GEOL 106 Lecture Notes - Inner Core, Continental Crust, Water Cycle

32 views2 pages
What causes the stress in the earth?
That’s what we need to answer now. So lets look at the
dynamic earth system more closely
Structure of the earth
Seismic waves have been critical in giving us a “picture”of the
inside of the earth ( an “xray” of the Earth ). The waves are
reflected and refracted at boundaries between different
Waves reveal a layered earth
P and S wave .. P waves can go through liquid .. s waves
cant.. determines 3 layers. Mantle, Outer core and Inner core.
We live on crust. 2900 km from crust to get to outer core (
depth of mantle) .. 5100 km from crust to get to core… 6371
km to get to centre of earth. Mantle (solid) outer core (liquid)
inner (solid) .
Continental crust in about 30 km thick and oceanic crust in 5
km thick.
Moho is the boundary between the crust and mantle.
Moho stands for Mohorivicic Discontinuity ..
What about the composition of the layers.
The core of the earth . outer/inner is mostly out of iron (Fe).
And the mantle is made out of minerals called silicates (O, Si,
Mg, Fe,Al,etc ) .. Iron, oxygen, silicon , aluminum ,
magnesium (Silicates :minerals that have O and Si as their
basic building blocks)
Chemical Composition of Mantle .. order of decreasing
abundance (by weight) … O. Si. Fe. Mg. etc
Chemical composition of average crust. (ie. Continental and
oceanic crust combind.) order of decreasing abundance (by
weight). O. Si. Al. Fe. Ca. etc
Difference between continental crust and oceanic crust.
o Continental :
More Si+O . Less Fe+Mg
Pink/white rocks called -> Felsic
o Oceanic :
More Fe+Mg . Less Si+O
Black rocks called - Mafic .. rich in mafic
minerals M for Mg and F for Fe.
Minerals with Fe in them are generally black
Increase in Fe content and Density
Cont crust ------ Felsic
Unlock document

This preview shows half of the first page of the document.
Unlock all 2 pages and 3 million more documents.

Already have an account? Log in

Get OneClass Notes+

Unlimited access to class notes and textbook notes.

YearlyBest Value
75% OFF
$8 USD/m
$30 USD/m
You will be charged $96 USD upfront and auto renewed at the end of each cycle. You may cancel anytime under Payment Settings. For more information, see our Terms and Privacy.
Payments are encrypted using 256-bit SSL. Powered by Stripe.