Folding and faulting of rocks
Download as PPTX, PDF1 like410 views
This document discusses the theories of continental drift, folding, faulting, and seafloor spreading. It describes Alfred Wegener's theory of continental drift, including the idea of a supercontinent called Pangaea. It also discusses how Harry Hess theorized that seafloor is younger than continents. Finally, it explains that seafloor spreading occurs as new crust is formed at mid-ocean ridges and pushes the plates apart over time.
Folding and faulting of rocks
- 1. Folding and Faulting of rocks Reported By: Cloyie Delos Santos GAS-A
- 2. Refers to the movement of the earth’s continents relative to each other, appearing to “drift” across the ocean bed.
- 4. Alfred Wegener A German meteorologist The origin of continents and oceans “Supercontinent” also known as Pangaea (“all land”) Formed by a series of continental collisions that began in Paleozoic to Mesozoic
- 5. Wegener’s Evidence Topographic Evidence- The continents seemed to fit together, not at the continuosly changing shoreline but at the edge of their contiental shelves. Fossil Correlation- Fossils are traces and remains of organisms that lived in prehistoric times Rock Formation- Rock samples from different places provide additional evidence. Paleoclimatic Evidence- Wegener also considered as evidence the glacial till deposits in the northern and southern latitudes.
- 6. Folding When a part of crust is pushed from opposite direction, compressional forces act on it.
- 7. Faulting When the rocks masses of the crust are pulled apart, the crust is acted upon by a tensional force producing cracks or breaks on the crust
- 8. Harry Hess An American geophysicist He theorized that seafloor is a hundred million years younger than the continents.
- 9. Seafloor spreading The ocean floor has been found to be moving gradually away from the rift. A rift is an elongated break or opening in the middle of the mid-oceanic ridge. It was observed that the rift continuously send the volcanic materials from below. Hot magma rises because it is less dense than the surrounding magma. When it reaches the surface it cools and solidifies becoming the sea floor.