Internal Structure of the Earth
The evidence used to study the earth’s interior are
1. mining
2. drilling
3. quarrying/excavation
A. Crust/Lithosphere
- Outermost layer of the earth
- Made of soils and other loose deposits of sand
- The dominant rocks are granites.
- Extends 0-50km
- Has 2 layers
1. Sial
- Also called continental crust
- Made of light coloured rocks
- Called sial because it’s made up of silica and aluminium.
2. Sima
- Also called oceanic crust
- Mainly made of basaltic rocks which are brittle.
- Called sima because it is made of silica magnesium and iron.
Mohorovicic Discontinuity (Moho)
- A definite zone of discontinuity between the crust and the mantle.
- Was discovered by Dr. Andrija Mohorovicic in 1909.
B. The Mantle/Asthenosphere
- Layer lying between the crust and the core
- Made of iron and magnesium
- Has two layers
1. Upper mantle
- Rocks are more elastic than those of sima.
- Temperature is about 1000?c.
2. lower mantle
- Rocks are like very viscous liquid.
- Temperature ranges between 1000?c to 3000?c.
marto answered the question on
March 22, 2019 at 06:55