Exam 1 - Geo

Hydrospere

Totality of all water on Earth (liquid, ice, and vapor).

Atmosphere

Totality of all gasses attached to Earth.

Biosphere

Totality of all life on Earth.

Geology

Study of Earth

Meteorology

Study of atmosphere, weather, and climate.

Astronomy

Study of the universe (interstellar space).

Lithosphere Layer

Made of solid rock.

Athenosphere Layer

Made of plastic; ductile.

Outer Core Layer

Made of liquid.

Inner Core Layer

Solid

How temperature changes within the Earth

Temperature increases as you go deeper.

How pressure changes within the Earth.

Pressure also increases as you go deeper.

Chemical Composition of Crust

Si, O

Chemical Composition of Mantle

Mg, Si, O

Chemical Composition of Core

Fe, Ni

The Scientific Method

Goes from making an observation, to a hypothesis, to making predictions, then comes experimentation and observation, then you can confirm, modify, or discard your original hypothesis.

Geologic Time

The vast span of time over which Earth’s geological development has occurred. Marked by major changes in Earth’s layers, fossil records, and climate shifts — like mass extinctions or the appearance of new life forms.

The Estimated Age of the Earth

4.54 billion years.

What does the Big Bang Theory explain?

Explains the way that the universe began.

What does the Big Bang Theory state?

The universe began as just a singularity that was infinitely hot then expanded and stretched to grow as large as it is now. When the universe began, it was just hot, tiny particles mixed with light and energy. As everything expanded and took up more space, it cooled down. The tiny particles grouped together, forming atoms. Then, those atoms came together. Over lots of time, atoms came together to form stars and galaxies.

What is the evidence for the expansion of the universe?

The Redshift of Galaxies (distant galaxies light are stretched toward the red end of the spectrum), Abundance of Light Elements (H and He that are created in a hot, dense space), and Cosmic Microwave Background (Detected everywhere in universe, the afterglow of the hot, dense early universe and has cooled over time).

Continental Crust

Thick, light.

Oceanic Crust

Thin, dense.

Expansion of the Universe

The universe expanded out of an infinitely dense point (singularity) approximately about 13.8 billion years ago (TBB) and has been expanding ever since.

Main Sequence Stars

Actively fusing hydrogen into helium. In balance: Gravity tries to collapse the star, but the energy from fusion pushes outward. Stable in size and brightness (for millions to billions of years).

Low Mass Stars Final Fate according to Mass

White dwarf.

Medium Mass Stars Final Fate according to Mass

White dwarf.

High Mass Stars Final Fate according to Mass

Black hole OR Neutron star.

Defintion of a Black Hole

An astronomical object with a gravitational pull so strong that nothing, not even light, can escape it. A black hole’s surface is called an event horizon, and that defines the boundary where the velocity needed to escape exceeds the speed of light. It is also the limit of the black hole’s influence; it is the boundary separating the region of influence of the black hole from the rest of the universe.

First Type of Galaxy

Spiral Galaxy - Flat, disk-shaped with a central bulge and spiral arms. They usually have a rotating disk and can have a bar of stars across the center (called barred spirals).

Second Type of Galaxy

Elliptical Galaxy - Round to oval (like a stretched-out sphere), no distinct features like arms. These can be huge, containing trillions of stars — often found in galaxy clusters.

Third Type of Galaxy

Irregular Galaxy - No definite shape — chaotic, kind of messy-looking. Many are believed to be the result of galaxy collisions or close gravitational interactions.

5 Conditions that make a Mineral

Naturally occuring, inorganic, solid, crystalline structure, and a chemical composition.

Atom

Building block of chemistry, the smaller unit of matter that can combine with other atoms to form molecules. Most of the atom is empty space. The rest consists of three basic types of subatomic particles: protons, neutrons, and electrons.

Proton

Forms the atomic nucleus, has a positive charge.

Neutron

Forms the atomic nucleus, electrically neutral, has no charge.

Electron

Circles the nucleus in cloud-like form, carrying electrons that have a negative charge. Like opposite ends of a magnet that attract one another, the negative electrons are attracted to a positive force, which binds them to the nucleus (positive charge).

How Elements are Differentiated/Defined

Elements are differentiated and defined by the number of protons in their atom’s nuclei, which is known as the atomic number. No two elements have the same atomic number, and this number defines the specific element.

Which elements on the Periodic Table have all of the electrons in their outer shell filled, and are therefore stable.

Last column on the periodic table, “noble gasses: He, Ne, Ar, Kr, Xe, Rn, Og”

Ionic Bonds

Form when one atom transfers electrons to another, creating charged ions that attract.

Covalent Bonds

Formed by atoms sharing electrons.

Metallic bonds

Occur when metal atoms have a “sea” of delocalized electrons surrounding positively charged ions.

Luster

How light reflects off mineral.

Cleavage

The way a mineral breaks or breaks in planes - flat surfaces (top and bottom)

Fracture

Irregular and conchoidal (curved).

Cleavages of Calcite

3 at 70/110

Cleavages of Halite

3 at 90

Chemical Structure of the Silica Tetrahedron

(SiO4)4-

Igneous rock

Rocks formed from molten material.

Volcanic (extrusive) rock

Cools above ground.

Plutonic (intrusive) rock

Cools underground.

Definition of Magma and what it consists of:

Magma is molten material of various elements from the mantle or crust.

Phaneritic Texture

Coarse-grained texture that can be seen with the naked eye. (Plutonic rocks)

Aphanitic Texture

Fine-grained texture that can’t be seen with the naked eye. (Volcanic rocks.)

Porphyritic Texture

Mixture of both phaneritic and apha

Felsic Composition of Rock

Lighter shades that contain Silicone (Si) and Oxygen (O)

Mafic Composition of Rock

Darker shades that contain Magnesium (Mg) and Iron (Fe).

Bowen’s Reaction Series

A concept in geology that describes the order in which minerals crystallize from cooling magma. It helps explain why certain minerals are often found together in igneous rocks — and why others aren’t. Minerals form one after another, each replacing the previous one as temperature drops. As magma cools, each mineral becomes unstable and reacts with the melt to form the next mineral.

Relation between Cooling Time and Final Size of Crystals in the Rock

If a crystal cools instantly, there is no time for crystals to grow, and they therefore are smaller. If a crystal grows slowly, there is enough time for crystals to grow, and they therefore are bigger.

Magma Differentiation

The process by which chemically different igneous rocks, such as basalt and granite, can form from the same initial magma. As magma cools, only some of it solidifies, its first minerals ‘steal’ elements from the liquid. The the leftover magma has a new composition.

How Pressure and Water content affect Melting

Pressure increases melting temperature (makes it harder to melt). Decompression melting is when minerals melt when pressure decreases. The addition of water lowers melting temperatures.

Driving force in Mass Wasting

Gravity. The erosion of gravity pushes material downslope. Can be slow and imperceptible or rapid and catastrophic.

Chemical Weathering and 2 Examples

The removal or addition of elements to rock by chemical reactions. Oxidation is rusting. Dissolution involves the complete breakdown and removal of minerals from rocks by water or acidic solutions, leaving behind ions in solution.

Jointing

Rock breaks due to decompression. Can be tectonic forces (stress from plate movements). Can be cooling/contraction. Can be unloading or exfoliation (overlying rock is eroded away). Can be hydration/dehydration (water entering or leaving the rock can cause it to expand or shrink).

Steam Gradient Affecting the Velocity of Water

Vertical drop over a distance.

Slope Affecting the Velocity of Water

Velocity decreases, and so particles drop.

Definition of Base Level of a Stream

The lower limit to how deep a stream can erode. Stream base level is temporary or local base.