Lernkarten
2.1 Parent Material
The bedrock is also called parent material. What does it determine for soils?
2.1 Parent Material
What are Magmatic rocks? Name three examples for a magmatic rock and explain how they are formed.
- Rhyolite
- Granite
- Basalt
These form through the crystallization of melted silicates on the earth's surface (Intrusive rocks/ plutonic rochs are slow cooling and extrusive rocks/ volcanic rocks are fast cooling). The soil development depends on the way of crystallization of the mineral.
2.1 Parent Material
What are Metamorphic rocks? Name three examples for a magmatic rock and explain how they are formed.
- Gneiss
- Slate
- Phyllite
These rocks consist of already produced minerals and are formed through high temperatures (~200°C (rock does not melt)) and very high pressure. They are formed in the depths of the earth's crust (not on the surface).
2.1 Parent Material
What are Sedimentary rocks? Name three examples for a magmatic rock and explain how they are formed.
- Breccia
- Conglomerate
- Claystone
These rocks cover 75% of the earth's surface but are only a very small part of the lithosphere. They are formed through the mechanical weathering of debris (breccia, conglomerate, sandstone, shale), through precipitation (rock salt, iron ore, flint, dolomite*, limestone*) or accumulation of plant or animal debris (dolomites*, limestones*).
* some types of xx
2.2 Diagenesis and Metamorphosis
What is "diagenesis"?
What is "metamorphosis"?
There is no sharp boundary between diagenesis and metamorphism.
Diagenesis: the process that describes physical and chemical changes in sediments first caused by water-rock interactions, microbial activity and compaction after their deposition. The increase of pressure and temperature only starts to play a role as sediments get buried much deeper in the Earth's crust.
Metamorphosis: occurs at higher temperatures and pressures than diagenesis.
(source: Wikipedia)
2.2 Diagenesis and Metamorphosis
Explain the lithosphere cycle.
Things are always evolving and changin. When living things die, they can become sediments. Diagenesis makes sedimentary rock from loose materials which then either build soil, go through metamorphosis again or sinks down, melts and becomes magma.
2.3 Minerals
What are minerals?
e.g. properties, composition, structure, importance
properties: homogenous components of the earth's crust in terms of physical and chemical properties
composition: solid chemical compounds such as salts, oxides, hydroxides. They occur in pure form.
structure: with a specific crystal structure or without a crystal structure (= amorphous minerals)
importance: important soil components, starting products for weathering and the formation of secondary minerals
