Composition—Some minerals, such as quartz , tend to be brittle and are thus more likely to break under stress. Other minerals, such as calcite, clay, and mica, tend to be ductile and can undergo much plastic deformation. In addition, the presence of water in rock tends to make it more ductile and less brittle.
What type of stress is more likely to make a rock fracture?
Sudden stress , such as a hit with a hammer, is more likely to make a rock break. Stress applied over time often leads to plastic deformation.
What are the 3 types of rock stress?
There are three types of stress: compression, tension, and shear .
What type of stress is more likely to make a rock fracture quizlet?
At the Earth’s surface, rocks usually break quite quickly, but deeper in the crust, where temperatures and pressures are higher, rocks are more likely to deform plastically. Sudden stress such as a hit with a hammer , is more likely to make a rock break.
Where stress on rocks is at its greatest?
Tension causes rocks to lengthen or break apart. Tension is the major type of stress found at divergent plate boundaries . Shear stress happens when forces slide past each other in opposite directions (Figure below). This is the most common stress found at transform plate boundaries.
What does tension stress happen on rocks?
Tension stress pulls rocks apart . Tension causes rocks to lengthen or break apart. Tension is the major type of stress found at divergent plate boundaries. Shear stress happens when forces slide past each other in opposite directions (Figure below).
Which type of stress tends to press the rocks towards each other?
Compression is a directed (non-uniform) stress that pushes rocks together. The compressional forces push towards each other. Shear is a directed (non-uniform) stress that pushes one side of a body of rock in one direction, and the opposite side of the body of rock in the opposite direction.
Which kind of stress can cause rock to bend twist or break apart?
Rocks that are pulled apart are under tension . Rocks under tension lengthen or break apart. Tension is the major type of stress at divergent plate boundaries. When forces are parallel but moving in opposite directions, the stress is called shear (figure 2).
What type of stress is tension?
Tension is the major type of stress at divergent plate boundaries . When forces are parallel but moving in opposite directions, the stress is called shear (figure 2).
Why do some rocks break and others flow?
Why do some rocks break and others flow? Erosion happens when rocks and sediments are picked up and moved to another place by ice, water, wind or gravity . Mechanical weathering physically breaks up rock. ... Over time pieces of rock can split off a rock face and big boulders are broken into smaller rocks and gravel.
When a rock has stress put on it and does not break it is called?
Elastic deformation occurs when the rock returns to its original shape when the stress is removed. When rocks under stress do not return to its original shape when the stress is removed, it is called plastic deformation. Finally, when a rock under stress breaks, it’s called a fracture .
When rocks are stressed beyond their elastic limit the deformation becomes permanent?
Plastic deformation takes place when a rock, mineral, or other substance is stressed beyond its elastic limit (Fig. 1). Plastic deformation is that deformation that produces a permanent change in the shape of a solid without that solid having failed by fracturing.
How do rocks respond to stress below the brittle ductile transition?
As we go deeper in the Earth the strength of these rocks initially increases. At a depth of about 15 km we reach a point called the brittle-ductile transition zone. Below this point rock strength decreases because fractures become closed and the temperature is higher , making the rocks behave in a ductile manner.
Which type of stress on rock is uniform in all directions quizlet?
Which type of stress on rock is uniform in all directions? – In situations such as deep burial, confining pressure exerts uniform stress in all directions.
What type of stress causes anticlines and synclines?
Anticlines and synclines most commonly form in sections of the crust that are undergoing compression , places where the crust is being pushed together. Crustal compression is commonly the response to stress from more than one direction, which causes tilting as well as folding.
Which type of stress pushes a mass of rock in two opposite directions?
Shearing pushes a mass of rock in two opposite directions.
What kind of stress on the rocks happens when plates are pushed towards each other pulled away from each other or slide past each other?
Tensional stress happens when rocks are pulled away from each other; compressional stress, on the other hand, happens when rocks are pushed towards each other. Shear stress, however, happens when rocks slide across each other in opposite direction; the sliding rocks in this case do not hit each other.
What type of stress causes the formation of mountains?
The force of compression can push rocks together or cause the edges of each plate colliding to rise. Mountains are a result of high-impact compression stress caused when two plates collided.
What type of stress squeezes and shortens rock?
Compression is the type of stress that squeezes and shortens a body of rock. Compression commonly reduces the amount of space that rock occupies, and pushes rocks higher up or deeper down into the crust.
Why might rock bend rather than break?
If the conditions are right, a rock may bend rather than break. This type of deformation is called ductile behavior and it results in rocks that “flow” rather than break. Some rocks naturally tend to behave ductily when subjected to stress. Shale, halite and gypsum bend rather than break.
What is the breakdown of rocks called?
Weathering is the breaking down or dissolving of rocks and minerals on Earths surface. Once a rock has been broken down, a process called erosion transports the bits of rock and minerals away. Water, acids, salt, plants, animals, and changes in temperature are all agents of weathering and erosion.
Which of the following factors causes the breaking down of rocks?
Factors such as surface area, rock composition, and location influence the rate of weathering . water, the faster the rock will break down. A greater surface area allows chemical weathering to affect more of a rock. Rock Composition Different kinds of rock break down at different rates.
What is the break in a rock along which movement have occurred?
A fault is a fracture or break in the rock along which movement has taken place.
Under which conditions would a body of rock be most likely to exhibit brittle?
A rock deformed quickly is likely to exhibit brittle behavior.
What is rock deformation explain different type of stresses which causes rocks to deform?
Rocks Are Stressed
Stress causes rocks to deform, meaning the rocks change size or shape. There are different kinds of stress that rocks experience, and these determine how the rocks deform. Tensional stress is when rock is stretched apart. ... Compressional stress is when rock is pressed together.
Is Quartz a ductile?
The majority of all minerals are brittle. An example is Quartz. ... Ductile – A mineral that can be stretched into a wire is ductile.
What type of stress is equal in all directions?
Uniform : The force acts equally in all directions. Also called confining stress or confining pressure.
What type of stress would you expect at convergent plate boundaries?
Compression is the most common stress at convergent plate boundaries. Rocks that are pulled apart are under tension. Rocks under tension lengthen or break apart.
Which of the characteristics below affect whether a rock deforms in a brittle or ductile manner?
Factors that affect whether rock behaves in a ductile or brittle manner include the composition of the rock , the temperature and pressure of the rock, and the amount and type of stress on the rock.
What is elastic limit and breaking stress?
What are elastic limit and breaking stress? The maximum value of stress applied on a material just before it produces permanent extension is called elastic unit. The value of stress applied on a wire just before it snaps or breaks is called breaking stress.
What happens to the rocks underneath earth when they are subjected to stress?
With increasing stress, the rock undergoes: (1) elastic deformation, (2) plastic deformation , and (3) fracture. ... At the Earth’s surface, rocks usually break quite quickly, but deeper in the crust, where temperatures and pressures are higher, rocks are more likely to deform plastically.
