Soil-types-of-Kerala.and precious land pdf

Introduction:
Folding, a fundamental process in structural geology, embodies the dynamic interaction between tectonic forces and the Earth's crust. Understanding the mechanics behind folding is essential for deciphering the deformation history of rock layers and unraveling the complexities of geological structures. This essay explores the mechanics of folding in structural geology, shedding light on the processes that shape the Earth's crust and drive geological evolution.

Fundamental Principles of Folding:
Folding occurs when compressional or extensional forces act upon rock layers, causing them to bend and deform. The mechanical behavior of rocks under stress is governed by principles of elasticity, plasticity, and rheology. Initially, rocks deform elastically, exhibiting reversible strain. However, as stress accumulates, rocks may undergo plastic deformation, resulting in irreversible changes in shape and structure. The rheological properties of rocks, such as their composition, temperature, and pressure conditions, influence their response to deformation and the style of folding observed.

Types of Folds:
Folds manifest in a variety of forms, each reflecting the interplay between tectonic forces and rock properties. Anticlines and synclines represent convex-upward and concave-upward folds, respectively, formed by compressional stresses. Overturned and recumbent folds involve significant tilting of the axial plane, indicating intense deformation. Monoclines and chevron folds exhibit more complex geometries, often associated with localized faulting or folding over basement structures. The diversity of fold types underscores the heterogeneous nature of tectonic processes and the intricate mechanics governing rock deformation.

Factors Influencing Folding:
Several factors influence the mechanics of folding, including the magnitude and direction of tectonic forces, the mechanical properties of rocks, and the presence of pre-existing structures. Convergent plate boundaries, where crustal plates collide, are primary sites of folding and mountain building. Divergent boundaries, characterized by crustal extension, may produce rift-related folding and basin formation. Additionally, the orientation of bedding planes, foliation, and fractures within rock layers can influence the style and orientation of folds.

Deformation Mechanisms:
The mechanisms driving folding include flexural slip, layer-parallel shortening, and buckling. Flexural slip occurs when layers of differing competence within a rock unit slide past each other, leading to the development of hinges and limbs in folds. Layer-parallel shortening involves the contraction of individual layers parallel to their bedding planes, resulting in the development of tight, closely spaced folds. Buckling occurs when compressive forces exceed the elastic limit of rocks, causing them to buckle and fold into characteristic shapes.

Conclusion:
The mechanics of folding in structural geology represent.

1. Soil types of Kerala
1) Alluvial soil
2) Coastal soil
3) Laterite soil
4) Redsoil
5) Black soil
6) Peat soil
7) Acid saline soil
Alluvial soils: These soils are seen alongthe banks of rivers and their tributaries and are scattered
throughout the state. The texture is sandy loam to clay loam. Horizons are not clearly
differentiated and they are moderate in the contents of organic matter, nitrogen and potassium.
These soils are found extensively in the lower basinsof Periyar (Idukki district?) and Pamba
(Pathanamthitta districts?river systems. Alluvial soils are more fertile than the other acid soils of
the state
Coastal soils: These soils are developed from marine deposits and are seen in the coastal tracts all
along the state. The pH ranges between 5 to 6, the texture sandy to sandy loam.These soils have
low fertility level with low content of organic matter, clay and have low cation exchange capacity
(CEC). They are excessively drained with rapid permeability. The soils in general are coarse
textured (sandy loam and sandy) with immature profile. Some soils of the coastal tract have
electrical conductivity (EC) ranging between 10 and 15 dSm
-1
during summer months.
Laterite soils: These soils include typical laterites and lateritic soils. Laterites of the State are
typical kaolinitic weathering products of gneissic and granitic rocks developed under humid
tropical conditions. The soils are characterized by presence of a mixture of hydrated oxides of
iron and aluminium in the form of vesicular mass. Heavy rainfall and temperature are conducive
for laterisation. The surface soil which is reddish brown to yellowish red is mostly gravelly loam
to gravelly clay loam in texture. The content of coarse fragments varies between 20 and 75 per
cent. Laterites are in general poor in available nitrogen, phosphorous and potassium and are low
in bases. They have poor water holding capacity, CEC and high phosphorous fixing capacity. The
organic matter content also is low. The pH of the soils ranges between 5.0-6.2 for these soils.
Extensive areas of these soils are found in the districts of Kozhikkode, Malappuram and Kannur.
They cover a major portion of midland and mid upland regions and are the most extensive of the
soil groups found in Kerala.
Redsoils: Redsoils are localized in occurrence and are found mostly in the southern parts of
Thiruvananthapuram district. Patches of red soils are also seen in Kasaragod, Kannur and
Kozhikode in the northern parts of the State and also in Kollam district in the south. These soils
occur in catenary sequence along with laterites and are found mainly as deposits by colluviation
in foothills and small hillocks. The soils have red colour due to the presence of haematite. These
soils are also kaolinitic in nature, acidic in reaction, loamy in texture, and are highly porous and

2. friable. They have high…?………p fixingcapacity with low content of orgaic matter and
essential plant nutrients.
Black soils: Black soil occurs in patches in Palakkad district and is the only soil which exhibits
near neutral to alkaline pH values. They are considered as extensions of the black cotton soils
observed in the adjacent Coimbatore district of Tamil Nadu. These soils are dark, low in organic
matter, calcareous, high in clay content and cation exchange capacity. They exhibit characteristic
cracking during the dry periods. The levels of potassium and calcium are moderate, while
nitrogen…?..
Peat soils: These soils are also known as
karisoils meaning soil with black charcoal colour.
These are acid sulphate soils. They occur in patches in the districts of Alappuzha, Kottayam, and
Eranakulam. The soils are poorly drained and heavy textured and lie 1-2 meters below the mean
sea level. They exhibit characteristics of submerged forest area and decomposed organic matter is
observed in the lower soil layers. The soils are highly acidic in reaction, the pH approaching
…to…during the summer months
Acid saline soil: These soils are found in the Kuttanad region (Kottayam and Alappuzha districts)
which is a unique agricultural area in the world. A good portion of this area lies below the sea
level and is submerged for the major part of the year. The area is subjected to seasonal ingress of
saline water as a result of tidal inflow from the sea. These soils are faced with the serious
problems of floods, acidity and salinity. They form the typical waterlogged soils and show
entirely different morphological, chemical and physical characteristics totally different from well
drained soils.

3. Land use:
The pattern of land utilization is given in table……….
The total cropped area is 26.69 lakh hector. The major sources of irrigation are wells, rivers, canals and
other sources. The area under cultivation of food crops is………ha. The major food crops include rice and
pulses and tuber crops like cassava. Fruit crops like banana, plantain, pineapple and commercial crops
like Rubber, cashew and oil seed crops like coconut are also grown. Vegetables are also grown in
considerable area spread over almost all districts. Spices like pepper, ginger, turmeric and beverage crops
like coffee, cocoa and tea are also grown in the state.
Table 2.Land utilization pattern
Land use Area (ha) percentage
Total geographical area 3886287
Forests 1081509 27.83
Land put to non-Agri use 371906 9.57
Barren and uncultivable Land22046 0.57
Permanent pastures and other
grazing land
228 0.01
Land put under miscellaneous
tree crops
4423 0.11
Cultivable waste 98014 2.52
Fallow other than current fallow45374 1.17
current fallow 76945 1.98
Net area sown 2078715 53.49

4. The state is bound on the north and north east by Karnataka, and on the east and south by Tamil Nadu.
The state has a 580 km long coastal line in the north south direction. The width of the state varies from
30 km in north to 120 km in central region. The area of the state is 38863 square km which is about 1.18
per cent of the total area of Indian union
Kerala state consists of 14 districts, 63taluks and 1452revenue villages. The population density is 859 per
square km
Geology
The main geological formation of the State belongs to the Archaean period (Koshy and Varghese, 1972).
The crystalline rocks belonging to the formations are mainly of the acid type but basic igneous rocks are
also found. Charnokite, granite and grasses are the main crystalline rocks found in Kerala. These
formations remain close to the surface in the slopes of Western Ghats. The sedimentary formations of
laterite of the tertiary period extent along the midland and coastal regions continuous from Varkala
(Thiruvananthapuram) in south to Kasaragode in the north. The recent formations like coastal sandy
alluvium marine and lacustrine deposits occur as a narrow belt all along the west court. The parent
materials of the soils of the state were decided in to four groups by the (soil survey staff 1978).
They are,
i.Crystalline rocks consisting of representatives of the Archaean period.
ii.Residual laterites formed by the
in situalteration of Archaean rocks.
iii.Varkala formation – Lignite bearing sedimentary beds with a laterite capping.
iv.Recent formations- Alluvial, marine and lacustrine deposits.
Climate
The state is relatively rich in rainfall, with an annual rainfall of 2600mm. Ninety per cent of the
precipitation occurs during the two monsoons, June to August (South West) and October to November
(North East). About 60 per cent of the annual rainfall is received during southwest monsoon. During
December to March there is very little rainfall which contributes the summer shower. The quantum of
annual precipitation of Kerala is concentrated around lesser periods towards the northern parts of the
State while it is spread over larger periods towards south. But due to the steep topography of Kerala
state and uneven geomorphology a major share of rainfall received gets drained into Arabian Sea within
a short time
The temperature is influenced by variation in altitude. High altitude results in temperate climatic
conditions in the high ranges especially of Idukki district in the south and Wayanad district in the north.
In the rest of the area with low altitude humid tropical climate prevails. Range in temperature.
Forest trees
The forest plantations include trees like teak, eucalyptes, bamboo, rosewood and mahogany as well as
some mixed plantations.

5. sL
No
Zones Location Crops grown
12 3 4
1Dry forest loamIn and around Chinnar Plantation crops other than
spices, coconut and tapioca
2Semi dry redloamIsolated pockets in Thiruvananthapuram
and Neyyattinkara taluks
Coconut, tapioca, paddy and
fruit plants like cashew and
mango
3Semidry lateriteParts of Kollam, chirayinkil,
Thiruvananthapuram, Neyyattinkara and
Nedumangad thaluk
Paddy, coconut and fruit
crops like cashew and mango
4Semidry alluviumRiverbeds and coastal areas of Kollam,
chirayinkil,
Thiruvananthapuram,Neyyattinkara,
ottappalam, thalappilly, palakkad alathur
taluks
Paddy, coconut, tapioca
cashew and mango
5Semidry black soilEastern most parts of chittur and palakkad
taluks
Paddy, cotton and coconut
6Semi Dry Forest
Loam
Kumily and parts of Peerumedu talukTapioca, tea, coffee and
rubber
7Sub humid Red
loam
Kasaragod and Kannur, Parts of Kasaragod,
Hosdurg and Taliparamba taluks
Coconut, cashew, paddy,
rubber, pepper and arecanut
8Sub humid lateriteParts of Kannur,m Tirur, Chought, Parur,
Kasaragod, Hosdurg, Taliparamba,
Tellichery, Badagara, Talappilly, Thrissur,
Mukundapuram, aluva, Kanayannur,
Alathur, Chittur, Eranad, Mannarghat,
Palakkad, Kunnathur, Kottarakkara,
pathanapuram, Neyyattinkara and
Nedumangad thaluks
Paddy, coconut, rubber,
cashew, pepper, arecanut,
tapioca and mango
9sub humid
Alluvium
Coastal areas and riverbeds in the regions
under item 8
Paddy, coconut,
mango,cashew, rubber,
pepper, arecanut and tapioca
10Sub humid salinePokkali lands in the coastal parts of parur,
kanayannur and Cochin taluks
Paddy and coconut
11Sub humid forest
loam
Parts of Eranad, Mannarghat, Devikulam
and pathanapuram taluks
Pepper, tea, cardamom,
tapioca and paddy
12Humid lateriteParts of Kasaragod, Taliparamba,
Tellicherry, Quilandy, Kozhikode, Badagara,
Kunnathunad, Meenachil, Kanjirappally,
pathanamthitta, Chengannur, Mavelikkara
and Nedumangad taluk
Vegetables,nutmeg, cashew,
fodder grasses and pineapple
13Humid AlluviumRiver beds of taluk areas described under
item 12, western part of Chengannur and
Mavelikkara taluks, coastal areas of
Cherthala, Ambalapuzha and
Karunagappally taluks
Paddy, coconut, cocoa,
tapioca, areca nut, mango and
banana

6. 14Humid Greyish
Onattukara
Onattukara -parts of Mavelikkara,
Karunagappally and Karthikappally taluks
Paddy, coconut, sesamum and
tapioca
15Humid saline Around Vembanad lake (Areas with acid
saline soils)
Paddy andcoconut
16Humid forest loamParts of Eranad, South Wayanad and North
Wayanad, Kasaragod, Hosdurg,
Taliparamba taluks; Tellicherry,
Pathanamthitta, Pathanapuram,
Neyyattinkara, Devikulam and peerumedu
taluks
Coffee, tea, pepper,
cardamom, rubber, ginger,
paddy, mango and jack
17Per Humid lateriteParts of S.Wayanad, Quilandy, Eranad,
Kunnathunad, DEvikulam, Thodupuzha
Kothamangalam, Meenachil and
Kanjirappally taluks
Paddy, coconut, tapioca,
rubber, pepper, areca nut,
cocoa, mango, jack, cashew,
ginger, and banana
18Per Humid Forest
loam
A small pocket in and around Vythiri, patrts
of Devikulam, Thodupuzha and Peerumedu
taluk
Paddy, coconut, Coffee,
tapioca, pepper, Tea, cocoa
and cardamom
19Wet laterite Parts of South Wayanad, Eranad,
Mukundapuram, Devikulam, Peerumedu,
Pathanamthitta taluk
Cardamom, tea, coffee,
tapioca, rubber, pepper,
ginger and paddy
20Wet Forest LoamParts of Neriamangalam, Devikulam,
Thodupuzha, Kanjirappally, Meenachil and
Peerumedu Taluk
Paddy, tapioca, pepper, tea,
coffee and cardamom