Geography Question 1

Relief

Andes Mountains

-Formed by the subduction of the Nazca and South American plates, causing uplift

-Formed in the Jurassic period but began to take their present form in the Cretaceous period

-World's longest continental mountain range - 7000km 

-Highest point 6,962m 

Basin

-Three types of rivers contribute sediment to the basin - clear, black and white.

-Whitewater carries sediment and floods can rise 16-20m due to the basin having a gradient of 2cm per km and 8 tonnes of alluvium per ha.

-Clear waters rise from the Brazilian plateau and carry little sediment as they run over old hard rock

-Blackwater tributaries rise from the Guyana plateau and carry swamp material darkening their waters.

Amazon river

-Sediments carried in three main ways: Dissolved load, suspended load and bed load.

Weathering

-Chemical weathering: Rain bonds with Carbon Dioxide forming acid rain, which breaks rock down into sediments. Rainwater bonds with minerals in the rocks on the Andes and weakens the bonds.

-Physical weathering: Perspiration builds up in the rock wedge's during the day, and overnight as the temperatures drop the water forms ice, which expands and breaks the rock into sediments. When the temperature is -15 degrees -5 degrees ice wedges form and break the rock into the sediments. 

-Thin soil saturated by rain which then slips down the Andes

Climate

No Dry

-Two rain processes interact in…