Introduction Flashcards
(36 cards)
What is the Nebular Hypothesis?
Solar system began as a giant rotating cloud of gas and dust called the solar nebula. Rotating nebula began to contract about 5 billion years ago and developed into a flat, disk shape with the proto-Sun at the center. Inner planets formed from metallic and rocky substances. Larger outer planets formed from fragments of ices that accumulated around rocky cores.
A nebula is composed mostly of what?
Hydrogen and helium
The larger outer planets formed from what kinds of ice fragments?f
H20, CO2, NH3 (ammonia), and CH4 (methane)
What happens as a nebula cools?
Tiny solid particles condense and coalesce into asteroid-size bodies. These in turn accrete (coalesce) into planets.
How long did it take for the solar system to form?
A few tens of millions of years
Hot, softened inner (terrestrial) planets separated into layers based on what?
The densities of different materials. Heavy metals (mostly iron) sank to the center while lighter, molten materials migrated towards the surface to produce a primitive crust. This chemical separation established the basic divisions of Earth’s interior and surface.
What is physical geology?
The study of the materials that compose Earth and the processes that operate on and beneath its surface.
What is historical geology?
The study of the origin of Earth and its development through time.
What are some issues addressed by geology?
Natural hazards, mineral resources, world population growth, environmental issues.
What is Earth System Science
The study of Earth as a system composed of numerous interacting parts or subsystems.
What is a system?
Any size group of interacting parts that form a (more) complex whole.
What is an open system?
A system that allows energy to freely flow in and out. e.g. leaf, ocean
What is a closed system?
Energy moves freely in and out of a closed system, while matter does not enter or leave the system. e.g. Earth
What kind of systems are the “spheres” that comprise the Earth?
Open systems
What are igneous rocks?
Rocks formed from cooling and solidification of magma (molten rock). e.g. granite, basalt
How are sedimentary rocks formed?
Sediments are derived from weathering of preexisting rock. Sediments accumulate as layers at Earth’s surface. Buried sediments are converted into rocks. e.g. sandstone and limestone
How are metamorphic rocks formed?
By “changing” preexisting igneous, sedimentary, or other metamorphic rocks. The driving forces are increased heat and pressure. e.g. gneiss (pronounced “nice”) and marble
What is the rock cycle? Give an example.
The loop that involves the processes by which one rock changes to another. Any rock type can be converted to another rock type under appropriate conditions.
High temps melt rock to form magma which cools and solidifies into igneous rock. Weathering breaks down this igneous rock into sediment. Sediment is then buried and converted to sedimentary rock. Higher heat and pressure convert this sedimentary rock into metamorphic rock. Melting of metamorphic rock produces magma.
Give the planets in order.
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
(My Very Excellent Mother Just Served Us Noodles)
Which are the terrestrial planets?
Mercury, Venus, Earth, and Mars.
Describe the terrestrial planets
They are the closest to the sun. Generally small, rocky bodies with densities greater than 3gm/cm^3.
Composed mainly of silicates, Fe and Ni (iron and nickle). Volcanism mostly basaltic.
Which are the Jovian (giant) Planets.
Jupiter, Saturn, Uranus, and Neptune.
Describe the Jovian Planets.
Each has solid rocky core surrounded by layers of frozen or liquid hydrogen, helium, methane, and ammonia. They have multiple moons and ring systems composed of dust to boulder-sized particles of mostly ice.
Describe the Earth as it was 4.5 billion years ago.
Initially a magma ocean hundreds of kilometers deep. Magma ocean cooled and crystallized from the bottom up over millions of years to form a solid mantle capped by a primitive crust of basalt.
