How does the strength of continental crust vary with depth group of answer choices?
How does the strength of continental crust vary with depth? D) Rocks become stronger with depth and then get weaker deep in the crust.
How does the strength of the continental crust vary with increasing depth quizlet?
How does the strength of the continental crust vary with increasing depth? The strength of the continental crust first increases & then decreases with increasing depth.
Why do rocks become stronger with depth in shallow levels of the crust?
Why do rocks become stronger with depth in shallow levels of the crust? “Rocks in the upper crust become STRONGER/WEAKER with depth because increasing confining pressure acts to hold rocks together and makes slipping along any fractures more difficult.”
What causes the stress that forms joints?
Formation. Joints arise from brittle fracture of a rock or layer due to tensile stress. This stress may be imposed from outside; for example, by the stretching of layers, the rise of pore fluid pressure, or shrinkage caused by the cooling or desiccation of a rock body or layer whose outside boundaries remained fixed.
Why is continental crust less dense?
Continental crust is less dense because of its composition. Continental crust is made up of felsic material (SiO4)– mainly granite. The density of continental crust is 2.9 g/cm^3. Oceanic crust, while thinner, is made of mafic materials (Fe, Mg)– mainly basalt.
Why continental crust is thicker?
The crust is thickened by the compressive forces related to subduction or continental collision. The buoyancy of the crust forces it upwards, the forces of the collisional stress balanced by gravity and erosion. This forms a keel or mountain root beneath the mountain range, which is where the thickest crust is found.
How would a rock respond to stresses applied at depth quizlet?
How would a rock respond to stresses applied at depth? High-temperature veins form; mobilization of chemical constituents. Minerals recrystallize into larger or smaller crystals. Ductile behavior occurs; flowing of the rock.
When a rock is buried deep in the earth?
Burial metamorphism commonly occurs in sedimentary basins where rocks are buried deeply by overlying sediments. As an extension of diagenesis a process that occurs during lithification (Chapter 5) burial metamorphism can cause clay minerals such as smectite in shales to change to another clay mineral illite.
Why do rocks become stronger with depth in shallow levels of the crust quizlet?
"Rocks in the upper crust become STRONGER/WEAKER with depth because increasing confining pressure acts to hold rocks together and makes slipping along any fractures more difficult."
How would a rock responds to stresses applied at depth?
How would a rock respond to stresses applied at depth? High-temperature veins form; mobilization of chemical constituents. Minerals recrystallize into larger or smaller crystals. Ductile behavior occurs; flowing of the rock.
How would a rock respond to stresses applied at depth?
How would a rock respond to stresses applied at depth? High-temperature veins form; mobilization of chemical constituents. Minerals recrystallize into larger or smaller crystals. Ductile behavior occurs; flowing of the rock.
How do joints influence the strength of rocks?
The influence of joints on rock behaviour is also attributed to the following (46): their lower strength in comparison with the surrounding rock materials, where they are embedded, the occurrence of anisotropic regions due to their presence and the establishment of a 'scale effect'.
Why is continental crust thicker and less dense than oceanic crust?
The oceanic crust is formed by partial melting of the mantle at mid-ocean ridges. The continental crust is formed even more cycles of partial melting over time, resulting less dense rocks. Click Here to return to the search form.
Why is continental crust lighter?
The continental crust is continental crust because of its density, not the other way around. The most dense is the material, the deepest it goes. The continental crust is made up of lighter granitic rock, while deep-sea drilling reveals that the oceanic crust is basaltic in composition. Show activity on this post.
Why are continental plates less dense?
Continental plates, on the other hand, are made of rocks similar to granite, like the countertops in your home might be made of. These rocks are less dense, and thus the continental plates are also less dense.
How do rocks respond to differential stress at different depths inside the Earth?
elastic deformation: For small differential stresses, less than the yield strength, rock deforms like a spring. It changes shape by a very small amount in response to the stress, but the deformation is not permanent. If the stress could be reversed the rock would return to its original shape.
What happen when rock is buried deep below the surface?
The deeper the layers are buried the hotter the temperatures become. The great weight of these layers also causes an increase in pressure, which in turn, causes an increase in temperature.
How do geologists determine the stability conditions of minerals buried at great depths?
how do geologists determine the stability conditions of minerals buried at great depths? Observing deep rocks that were uplifted due to tectonics and exposed; And conducting laboratory experiments with high-temperature and high-pressure conditions.
What are the factors that affect the strength of rock explain?
The principal factors controlling the strength of solid rocks are: I) mineral composition, structure and texture; 2) bedding, jointing and anisotropy; 3) water content; 4) state of stress in the rock mass.
How would a rock respond to stress is applied at depth quizlet?
How would a rock respond to stresses applied at depth? High-temperature veins form; mobilization of chemical constituents. Minerals recrystallize into larger or smaller crystals. Ductile behavior occurs; flowing of the rock.
What controls the strength of a rock mass?
The rock materials forming a large pit slope determine the rock mass strength modified by discontinuities, folding, faulting, old workings, and weathering.
Will a thicker layer normally contain more or fewer joints than a thinner layer given that their properties are similar?
3. Will a thicker layer normally contain more or fewer joints than a thinner layer, given that their properties are similar? More, because stiff layers resist strain more and therefore build up stress that make then fracture.
Why is the continental crust thicker?
The crust is thickened by the compressive forces related to subduction or continental collision. The buoyancy of the crust forces it upwards, the forces of the collisional stress balanced by gravity and erosion. This forms a keel or mountain root beneath the mountain range, which is where the thickest crust is found.
Why continental and oceanic crusts differ in their density?
The density of the continental crust is much less as compared to the oceanic crust. It has an approximate value of 2.6 g/cm3. Due to this difference in densities in magma between the oceanic crust and the continental crust, the continents stay in their places, and both crusts are able to float on the magma.
Why the thickness of the crust below the continents is less as compared to ocean?
Though mantle is more dense than oceanic crust and continental crust. The continental crust is made up of sedimentary rocks while oceanic crust is made up of pillows,dykes and gabbros. Density means mass per unit of a substance. Thus,we can say that the continental crust is less thick than oceanic crust.
How do rocks respond to differential stress at different depths inside the Earth quizlet?
differential stress that pulls apart or elongates rock bodies. along divergent plate boundaries where plates are moving apart. -at deeper crustal levels where temps are high, shear stress distorts rock masses by ductile flow, usually along shear zones.
What happened to the temperature and pressure if the rocks are buried down deep?
The deeper the layers are buried the hotter the temperatures become. The great weight of these layers also causes an increase in pressure, which in turn, causes an increase in temperature.
What happens to pressure on rocks in regional metamorphism as it goes deeper?
Metamorphism therefore occurs at temperatures and pressures higher than 200oC and 300 MPa. Rocks can be subjected to these higher temperatures and pressures as they become buried deeper in the Earth. Such burial usually takes place as a result of tectonic processes such as continental collisions or subduction.
What are the four factors that influence the strength of a rock and how it will deform?
Factors that influence the strength of a rock and how it will deform include temperature, confining pressure, rock type, and time. Stress is the force per unit area acting on a solid.
What are the main ways of determining the strength of a rock?
Following are common laboratory tests for determining strength of rocks:
- Unconfined compression tests for rocks.
- Triaxial compression test for rocks.
- Splitting tension test for rocks.
- Beam bending test for rocks.
- Ring shear test for rocks.
Jun 1, 2016