. This
formed young mountain ranges, such as the Alps.
– Neogene Period (23 to 2.58 mya). Continental
movements occurred, most importantly between
North and South America.
– Quaternary Period (2.58 mya to present). There
were periods of glaciation when ice covered a
large part of the continents. This caused intense
erosion in mountain areas.