Soil Formation

Rock mineral and organic matter combination

Rock minerals cannot support plant growth, organic matter not structurually sound

RM/OM 50% whilst pores the other 50%

Mineral compostion of the parent rocks

Limestone and chalk made of prehistoric animals, whilst coal of plants

Silicon combines with O2, the less the easier they break up

Magma solidifcation,

Ultrabasic -45 Basic - 45-55 Intermediate 55-65 Acidic -65-85

Removal of early formed crystals from homogenous magma so these crystals prevented from further reaction with the residual melt

Foun in silica rich magma formed by fractional crystallisation associated with continental crust, then magma rise and cooling

Quartz, feldspar and micas high melting points, crystalling first

Explains order of mineral crystallisation with cooling

Physical Chemistry

Different mineral compositon, different rates of thermal expansion

Temperature difference between inner-outer parts of rock causes

Freeze-thaw

Hydrolysis, carbonation, hydratio, dissolution, oxidation/reduction

This is caused by biological activity with CO2 respiration and dissolution in H2O forming carbonic acid

This is mineral water absorption without ion formation

This is minerals dissolving in water like NaCl and KCl

This is the take up and removal of oxygen or electrons

All dead and living life, based on carbon content being 58% of total weight of organic matter

Binds soil particles in to aggreagtes, supplies nutrients to plants

Form electrostatically with water and minerals and organic matter