Soil Profile

The  development of a soil from inorganic and organic material is a complex process. Weathering easy the physical and the chemical break down of rocks and the first step in soil development.weatherd

Soil profile 

Vertical and horizontal movements of the materials in a soil system create a distinct layering, parallel to the surface, collectively called a soil profile. The layers are called zones or soil horizons.

The Horizon 

O horizon

The O horizon consists entirely of plant litter and other organic material.The O horizon, when it is present, is the uppermost horizon. The O stands for 'organ.' You can think of dead plants and animal parts falling on the surface of the soil. Sometimes it's very recognizable and sometimes.

A Horizon

Topsoil is called the A horizon, the topsoil is usually the darkest layer of the soil because it has the highest proportion of organic material. The topsoil is the region of most intense biological activity: insects, worms, and other animals burrow through it and plants stretch their roots down into it.

E Horizon

Some soils have an E horizon, or zone of leaching, a light-coloured layer that is leached of iron-bearing components. This horizon is light in colour because it contains less organic material than the O and A horizons and little inorganic colouring material such as iron oxides.

B Horizon

The B horizon, or zone of accumulation, underlies the O, A, or E horizon.It is the horizon, characterized by the accumulation of calcium carbonate.This layer is lighter brown and holds more water than the topsoil because of the presence of iron and clay minerals. There is less organic material.

C Horizon 

The C horizon lies directly over the unaltered parent material and consists of parent material partially altered by weathering processes.The C horizon may be oxidized.

R Horizon 

The R horizon, or unaltered parent material, is the consolidated bedrock that underlies the soil. An R layer is bedrock. When a soil has direct contact with bedrock, especially close to the soil surface, the bedrock becomes a variable when developing land use management plans and its presence is noted in the soil profile description.

Border

 India's states share the border :

Pakistan

 Jammu and Kashmir, Punjab, Rajasthan and Gujarat

Afghanistan 

Jammu and Kashmir

China 

Jammu and Kashmir,Himachal Pradesh, Uttrakhand, Sikkim and Arunachal Pradesh

Bangladesh 

Mizoram, Tripura, Assam, Meghalaya, West Bengal

Myanmar

Arunachal Pradesh, Nagaland, Manipur, Mizoram

Nepal 

Uttrakhand, Utter Pradesh,  Bihar,  West Bangal, Sikkim

Bhutan 

Sikkim,  West Bengal,  Assam,  Arunachal Pradesh.

Notes

•  Bangladesh and India share a 4096 km ,long international border, the fifth longest land border in the world
• Tripura is surrounded by Bangladesh from three sides. 
• Redcliffe  line  ---  India and Pakistani 
• Durand line  ---  India and Afghanistan 
• MacMohan line  ---  India and China 

Convection Current

Convection  Current

Convection current condition in the mantle zone seems to cause Plate motion. This is thought to be  slow displacement or Convection of a mental material under the action of temperature difference between its floor and the roof. As the rocks are heated deep in the earth they become less dance and rise to spreading ridges. As the rocks move litelitera,  they cool, becoming dense enough to sink at subduction zones.

 

A Convection Current is a process which involves the movement of energy from one place to another and the meaning of Convection is "heat transfer". It is also called to as convection heat transfer.Heat energy can transfer by convection when there is a significant difference in temperature between two parts of a fluid. When this temperature difference exists, hot fluids rise and cold fluids sink. Convection that occurs naturally is called natural convection or free convection. If a fluid is circulated using a fan or a pump, it's called forced convection. The cell formed by convection currents is called a convection cell.

Convection Current Hypothesis

The hypothesis suggests that the mountain range were initiated and developed due to the convection currents supported to the exist in the plastic - type mental blow the crust of the earth. The origin of the currents may be due to very hot liquid core of the Earth. Some phenomena of convection currents are given below :

• Convection currents  travel horizontally under the crust of the Earth.
• In the journey of convection currents, they pull along the light material of the continental margins and in the process themselves become cold and heavy.
• Thus,  two types of convection currents come into play forming almost cycle:  first - the ascending currents of light and hot material, and second the descending current of heavy and a cold material.
• In the Divergent plate boundaries, if the Ascending  rising limb of convection current beneath the earth's crust volcanic arc were formed.
•  In the  convergent plate boundaries,  if the descending limb of convection current beneath the earth's crust mountain building were formed.

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Plate Tectonic Theory

Movements of Plates

 
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Types of Plate movement

Movements of Plates

Plate Tectonic theory is in the type of drift, with respect to the adjoining plates along the plate boundaries.

H.Hess produced the concept of plate tectonic in 1960 in support of continental drift.  All the activities  occur along the plate margin e.g. seismic events, volcanicity, mountain building, folding, faulting etc. Plate margin are generally divided into three main groups as follows

1. Constructive plate boundaries

2. Destructive plate boundaries

3. Conservative plate boundaries

    

Constructive Plate Boundaries

Constructive plate boundaries are also called is divergent plate boundary or accreting plate boundaries. This is a zone along with two plates are in the motion away from each other as a result of fisher developers, and create new margin. Infect oceanic plates split apart along the mid oceanic ridge and move in the opposite direction. The fissure represents the zone of spreading and created new crust by upwelling of material from the mental. It is the best example seen in the case of the North American plate versus Eurasian plate. Eurasian plate is moving away towards south east whereas North American plate  is drifting towards south west.

 Oceanic Divergent

The divergent plate boundary on the ocean floor is marked by the crust of the mid oceanic ridge. The existence of the Rift Valley at the ridge  crest, associated with Basaltic lava. Volcanism appears to be the result of the ocean divergent. Eruption of the Lava creates new ocean floor within the Rift Valley.

Continental divergent

This is also known as continental ruptures and causes elevations of continent,this column of hot molten rock is called mantle plume. Due to elevation the crust becomes thinner above the uplift and the tensional force cause the plate to fracture forming a rift valley along a central graben.

The volcanic country Iceland is a island located in the MID ATLANTIC RIDGE

Its believed that the mid Atlantic ridge which forms a major part of the sub oceanic ridge encircling to the globe from Arctic ocean to South Africa. This type of presses is sometimes also referred as sea floor spreading.

some scientist have postulated development of new spreading centers under the African plate along the East African rift zone.

Destructive Plate Boundaries

Destructive plate Boundaries are also called as convergent plate or consuming plate boundaries because two plates move towards each others and leading edge of one plate overrides the other plate and the overridden plate is subducted  into the mantle and thus part of the is lost in mantle.There can be three types of situations as

1. Ocean -ocean  convergence
2. Continent-continent convergence
3. Ocean -continent convergence

Ocean -Ocean  Convergence

Two oceanic crusts converge and one plate bends down ward beneath the other. This phenomenon is called Subduction. Subduction of plate forming the oceanic crust is cause of the trench which is formed immediately over the zone of subduction.the magma bodies rise slowly to the surface forming a curved line of volcanoes which form a string of volcanic island  knows as island arc.

Examples: The deepest Trench is located at the southern ssubduction end of the Mariana Trench caused by the convergence of Pacific plate.

Ocean-Continent Convergence
A plate containing the oceanic crust is subducted  under the continental crust because it's less dence comparitivily oceanic crust. Magma that rises from the subduction zone and forms  a Volcanic arc. But the continental crust remains intact and with the upward rising of hot magma from  the subduction zone becomes thicker and formed a  young mountain range.

• The Peru Chile trench developed of the South America coast line is described as a typical example of subtraction.

• The South America Continental plate supporting the high range of Andes mountain is considered a proof enough for this typical case.

 

Continental -Continental Convergence

Two continents move towards each others and the leading edge of the both plates are composed of Continental rock, it is more difficult for subtraction to start. in this case a continental collision boundary may develop, in which the edges of the plates crumpled into mountains. this type of  convergent boundary condition has produced some of the highest linear mountain system on the earth, such as Alpine in Himalayan mountain belts.

Conservative Plate Boundaries

These  are also called as share plate margin and transform boundaries or transform fault. Here  two plates pass or slide past one another along transform faults and this crust is neither created or destroyed. most such boundaries occur in Oceanic crust but some occur on continents are well known Continental transform boundary is the

San Anderson fault in California Where are segment of the Pacific plate is sliding horizontally past assignment of North American plate

 

 

 

Mineralization along different Boundaries

Deposit at Convergent Boundaries

• Deposits(Zn,Pb,Ag) are related to subtraction in the Western United State during cretaceous to middle tertiary.
• Cu, Fe, No, Au and  Ag are closely associated with calkaline magnetism in such zone.
• The tin  tungsten belts of Bolivia, East India archipelago( an areas  encompasses twelve seas, two gulfs, and one strait in the East Indies)    and South China are located along similar tectonic setting.

Deposits a Divergent Plate Boundaries

• An example of recent thermal plume(rising air in the lower altitudes of the Earth's atmosphere)generated rift in Red Sea.
• Valley of the Red Sea has given rise to a number of a hot spring pools.
• Sulfide deposits and  metallic deposits Fe, In, Cu, Pb,  Au and Ag are formed.

Deposits at along Transform Fault

• The coast range of California also host late Cenozoic  Mercury deposits.
• McLaughlin hotspots gold deposit in California coast ranges.
• Salton sea geothermal system of the Imperial Valley California has a significant energy potential.

Plate Tectonic

Plate tectonic theory

The concept of plate tectonic has make established   ground in explaining many important problem of physical geology including mountain building, folding, faulting, seismicity, volcanism etc. The  theory of plate tectonic developed by Geo scientist during 1960s is described as a most revolutionary concept in the history of geology. The term plate was first used by J.T. Wilson in  1965  and result of continental drift theory of Wegener.  according to this concept the rigid lithospheric slabs or block and solid crystal plates are  called plate. The whole mechanism of evolution, nature and the motion of plates is known as plate tectonics. The rigid lithosphere is capable to moving bodily over the Asthenosphere( hot-plastic flexible layer of upper Mantle). There are  six major  and  20  minor plates  have been identified .About twelve of these plates have been so far distinguish and the name of twelve major and minor lithospheric plates under focus to study of Geoscientist e.g.

• The Pacific plate,
• The North American plate,
• The South American plate,
• The African plate,
• The Antarctic plate,
• The Indian Australian plate the European plate,
• The Arabian plate,
• The nazea plate,
• The Caribbean plate,
• The scotia plate and
• The Philippines plate.

 

  Plate tectonic theory is based in two major concepts

 (a)  The concept of continental drift   and

 (b) Concept of sea-floor-spreading.

The main ideas underline the theory of plate tectonics are the out-come to the   study   of the structure of the ocean-floor and the formation of young oceanic-crust in  mid oceanic ridge.  

 Chemical composition of interior

Inner part        Fe, Ni

Outer part       Fe, Ni + silica

Mental.           Olivine                                                       

Oceans.           Basalt

Mental.           Granite and Andesite 

Location of the rock	example	Properties	Reaction (if we melting)
Mental	Olivine	Highly heaviest fluid	Mercury
Oceanic crust	Basalt	Less heavier fluid	Water
Contcrustal crust	Andesite	Less mobile light fluid	Honey
Continental crust	Granite	Least mobile lightest fluid	Wax

 

 Movement  of  Plates

Plates	Divergent boundaries	Convergent boundaries	Transform boundaries
Similar Names	Constructive plate margin or accreting plate margin	Destructive plate margin  or consuming plate margin	Shear plate margin or conservative plate margin
Cause	Ascending Limb of convection current beneath the earth's crust	Descending Limb of convection current beneath the earth's crust	Horizontal movement of convection current beneath the earth's crust
Mechanism	Two plates are in the motion away from each other	Two plates are in the motion towards each other	Two plates are slide apart each other
Formation	Mid -oceanic -ridge, rift valley, shallow focus earthquakes and volcanic eruption	Mountains formation and major earthquakes	Fault create and shallow focus earthquakes with horizontal slips
Examples	North America plate Vs  Eurasian plate	Indian plate and Tibetan plate	San-Andres Fault