Big Bang

Big Bang: 13 billion years ago

All matter and energy in the Universe started out as infinitesimally small point, universe begin 13.8 / 12.5 billion years ago (dependent measurements).

Coalesce: 200 million years after big bang

Hydrogen, etc., cluster. Swinging nebulae of hydrogen and helium. Proto-planetary disk.

Star formation: 800 million years after big bang

Stellar nucleasynthesis; elements up to 26 protons.

Planet Formation: 5 or 6 million years ago

Planet formulation in the solar system. Rings of “planetesimals” form. As gas and particples start to acrete.

As they start collapsing this, the inside becomes molten and thus allows stuff to shift. Outside starts flattening

Planet formulation in our solar system: 4.56 billion year ago

How’d we know?

We found and dated elements. ga = geological age = billion years

• Acasta Gniss: 4.03 billion yars ago
• Zircons 3.0 Ga sediments, 4.404 ga zircons

Earth Core: 4.55 billion years ago

different processes of differentiation…

1. magma ocean
2. fraction out / setting: irons sink into core etc.
3. mantle forms

via gravity

Moon Formulation: 4.5 billion years ago

Moon forms.

Earth Structure

think like an egg (dense yolk, jingly white, britle shell)

Core

center of the earth, most dense (hard, dense)

Mantle

denser, the thing in the middle (more solid, jiggly)

Crust

least dense, brittle

Rocks

mafic

iron-rich rocks

felsic

sillocon rich rocks; relatively light

Order of the cores

1. inner core: very hot, solid since density
2. outer core: molten, kind of jiggly, moves iron around
3. lower mantle: ultramafic composition, contains hot and solid rock, convect because hot mantle rises and cold one lowers
4. oceanic crust: basalt / gabbro, mafic composition

terms

Two key concepts.

• composition: where stuff is
• behavior: how stuff acts

earth composition

crust

“surfarce of the earth

mantle

below, flowky

mantle behavior

these are “behavior” terms (about how stuff is)

lisophere

higher, near continental crust, brittle, breakable

asthenosphere

closer inside the earth, flowing

isostacy

How did lisophere differentiate?

For some deep depth liquid, a high-density rock would flow down more creating “ocean floor” and a low density rock would float up.

Rock Types

Igneous Rock

Basically volcano formed rocks

Sedementary Rock

rocks collect and form other rocks