Tectonic Elements of Indian Subcontinent

8/10/2019 Tectonic Elements of Indian Subcontinent

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Tectonic elements of indian subcontinent

Definition:

The Indian subcontinent, also Indian Subcontinent, is aregion of the Asian(and, in turn, the Eurasian) continenton the Indian tectonic platefrom the Hindu Kushor HinduKoh, Himalayasand including the Kuen LunandKarakoramranges, forming a land mass which extends

southward into the Indian Ocean.

It is sometimes synonymous with South Asia,[1]andvarious other termsused for the region.
http://en.wikipedia.org/wiki/Asiahttp://en.wikipedia.org/wiki/Eurasiahttp://en.wikipedia.org/wiki/Continenthttp://en.wikipedia.org/wiki/Indian_Platehttp://en.wikipedia.org/wiki/Hindu_Kushhttp://en.wikipedia.org/w/index.php?title=Hindu_Koh&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Hindu_Koh&action=edit&redlink=1http://en.wikipedia.org/wiki/Himalayashttp://en.wikipedia.org/wiki/Kuen_Lunhttp://en.wikipedia.org/wiki/Karakoramhttp://en.wikipedia.org/wiki/Indian_Oceanhttp://en.wikipedia.org/wiki/South_Asiahttp://en.wikipedia.org/wiki/Indian_subcontinenthttp://en.wikipedia.org/wiki/Indian_subcontinenthttp://en.wikipedia.org/wiki/Indian_subcontinenthttp://en.wikipedia.org/wiki/Indian_subcontinenthttp://en.wikipedia.org/wiki/South_Asiahttp://en.wikipedia.org/wiki/Indian_Oceanhttp://en.wikipedia.org/wiki/Karakoramhttp://en.wikipedia.org/wiki/Kuen_Lunhttp://en.wikipedia.org/wiki/Himalayashttp://en.wikipedia.org/w/index.php?title=Hindu_Koh&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Hindu_Koh&action=edit&redlink=1http://en.wikipedia.org/wiki/Hindu_Kushhttp://en.wikipedia.org/wiki/Indian_Platehttp://en.wikipedia.org/wiki/Continenthttp://en.wikipedia.org/wiki/Eurasiahttp://en.wikipedia.org/wiki/Asia


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Geology

Most of this region rests on a distinct tectonic plate, theIndian Plate(the northerly portion of the Indo-AustralianPlate), and is isolated from the rest of Asia by mountainbarriers.

A component of Pangaeasome 250 million years ago, the

subcontinent split from Gondwanaduring the Cretaceousperiodsome 90 million years ago, and then driftednorthbefore colliding with the Eurasian Plateabout 50-55 (or~35) million years ago and giving birth to the Himalayanrangeand the Tibetan plateau.

The subcontinent continues to move northeastward some5 cm annually, pushing the Himalayas up higher.
http://en.wikipedia.org/wiki/Tectonic_platehttp://en.wikipedia.org/wiki/Indian_Platehttp://en.wikipedia.org/wiki/Indo-Australian_Platehttp://en.wikipedia.org/wiki/Indo-Australian_Platehttp://en.wikipedia.org/wiki/Pangaeahttp://en.wikipedia.org/wiki/Gondwanahttp://en.wikipedia.org/wiki/Cretaceoushttp://en.wikipedia.org/wiki/Cretaceoushttp://en.wikipedia.org/wiki/Continental_drifthttp://en.wikipedia.org/wiki/Eurasian_Platehttp://en.wikipedia.org/wiki/Himalayan_rangehttp://en.wikipedia.org/wiki/Himalayan_rangehttp://en.wikipedia.org/wiki/Tibetan_plateauhttp://en.wikipedia.org/wiki/Tibetan_plateauhttp://en.wikipedia.org/wiki/Himalayan_rangehttp://en.wikipedia.org/wiki/Himalayan_rangehttp://en.wikipedia.org/wiki/Eurasian_Platehttp://en.wikipedia.org/wiki/Continental_drifthttp://en.wikipedia.org/wiki/Cretaceoushttp://en.wikipedia.org/wiki/Cretaceoushttp://en.wikipedia.org/wiki/Gondwanahttp://en.wikipedia.org/wiki/Pangaeahttp://en.wikipedia.org/wiki/Indo-Australian_Platehttp://en.wikipedia.org/wiki/Indo-Australian_Platehttp://en.wikipedia.org/wiki/Indo-Australian_Platehttp://en.wikipedia.org/wiki/Indo-Australian_Platehttp://en.wikipedia.org/wiki/Indian_Platehttp://en.wikipedia.org/wiki/Tectonic_plate


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Tectonic ProcessesThe upper layer of the mantle has convection currentsthat break the overlying crust in huge blocks calledTectonic Plates: Huge blocks of the earths crust thatslide around slowly, pulling apart (diverge) to opennew ocean basins or crashing into each other(converge) to create new, larger landmasses

When an oceanic plate collides with a continentallandmass, the continental plate will ride up over theseafloor.

Continents drift togethergiant landmass (i.e.Pangaea)


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Tectonic Processes (cont.)

Earthquakes are caused by grinding and jerking asplates slide past each other or as they converge ordiverge

Mountain ranges are pushed up at the margins ofcolliding plates (i.e. Himalayas- Indian subcontinentinto Asia)

Speed of processes vary- 1cm a year to 18cm a year


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2004 Indian Ocean earthquake

The 9.3 moment magnitude2004 Indian Ocean earthquakewascaused by the release of stresses built up along the subductionzonewhere the Indian Plate is sliding under the Burma Platein theeastern Indian Ocean, at a rate of 6 cm/yr (2.5 in/yr).

The Sunda Trenchis formed along this boundary where the Indo-Australian and Eurasian Plates meet. Earthquakesin the region areeither caused by thrust faulting, where the faultslips at rightangles to the trench; or strike-slip faulting, where material to theeast of the fault slips along the direction of the trench.

Like all similarly large earthquakes, the December 26, 2004 event

was caused by thrust-faulting. A 100 km (60 mi) rupture causedabout 1,600 km (994 mi) of the interface to slip, which moved thefault 15 m (50 ft) and lifted the sea floor several meters (yards),creating the great tsunami.
http://en.wikipedia.org/wiki/Moment_magnitude_scalehttp://en.wikipedia.org/wiki/2004_Indian_Ocean_earthquakehttp://en.wikipedia.org/wiki/Subduction_zonehttp://en.wikipedia.org/wiki/Subduction_zonehttp://en.wikipedia.org/wiki/Subduction_zonehttp://en.wikipedia.org/wiki/Subduction_zonehttp://en.wikipedia.org/wiki/Burma_Platehttp://en.wikipedia.org/wiki/Sunda_Trenchhttp://en.wikipedia.org/wiki/Earthquakehttp://en.wikipedia.org/wiki/Earthquakehttp://en.wikipedia.org/wiki/Thrust_faulthttp://en.wikipedia.org/wiki/Fault_%28geology%29http://en.wikipedia.org/wiki/Tsunamihttp://en.wikipedia.org/wiki/Tsunamihttp://en.wikipedia.org/wiki/Tsunamihttp://en.wikipedia.org/wiki/Fault_%28geology%29http://en.wikipedia.org/wiki/Thrust_faulthttp://en.wikipedia.org/wiki/Earthquakehttp://en.wikipedia.org/wiki/Sunda_Trenchhttp://en.wikipedia.org/wiki/Sunda_Trenchhttp://en.wikipedia.org/wiki/Sunda_Trenchhttp://en.wikipedia.org/wiki/Burma_Platehttp://en.wikipedia.org/wiki/Subduction_zonehttp://en.wikipedia.org/wiki/Subduction_zonehttp://en.wikipedia.org/wiki/Subduction_zonehttp://en.wikipedia.org/wiki/2004_Indian_Ocean_earthquakehttp://en.wikipedia.org/wiki/Moment_magnitude_scale


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Rocks and Minerals

Mineral: naturally occurring, inorganic, solid elementor composed with a definite chemical compositionand a regular internal crystal structure

Most fundamental characteristics: 1) ChemicalComposition and 2) Crystal Structure

No 2 Minerals are the same

Rock: solid, cohesive, aggregate of one or moreminerals


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The Rock Cycle

The rock cycle includes a variety of geologic processesthat can transform any rock


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The Rock Cycle (cont.)

Three major rock classifications: igneous,sedimentary, and metamorphic

Igneous Rocks: The most common rock type; madeby cooling magma

Sedimentary rock is formed from the long-termdeposit and compaction of sediments into rock.

Metamorphic rock is rock formed when anothertype of rock is changed by pressure, heat, and

tectonic processes. (i.e. limestonemarble)


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IGNEOUS ROCK METAMORPHICROCK

SEDIMENTARY ROCK


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Weathering

Mechanical weathering is the physicalbreakup of rocks into smaller pieces withoutchanging the chemical composition.

Chemical weathering is the selective removalor alteration of specific components thatleads to weakening and disintegration of the

rock


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Economic Geology and

Mineralogy

Economic geology is the study of minerals that areheavily used in manufacturing and an important partof commerce.

Metals have been very important in human affairs (i.e.Stone Age)

Most economically valuable resources exist everywherein small amounts

Economic geology is the study of minerals that areheavily used in manufacturing and an important partof commerce.

Metals have been very important in human affairs (i.e.Stone Age)

Most economically valuable resources exist everywherein small amounts


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Metals & Nonmetals

Metals consumed in greatest quantity: iron,aluminum, manganese, copper and chromium-produced mainly in mountainous areas

Nonmetals (covers silicate minerals to sand, gravel,salts, etc.): durable, highly valuable, and easilyportable

i.e. Gemstones

Sand and gravel production comprise by far thegreatest volume and dollar value of all nonmetalmineral resources.


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MiningPlacer mining- washing out metals deposited in the gravel ofstreambeds (i.e. gold)destroys streambeds but fills the waterwith suspended solids that smother aquatic life

Other types of mining: open-pit mining, strip mining, andunderground mining

Risk of fires: inaccessibility and size of the fires make manyimpossible to extinguish and control

Toxic Soup in metal mines can leak into lakes and endangerwildlife- 12,000 miles of rivers and streams in the U.S. arecontaminated by mine drainage

1997 federal Surface Mining Control and Reclamation Actrequires better restoration of strip-mined lands; but restorationis difficult because it is expensive


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Processing Ores

Metals are extracted from ores by heating or withchemical solvents- releases large quantities of toxicmaterials

Smelting: roasting ore to release metals; major sourceof air pollution

Heap-Leach Extraction: piling crushed ore in huge

heaps and spraying it with a dilute alakine-cyanidesolution; large water pollutant


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Conserving Geologic Resources

Recycling

Metals are easily recyclable and require

much less energy than extracting newmetals (i.e. Aluminum)

New materials can be substituted for old

Using iron and steel replaced by polymers,aluminum, etc.


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Geologic Hazards

Earthquakes, volcanic eruptions, floods, andlandslides and other catastrophic events, though rare,have shaped the earth significantly


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Earthquakes can be very

destructiveEarthquakesare sudden movements in the earths crustthat occur along faults where one rock mass slides pastanother one

Mysterious, sudden, and violent

Worst death toll occurs in cities with poorly constructedbuildings

Most seismically active region in the U.S. is along the westcoast where tectonic plates are colliding

Tsunamis are giant seismic sea swells generated from thecenter of an earthquake. They are incredibly destructive tocoastal areas.


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Volcanoes

Volcanoes and undersea magma vents produce much of theearths crust but release large volumes of ash and dust into theaircan block sunlight

Ring of Fire- seismic activity and active volcanoes around theedge of the Pacific Ocean

More than 500 million people live in the danger zone aroundvolcanoes

Nuees ardentes (glowing clouds) are deadly, denser than airmixtures of hot gases and ash like those that inundated Pompeii

Mudslides are also dangerous


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Landslides

Mass wasting: geological materials are moved downslope from one place to another

i.e. Rockslides and avalanches

Over $1 billion in property damage is done every year bylandslides in the U.S.

Many human activities such as road construction andforest clearing increase the frequency and damagedone by landslides


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Thank you


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Documents

Tectonic Elements of Indian Subcontinent