Movement of Plates; Formation of Folds and Faults PDF
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This document describes the movement of tectonic plates, focusing on the formation of geological folds and faults. It explains different types of plate boundaries and how they relate to the creation of folds, like anticlines and synclines, and faults, such as normal and strike-slip faults. The document also has questions at the end.
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Movement of plates; formation of folds and faults Movement of plates The movement of these tectonic plates is likely caused by convection currents in the molten rock in Earth's mantle below the crust. Earthquakes and volcanoes are the short-term results of this tectonic movement....
Movement of plates; formation of folds and faults Movement of plates The movement of these tectonic plates is likely caused by convection currents in the molten rock in Earth's mantle below the crust. Earthquakes and volcanoes are the short-term results of this tectonic movement. The movement of the plates creates three types of tectonic boundaries: convergent, divergent, and transform boundaries. Convergent Plates move towards each other, leading to collisions and the formation of mountains, volcanoes, and trenches. Divergent Plates move away from each other, creating new oceanic crust and rift valleys. Transform Plates slide horizontally past each other, causing earthquakes and creating fault lines. what are folds? Folds are geological features created by the deformation of rock due to compressive stress. what are faults? A fault is a fracture or zone of fractures between two blocks of rock. Convergent boundaries and folds Convergent boundaries Examples of Folds: cause intense Anticlines compressional forces that Synclines bend and buckle rock Monoclines layers, forming folds. Anticlines Rock layers bend upwards, creating an arch-like structure. Synclines Rock layers bend downwards, creating a trough-like structure. Monoclines A monocline is a simple bend in the rock layers so that they are no longer horizontal. The difference of the three folds Anticlines are arch-like folds where the oldest rock layers are found in the center. Synclines are the opposite of anticlines and are concave up, with the youngest rock layers found in the center. Monoclines are folds where one limb of the fold is practically horizontal, while the other limb is steeply dipping. Divergent boundaries and Normal faults Divergent boundaries Examples of Faults: cause tensional forces that Hanging Wall stretch and break rock Footwall layers, creating normal faults. Hanging Wall The block of rock above the fault plane. FootWall The block of rock below the fault plane. Transform Boundaries and strike-slip faults Transform boundaries Examples of Faults: cause shearing forces that Left-Lateral Fault cause rock layers to slide Right-Lateral Fault horizontally past each other, creating strike-slip faults. Left-Lateral Fault Blocks move in opposite directions, with the left-hand side moving towards the observer. Right-Lateral Fault Blocks move in opposite directions, with the right-hand side moving towards the observer. The difference of Normal and strike-slip faults Normal faults result from tensional forces when rocks are displaced away from each other. Strike-slip or transform faults results from either compressional or extensional forces when rocks slip parallell to each other. Questions? Thank you!!
