Geomorphology 1254

1. Geomorphology 1254

2. • compensate, and more dissolved carbon dioxide
reacts with the water to make more carbonic acid.
The process raises the concentration by about
8 mg/l, but it also brings the carbon dioxide partial
pressure of the air (a measure of the amount of
carbon dioxide in a unit volume of air) and in the
water into disequilibrium. In response, carbon
dioxide diffuses from the air to the water, which
enables further solution of limestone through the
chain of reactions.
Diffusion of carbon dioxide through water is
a slow process compared with the earlier reactions
and sets the limit for limestone solution rates.
Interestingly, the rate of reaction between carbonic
acid and calcite increases with temperature, but
the equilibrium solubility of carbon dioxide
decreases with temperature. For this reason, high
concentrations of carbonic acid may occur in cold
regions, even though carbon dioxide is produced
at a slow rate by organisms in such environments.
Carbonation is a step in the complex weather -
ing of many other minerals, such as in the
hydrolysis of feldspar.
Hydrolysis
Generally, hydrolysis is the main process of
chemical weathering and can completely decom -
pose or drastically modify susceptible primary
minerals in rocks. In hydrolysis, water splits into
hydrogen cations (H+) and hydroxyl anions
(OH–) and reacts directly with silicate minerals in
rocks and soils. The hydrogen ion is exchanged
with a metal cation of the silicate minerals, com -
monly potassium (K+), sodium (Na+), calcium
(Ca2+), or magnesium (Mg2+). The released cation
then combines with the hydroxyl anion. The
reaction for the hydrolysis of orthoclase, which has
the chemical formula KAlSi
3O8, is as follows:
2KAlSi
3O8 + 2H+ 2OH– 2HAlSi3O8 + 2KOH
So the orthoclase is converted to aluminosilicic
acid, HAlSi3O8, and potassium hydroxide, KOH.
The aluminosilicic acid and potassium hydroxide
are unstable and react further. The potassium

3. • compensate, and more dissolved carbon dioxide
reacts with the water to make more carbonic acid.
The process raises the concentration by about
8 mg/l, but it also brings the carbon dioxide partial
pressure of the air (a measure of the amount of
carbon dioxide in a unit volume of air) and in the
water into disequilibrium. In response, carbon
dioxide diffuses from the air to the water, which
enables further solution of limestone through the
chain of reactions.
Diffusion of carbon dioxide through water is
a slow process compared with the earlier reactions
and sets the limit for limestone solution rates.
Interestingly, the rate of reaction between carbonic
acid and calcite increases with temperature, but
the equilibrium solubility of carbon dioxide
decreases with temperature. For this reason, high
concentrations of carbonic acid may occur in cold
regions, even though carbon dioxide is produced
at a slow rate by organisms in such environments.
Carbonation is a step in the complex weather -
ing of many other minerals, such as in the
hydrolysis of feldspar.
Hydrolysis
Generally, hydrolysis is the main process of
chemical weathering and can completely decom -
pose or drastically modify susceptible primary
minerals in rocks. In hydrolysis, water splits into
hydrogen cations (H+) and hydroxyl anions
(OH–) and reacts directly with silicate minerals in
rocks and soils. The hydrogen ion is exchanged
with a metal cation of the silicate minerals, com -
monly potassium (K+), sodium (Na+), calcium
(Ca2+), or magnesium (Mg2+). The released cation
then combines with the hydroxyl anion. The
reaction for the hydrolysis of orthoclase, which has
the chemical formula KAlSi
3O8, is as follows:
2KAlSi
3O8 + 2H+ 2OH– 2HAlSi3O8 + 2KOH
So the orthoclase is converted to aluminosilicic
acid, HAlSi3O8, and potassium hydroxide, KOH.
The aluminosilicic acid and potassium hydroxide
are unstable and react further. The potassium

4. • compensate, and more dissolved carbon dioxide
reacts with the water to make more carbonic acid.
The process raises the concentration by about
8 mg/l, but it also brings the carbon dioxide partial
pressure of the air (a measure of the amount of
carbon dioxide in a unit volume of air) and in the
water into disequilibrium. In response, carbon
dioxide diffuses from the air to the water, which
enables further solution of limestone through the
chain of reactions.
Diffusion of carbon dioxide through water is
a slow process compared with the earlier reactions
and sets the limit for limestone solution rates.
Interestingly, the rate of reaction between carbonic
acid and calcite increases with temperature, but
the equilibrium solubility of carbon dioxide
decreases with temperature. For this reason, high
concentrations of carbonic acid may occur in cold
regions, even though carbon dioxide is produced
at a slow rate by organisms in such environments.
Carbonation is a step in the complex weather -
ing of many other minerals, such as in the
hydrolysis of feldspar.
Hydrolysis
Generally, hydrolysis is the main process of
chemical weathering and can completely decom -
pose or drastically modify susceptible primary
minerals in rocks. In hydrolysis, water splits into
hydrogen cations (H+) and hydroxyl anions
(OH–) and reacts directly with silicate minerals in
rocks and soils. The hydrogen ion is exchanged
with a metal cation of the silicate minerals, com -
monly potassium (K+), sodium (Na+), calcium
(Ca2+), or magnesium (Mg2+). The released cation
then combines with the hydroxyl anion. The
reaction for the hydrolysis of orthoclase, which has
the chemical formula KAlSi
3O8, is as follows:
2KAlSi
3O8 + 2H+ 2OH– 2HAlSi3O8 + 2KOH
So the orthoclase is converted to aluminosilicic
acid, HAlSi3O8, and potassium hydroxide, KOH.
The aluminosilicic acid and potassium hydroxide
are unstable and react further. The potassium