EARTH'S FORMATION Flashcards
Geology definition
the study of earth (interior and exterior), minerals and rock and the surface processes acting over the vastness of geological time
Horizontality
sediments are deposited horizontally because of gravity
Folding happens later stressed imposed on layers
superposition
youngest towards the top and oldest at the bottom if not disturbed
cross cutting relationship
intrusions are younger than rocks they cut through
lateral continuity
layers are continuous until encountered solid bodies that block deposition
explanation for the formation of our universe
catastrophism
uniformitarianism
catastophism
sudden catastrophe
earth is a few thousand years old
o Uniformitarianism
- todays physical processes happened throughout geological time
Landforms change over long time
Ka
(kilo anum) = 100 years
Ma
(mega anum) = 1,000,000 years
o Ga
giga anum) = 1, 000,000,000 years
- Nebular theory
o Nebula is compressed due to gravity, overcoming gas pressure
o Gravity pulls articles close together raising the temp- cloud collapses and flattens into accretionary disk and rotate
o Dust particles stick together and form planetesimals
o Largest planetesimals in each orbit continue to grow to become protoplanets
o Universe
all existing matter and space; the cosmos
o Galaxy
: gravitationally bound system of stars, interstellar gas and matter
o Solar system
gravitationally bound system of a star and all objects that orbit it
order of the nucleosyntheses
big bang nucleosyntheses
stelar nucleosyntheses
supernova nucleosyntheses
o Big bang nucleosynthesis
First few minutes after big bang
Lightest element (h, He, Li) created
Earths age found by: radiometric dating (half life)
o Stelar nucleosynthesis
During the lifetime of stars
Heaver elements between Li and Fe created
o Supernova nucleosynthesis
Death of stars
Elements heavier than Fe created
terrestrial planets
formed from rocky material and meager atmosphere because it was too hot for the gases to remain
metal core surrounded by rock
Mercury, Venus, Earth, Mars
Jovian/ ice planets
able to collect larger amounts of gases and ices to form very thick atmospheres in the cooler outer reaches of the forming solar system, has ring systems
Jupiter, Saturn, Uranus, Neptune
gas giants
Jupiter and Saturn
mainly H and He with rock/ice core
mercury
- smallest, closest to the sun, hot intense solar winds, no atmosphere
- no detectable atmosphere, -173- 429C, surface has lava plains and cratered
Venus-
- similar to earths diameter, volcanic landforms, complex mountainous areas, greenhouse planet, tiny water, dense atmosphere
earth
- active plate tectonics, liquid water at surface, nitrogen and oxygen dominated atmosphere
mars
- active plate tectonics, liquid water at surface, nitrogen and oxygen dominated atmosphere
ice giants
Uranus and Neptune
water, ice, ammonia ice, methane ice and rocky core
Jupiter
o Largest planet, H and He, no solid surface, bands and stroms “great red spot”
Saturn
o Prominent ring system (icy particles, dust and boudlers), metallic hydrogen layer giving a magnetic field, ammonia in the atmosphere= yellow
Uranus
o H, He, H2O, ammonia and methane, coldest, tilted axis of rotation
Neptune
o Active visible weather patterns
planet requirements
orbit a star
big enough for spherical shape due to gravity
big enough that its gravity cleared away any other objects of a similar size near its orbit around the sun
