When RBI decreases Repo Rate, Banks don’t decrease their interest rates proportionately.

a. Banks don’t depend on RBI

• In India(& all developing countries ) ,RBI is not the main source of money to banks . Common people are main supplier(mainly because people don’t have much option to invest money in alternate investment facilities eg mutual funds etc )

b. Small saving schemes  rate not reduced

• Transmission is limited by high small savings rates. Banks worry that if they cut their deposit rates, customers will flee to small savings instruments. 

c. High Statutory Liquidity Ratio

• Large money has to be kept idle as SLR which banks cant lend
• This reduces their ability to pass the benefit to consumers .

d. Banks increasing their Spread

• Due to losses incurred to banks as a result of high NPAs & lowering of Credit Demand , Banks are increasing their Spread  in order to maintain their profits in absolute term.
• This has reduced the capacity of banks to decrease Lending Rates.

Timeline

• Banks to calculate lending rate on monthly basis.
• Lending Rate to be calculated using CRR Cost, Operating Cost, Marginal cost of funds (calculated using Repo Rate) (don’t need to go into detail. Just remember, MCLR has Repo Rate as component)

Lending Rate = MCLR + Spread (to be decided by banks)

Benefits?

• Better transmission of Monetary Policy
• Transparency & accountability to borrowers.

RBI’s Janak Raj internal study group(2017) showed MCLR did not yield all benefits . Banks keep on increasing ‘Spread’ based on their discretion .

So new method  was introduced

• Applicable from April 2019 (on recommendations of Dr. Janak Raj Committee)
• NEW loans to be linked with External Benchmark  system.

In this system

• Bank will be asked to choose any benchmark like
  • Repo rate   or
  • 91-day T-bill yield  or
  • 182-day T-bill yield   or
  • any other benchmarks by Financial Benchmarks India Pvt. Ltd.
• It has to be updated atleast every 3 months.
• Lending Rate of Bank will be External Benchmark + Spread (eg if Bank choose Repo Rate as External Benchmark, then Interest Rate will be Repo Rate + Spread)

Benefits?

• Better transmission of Monetary Policy
• Better transparency and accountability

There were various reasons for this

• Several ideological influences in Britain, such as Evangelicalism, Utilitarianism and free trade thinking.
• For renewal of Charter of company
• Pro socio-religious reform thrust in contemporary England => because Progressive Whig Party came into power back in Britain. 
• Role of Christian missionaries was also noticeable.

But the Company’s government was still tentative about interfering for fear of adverse Indian reaction unless a section of the Indian society was prepared to support reform. Such a group was soon to emerge through the introduction of English education

• Status of woman became the main focus of the reforming activities of colonial state as well as educated Indians
• At that time, way in which  civilisations were ranked , position of woman was one of the important criteria & here Indians were increasingly under attack by western observers from missionaries to civilians . Indian civilisation was  despised because it assigned such a low status to women .
• Hence, Indian Intelligentsia responded to this civilisation critique by advocating & supporting reforms to improve status of woman in Indian society.
• But such reforms remained very restricted to only few women belonging to high class because women remained  recipient of male patronage & never became involved in these reformist projects as conscious subjects of their own history .

Upper Class Women vs Peasant Women

• Peasant woman were better compared to Upper caste woman during that time
• They didn’t practice Purdah System , Right to Remarry was there  & Sati was also not that widespread among Peasant class unlike Higher caste

a. Confined only to narrow social group

• Reformist spirit appealed only to a small elite group who were primarily the economic & cultural beneficiaries of the colonial  rule .

• Indeed the high caste  character of the early 19th century explains to a large extent the relative silence on caste question & untouchability which had to wait till Gandhi

b. Faith in benevolent nature of colonial rule

• They had great faith in the benevolent nature of colonial rule & infact existence of these classes depended on Colonial rule .
• Because of faith , they relied more on legislation for imposing reform from the above

c. Colonial Character of the reforms

• Dominant colonial assumption was religion was the basis for Indian society &  this religion was encoded in the scriptures . Social evils were thought to be result of the distortion of scriptures by self seeking people , in this case the cunning Brahmins who had the monopoly over this textual knowledge .
• Civilising mission of the colonial state thus seen to lie in giving back the natives the truth of their own little read & even less understood shastras .
• Whole debate over Sati was grounded in scriptures & its abolition was not based on fact that it is  morally & ethically wrong but when government was convinced that custom was not enjoyed by the scriptures .
• As the colonial rulers gave supreme importance to scriptures, the Indian reformers too, as well as their detractors, referred to ancient religious texts to argue their respective cases. The brutality or the irrationality of the custom, or the plight of women, whom the reform was intended for, were lesser concerns in a debate

Note : The intellectuals did not however attacked the social system as a whole; their attack centred only on the perversions and distortions that had crept into it. They did not advocate a sharp rupture in the existing social structure of the country. They did not stand for structural transformation; changes were sought within the framework of the very structure. They were advocates of reform and not revolution.

a. Female Infanticide

b. Sati Abolition

• Sati Abolition was the greatest achievement of Lord Bentinck .
• Sati is self immolation of wife on funeral pyre of dead husband. 
• According to social reformers , it has always been there much the exception rather than a rule in Hindu life & during Mughal period, it was practiced in Rajputs & Kingdom of Vijayanagara . But during British period, it revived on much larger scale & experienced highest rate of development.

Reasons for practice of Sati

• Earlier it was practiced by Upper Caste Hindus but during British rule, it started in peasant families of lower & intermediate  caste who achieved social mobility & then sought to legitimize their new status by imitating their caste superiors.
• Greed of the relatives –   Child marriage was widespread at that time & many a times bride who has not even lived with groom was forced to perform Sati in order to get property of that man.
• Sati was widespread in areas where Dayabhaga school of personal Hindu law was applicable  . Areas where ] Mitakshara school was applicable, it was less prevalent because Mitakshara school gives lesser rights to wife to inherit property

Campaign against it

• First started by Christian Missionaries
• But very strong campaign under Raja Rammohan Roy gave real momentum
• Finally  in 1829 , Governor General Bentinck prohibited Sati by Govt Regulation Act XVII. Pressure was also put by the Court of Directors because they wanted to present credible image of Company’s rule in India in the British Parliament before renewal of Charter pending in 1833.

Although it reduced very much after that but the idea & myth of Sati persisted in popular culture & was continually reaffirmed through epics, ballads & folktales . Case of surfaced even in 1987 ( Roop Kanwar Case of village Deorala in Rajasthan).

c. Widow Remarriage

d. Child Marriage

e. Thugee

f. Slavery

• Renaissance literally means ‘rebirth’. It refers to the revival of Graeco-Roman (classical) learning in 15th-16th century after long winter of dark ages. In Indian context , intellectual revolution that took place in the nineteenth century in the fields of philosophy, literature, science, politics and social reforms is often known as Indian Renaissance. An important part of this Renaissance was reforming Hinduism from within on the basis of Post Enlightenment Rationalism.
• Very much like the Italian Renaissance, it was not a mass movement; but instead restricted to the upper classes. 
• Response of the educated Indian elite to civilisational critique was to reform  Hinduism from within,  in  the boundary  of post enlightenment rationalism . Such phenomenon is known as Bengal Renaissance
• Movement was started in Bengal by Raja Rammohan Roy who is often described as Father of Modern India .

Works done by Brahmo Samaj

• It propagated Monotheism (discarded the faith in divine Avataras) .
• It was against  idolatry and idol worship
• It attacked Casteism & Untouchability
• Any scripture could enjoy the status of ultimate authority transcending reason & conscience .
• It took no definite stand on the Doctrine of Karma & Transmigration of soul & left it to the individual Brahmos to believe either way.
• Worked for respectable position of the women in the society and for this
  1. Condemned Sati
  2. Favoured abolition of Purdah System
  3. Discouraged Child Marriages & Polygamy
  4. Crusaded for widow remarriage etc

• After Roy’s death in 1833, the leadership of the Brahmo movement was taken over by Debendranath Tagore who provided the movement with a better organisational structure and ideological consistency
• But the movement was actually taken out of the limited elite circles of Calcutta literati into the district towns of east Bengal by Bijoy Krishna Goswami and Keshub Chandra Sen in the 1860s.
  1. Goswami bridged the gap between Brahmoism and the popular religious tradition of Vaishnavism
  2. Sen’s specific focus was to reach larger numbers of non-Westernised Bengalis in the eastern Gangetic plains and to take the movement outside Bengal to other provinces of India

Schisms & other Developments

First schism in the Samaj in 1866

Basically, as Meredith Borthwick has shown, it was a schism between Keshav’s followers, for whom social progress and reform were more important than anything else, and the followers of Debendranath, who preferred to maintain their identification with Hindu society.This rift was, as it became clear soon, more about an identity crisis than about any fundamental difference of ideology: while some of the Brahmos wanted to define themselves as separate from the Hindus, others began to seek a position within the great tradition of Hinduism.

Second Schism in 1878

• A band of Keshub Chandra Sen followers left him
• On account of
  1. Marriage of Sen’s minor daughter to Prince of Cooch Bihar
  2. Also because he became devout follower of Ramakrishna and tried to bridge Brahmanism and Brahmo Samaj.
• They Started  Sadharan Brahmo Samaj and worked mainly for the social work & female education and famine relief . Consisted of Anand Mohan Bose & SN Shastri
• Thus Brahmo samaj also contributed prominent nationalists who later formed the backbone of the moderate phase of congress

In 1881, Sen formed his Naba Bidhan (New Dispensation) and started moving towards a new universalist religion. But by this time , successive ideological rifts and organisational divisions had weakened the Brahmo movement, confining it to a small elite group.

Limitations

• Limited to urban areas only
• Lot of internal rivalries

Achievements of Brahmo Samaj

• Abolition of Sati : Pressure was  put by the samajis & as a result Anti Sati legislation was passed  by Lord William Bentinck in 1829

• Worked for
  1. Abolition of the caste system and dowry system
  2. Emancipation of the women
  3. Improving educational system

• Brahmo Samaj ultimately failed and emerged as sectarian religious order after continuous schisms but nevertheless , its achievements were huge
  1. Rabindranath Tagore  admitted the failure of Samaj but also recognised the very important role played by Samaj of providing a shock to static Indian society and made it to think on rationalist lines.
  2. According to Bipin Chandra Pal , main impact of Samaj  was on Political Culture . It was from Brahma Samaj that idea of free thinking individual emerged who would be able to absorb democratic & western ideals.

• Derozio (Anglo-Indian Teacher at Hindu College) started Young Bengal Movement
• At age of 17, he started Young Bengal Movement.
• He was much more modern than Raja Ram Mohan Roy.
• He was a free thinker and a rationalist, helped promoting  a radical & critical outlook among his students who questioned authority, loved liberty and worshipped truth.
• Most radical at that time & was inspired by French Revolution
• First nationalist poet of Modern India
• Derozians, the followers of Derozio, were staunch rationalists; they measured everything on the yardstick of reason. He organised debates where ideas and social norms were freely debated. In 1828, he motivated them to form a literary and debating club called the Academic Association.
• In  1838, they formed ‘Society for the Acquisition of General Knowledge‘, where they discussed various aspects of Western science, and stood for a number of social reforms, such as the prohibition of caste taboos, child marriage,  polygamy etc.
• Young Bengal followed classical economics, and was composed of free traders who took inspiration from Jeremy Bentham, Adam Smith, and David Ricardo.
• They were passionate advocates of women’s rights and demanded education for them.
• He  was dismissed from the Hindu College in 1831 because of his radical views, and shortly afterwards he died of Cholera at the young age of 22.
• Derozians carried forward Rammohan’s tradition of educating the people in social, economic and political questions through newspapers, pamphlets and public associations. They carried on public agitation on public questions such as the revision of the Company’s Charter, the Freedom of the Press, better treatment for Indian labour in British colonies abroad, Trial by Jury, Protection of the Ryots from oppressive Zamindars, and Employment of Indians in the higher grades of government services. 

Why they didn’t succeed?

• Social conditions were not yet ripe for their ideas to flourish. The common people , who were not acquainted  with those ideologies, considered those young as arrogant. 
• Their total faith in the British and in English education, their rationalism and scientism derived from the west, set them apart from the masses of Indians and they never succeeded in organising any social movement in support of their proposed reforms.

• He was son of Dwarkanath Tagore , father of Rabindra Nath Tagore and a close friend of Raja Ram Mohan Roy .
• In 1839 , he started Tattvabodhini Sabha to disseminate the knowledge of the Upanishads
• Tattvabodhini Patrika was the principal organ of the Sabha to propagate the ideas .
• After death of Raja Rammohan Roy, he became the main organiser of Brahmo Samaj.
• In 1850 , he wrote  book called Brahmo Dharma where he
  • Emphasised on monotheism
  • Supported rationality and reject scriptural infallibility
  • Rejected Caste distinctions and idolatry
• Inspired his sons into reform movement ,most famous being Rabindranath Tagore
• He was part of Landholders Society and played important role in formation of British India Association

Introduction

• His original name was Ishwarachandra Bandopadhyay.
• He was born on 26 September 1820 in the Paschim Midnapore District of West Bengal to impoverished Brahmin parents.
• During the period from 1829 to 1841, Ishwar Chandra studied Vedanta, Vyakaran, Literature, Rhetorics, Smriti and Ethics in Sanskrit College. And in 1839 the title ‘Vidyasagar’ was conferred on him for his unusual talent.
• In 1841, at the age of twenty one years, Ishwar Chandra joined the Fort William College as a head of the Sanskrit department. In 1851 , Vidyasagar became a professor and later on the Principal of the Sanskrit College

Works toward Education

• He firmly believed that the regeneration of India was possible only through education.
• His work was aimed at extending the benefits of learning to common people. He stressed upon instruction through vernacular language.
• He also opened the doors of the colleges and other educational institutions to lower caste students, which was earlier reserved only for the Brahmins. For his immense generosity and kind-heartedness, people started addressing him as “Daya Sagar” (ocean of kindness).
• Having spent his early life in village Ishwar Chandra could realize the sorrowful condition of the womenfolk. He rightly believed that the emancipation of women was not possible as long as they remained ignorant. Ishwar Chandra, therefore, took upon himself the task of promoting the cause of female education.

Pioneer in the women upliftment

• Started girls schools in Bombay and Calcutta
• Encouraged women to study in the colleges
• He also collaborated with Drinkwater Bethune in establishing the Hindu Female School (at present known as Bethune School and College) in 1849.
• Took initiative in pushing the Widow Remarriage Act ,1856
• Instrumental in passing the Special Marriages Act of 1872.
• Wrote book for women emancipation titled BAHUVIVAH

Social Reforms

• He initiated the concept of widow remarriage and raised concern for the abolition of child-marriage and polygamy. He demonstrated that the system of polygamy  was not sanctioned by the ancient Hindu Shastras.
• He took the initiative in proposing and pushing The Hindu Widow Remarriage Act XV of 1856 in India during Governor-Generalship Lord Canning.

Bengali Connoisseur

• He brought a revolution in the education system of Bengal. In his book, “Barno-Porichoy” (Introduction to the letter), Vidyasagar refined the Bengali language and made it accessible to the common strata of the society.
• Vidyasagar invented Bengali prose through translation as well as own writings. 

• Paramhans Mandali’s transformation into Prarthana Samaj was the direct consequence of two visits of KC Sen to Bombay in 1864 & 1867
• It was founded by Atmaram  Pandurang in 1867 inspired from the Brahmo Samaj & the main spirit behind formation was MG Ranade who was ably assisted by KT. Telang & Bhandarkar 
• All leading members were Western educated Maratha Chitpavan Brahmins .
• It’s ideology was almost similar to Brahmo Samaj
  • Preached Monotheism
  • Denounced idolatry & priestly domination
  • Denounced caste distinctions
  • Favoured Widow Remarriage & raising age of marriage for both males & females . 
• Later they connected themselves with Maharshtrian Bhakti Tradition .
• Prarthana Samaj maintained distinction from Brahmo Movement of Bengal & the most notable distinction was they were moderate & more accommodative. They didn’t signal a sharp break & this gradualist approach made it more acceptable
• It’s branches were opened in Surat, Ahmedabad , Poona & reached even in South India where leader was Veerasalingum Pantulu
• It faced crisis in 1875 when  Swami Dayanand visited Gujarat & Maharashtra & offered possibilities of a more radical & self assertive religious program .  A group of Samaj members under SP Kelkar broke & felt attracted to Arya Samaji ideology of Dayanand .

Side Topic : MG Ranade

• He was co-founder of Prarthana Samaj
• He was a product of the Elphinstone College, Bombay & was Judge of the Bombay High Court during 1891- 1901.
• He held that the caste distinction was the main blot on Indian social system. 
• Under his guidance the Paramhans Sabha was reorganised in 1867 under the name Prarthana Samaj. 
• He was the founding member of Indian National Congress , member of Bombay Legislative Council and founding member of Indian Social Conference (1887)
• He was the editor of the Anglo Marathi paper – Induprakash

• He was from Satara , Maharashtra
• In 1873, Phule established the Satyashodhak Samaj, an organization for challenging Brahmanic supremacy.
• He promoted  women education along with his wife Savitribai Jyotirao Phule  by opening women schools.
• He also worked for widow remarriage and to prevent female infanticide, he opened homes for newborn infants.
• He wrote book titled  GULAMGIRI

Ideology of Satyashodak Samaj

• It was against  untouchability & caste system  
• It opposed idolatry and  Brahmin’s role as intermediary between person and god 
• Promotion of rational thinking
• It also rejected Vedic supremacy

• Started by Gopal Krishna Gokhale in 1905
• Aims
  • Create a band of dedicated workers for nation building
  • Carry out activities for the upliftment of Indians 

• Sri Narayan Guru was social reformer born in 1854 in Kerala into Ezhava family

• He championed
  • bhakti for spiritual freedom
  • social equality
  • rejected casteism
  • Rejected divisiveness based on caste, religion etc
• He was a pioneer reformer who rejected the caste system and stressed on the equality of man. He gave the universal message, “One caste, one religion, one God”
• He was influenced by Vedanta.
• He supported Temple entry  movements.
• Sri Narayana Guru  condemned animal sacrifice
• He urged the Ezhavas to leave the toddy tapping profession and even to stop drinking liquor.

• Dr. Palpu, a devotee of Guru established the Sree Narayana Dharma Paripalana Yogam (SNDP Yogam) in 1903 to further Narayana Guru’s message

• Karst region is in Dinarik Alps in Yugoslavia.
• Such topography is also found in regions of the Himalayas, Rockies, Andes, Atlas, Shan Plateau, Belo Horizonte etc.
• In India, this is found in Chirapoonji, Jammu-Kashmir, Himachal Pradesh, Panch Marhi (M.P.), Bastar (Chattisgarh and Coastal areas near Vishakhapatnam.

1 . Lapies

• Lapies are the irregular grooves and ridges formed when most of the surfaces of limestone are removed by the solution process.

2. Swallow Hole /Sink Holes

• A sinkhole is an opening more or less circular at the top and funnel-shaped towards the bottom. 
• On the surface of limestone, there are numerous small depressions carved out by solution at a point of weakness.  Holes size grow through continuous solvent action to form Sink Hole.

3. Limestone Gorge

• When the roof of an underground tunnel collapses, a  limestone gorge is formed.

4. Karst Window/ Karst fenster

• It is a spring that emerges from underground, discharge its water and then abruptly disappears underground through a nearby sinkhole.

5. Doline

• Due to high chemical activity on swallow holes, their size and depth increases. Its diameter may extend up to some kilometres and its depth may run up to 100 meters.
• It can be cylindrical, conical, bowl or dish-shaped.
• The name doline comes from Dolina, the Slovenian word meaning valley.

6. Uvala

• Series of smaller sinkholes coalesce into a compound sinkhole is called uvala.

7. Polze

• Polje is an elongated basin having a flat floor and steep walls.
• It is formed by the coalescence of several sinkholes. The basins often cover 250 square km and may expose “disappearing streams.”

8. Cave

• In areas where there are alternating beds of rocks (shales, sandstones, quartzites) with limestones or dolomites in between or in areas where limestones are dense, massive and occurring as thick beds, cave formation is prominent.
• Water percolates down through the cracks and joints and moves horizontally along bedding planes. It is along these bedding planes that the limestone dissolves to form wide gaps called caves.

9. Tunnel

• Caves having openings at both ends are called tunnels.

• Where subterranean streams descend  to underground passages, the region may be honeycombed with caves
• The most important features in limestone caves are Stalactites, Stalagmites and Pillars.

1 . Stalactites

• Formed on roof of caves .
• As rainwater seeps through the limestone, the water dissolves Calcium Carbonate in it. When from roof, water drips down, it leaves behind Calcium Carbonate (CaCO3) forming Stalactite .
• They are thinner, long and pointed.

2. Stalagmite

• They are formed on the floor.
• All the dripping water has to land somewhere . When a drop finally hits cave floor , it deposits even more Calcite there in unassumed mound .
• They are shorter, fatter and more round.

3. Cave Pillars

• Over a long time, stalactites hanging from roof is eventually joined to Stalagmite growing from floor to form pillar.

• When rain falls , part of it sinks into ground , some of it is evaporated back into the atmosphere & rest runs off as rivulets , streams and tributaries of rivers . This running water is potent agent of erosion  .
• The river performs three types of work. They are erosion, transportation and deposition.

In this stage

• Predominant Work = Erosion
• Predominant action = vertical corrasion.

Landforms formed in this stage

1. Valleys

1.1 V-Shaped Valley

• In upper course, vertical corrasion is at work . Downward cutting takes place so rapidly that lateral corrasion can’t keep pace. After some time, the loosened material slowly creeps downward and takes shape of V.
• The valley thus developed is deep , narrow & distinctively V-Shaped.

1.2 Gorges / I-shaped Valley

• In some cases,  rocks are very resistant and hence afterward loosening don’t take place (because of resistant rock). The  valley formed is so narrow & sides are so steep that gorges are formed .
• Eg : Indus Gorge in Kashmir .

1. 3 Canyons

• Canyons are extended form of gorges.
• In arid regions, where there is little to widen the valley sides and river cuts deep into the valley floors , precipitous valleys called Canyons are formed.
• Eg Grand Canyon of Colorado river in Arizona state of USA .

2. Falls

2.1 Rapids

• These can form in any part of river course but are more numerous in mountain course.
• They are formed when there are different layers of hard rock and soft rocks . Due to unequal resistance of hard & soft rocks , there is unequal erosion of both set of rocks . The hard rocks will make river to jump and fall down 

2.2 Cataract

• Falls similar to rapids but of greater dimensions are referred to as Cataracts.
• There are 5 along the Nile that interrupt the smooth navigation.

2.3 Waterfalls

• When rivers plunge down in a sudden fall of some height , they are known as waterfalls. Their force usually wears out a plunge pool beneath .
• They can be formed in various ways
  • When a bar of resistant rock lies transversely across a river valley . Eg Niagara Falls in US
  • At fault line across river. Eg Victoria falls on River Zambezi
  • When river plunges down the edge of a plateau like River Congo .

3. Entrenched /Incised Meanders

• These are formed when downcutting process is slow & river cause lateral erosion leading to asymmetric valley formation .
• Note : These are different from meanders which occur due to both erosion and deposition. In this, only erosion  takes place. 

In Middle Course,

• In Middle Course, Erosion  , Transportation and deposition is done by the river .
• But amount of erosion is very lower than Youthful stage and in that too, Lateral Corrasion tends to replace vertical corrasion.
• The volume of the water increases with the confluence of many tributaries & this increases the river’s load.
• Predominant work of the river =  predominantly transportation with some deposition (main deposition happen in Oldage Stage).

Landforms formed in Middle Stage

1 . Alluvial Fans

• Alluvial fans  are formed when streams flowing from higher levels break into foot slope plains of low gradient. Normally very coarse load is carried by streams flowing over mountain slopes. This load becomes too heavy for the streams to be carried over gentler  gradients and gets dumped and spread as a broad low to high cone shaped deposit called alluvial fan.
• Examples : Alluvial fans are found in Kosi river when it enters Bihar just after exiting Himalayas

2. Alluvial Cone

3. Flood Plains

• Rivers in their course carry large quantities of sediments . During annual or sporadic floods, these materials are spread over the low lying adjacent areas.
• A layer of sediment is thus deposited during each flood , gradually building up a fertile flood plain.

4. Levees

• With the continuous deposition of soil on the banks by the river, the level of banks rises and they look like natural dams known as levees . 
• During flooding as the water spills over the bank, the velocity of the water comes down and large sized and high specific gravity materials get dumped in the immediate vicinity of the bank as ridges. They are high nearer the banks and slope gently away from the river

In Lower/Oldage Course,

• River moving downstream across a broad and level plain is heavy with debris brought down from the upper course . Hence, work of the river is mainly deposition, building up its bed & forming extensive flood plains.
• Vertical corrasion has almost ceased though some lateral corrasion still goes on to erode its bank (like in Meanders).

Landforms formed in Later Stage

1 . Meanders

• A meander is a winding curve or bend in a river.
• Meanders are the result of both erosional and depositional processes.(explained in diagram below)
• The irregularities of the ground , force the river to swing in loops.  Once the channel begins to flow in sinusoidal path , the amplitude & concavity of loop increases rapidly due to dense erosion occurring at the outside and deposition occurring inside .
• Note : Meanders can be found in Middle as well as Later Stage

2. Ox-bow Lakes

• An oxbow lake is U-shaped body of water that forms when a wide meander from the main stream of river is cut off creating free standing body of water.
• It has different nomenclature at different places – Billabong in Australia, Rasacas in Texas etc
• Both meanders and ox bow lakes are formed both in middle and lower course. Ox Bow is more commonly found in lower course .

3. Braided Streams

• A braided stream is one which does not flow in a single definite channel but rather a network of everchanging, branching and reuniting channels.
• Thread-like streams of water rejoin and subdivide repeatedly to give a typical braided pattern

4. Delta

• When a river reaches the sea , the fine material it has not yet dropped are deposited at its mouth , forming a fan shaped alluvial area known as Delta .
• This alluvial tract is , infact , a seaward extension of the flood plain.
• Delta extend sideways and seaward at an amazing rate . The River Po extends its delta by over 40 feet a year
• (GK) Ganges Brahmaputra delta is the largest delta in the world.

Deltas differ in their size , shape , growth & importance. A number of factors such as the rate of sedimentation , the depth of the river  & sea bed and character of  tides , currents & waves greatly influence formation of Delta.

Different type of Deltas

a. Bird’s foot Delta

• Deposited alluvial material divides the river into smaller distributaries. Several distributaries look like the foot of a bird.
• Example : Mississippi is example.

b. Arcuate shaped Delta

• Delta  look fan shaped with numerous distributaries
• Examples are Amazon, Ganga & Mekong.

c. Estuarine Delta

• When river has their deltas submerged in coastal waters (mainly due to submerged coast like India’s western coast) or don’t have much deposition to form delta.
• Most of India’s west flowing rivers originating in Western Ghats.

d. Cuspate Delta

• Have tooth like projection at their mouth.
• Example : Ebro of Spain.

Conditions favourable for formation of deltas are

• Active vertical & lateral erosion in upper course to provide  sediments to be eventually deposited as Deltas.
• The sea adjoining the delta should be shallow or else the load will disappear in the deep waters.
• The coast should be sheltered, preferably tideless.
• There should be no large lakes in the river course to filter off the sediments.
• There should be no strong current running at right angle to the river mouth.

Importance of Deltas

a. Ecological importance

• Deltas absorb runoff from both floods (from rivers) and storms (from lakes or the ocean), filter water and thus reduces the impact of pollution flowing from upstream.
• Deltas are also important wetland habitats. They support extremely diverse and specialized flora and fauna and are areas of dense forests.  

b. Economic importance

• Deltas are important places for trade and commerce, and major ports.
• Deltas due to rich accumulation of silt are fertile agricultural areas. World’s largest delta is the Ganges–Brahmaputra delta in India and Bangladesh,  is densely populated supporting livelihood of millions. Fish, other seafood, and crops such as rice and tea are leading agricultural products of the delta.
• Deltas possess well sorted sand and gravel which is quarried.
• Due to their diversity they are centres of tourism and recreation.

Threat to Deltas

• Diversion of water for irrigation and creation of dams reduce sedimentation, which can cause delta to erode away.
• Climate change and rising sea level – rising sea level flood deltas bringing in saline water and threatening wetland ecosystem. For example nearly 31 square miles of Sundarbans have vanished entirely due to sea level rise.
• Use  of water upstream can greatly increase salinity levels as less fresh water flows to meet salty ocean water. 

While nearly all deltas have been impacted to some degree by humans, the Nile Delta and Colorado River Delta are some of the most extreme examples of ecological devastation

a. Solution

• When something is dissolved in water  , it is called solution.

b. Hydration

• Hydration is the chemical addition of water. Minerals take up water and expand
• Calcium sulphate takes in water and turns to gypsum, which is more unstable  

c. Oxidation & Reduction

• Oxidation means a combination of a mineral with oxygen to form oxides or hydroxides.  Eg : Oxidation of  iron to form rust

• When oxidised minerals are placed in an environment where oxygen is absent, reduction takes place. Such conditions exist usually below the water table, in areas of stagnant water and waterlogged ground. 

d. Carbonation

• Carbonation leads to dissolution of Carbon Dioxide into water to form Carbonic Acids which will dissolve calcium and magnesium compounds

Physical Weathering is the disintegration of rock mainly induced by elements of weather and natural forces.

Physical weathering can be further divided into following categories :-

• Gravitational forces such as overburden pressure, load and shearing stress.
• Expansion forces due to temperature changes => Rocks expand during day and contract during night in arid and semi-arid regions=> the rocks  crack and eventually splits up.
• Exfoliation : Rocks generally heat or cool more on the surface layers. The alternate changes in temperature could cause their outer layers to peel off from the main mass of the rock in concentric layers just as the skin of an onion.
• Frost wedging : when water freezes, it expands. As water expands between the rock wedges expand, it puts great pressure on rocks resulting in weathering.
• Water  pressures controlled by wetting and drying

Weathering due to growth or movement of organisms.

• Burrowing &wedging by organisms like earthworms, termites, rodents etc. => exposing  new surfaces to chemical attack  
• Human beings by disturbing vegetation, ploughing and cultivating soils=> this creates  new contacts 
• Plant roots exert great pressure breaking rocks apart.

Ecological Importance

• Weathering is the initial stage in the formation of soil. It breaks down the initial rock mass into smaller fragments thus preparing the rock material for the formation of soil.

• Trees are able to ‘mine’ essential nutrients such as calcium through their association with symbiotic mycorrhizae through small pores in the mineral soil, which is possible only due to weathering.

• Erosion, with the aid of weathering, helps in mass wasting and reduction of relief. This leads to modifications in various landforms.

Economic Importance

• It leads to the formation of various natural resources such as clay used in making bricks.

• Placer deposits are formed due to weathering . These placer deposits are source of rare earth metals, thorium etc

• It weakens the rocks, thus facilitating the mining and quarrying activities

Hence, we can say that although weathering is a disintegrating process yet it plays an integral role in sustaining life on earth.

• These movements transfer the mass of rock debris down the slopes under the direct influence of gravity ( happens only under influence of gravity & no other geomorphic agent is involved)

• Weathering is not a prerequisite for mass movement although it aids mass movements. Mass movements are very active over weathered slopes .

Mass Movement can be grouped under two classes

1 . Slow Movement

2. Rapid Movement

• There are many reasons for this. 
  • One, the Himalayas are tectonically active. 
  • They are mostly made up of unconsolidated and semi-consolidated deposits. 
  • The slopes are very steep.

• Many slopes are steeper with almost vertical cliffs and escarpments in the Western Ghats and Nilgiris.
• Mechanical  weathering due to temperature changes and ranges is pronounced. 
• They receive heavy amounts of rainfall over short periods. So, there is almost direct rock fall quite frequently in these places along with landslides and debris avalanches.

a. Metallic Minerals

These minerals contain metals and can be sub-divided into

b. Non-Metallic Minerals

• These minerals do not contain metal content.
• Sulphur, phosphates and nitrates are examples of non-metallic minerals.
• Cement is a mixture of non-metallic minerals.

• A rock is an aggregate of one or more minerals.
• Rocks do not have definite composition of mineral constituents.
• Petrology is the science of rocks.
• The age of the rock is determined based on Carbon-14 dating.

a. Igneous Rocks

• Igneous rocks (Ignis in Latin means ‘Fire’) are formed when magma cools and solidifies.
• They  are known as primary rocks

• Igneous rocks are classified based on texture. 
  1. If cooled slowly at great depths : Large grains  
  2. Sudden cooling (at the surface) :  small grains.
  3. Intermediate  cooling : intermediate size of grains .

• Granite, gabbro, pegmatite, basalt, volcanic breccia and tuff are some of the examples of igneous rocks.

b. Sedimentary Rocks

• Formed by lithification of sediments
• They are also known as detrital rocks
• Examples : sandstone,  shale, loess , chalk, coal , limestone etc

c. Metamorphic Rocks

• Metamorphic rocks are formed when already consolidated rocks undergo reorganization in structure due to excessive pressure (through the process called Metamorphism)
• Eg : Gneiss, syenite, slate, schist, marble, quartzite, anthracite, diamond  etc.

Igneous  and metamorphic rocks together account for 95 percent of the earth while rest 5% are sedimentary rocks.

Rocks do not remain in their original form for long but may undergo transformation.  Rock cycle is a continuous process through which old rocks are transformed into new ones.

• Weak Zones in the Earth Crust: The parts of the earth where two tectonic plates collide against or drift apart from each other are considered very weak. Volcanoes may erupt in such zones, for example, African and Eurasian plates.

• Magma Saturated with Gases : The magma, in the interior of the earth, is often found saturated with gases like carbon dioxide, and hydrogen sulphide. These gases together with water vapour make the magma highly explosive. Magma is forced out as lava on the surface of the earth due to the pressure exerted by these gases.

Volcanoes are classified on the basis of nature of eruption and the form developed at the surface.

a . Shield Volcanoes

• These are made up of basalt, a type of lava that is very fluid when erupted. Since Basalt is very fluid , it make these volcanoes less steep.
• Eg : Hawaiian volcanoes are the most famous examples.
• They become explosive if water gets into the vent; otherwise, they are characterised by low-explosivity.

b. Composite Volcanoes

• Composite volcanoes are  cone-shaped volcanoes composed of different layers of lava, ash and rock debris.
• Magma which erupt in this case is Andesitic in nature . Hence, eruption is violent and explosive. Along with that, Andesitic lava is less fluid making the Composite volcanoes very steep.
• Along with lava, large quantities of pyroclastic material also comes out.
• Examples include Mt Stromboli , Mt Vesuvius, Mt St Helens, Mt Fuji etc.

c. Caldera

• These are the most explosive of the earth’s volcanoes.
• They are usually so explosive that when they erupt they tend to collapse on themselves .The collapsed depressions are called calderas.

d. Flood Basalt Provinces

e. Mid Oceanic Ridge Volcanoes

• These volcanoes occur in the oceanic areas at points where Oceanic – Oceanic tectonic plates diverges. 
• There is a system of mid-ocean ridges more than 70,000 km long that stretches through all the ocean basins.
• The central portion of this ridge experiences frequent but peaceful eruptions.

a. Active Volcanoes

• Volcanoes which erupt frequently.
• Generally, their vent remains open.
• Examples : Mount Etna of Italy, Cotopaxi in Ecuador (highest volcano) and many others situated in Pacific ring of fire .

b. Dormant Volcanoes

• These volcanoes may not have erupted in the recent past but there is a possibility of eruption at any time.
• Examples : Mt. Vesuvius of Italy , Mt. Fujiyama of Japan and Mt Kilimanjaro in Tanzania.

c. Extinct Volcanoes

• These volcanoes have exhausted their energy and have  not erupted during the known geological period.
• Their Crater is generally filled with water making it a lake.
• Examples : Popa in Myanmar and Mt. Kenya in eastern Africa

a. Ring of Fire

• Pacific Ring of Fire is the Circum-Pacific region that has the greatest concentration of active volcanoes. Two-third of world’s volcanoes lie here.
• Volcanoes are found here due to Oceanic -Oceanic & Oceanic-Continental Plate convergence .

b. Mid Atlantic Region

• Formed due to Oceanic -Oceanic plate divergence .
• Basaltic Eruptions  happens here which  are peaceful in nature .
• Mid Oceanic Ridge Volcanoes are found here.

c. Great Rift Valley

• In Africa some volcanoes are found along the East African Rift Valley. 
• Kilimanjaro and Mt. Kenya are extinct volcanoes. The only active volcano in West Africa is Mt. Cameroon.

d. Mediterranean Volcanism

• Volcanoes of the Mediterranean region are mainly associated with the Alpine folds.
• Examples : Mt. Vesuvius,  Mt. Stromboli (known as the Light House of the Mediterranean Sea

e. Hotspot  Volcanoes

• These have to do with plate tectonics .
• In these volcanoes, magma from  the deep mantle come outside directly through plume  .
• Lava is of Basaltic nature => Shield Volcanoes are formed in this activity which are not explosive.
• Their location remains fixed but plates on them can move leading to formation of island arcs or plateau depending upon conditions .

• Eg Hawaii, Reunion Island , Kurile, Aleutian island , Iceland , Yellowstone (US Continental)

• When Lava  is basaltic (like in case of hotspots) , it can  flow easily . It will keep on forming layer above layer.
• When this process goes on for large amount of time ,Lava Plateau is created .
• Eg: Deccan Plateau was formed in this way when Indian plate passed over Reunion Island hotspot during the cretaceous period.

Side Topic : Formation of Deccan Plateau

• During Cretaceous Period , Indian Plate was moving northward and passed over Reunion islands (near Madagascar island in Indian Ocean)
• Hotspot  volcanism was active over there which resulted in outpour of highly basaltic lava at that point . As the plate movement was extremely slow, India remained over the Reunion hotspot for a considerable long time which led to Basaltic deposits in Deccan area  . Hence , Deccan Basaltic Plateau formed.
• 16-17 percent of India is under Deccan traps.

• Volcanism creates new landforms (all the landforms we have seen above)

• Volcanic rocks yield very fertile soil upon weathering and decomposition. For example black soil of Deccan Plateau in India is made for volcanic rocks and it is best suited to grow cotton .

• Source of Diamonds :  Eg – Kimberlite rock of South Africa, the source of diamonds, is the pipe of an ancient volcano.

• Geothermal Energy : In the vicinity of active volcanoes, waters in the depth are heated from contact with hot magma giving rise to springs and geysers. The Puga valley in Ladakh region and Manikaran (Himachal Pradesh) are promising spots in India for the generation of geothermal electricity.

• Volcanism has also helped in the formation of atmosphere in the past. (How? – explained below)

• Degassing : Volcanic activity released essential gasses such as water vapor, carbon dioxide, methane, ammonia and very little free oxygen from the interior of the earth through a process called degassing.  

• Volcanic eruptions injected ash and sulphur-rich aerosol clouds into the atmosphere which shaded sunlight and reduced the amount of solar radiation reaching the Earth’s surface thus cooling the planet. As the earth cooled, water vapor condensed to form rain dissolving carbon dioxide and other gases.

• Volcanic eruptions pour sulfur dioxide and other particles into the stratosphere. Gases react with water to form aerosols that linger in the stratosphere, reflecting sunlight and heat from the sun and thus lowering temperatures in the troposphere

• Intense volcanism has significantly increased the amount of carbon dioxide in the atmosphere and causes global warming. Volcanic eruptions produce more than 100 million tons CO2 each year.   For Example: The 1980 eruption of Mount St. Helena vented approximately 10 million tons of CO2 into the atmosphere in only 9 hours. 

• Dark lava flow absorbs more of the solar energy (low albedo) , so a large enough lava flow could warm a local region. 

—> Volcanoes can have both a cooling and warming effect on climate. However, in the long term frequent volcanic eruptions will have a net effect of cooling the earth and counter global warming.