Ch 3. The Earth's Crust And Interior Flashcards
What is the radius of the Earth ?
6370 Km
Name two projects which are studying the interior of the Earth ?
Deep Ocean Drilling Project and Integrated Ocean Drilling Project
Deepest drill in the world is located at ____ which has the depth of ____ Km
At Kola in the Arctic Ocean, 12 Km deep
What is the temperature at the core of Earth ?
5000 - 6000°C
Mean thickness of Oceanic crust is ____ and Continental crust is ____
5Km and 30Km
What is Conrad discontinuity ?
The zone of transition between upper continental crust and lower continental crust
What components are found in the Oceanic crust ?
Silicate and Magnesium (SIMA)
What is the mean density of the materials in the Oceanic crust ?
2.7 g/cm3
The major components of Continental crust are ?
Silica and Aluminium (SIAL)
What is a Craton ?
A large, coherent domain of Earth’s continental crust that has attained and maintained long-term stability, having undergone little internal deformation, except perhaps near its margins due to interaction with neighbouring terranes.
What is Moho / Mohorovicic discontinuity ?
The zone of transition between Crust and Mantle
What is the depth of Mantle ?
2900 Km from Moho’s discontinuity
What elements are found in the Mantle ?
Silica and Magnesium (SIMA)
What is the density of Mantle ?
3.3 - 5.4 g/cm3
What is the thickness of Lithosphere ?
10-200 Km
What is Asthenosphere ?
It is a highly viscous, mechanically weak, ductile, deforming area of upper mantle which exists just below the lithosphere
What is the thickness of Asthenosphere ?
80 - 200 Km
What is Repetti discontinuity ?
The area of discontinuity between upper mantle and lower mantle
What is Mesosphere ?
The portion of the Mantle which exists just below the asthenosphere but above the core of Earth is called Mesosphere
What is the density of Earth’s core ?
13 g/cm3
What elements are found in the Earth’s core ?
Nickel and Iron (NIFE)
What is Guttenberg’s discontiniuty ?
The area of discontinuity between Mantle and Core
The thickness of outer core and inner core is ?
2200 Km and 1220 Km
What is Lehmann-Bullen discontinuity ?
The area of discontinuity between outer core and inner core
What is barysphere ?
Core of the earth is also called as Barysphere
“Rate of increase” of temperature decreases with the increasing depth – true or false ?
True
What are exogenic processes ?
Processes that are generated on or above the surface of the earth
What are endogenic processes ?
Processes that are generated within or inside the earth
Which mountains are developed in the Caledonian Orogeny
Caledonian Orogeny (320 million years ago) - Mountains of Scandinavia and Scotland, some mountains in North America
Which mountains are developed in the Hercynian Orogeny
Hercynian Orogeny (240 million years ago) - Ural mountains, Pennies and Welsh mountains in Britain : Harz mountains in Germany : the Appalachians in America : high plateau of China and Siberia
Which mountains are developed in the Alpine Orogeny
Alpine Orogeny (30 million years ago) - The Alps, Himalayas, Rockies and Andes mountains
What are the different types of mountains ?
Structural (Fold and Block), Volcanic and Residual / Dissected mountains
What are geosynclines ?
When an area of sea separates two plates, sediments settle on the seafloor in those depressions known as geosynclines
What are types of foldings in a fold mountain ?
Anticline - crest : Syncline - trough
Asymmetric fold, Over fold, Recumbent fold, Nappe
Which type of mountains are called as the mountains of elevation ?
Fold mountains
What are Horsts and Graben in a Block mountain ?
Horst - raised block
Graben - depressed block
Which type of mountains are called Mountains of Accumulation
Volcanic Mountains
Shield Volcano is formed due to ____ type of lava
Basic lava
Cone Volcano is formed due to ____ type of lava
Acidic lava
Dissected mountains are also called as ?
Residual mountains, Relict mountains and circum-denudation mountains
What is a Plateau ?
A Plateau is a flat-topped tableland
How are Tectonic Plateaus formed ?
Formed by the upliftment of the Earth’s crust
How are Lava Plateaus formed ?
Developed by highly fluid basaltic lava
What is pyroclastic flow ?
A basically dense fast moving flow of solidified lava, volcanic ash and hot gasses.
What is a Dissected Plateau ?
Plateaus that are formed by the continuous processes of weathering and erosion by running water, ice and winds, of high and extensive plateaus
What is a Plain ?
A Plain is a territory of lowland either level or undulating. It rarely rises in excess of a couple hundred feet over the sea level
What are Structural Plains ?
These are structurally depressed zones that are developed from horizontally bedded rocks which are comparitively undisturbed by the movement of earth crust
What are Outwash Plains ?
An outwash plain, also called a sandur, sandr or sandar, is a plain formed of glaciofluvial deposits due to meltwater outwash at the terminus of a glacier.
What are Aeolian Landforms ?
Winds may blow Aeolian deposits - very fine particles known as Loess from interior deserts, or barren surfaces and deposit them upon hills, valleys or plains forming a loess plateau
What are Peneplains and Pediplains ?
Peneplains -
a more or less level land surface produced by erosion over a long period, undisturbed by crustal movement.
Pediplains -
an extensive plain formed in a desert by the coalescence of neighbouring pediments.
