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fandomhigh2005-11-02 08:21 am
equalsmcsquared.livejournal.com) wrote in fandomhigh2005-11-02 08:21 am
Entry tags:
Geology
*There are no snacks or coffee available this morning. Odd, that.*
Please don't forget to sign the roll sheet.
Today, we will begin discussing crustal deformation.
I refer you to the first figure in your handouts. The topographic map illustrated in Figure 10l-1 suggests that the Earth's surface has been deformed. This deformation is the result of forces that are strong enough to move ocean sediments to an eleveation many thousands meters above sea level. In previous lectures, we have discovered that this displacement of rock can be caused by tectonic plate movement and subduction, volcanic activity, and intrusive igneous activity.
Deformation of rock involves changes in the shape and/or volume of these substances. Changes in shape and volume occur when stress and strain causes rock to buckle and fracture or crumple into folds. A fold can be defined as a bend in rock that is the response to compressional forces. Folds are most visible in rocks that contain layering. For plastic deformation of rock to occur a number of conditions must be met, including:
*The rock material must have the ability to deform under pressure and heat.
*The higher the temperature of the rock the more plastic it becomes.
*Pressure must not exceed the internal strength of the rock. If it does, fracturing occurs.
*Deformation must be applied slowly.
Please don't forget to sign the roll sheet.
Today, we will begin discussing crustal deformation.
I refer you to the first figure in your handouts. The topographic map illustrated in Figure 10l-1 suggests that the Earth's surface has been deformed. This deformation is the result of forces that are strong enough to move ocean sediments to an eleveation many thousands meters above sea level. In previous lectures, we have discovered that this displacement of rock can be caused by tectonic plate movement and subduction, volcanic activity, and intrusive igneous activity.
Deformation of rock involves changes in the shape and/or volume of these substances. Changes in shape and volume occur when stress and strain causes rock to buckle and fracture or crumple into folds. A fold can be defined as a bend in rock that is the response to compressional forces. Folds are most visible in rocks that contain layering. For plastic deformation of rock to occur a number of conditions must be met, including:
*The rock material must have the ability to deform under pressure and heat.
*The higher the temperature of the rock the more plastic it becomes.
*Pressure must not exceed the internal strength of the rock. If it does, fracturing occurs.
*Deformation must be applied slowly.