GSCI 1050 Lecture Notes - Lecture 17: Isostasy, Oceanic Crust, Metamorphic Rock
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These is greater stress in one direction pushing inward and the rock tends to get higher and narrow horizontally. Occurs at convergent plate boundaries: tension stress in one direction is greater as rock is pulled apart. When the rock is pulled so much that it breaks, that is called a fault. When the rock is stretched out, gravity pushes is down more, creating rift basins. Occurs at divergent plate boundaries: shear rocks are sliding past one another in opposite directions. Joints cracks along which a rock has been broken, but the two sides have not slid past each other. a. Joints may become filled with minerals, forming a vein. These cracks are an example of secondary porosity and water flows through them. Given names depending on where they are relative to the fault planes c. ii. Footwall the block below the plane c. iii. Hanging wall the wall above the plane: displacement the movement along a fault.
