Geology: Earth's Structure and Composition

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Questions and Answers

What is the term that refers to the deformation of the earth's crust?

Lithology

Geomorphology

Tectonics (correct)

Stratigraphy

What is the primary source of information about the Earth's interior?

Seismic wave data and lava extrusion (correct)

Satellite imaging

Deep drilling exploration

Geological mapping

What is the characteristic of the Earth's inner core?

Soft and porous

Brittle and cold

Hard and permeable

Dense and intensely hot (correct)

What is included in the broad sense of structure in geology?

Many physical and chemical characteristics of rocks and soils Signup and view all the answers

What is the term that refers to the study of the physical features of the Earth's surface?

Geomorphology Signup and view all the answers

What is the characteristic of the Earth's outer shell?

Brittle and cold Signup and view all the answers

What is the cause of folds forming at different angles during rock deformation and compression?

Twisting or tilting Signup and view all the answers

What is the size range of folds?

From hand-held specimens to mountain-sized Signup and view all the answers

What is the characteristic of the central part of an anticline?

More ancient rocks Signup and view all the answers

What is the characteristic of the central part of a syncline?

Younger rocks Signup and view all the answers

What is the fold angle formed by?

Lines continuing the flanks of the fold up to the place of intersection Signup and view all the answers

What is the fold bend (flexure) defined as?

The line connecting the points of the maximum bending of the layer within the curve of the fold Signup and view all the answers

What is the characteristic of flexure in a fold?

It connects the points of the bend of one layer only Signup and view all the answers

What type of tectonic feature is a fold?

Convergence Signup and view all the answers

What is the relationship between an anticline and a syncline?

An anticline and a syncline are opposite structures Signup and view all the answers

What happens to the rocks in an anticline during erosion?

The oldest rocks are brought to the surface Signup and view all the answers

What is the purpose of the rock hammer in the photo of the overturned folds?

To provide scale for the photo Signup and view all the answers

What is the type of offset shown in the photograph above, where the fence has been offset to the right?

Right-lateral offset Signup and view all the answers

What can occur to rocks during mountain building processes?

Both faulting and folding Signup and view all the answers

What is the name of the largest fault system in North America?

San Andreas Fault Signup and view all the answers

Under what conditions can folds form in rocks?

High temperature and pressure Signup and view all the answers

What can influence whether a rock faults or folds?

Temperature, pressure, rock composition, and strain rate Signup and view all the answers

What can occur to rocks before they fault?

They always fold first Signup and view all the answers

What is the primary cause of earthquakes?

Movement of tectonic plates Signup and view all the answers

What happens to rocks when they are subjected to large amounts of stress at the Earth's surface?

They break and exhibit brittle behavior Signup and view all the answers

What is the term for the change in shape or volume of a rock due to stress?

Strain Signup and view all the answers

What is the primary location of earthquakes around the world?

At the boundaries of tectonic plates Signup and view all the answers

What is a geologic fault?

A fracture in the Earth's crust with loss of cohesion and displacement Signup and view all the answers

How do rocks behave deep within the Earth?

They flow plastically and exhibit ductile behavior Signup and view all the answers

Study Notes

Elements of Structure

Fault lines, folds, stratified layers, lines of weakness/crevasses, and holes/mottles are key elements of structure
Variations in features of continents and oceans, depressions, valleys, sinkholes, mountains, plateaus, plains, and geosyncline are also part of structure
Colour, shapes, embedment, mineral content, and alignment are also important structural features

Earth's Interior

The deep interior of the Earth is still a mystery
We have only penetrated the outermost portion with deep drilling exploration
What we know today comes from seismic wave data or lava that has extruded onto the Earth's surface
The Earth's interior is like a concentric series of rings, progressing from the dense and intensely hot inner core towards the brittle outer shell of the crust

Structure in Broad Sense

Structure includes physical and chemical characteristics of rocks and soils
Mountains, plateau, ridges, plains, and geosyncline environments are part of the broad sense of structure

Tectonic and Structural Geomorphology

Tectonics refers to the deformation of the Earth's crust
Twisting or tilting during rock deformation and compression can cause folds to form at different angles
Folds can be small and viewed in hand-held specimens or large and viewed from aerial photos

Folds and Their Elements

Folds represent wave-like bendings of rock layers of various sizes and forms
Two types of folds are distinguished: convex folds (anticlines) and concave folds (synclines)
In anticlines, layers are arched upwards, and their central parts often contain more ancient rocks
In synclines, layers are warped downwards, and the central parts in them are characterized by the development of younger rocks
Each fold has basic elements: core or internal part, curve of the fold, flanks, and fold angle
Energy released moves out in all directions as waves, like ripples radiating outward when you drop a pebble in a pond

Earthquakes and Faults

Earthquakes occur at plate boundaries due to internal forces within the Earth, causing the Earth's crust to bend, compress, and stretch
Plate tectonics cause many physical features like volcanoes, earthquakes, and geologic features like faults
A geologic fault is a fracture in the Earth's crust causing loss of cohesion and accompanied by displacement along the fracture
Rocks can break (brittle behavior) when put under large amounts of stress
Deep within the Earth, rocks flow plastically (ductile behavior)
Force or stress can cause a change in shape or volume of the rock, called strain
Depending on the direction of offset, it can be a "right-lateral offset" or a "left-lateral offset"

Folding and Faulting

During mountain building processes, rocks can undergo folding as well as faulting
Rocks can deform ductilely, particularly if they are subjected to heat and pressure
Entire mountain ranges, like the Appalachians, have extensive fold systems
Conditions of whether a rock faults or folds vary with temperature, pressure, rock composition, and strain rate
In the same location, some rocks can fold while others fault
Often, folding is just a precursor to faulting

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Description

Test your knowledge of the Earth's structure and composition! This quiz covers various geological features such as fault lines, folds, stratified layers, and more. Explore the different types of rocks, minerals, and their properties. Get ready to dig deep into the Earth's secrets!