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:

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

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)

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.

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

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

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

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

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

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

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

13- coast: land close to the sea.

14- mountain: natural elevation of land very high.

15- mountain range: part of a mountain system.

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

17- glacier: create U-shaped valleys

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

19- hill: natural elevation not very high

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

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

22- fluvial valley: has V-shape

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

THE MOST IMPORTANT LANDFORMS ON EACH CONTINENTS:

Mountains, plateaus and plains.

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

• 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.