Intro to Earth Science

What is a mineral?

• Naturally occurring

• Inorganic solid

• Definite chemical composition

• Highly ordered atomic arrangement

The 6 properties of Minerals

1. Color

2. Streak

3. Hardness

4. Cleavage/Fracture

5. Reaction to acid

6. Density

The two elements in a silicate tetrahedron

• Silicon (1)

• Oxygen (4)

Polymorphs

Minerals with the same composition but different atomic structures.

The 9 main mineral groups

1. Native elements

2. Oxides

3. Hydroxides

4. Sulfides

5. Sulfates

6. Carbonates

7. Phosphates

8. Halides

9. Silicates

The two most abundant elements in the earth’s crust

1. Oxygen

2. Silicon

Isolated tetrahedrons

Where the tetrahedrons are not bonded to each other instead they are bonded to different elements (i.e. olivine).

Single chain tetrahedrons

Where the tetrahedrons are bonded into a chain (i.e. pyroxine)

Double Chain tetrahedrons.

Where the tetrahedrons are in two chains bonded to each other. (i.e. amphiboles)

Sheet tetrahedrons

Where the tetrahedrons are bonded into sheets (i.e mica, biotite, and clay)

3-D Network tetrahedrons

Where the tetrahedrons are bonded in a complex three dimensional network (i.e. felspar, quartz)

Solid solution series

Where an ion substitutes for another in the crystal structure.

Rules for mineral construction

1. Similar ionic radius

2. Similar charge

Igneous rock formation

The cooling and solidification of molten liquid rock.

What does Igneous rock color tell you?

Chemical composition.

What two things does Igneous grain size tell you?

1. Speed of cooling

2. Intrusive or extrusive cooling

Where do intrusive igneous rocks form?

Inside the earth’s crust.

Where do extrusive igneous rocks form?

On the surface of earth’s crust.

Igneous Phaneritic rock

An igneous rock with large crystals that can be seen by the naked eye. (i.e. granite)

Igneous Aphanitic rock

An igneous rock with fine crystals that cannot be seen by the naked eye. (i.e. andesite, basalt)

Igneous Pegmatitic rock

An igneous rock with exceptionally large crystals (i.e. topaz, fluorite)

Igneous Glassy rock

An igneous rock without specific crystal grains and has a glassy texture (i.e. obsidian)

Igneous Vesicular rock

An igneous rock that contains holes that were caused by gas (i.e. pumice)

Igneous Porphyritic rock

An igneous rock with larger crystals visible crystals and finer groundmass (i.e. andesite)

Ultramafic Igneous Rocks

Rocks that are made of mostly mafic materials like olivine and extremely little in felsic materials.

What color are mafic rocks usually?

Dark to Black

What color are felsic rocks usually?

Light to medium grey

Sill intrusion

When magma intrudes between layers of rock.

Laccolith intrusion

A upper-crust intrusion that creates a dome shape.

Batholith intrusion

A very large lower-crust intrusion.

Dike intrusion

An intrusion that usually runs perpendicular they can also feed magma into other intrusions.

Bowen’s Reaction Series

A series that describes which minerals crystalize first when magma cools.

What is the first to crystalize in Bowen’s Reaction Series?

Olivine

What is the last to crystalize in Bowen’s Reaction Series?

Quartz

The 4 transporting agents of sediment

1. Water

2. Wind

3. Landslides

4. Glaciers

The 5 properties of sedimentary rocks.

1. Grain size

2. Angularity/Roundness

3. Sorting

4. Bedding Features

5. Fossils

What direction is the current flowing?

One direction (unidirectional)

What direction is the current flowing?

Two directions (bidirectional)

What can grain size tell you about a sedimentary rock?

• Corse — High energy environment (i.e. fast stream)

• Fine — Low energy environment (i.e. slow stream)

Sedimentary bedding

The layering of sediment to create bedding in the rock produced.

Sorting

A concept that describes the quality of how sediment grains are sorted.

Weathering

Weathering of pre-existing rocks into smaller sediments or ions.

Transport

The movement of sediment from its origin.

Deposition

When sediment is deposited.

Compaction

When the deposited sediment is compacted and packed together.

Lithification

In the process, sediments are converted to rock by pressure.

Shape of sediment grains

• Angular — The origin of the sediment is close

• Rounded — The origin of the sediment is farther away

Inorganic Chemical Sedimentary Rocks

A rock that is formed when water with dissolved ions evaporates (i.e. rock salt)

Biochemical Sedimentary Rocks

A rock that is formed by organisms pulling ions out of water to form shells. When the organism dies the shells become sediment that becomes compacted (i.e. limestone, coquina)

Detrital Sedimentary Rocks

A rock that is formed by the cementation of solid rock fragments (i.e. conglomerate)

Sedimentary Fossils

The process where remains of organisms get compacted with sediments to become fossils.

Sedimentary basins

Where parts of the earth’s crust sinks and sediments collect to create a large section of sedimentary rocks.

Metamorphosis

Alteration of pre-existing rock due to increases in pressure/temperature to form a new rock

Foliation

Layering due to alignment of the minerals in metamorphic rock

Contact Metamorphism

Small scale metamorphism due to igneous intrusions.

Regional Metamorphosis

Large scale metamorphism due to plate tectonics and compressional stress.

Burial metamorphism

When sedimentary rocks are burried deep enough to expierence heat and pressure

Parent rock

Rocks that existed before the process of metamorphosis.

Recrystallization

The process where crystals are packed together which creates a new crystal structure.

Scientific Method

The process used by scientists to acquire knowledge through the usage of observation and skepticism.

What are the steps in the scientific method?

1. Observation

2. Problem or Question

3. Hypothesis

4. Testing and Observations

5. Presenting and Publish Findings

6. Scientific theory

Hypothesis

An explanation based on limited evidence that serves as a starting point for research.

Observation

The act of perceiving something and registering its significance.

Scientific Theory

A well-supported explanation of some aspect of the natural world with repeatable results.

The 3 parts of an atom.

• Proton

• Neutron

• Electron

Proton

A subatomic particle with a positive charge and an atomic mass of about 1. Found in the nucleus of the atom.

Neutron

A subatomic particle with a neutral charge and an atomic mass of about 1. Found in the nucleus of the atom.

Electron

A subatomic particle with a negative charge with a very small atomic mass. Found on the electron shells of the atom.

Valance shell

The outermost shell of an atom.

Valance electrons

The outermost electrons in the valance shell.

Atomic number

The number of protons in the nucleus of each atom of that element. Atoms are neutral, the number of electrons is equal to the number of protons.

Atomic Mass

The mass of an atom is a weighted average that is largely determined by the number of its protons and neutrons

Isotopes

Atoms of the same element with the same amount of electrons but a different amount of neutrons.

Ions

An atom with a net charge due to the loss/gain of electrons.

Cation

A positively charged ion that has more protons than electrons.

Anion

A negatively charged ion that has more electrons than protons

Covalent bonding

When atoms bond and share electrons to form electron pairs.

Ionic bonding

When atoms with opposite electrical charges are attracted to each other.