Earth Science: Rocks, Energy, and Earth's Resources

A comprehensive 50-card review set covering the rock cycle, sedimentary and metamorphic rock classification, mineral and energy resources, alternative energy sources, nuclear fission, and water, air, and land conservation.

What is any solid mass of mineral or mineral-like matter that occurs naturally as part of Earth?

A rock.

What are the three major types of rocks?

Igneous, sedimentary, and metamorphic rocks.

What is the continuous process that causes rocks to change from one form to another?

The rock cycle.

What primary energy sources power the rock cycle?

The Sun, gravity, and Earth's internal heat.

What is the physical difference between magma and lava?

Magma is molten rock beneath Earth's surface, while lava is molten rock that reaches Earth's surface.

What is the distinction between intrusive and extrusive igneous rocks?

Intrusive igneous rocks form when magma cools beneath the surface of the earth, whereas extrusive igneous rocks form when lava cools above the surface of the earth.

How does the rate of cooling determine the texture of an igneous rock?

Slow cooling produces a coarse-grained texture, rapid cooling produces a fine-grained texture, and very rapid cooling produces a glassy texture.

What are the two major compositional groups of igneous rocks?

Granitic composition (mostly quartz and feldspar, lighter in color) and basaltic composition (iron-rich, darker silicates).

What are the four major processes that form sedimentary rocks?

Weathering, erosion, deposition, and compaction/cementation.

What is the difference between erosion and deposition?

Erosion involves weathering and the transport/carrying away of sediment, whereas deposition occurs when sediments are dropped by water, wind, ice, or gravity.

What occurs during the processes of compaction and cementation of sediments?

Compaction squeezes sediments together, while cementation occurs when dissolved minerals precipitate into tiny spaces between sediment grains.

How do clastic sedimentary rocks differ from chemical sedimentary rocks?

Clastic rocks form from weathered pieces of preexisting rocks, while chemical rocks form when dissolved minerals precipitate out of solution.

Which rock types are classified as clastic sedimentary rocks?

Conglomerate, breccia, and sandstone.

Where are the oldest layers found in undisturbed sedimentary rocks?

At the bottom.

What do ripple marks in a sedimentary rock indicate about its formation environment?

They indicate that the rock formed along a beach or a stream bed.

What are the two main types of metamorphism?

Contact metamorphism (magma intrudes rock, causing localized low-grade changes) and regional metamorphism (occurs during mountain building, causing large-scale dramatic deformation).

What are the three primary agents of metamorphism?

Heat, pressure, and hydrothermal (chemical) solutions.

What distinguishes foliated metamorphic rocks from nonfoliated metamorphic rocks?

Foliated rocks possess a layered or banded appearance (such as gneiss and schist), while nonfoliated rocks do not have a banded texture (such as marble, quartzite, and anthracite).

What three main physical characteristics are examined to identify rocks in a rock identification lab?

Overall color, composition, and texture.

What is the term for the original rock from which a metamorphic rock forms?

Parent rock.

According to the rock cycle, how does an igneous rock transition directly into a sedimentary rock?

Through weathering and erosion into sediments, followed by deposition, compaction, and cementation.

How does a renewable resource differ from a nonrenewable resource?

A renewable resource can naturally be replenished over fairly short time spans (such as months, years, or decades), whereas a nonrenewable resource takes millions of years to form and accumulate.

What are the three primary examples of fossil fuels?

Coal, oil (petroleum), and natural gas.

What is the chemical formula for propane?

$$C_3H_8$$

What are the four progressive stages that coal goes through during its development?

Peat, lignite, bituminous coal, and anthracite.

What is the biological origin of coal compared to oil and natural gas?

Coal formed primarily from ancient plants buried in swamps, while oil and natural gas formed from tiny marine organisms buried under sediments millions of years ago.

What geological structure can trap oil and natural gas beneath an impermeable cap rock?

An anticline (arched rock).

What are two energy sources that can provide petroleum-like fuels beyond conventional drilling?

Tar sands and oil shale.

What is tar sand composed of?

A mixture of bitumen, water, clay, and sand.

What waxy organic material is contained in oil shale?

Kerogen.

How do hydrothermal mineral deposits form?

Mineral-rich hot water seeps into fractures and cracks between rocks, cools, and precipitates mineral deposits such as gold, silver, and mercury.

What are placer deposits and how do they originate?

Placer deposits occur when eroded heavy minerals (such as gold) settle out of moving water.

What is an example of a nonmetallic mineral resource, and can it be used as a source of energy?

Limestone is a nonmetallic mineral resource, and it is not used as a source of energy.

What is the most abundant energy resource available on Earth?

Solar energy (sunlight).

What are two distinct disadvantages of solar energy?

The equipment is expensive to manufacture/install, and sunlight is not constantly available (ineffective at night or during cloudy days).

How do photovoltaic flat panels generate electrical energy from sunlight?

Silicon semiconductors inside the flat panels absorb photons from sunlight to create an electrical current.

What percentage of electricity demand in the United States could wind power provide over the next $50$ to $60$ years?

$15\%$ to $25\%$

What are three major obstacles facing the expansion of wind power?

The technical difficulty of buying large plots of land, noise pollution, and the cost of building transmission lines.

What type of stored energy is harnessed by holding water in a reservoir behind a hydroelectric dam?

Potential energy.

Why do hydroelectric dams have a limited lifespan?

Sediment gradually builds up behind the dam in the reservoir.

What is geothermal energy and what is the typical lifespan of a geothermal reservoir?

Energy harnessed from natural underground hot water and steam, with a typical reservoir lifespan of $10$ to $15\text{ years}$.

How is tidal power harnessed to generate electricity?

By constructing a dam or barrage across the mouth of an estuary or bay, where the moving tides turn turbines that power electric generators.

What is the scientific definition of nuclear fission?

The splitting of an atomic nucleus into smaller fragments.

What subatomic particle is fired to initiate the fission of an unstable nucleus like Uranium-$235$?

A neutron.

What is the natural abundance of the Uranium-$235$ isotope relative to Uranium-$238$?

About $0.7\%$ (or $1\%$), with the remaining $99\%$ or more being non-fissionable Uranium-$238$.

What enrichment level of Uranium-$235$ is required to produce weapons-grade material?

Approximately $80\%$ to $85\%$

What is the primary function of control rods inside a nuclear reactor core?

They absorb neutrons to control and regulate the rate of the fission chain reaction, preventing overheating or a meltdown.

What percentage of Earth's surface is covered by water?

$$71\%$$

How does point source pollution differ from nonpoint source pollution?

Point source pollution comes from a single, specific, identifiable location (like factory pipes or sewer pipes), whereas nonpoint source pollution comes from many scattered sources carried by runoff.

What environmental laws were passed in $1970$ and $1972$ to regulate pollution in the United States?

The Clean Air Act was passed in $1970$ to set limits on air pollution, and the Clean Water Act was passed in $1972$ to reduce point source water pollution.