330 likes | 449 Vues
Learn about the processes of folding and faulting in geology, where compression leads to the formation of fold mountains like the Alps, Himalayas, and Rockies. Discover the types of folds such as anticlines and synclines, as well as faults like normal and reverse faults. Explore horsts, grabens, and strike-slip faults in the Earth's crust.
E N D
Folding generally takes place in areas of sedimentary rocks that have been laid down in horizontal layers called strata. When compression produces thrust [convergence], the earth folds along lines of strength and weakness. This creates long ranges of FOLD MOUNTAINS – Alps, Himalayas, Rockies…
Faulting –adjacent surfaces are displaced relative to one another
Normal Fault • In normal faulting, the hanging wall block moves down relative to the footwall block. • Normal faults are associated with crustal TENSION.
Reverse Fault • In reverse faulting, the hanging wall block moves up relative to the footwall block. • Reverse faults are associated with crustal COMPRESSION and are also known as thrust faults.
A horst occurs when a mass of the earth's crust that lies between two faults and is higher than the surrounding land.
A graben is an elongated depression between geologic faults.
Strike-slip Fault • In strike-slip faulting, the two blocks move either to the left or to the right relative to one another.