Geology Chapter 1 & 2: Earth in Context

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Questions and Answers

What is the formula for a rate of movement?

Distance = Speed x Time OR $D=v*t$

How did the Solar System form?

The Solar System formed from a rotating cloud of gas and dust known as the solar nebula. As this nebula collapsed under its own gravity, it began to spin faster. The spinning cloud flattened into a disk with a hot, dense center that eventually ignited and became the Sun. The remaining material in the disk clumped together to form the planets, moons, asteroids, and comets.

What is geology?

Geology is the study of the Earth, its composition, structure, processes, and history. It encompasses various aspects, including the formation of rocks, minerals, fossils, landforms, and the Earth's internal structure.

What percentage of the Earth's surface is ocean?

71% (C) Signup and view all the answers

What is differentiation?

Differentiation refers to the process by which the Earth's interior separated into different layers based on density. Heavier materials like iron and nickel sank to form the core, while lighter materials like silicon and oxygen formed the mantle and crust. Signup and view all the answers

What are the different materials that Earth is made of?

The Earth is composed of various materials, primarily: iron, nickel, silicon, oxygen, aluminum, and magnesium. These elements are arranged in various layers, with the heaviest elements concentrated in the core and the lighter elements forming the mantle and crust. Signup and view all the answers

Draw and describe the structure of the Earth based on ______ properties

physical Signup and view all the answers

What are the differences between oceanic and continental crust?

Oceanic crust is thinner, denser, younger, and primarily composed of basalt and gabbro. Continental crust is thicker, less dense, older, and composed of a variety of rocks, including granite and sedimentary rocks. Signup and view all the answers

Continental crust is older than oceanic crust.

True (A) Signup and view all the answers

Who developed the theory of continental drift?

Alfred Wegener Signup and view all the answers

What was the name of Wegener's supercontinent?

Pangaea Signup and view all the answers

What was the name of the ocean surrounding it?

Panthalassa Signup and view all the answers

What lines of evidence were added to develop Plate Tectonics?

Additional evidence that supported Plate Tectonics included: seafloor spreading, magnetic reversals, and the distribution of earthquakes, volcanoes, and mountain ranges. Signup and view all the answers

Describe each of the following plate boundaries in detail and give examples of each: Divergent; Oceanic-Oceanic Convergent; Oceanic-Continental Convergent; Continental-Continental Convergent; and, Transform

Divergent boundaries are where plates move apart, creating new crust. Examples include the Mid-Atlantic Ridge and East Pacific Rise. Oceanic-Oceanic convergent boundaries are where two oceanic plates collide, resulting in the formation of island arcs like the Aleutian Islands and Japan. Oceanic-Continental convergent boundaries are where an oceanic plate collides with a continental plate, leading to the formation of mountain ranges like the Andes and Cascades. Continental-Continental convergent boundaries are when two continental plates collide, causing the formation of large mountain ranges like the Himalayas and Alps. Transform boundaries are where plates slide past each other horizontally, resulting in earthquakes like the San Andreas Fault. Signup and view all the answers

Which type(s) of plate boundaries have earthquakes? Volcanoes? Is crust created or destroyed? What type of crust is destroyed?

Earthquakes occur at all types of plate boundaries (divergent, convergent, and transform). Volcanoes are primarily associated with convergent boundaries (where subduction occurs) and divergent boundaries (where new crust is created). Crust is created at divergent boundaries and destroyed at convergent boundaries. Oceanic crust is typically the crust that is destroyed during subduction. Signup and view all the answers

Describe what happens to the sea floor in terms of age, depth, and thickness moving from the center of a mid ocean ridge to a coastline.

As you move away from the center of a mid-ocean ridge toward the coastline, the seafloor progressively gets older, deeper, and thicker. This is because new ocean floor is continuously being created at mid-ocean ridges and then spreads outward, pushing older seafloor away. Signup and view all the answers

What is a subduction zone? Where do they form? Name two types of crust and 3 features formed in a subduction zone. Draw a diagram and label the different parts.

A subduction zone is a region where one tectonic plate slides beneath another. They form at convergent boundaries where two plates collide. Two types of crust involved are oceanic crust and continental crust. Three features formed in a subduction zone include a deep ocean trench, volcanic arc, and accretionary wedge. [Diagram of a subduction zone would be included here] Signup and view all the answers

What is a hot spot? How do they form? Name 2 examples.

A hot spot is a region of volcanic activity that is not associated with a plate boundary. They form when plumes of hot mantle material rise up from deep within the Earth's interior. The hot mantle plume melts the overriding plate, creating volcanoes. Two examples of hot spots are the Hawaiian Island chain and Yellowstone National Park. Signup and view all the answers

Describe how a hot spot track supports plate tectonics using an example.

Hot spot tracks are chains of volcanoes that align in a straight line. They form as a tectonic plate moves over a stationary hot spot. The Hawaiian Island chain is a classic example of a hot spot track. The islands progressively get older as you move further away from the active volcano on the island of Hawaii. This age progression provides strong evidence for the movement of tectonic plates over a relatively fixed point. Signup and view all the answers

What does "intraplate" mean?

Intraplate refers to geological activity that occurs within a tectonic plate, rather than at its boundaries. It is often associated with hot spot volcanism or other localized stresses within the plate. Signup and view all the answers

Using your plate boundary map ... determine the type and name of the closest plate boundary traveling due East from Utah and due West from Utah.

The closest plate boundary traveling due east from Utah is the Rocky Mountain Trench, which is a transform boundary. The closest plate boundary traveling due west from Utah is the San Andreas Fault, which is also a transform boundary. Signup and view all the answers

What is the tectonic setting of Utah?

Utah is located within the Basin and Range Province, a region characterized by numerous mountain ranges and valleys. The tectonics of this area are controlled by the interaction of the North American Plate with the Pacific Plate and the associated westward motion of the North American Plate. The Basin and Range Province is a complex geological region with a history of faulting, volcanic activity, and rock uplift. The collision of the North American Plate with the Pacific Plate has caused the crust to stretch and thin, leading to the formation of faults and the uplift of mountains. Signup and view all the answers

Explain in detail how Plate Tectonics explains the occurrence of each of the following: mountains, volcanoes, earthquakes, deep-ocean trenches. What would the earth be like without plate tectonics?

Mountains form where tectonic plates collide and compress the Earth's crust. Volcanoes are common at convergent plate boundaries where subduction occurs, as well as at divergent boundaries where magma rises to the surface. Earthquakes occur along plate boundaries and within plates, where stresses are released due to plate movement. Deep-ocean trenches are formed at convergent boundaries where one plate subducts beneath another. Without plate tectonics, the Earth's surface would be much flatter, with fewer mountains, volcanoes, and earthquakes. There might be fewer deep-ocean trenches and a lack of the dramatic features that define the Earth's surface today. Signup and view all the answers

In March of 2011, a devastating earthquake and tsunami struck Japan. Explain the tectonic setting in detail that ultimately caused this earthquake.

The 2011 Tohoku Earthquake and tsunami were caused by the subduction of the Pacific Plate beneath the North American Plate. The Pacific Plate is moving westward towards the Japanese archipelago, dipping beneath the North American Plate at a rate of about 8.5 cm per year. The built-up pressure from this convergence eventually led to a sudden release of energy in the form of a massive earthquake, which triggered a devastating tsunami. Signup and view all the answers

Describe seafloor spreading. How does seafloor spreading account for the distribution of ages of the ocean crust?

Seafloor spreading is the process by which new oceanic crust is created at mid-ocean ridges. As molten rock (magma) rises from the Earth's mantle, it cools and solidifies, forming new oceanic crust. This new crust is then pushed away from the ridge, creating a symmetrical pattern of ages. The crust closest to the ridge is the youngest, while the crust farthest from the ridge is the oldest. Signup and view all the answers

Calculate the half and full spreading rates in cm/year for the locations in the table below. Keep in mind that there are 100,000 cm in 1 km (so 1100 km = 1100 x 100,000 cm). Ma = millions of years (So 64 Ma = 64,000,000 years)

Pacific-Antarctic: Half-spreading rate = (1800 km * 100,000 cm/km) / (80 Ma * 1,000,000 years/Ma) = 2.25 cm/year Full-spreading rate = 4.5 cm/year. Nazca-Cocos: Half-spreading rate = (950 km * 100,000 cm/km) / (20 Ma * 1,000,000 years/Ma) = 4.75 cm/year Full-spreading rate = 9.5 cm/year. Signup and view all the answers

What is a mineral?

A mineral is a naturally occurring, solid, inorganic substance with a defined chemical composition and a crystalline structure. Signup and view all the answers

Are the following substances minerals? If not, why not? Salt, Gold, Steel, Diamonds, Ice, Pearls, Coal, Brass, Copper, Sugar, Obsidian.

Salt, Gold, Diamonds, Obsidian (C) Signup and view all the answers

What are the key properties useful in identifying minerals?

Key properties used for identifying minerals include: color, streak, luster, hardness, cleavage, fracture, crystal habit, specific gravity, and chemical reactions. Signup and view all the answers

Know how to identify a mirror plane and a rotation axis on a crystal.

A mirror plane is a plane of symmetry that divides a crystal into two identical halves. A rotation axis is a line passing through the center of a crystal that allows the crystal to be rotated to occupy the same position. Signup and view all the answers

Which minerals are mafic?

Olivine, Pyroxene, Amphibole (C) Signup and view all the answers

Which minerals would you expect to find in the oceanic lithosphere?

Oceanic lithosphere is mainly composed of mafic minerals such as olivine, pyroxene, and amphibole. These minerals are characteristic of the basalt and gabbro that make up the oceanic crust. Signup and view all the answers

Which minerals would you expect to find in the continental lithosphere?

The continental lithosphere is composed of a wider variety of minerals, including both mafic and felsic minerals. Felsic minerals such as quartz, feldspar, and muscovite are more common in continental crust, while mafic minerals can be found in specific rock types like basalt and gabbro. Signup and view all the answers

Flashcards

What is geology?

Geology is the study of Earth's physical structure, composition, history, and processes.

How does geology affect your life?

Geology influences our lives through the resources we use (like minerals, water, energy), understanding natural hazards (earthquakes, volcanoes), and shaping landscapes for living.

What is differentiation?

Differentiation is the process where Earth's interior separated into layers based on density, with heavy elements sinking to form the core and lighter elements rising to form the crust.

What are the Earth's layers based on chemical properties?

The Earth is made up of the crust, mantle, and core. The crust is the outermost, thin layer, the mantle is a thick, dense layer, and the core is a very hot, dense, metallic sphere.