rocks are found in the south and southeastern Libya and in
northern Fezzan. By and large, Libya contains thick
sequences of moderately deformed Paleozoic rocks, and
aside from the northwest and northeast, Mesozoic sedimentary rocks are comparatively thin. Tertiary rocks occupy
the greater part of the Sirte embayment and northern
Benghazi (Goudarzi 1970). Tertiary and Quaternary extrusive and intrusive rocks occupy wide regions in the central
part of the country and smaller areas in south-central Fezzan
and northern Tripoli.Quaternary age and the greater part of
the Libyan desert are both covered by immense gravel plains
and sand dunes (these sand dune areas were also formed
during the Quaternary time) (Goudarzi 1970).
In Libya, the soil mineralogy is strongly dependent on the
parent material (or parent rock) from which soils were
formed. Besides, dry climatic conditions affect both the form
and rate of physical and chemical weathering of the soil
parent material (Zurqani et al. 2019). Hence, the Libyan soils
consist of the following parent materials (Solkhozprom
Export 1980; Ben Mahmoud 1995):
• Local (Residuum) parent material: Local residuums the
parent material that weathered in place from bedrock,
typically millions of years old, and it is usually called
(Eluvial), and these sediments are found in the mountains
of Tripoli and the Al Jabal Al Akhda, and these sediments
include Igneous rocks (Basalt) and Marine sedimentary
rocks.
• Transported parent material: Transported parent
material is material that is formed from the rocks as a
result of weathering processes and then is transported to
sites near or far from the parent rock by wind, water, and
gravity. This type of parent material covers large areas in
Libya and can be divided into
– Wind transported parent material (Eolian): Eolian
is the sediments that were transported by the winds,
and they are one of the most widespread Libyan soil
materials. This parent material covers the areas of the
Jafara Plain, the coastal areas, and some other regions
such as Sarir, Kufra, Qaminis, Suluq, and Sirte. These
sediments are in the size of grains of sand and thus are
known as sandy sediments, or in the size of silt and are
known as silty sediments, also called loess.
– Water transported parent material (Alluvium):
Alluvium is the parent material transported by water,
and it consists of igneous and sedimentary rocks.
Within this type of parent material, there are several
important types:
• Floodplain sediments (Alluvial): These sediments cover
the lands of the valleys and contain various amounts of
sand, clay, and gravel, as well as some amounts of calcium carbonate and gypsum.
• Deluvial (colluvial), or Mixed (Eluvial-Deluvial) sediments: These sediments are found on talus drift and creep
fans in the hilly regions in Al Jabal Al Akhdar and the
Tripoli Mountains. Generally, these sediments are not
formed as layers, but are formed in the soils of Vertisols
and Inceptisols in the Al Jabal Al Akhdar region. In
addition, they formed the soils of Entisols and Inceptisols
in the mountainous region of Tripoli.
• Stream water sediments (Proluvial): These types of
sediments are accumulated on the lower parts of the
slopes forming large debris cones. They are found in the
areas of AlJabal AlAkhdar and the Tripoli Mountains in
small waterways and some small valleys. Usually, they
differ in the textures, are rich in stones, and stones are
often intercalated with carbonates and gypsum. These
sediments are considered to be the parent materials of the
Xeralfs (Terra Rossa soils of the Mediterranean region).
They may be also found combined with the sediments of
the flood valleys, as is the case in the regions of Al Marj
and east Gharyan.
• Marine floor and Salt Lake (Sabkha) sediments: These
sediments are found along the Libyan coastal strip, which
are shallow marine pools, consisting of layers of different
textures. Usually, they contain saline or salt crust on the
surface, and this type of parent material formed the Salids
(one of accumulation of an excessive amount of salts that
are more soluble than gypsum).
• Coastal mound sediments: These types of sediments can
be distinguished based on their geological structure,
which includes Qerqarish formation sediment (consists of
sand, clay, and limestone deposits), GasrAl Hajj formation sediment (consists of pebbles that vary in size,
number, and degree of cohesion associated with layers of
caliche), and Jafara formation sediment (consists of sandy
and silt deposits with layers of caliche rocks).
Due to this dissection and the effect of lithological variations, it is clear that the surface geological structure of the
country varies from one region to another, and this variation
is largely reflected in the parent materials of the Libyan soils.
Hence, wherever these materials are found they differ in
terms of their physical, mineral, and chemical properties,
which in turn are nearly inherited to the soils in which they
will be formed.
3.2.5 Time
Time is also a component for the other factors to interact
with the soil. Over time, soils exhibit features that reflect the
other forming factors (vegetation and climate act on parent
material and topography). Soil formation is a continuous
42
K. R. Ben Mahmoud and H. A. Zurqani
northern Fezzan. By and large, Libya contains thick
sequences of moderately deformed Paleozoic rocks, and
aside from the northwest and northeast, Mesozoic sedimentary rocks are comparatively thin. Tertiary rocks occupy
the greater part of the Sirte embayment and northern
Benghazi (Goudarzi 1970). Tertiary and Quaternary extrusive and intrusive rocks occupy wide regions in the central
part of the country and smaller areas in south-central Fezzan
and northern Tripoli.Quaternary age and the greater part of
the Libyan desert are both covered by immense gravel plains
and sand dunes (these sand dune areas were also formed
during the Quaternary time) (Goudarzi 1970).
In Libya, the soil mineralogy is strongly dependent on the
parent material (or parent rock) from which soils were
formed. Besides, dry climatic conditions affect both the form
and rate of physical and chemical weathering of the soil
parent material (Zurqani et al. 2019). Hence, the Libyan soils
consist of the following parent materials (Solkhozprom
Export 1980; Ben Mahmoud 1995):
• Local (Residuum) parent material: Local residuums the
parent material that weathered in place from bedrock,
typically millions of years old, and it is usually called
(Eluvial), and these sediments are found in the mountains
of Tripoli and the Al Jabal Al Akhda, and these sediments
include Igneous rocks (Basalt) and Marine sedimentary
rocks.
• Transported parent material: Transported parent
material is material that is formed from the rocks as a
result of weathering processes and then is transported to
sites near or far from the parent rock by wind, water, and
gravity. This type of parent material covers large areas in
Libya and can be divided into
– Wind transported parent material (Eolian): Eolian
is the sediments that were transported by the winds,
and they are one of the most widespread Libyan soil
materials. This parent material covers the areas of the
Jafara Plain, the coastal areas, and some other regions
such as Sarir, Kufra, Qaminis, Suluq, and Sirte. These
sediments are in the size of grains of sand and thus are
known as sandy sediments, or in the size of silt and are
known as silty sediments, also called loess.
– Water transported parent material (Alluvium):
Alluvium is the parent material transported by water,
and it consists of igneous and sedimentary rocks.
Within this type of parent material, there are several
important types:
• Floodplain sediments (Alluvial): These sediments cover
the lands of the valleys and contain various amounts of
sand, clay, and gravel, as well as some amounts of calcium carbonate and gypsum.
• Deluvial (colluvial), or Mixed (Eluvial-Deluvial) sediments: These sediments are found on talus drift and creep
fans in the hilly regions in Al Jabal Al Akhdar and the
Tripoli Mountains. Generally, these sediments are not
formed as layers, but are formed in the soils of Vertisols
and Inceptisols in the Al Jabal Al Akhdar region. In
addition, they formed the soils of Entisols and Inceptisols
in the mountainous region of Tripoli.
• Stream water sediments (Proluvial): These types of
sediments are accumulated on the lower parts of the
slopes forming large debris cones. They are found in the
areas of AlJabal AlAkhdar and the Tripoli Mountains in
small waterways and some small valleys. Usually, they
differ in the textures, are rich in stones, and stones are
often intercalated with carbonates and gypsum. These
sediments are considered to be the parent materials of the
Xeralfs (Terra Rossa soils of the Mediterranean region).
They may be also found combined with the sediments of
the flood valleys, as is the case in the regions of Al Marj
and east Gharyan.
• Marine floor and Salt Lake (Sabkha) sediments: These
sediments are found along the Libyan coastal strip, which
are shallow marine pools, consisting of layers of different
textures. Usually, they contain saline or salt crust on the
surface, and this type of parent material formed the Salids
(one of accumulation of an excessive amount of salts that
are more soluble than gypsum).
• Coastal mound sediments: These types of sediments can
be distinguished based on their geological structure,
which includes Qerqarish formation sediment (consists of
sand, clay, and limestone deposits), GasrAl Hajj formation sediment (consists of pebbles that vary in size,
number, and degree of cohesion associated with layers of
caliche), and Jafara formation sediment (consists of sandy
and silt deposits with layers of caliche rocks).
Due to this dissection and the effect of lithological variations, it is clear that the surface geological structure of the
country varies from one region to another, and this variation
is largely reflected in the parent materials of the Libyan soils.
Hence, wherever these materials are found they differ in
terms of their physical, mineral, and chemical properties,
which in turn are nearly inherited to the soils in which they
will be formed.
3.2.5 Time
Time is also a component for the other factors to interact
with the soil. Over time, soils exhibit features that reflect the
other forming factors (vegetation and climate act on parent
material and topography). Soil formation is a continuous
42
K. R. Ben Mahmoud and H. A. Zurqani