Earth Science Exam Review: Geology, Earth History, and Plate Tectonics

What does the Big Bang Hypothesis describe?

The origin of the universe.

What does the Nebula Hypothesis explain?

The origin of the Solar System.

Which part of the Earth has the largest volume and deforms plastically?

The Mantle.

What is the composition of the Outer Core?

Mostly iron (Fe) and is liquid.

What is the age of the Earth?

About 4.54 billion years.

What is the difference between intrusive and extrusive igneous rocks?

Intrusive rocks have larger crystals due to slow cooling, while extrusive rocks have smaller crystals due to rapid cooling.

What are silica-oxygen tetrahedra?

The basic building blocks of silicate minerals, where silicon is surrounded by four oxygen atoms.

What is lithification?

The process of turning sediment into sedimentary rock.

What is the process of metamorphism?

The heating of rocks under pressure in Earth's interior.

What is the significance of half-life in geology?

It is used to determine the age of rocks and fossils through radiometric dating.

What is the concept of superposition?

In undisturbed sedimentary rock layers, the oldest layers are at the bottom and the youngest are at the top.

What is the difference between clastic and chemical sedimentary rocks?

Clastic rocks are formed from fragments of other rocks, while chemical rocks form from the precipitation of minerals from solution.

What is the role of water flow speed in sediment transport?

Higher water flow speeds can transport larger sediment grains.

What is faunal succession?

The principle that sedimentary rock layers contain fossilized flora and fauna that succeed each other in a definite and recognizable order.

What is an unconformity in geology?

A gap in the geological record that represents a period of erosion or non-deposition.

What is the composition of quartz?

Silicon dioxide (SiO2).

What type of rock is formed from volcanic ash?

It can be both an igneous and a sedimentary rock, depending on the context.

What is the primary component of the Earth's atmosphere?

Nitrogen, followed by oxygen.

What is the difference between oceanic crust and continental crust?

Oceanic crust is thinner and denser than continental crust.

What are mantle plumes?

Upwellings of abnormally hot rock within the Earth's mantle.

What is the significance of the Mid-ocean ridge?

It is a divergent boundary where new oceanic crust is formed.

What is sediment deposition?

The process by which sediment settles out of the transporting medium.

What is the difference between magma and lava?

Magma is molten rock beneath the Earth's surface, while lava is magma that has reached the surface.

What is the primary cause of erosion?

Natural forces such as water, wind, and ice.

What is the role of minerals in rocks?

Minerals are the building blocks of rocks and determine their properties.

What is the process of sediment transport?

The movement of sediment by wind, water, or ice.

How do sedimentary rocks preserve environmental information?

They contain fossils and sedimentary structures that reflect the conditions of their formation.

How do faunal succession and absolute age dating contribute to the geologic time scale?

Faunal succession provides relative ages, while absolute age dating uses radioactive decay to assign numerical ages, together forming the geologic time scale.

What is radioactive decay?

Radioactive decay is the process by which unstable atomic nuclei lose energy by emitting radiation, allowing for the calculation of absolute ages.

What are the relative half-lives of Uranium-238 and Carbon-14?

Uranium-238 has a half-life of about 4.5 billion years, while Carbon-14 has a half-life of about 5,730 years.

What are seismic waves?

Seismic waves are waves of energy that travel through the Earth, with P waves (primary waves) able to travel through liquids and S waves (secondary waves) unable to.

What are the compositional layers of Earth's interior?

The compositional layers include the crust, mantle, outer core, and inner core.

What are the mechanical layers of Earth's interior?

The mechanical layers consist of the lithosphere, asthenosphere, mesosphere, outer core, and inner core.

Where do faults, earthquakes, and volcanoes occur relative to tectonic plate boundaries?

They typically occur at or near tectonic plate boundaries.

Why do mid-ocean ridges have higher topography than other parts of the seafloor?

Mid-ocean ridges are elevated due to the upwelling of magma and the creation of new oceanic crust.

What are the characteristics of convergent plate boundaries?

Convergent boundaries can involve oceanic crust on one or both sides or continental crust on both sides, leading to subduction or mountain building.

What occurs at divergent plate boundaries?

Divergent boundaries involve the rifting of continental crust or the formation of mid-ocean ridges as tectonic plates move apart.

What occurs at transform plate boundaries?

Transform boundaries involve lateral sliding between major tectonic plates, often resulting in earthquakes.

How do changes in Earth's magnetic field help geologists?

Changes in Earth's magnetic field provide evidence for seafloor spreading and help reconstruct past movements of tectonic plates.

What are hot spots or mantle plumes?

Hot spots are volcanic regions fed by underlying mantle plumes, providing insights into plate motions and volcanic activity.

How did the San Andreas Fault form?

The San Andreas Fault formed due to the lateral movement of tectonic plates, specifically the Pacific and North American plates.

What influences sea level from tectonics?

Sea level is influenced by tectonic uplift and subsidence, as well as changes in the volume of water in the oceans.

How do geologists reconstruct relative ages from sedimentary rocks?

Geologists use the principle of superposition, where older layers are at the bottom and younger layers are at the top.

What conditions must be met for radioactive decay methods to work?

The rock must contain radioactive 'parent' atoms and remain undisturbed since its formation.

What were initial objections to the idea of continental drift?

Initial objections included lack of evidence for a mechanism and the inability to explain how continents could move.

Why is oceanic crust topographically low compared to continental crust?

Oceanic crust is denser and thinner than continental crust, resulting in lower elevation.

How does the distribution of continents affect ocean circulation?

The arrangement of continents influences ocean currents, which in turn affects climate patterns.

Why do changes in ocean circulation affect climate?

Changes in ocean circulation can alter heat distribution across the planet, impacting weather and climate systems.