Earth & Space Science Introduction Chapter

Earth and Space Science Introduction

• Earth Science: the collective study of Earth and other planets, including geology, oceanography, meteorology, and astronomy

Branches of Earth Science

• Geology: divided into physical geology (study of Earth's materials and processes) and historical geology (study of Earth's origin and changes over time)
• Oceanography: integrates chemistry, physics, geology, and biology to study oceans
• Meteorology: study of atmosphere and processes that produce weather and climate
• Astronomy: study of the universe, including our solar system and its relation to other solar systems

Spheres of Earth

• Hydrosphere: dynamic system of water, including oceans, lakes, streams, and groundwater (71% of Earth's surface, 97% of Earth's water)
• Atmosphere: life-giving gaseous envelope surrounding Earth, essential for life
• Biosphere: includes all life on Earth, interacting with other spheres
• Solid Earth/Geosphere: study of Earth's solid interior and surface features

Concepts

• System: a group of interacting, interdependent parts forming a complex whole
• Environment: everything that surrounds and influences an organism (biological, social, nonliving)
• Natural hazards: Earth processes that become hazardous to humans (e.g., floods, earthquakes, volcanic eruptions)

Layers of the Earth

• Crust: rocky outer skin, divided into continental and oceanic crust
• Mantle: solid, rocky shell extending to a depth of 1,800 miles
• Core: iron-nickel alloy core with a density of 11 g/cm3

Geologic Time Scale

• Divided into eons, eras, periods, epochs, and ages
• Critical for understanding Earth's history and processes

Renewable and Nonrenewable Resources

• Renewable: resources replenished by nature at a rate greater than consumption (e.g., solar energy, wind power)
• Nonrenewable: resources consumed at a rate higher than replenishment (e.g., fossil fuels)

Scientific Method

• Process of forming hypotheses, testing, and verifying or rejecting theories
• Involves observation, measurement, formulation of hypotheses, and experimentation

Minerals and Rocks

• Mineral: naturally occurring inorganic solid with a definite chemical structure and unique physical properties
• Rock: aggregate of minerals

Atomic Structure

• Atom: smallest unit of matter, consisting of protons, neutrons, and electrons
• Proton: positively charged, found in the nucleus
• Neutron: neutral, found in the nucleus
• Electron: negatively charged, orbits the nucleus

Chemical Bonding

• Ionic bond: transfer of electrons between atoms
• Covalent bond: sharing of valence electrons between atoms
• Metallic bond: free movement of valence electrons between atoms### Silicate Minerals
• Silicate minerals consist of a pyramid-shaped structure with 4 oxygen ions (O2-) surrounding 1 silicon ion (Si4+), with a net charge of -4.
• The complex ion bonds with positively charged ions, and each O2- has one valence electron bonded to the Si4+, while the remaining oxygen valence electron is available to bond with another positive ion or an adjacent tetrahedra.
• The simplest way for the tetrahedra to become neutral compounds is through the addition of positively charged ions, such as Magnesium and/or Iron, which pack between tetrahedra, forming a dense three-dimensional structure.
• The tetrahedra can also link in a variety of configurations, including single chains, double chains, and sheet structures, which develop due to the sharing of oxygen ions.
• The ratio of oxygen ions to silicon ions is different in various types of silicate structures, and the amount of silicon content is extremely important in igneous rocks.
• With the exception of quartz, the structure of silicate minerals has a negative charge, requiring positive ions to form a chemical compound.
• The positive ions that generally link silicate structures include Iron, Magnesium, Potassium, Sodium, Aluminum, and Calcium.

Physical Properties

• The partial covalent bonds of the tetrahedra are stronger than the ionic bonds that hold each silicate structure together, resulting in the physical properties of cleavage and, to some degree, hardness.
• Examples of minerals with excellent cleavage include quartz and mica.
• A decrease in density results as the number of shared oxygen ions increases, with examples including olivine and garnet having high specific gravity, while quartz and feldspar have a lower specific gravity.

Formation of Silicate Minerals

• Most silicate minerals form during the crystallization of molten material, with the environment during crystallization and chemical composition of the molten material determining which minerals form.
• Examples include olivine crystallizing at temperatures around 1200°C, while quartz crystallizes at lower temperatures near 700°C.
• Some silicate minerals form from the weathered products of other silicate minerals, while others form during the extreme pressures exerted during mountain building.
• Each silicate mineral has a structure and composition that indicates the conditions under which it formed.

Silicate Mineral Groups

• Light Silicate Minerals:
  • Generally light in color
  • Have a specific gravity of about 2.7
  • Contain varying amounts of aluminum, potassium, calcium, and sodium
  • Examples include feldspar, quartz, muscovite, and clay minerals
• Dark Silicate Minerals:
  • Generally dark in color due to the presence of iron and/or magnesium ions
  • Have a higher specific gravity than the light silicates, between 3.2 and 3.6
  • Examples include olivine, pyroxene, amphibole, and biotite

Non-Silicate Minerals

• Carbonates:
  • The two most common carbonates are calcite (CaCO3) and dolomite [CaMg(CO3)2]
  • Both have similar physical and chemical characteristics, such as vitreous luster, hardness between 3 and 4, and rhombic cleavage
• Sulfates:
  • Gypsum (CaSO4 *2H2O) is the most common sulfate mineral
  • Typically forms as seawater evaporates
• Halides:
  • Halite (NaCl) is the most common halide mineral
  • Also forms as seawater evaporates
• Evaporites:
  • Form as seawater evaporates
  • Examples include calcite, gypsum, and halite
• Other non-silicate minerals:
  • Examples include hematite (iron), sphalerite (zinc), galena (lead), gold, silver, carbon (diamonds), fluorite, corundum, and uraninite (a source of uranium)

Igneous Rocks

• Magma is molten material that forms inside the Earth
• Lava is molten material on the Earth's surface with little or no gas components
• Crystallization is the cooling and solidification of magma or lava, resulting in the formation of igneous rocks
• Igneous rocks can be classified by:
  • Texture
  • Mineral Composition
• Igneous rocks that form when molten rock solidifies at the surface are termed extrusive or volcanic, while those that form at depth are termed intrusive or plutonic

Earth and Space Science Introduction

• Earth Science: the collective study of Earth and other planets, including geology, oceanography, meteorology, and astronomy

Branches of Earth Science

• Geology: divided into physical geology (study of Earth's materials and processes) and historical geology (study of Earth's origin and changes over time)
• Oceanography: integrates chemistry, physics, geology, and biology to study oceans
• Meteorology: study of atmosphere and processes that produce weather and climate
• Astronomy: study of the universe, including our solar system and its relation to other solar systems

Spheres of Earth

• Hydrosphere: dynamic system of water, including oceans, lakes, streams, and groundwater (71% of Earth's surface, 97% of Earth's water)
• Atmosphere: life-giving gaseous envelope surrounding Earth, essential for life
• Biosphere: includes all life on Earth, interacting with other spheres
• Solid Earth/Geosphere: study of Earth's solid interior and surface features

Concepts

• System: a group of interacting, interdependent parts forming a complex whole
• Environment: everything that surrounds and influences an organism (biological, social, nonliving)
• Natural hazards: Earth processes that become hazardous to humans (e.g., floods, earthquakes, volcanic eruptions)

Layers of the Earth

• Crust: rocky outer skin, divided into continental and oceanic crust
• Mantle: solid, rocky shell extending to a depth of 1,800 miles
• Core: iron-nickel alloy core with a density of 11 g/cm3

Geologic Time Scale

• Divided into eons, eras, periods, epochs, and ages
• Critical for understanding Earth's history and processes

Renewable and Nonrenewable Resources

• Renewable: resources replenished by nature at a rate greater than consumption (e.g., solar energy, wind power)
• Nonrenewable: resources consumed at a rate higher than replenishment (e.g., fossil fuels)

Scientific Method

• Process of forming hypotheses, testing, and verifying or rejecting theories
• Involves observation, measurement, formulation of hypotheses, and experimentation

Minerals and Rocks

• Mineral: naturally occurring inorganic solid with a definite chemical structure and unique physical properties
• Rock: aggregate of minerals

Atomic Structure

• Atom: smallest unit of matter, consisting of protons, neutrons, and electrons
• Proton: positively charged, found in the nucleus
• Neutron: neutral, found in the nucleus
• Electron: negatively charged, orbits the nucleus

Chemical Bonding

• Ionic bond: transfer of electrons between atoms
• Covalent bond: sharing of valence electrons between atoms
• Metallic bond: free movement of valence electrons between atoms### Silicate Minerals
• Silicate minerals consist of a pyramid-shaped structure with 4 oxygen ions (O2-) surrounding 1 silicon ion (Si4+), with a net charge of -4.
• The complex ion bonds with positively charged ions, and each O2- has one valence electron bonded to the Si4+, while the remaining oxygen valence electron is available to bond with another positive ion or an adjacent tetrahedra.
• The simplest way for the tetrahedra to become neutral compounds is through the addition of positively charged ions, such as Magnesium and/or Iron, which pack between tetrahedra, forming a dense three-dimensional structure.
• The tetrahedra can also link in a variety of configurations, including single chains, double chains, and sheet structures, which develop due to the sharing of oxygen ions.
• The ratio of oxygen ions to silicon ions is different in various types of silicate structures, and the amount of silicon content is extremely important in igneous rocks.
• With the exception of quartz, the structure of silicate minerals has a negative charge, requiring positive ions to form a chemical compound.
• The positive ions that generally link silicate structures include Iron, Magnesium, Potassium, Sodium, Aluminum, and Calcium.

Physical Properties

• The partial covalent bonds of the tetrahedra are stronger than the ionic bonds that hold each silicate structure together, resulting in the physical properties of cleavage and, to some degree, hardness.
• Examples of minerals with excellent cleavage include quartz and mica.
• A decrease in density results as the number of shared oxygen ions increases, with examples including olivine and garnet having high specific gravity, while quartz and feldspar have a lower specific gravity.

Formation of Silicate Minerals

• Most silicate minerals form during the crystallization of molten material, with the environment during crystallization and chemical composition of the molten material determining which minerals form.
• Examples include olivine crystallizing at temperatures around 1200°C, while quartz crystallizes at lower temperatures near 700°C.
• Some silicate minerals form from the weathered products of other silicate minerals, while others form during the extreme pressures exerted during mountain building.
• Each silicate mineral has a structure and composition that indicates the conditions under which it formed.

Silicate Mineral Groups

• Light Silicate Minerals:
  • Generally light in color
  • Have a specific gravity of about 2.7
  • Contain varying amounts of aluminum, potassium, calcium, and sodium
  • Examples include feldspar, quartz, muscovite, and clay minerals
• Dark Silicate Minerals:
  • Generally dark in color due to the presence of iron and/or magnesium ions
  • Have a higher specific gravity than the light silicates, between 3.2 and 3.6
  • Examples include olivine, pyroxene, amphibole, and biotite

Non-Silicate Minerals

• Carbonates:
  • The two most common carbonates are calcite (CaCO3) and dolomite [CaMg(CO3)2]
  • Both have similar physical and chemical characteristics, such as vitreous luster, hardness between 3 and 4, and rhombic cleavage
• Sulfates:
  • Gypsum (CaSO4 *2H2O) is the most common sulfate mineral
  • Typically forms as seawater evaporates
• Halides:
  • Halite (NaCl) is the most common halide mineral
  • Also forms as seawater evaporates
• Evaporites:
  • Form as seawater evaporates
  • Examples include calcite, gypsum, and halite
• Other non-silicate minerals:
  • Examples include hematite (iron), sphalerite (zinc), galena (lead), gold, silver, carbon (diamonds), fluorite, corundum, and uraninite (a source of uranium)

Igneous Rocks

• Magma is molten material that forms inside the Earth
• Lava is molten material on the Earth's surface with little or no gas components
• Crystallization is the cooling and solidification of magma or lava, resulting in the formation of igneous rocks
• Igneous rocks can be classified by:
  • Texture
  • Mineral Composition
• Igneous rocks that form when molten rock solidifies at the surface are termed extrusive or volcanic, while those that form at depth are termed intrusive or plutonic