Structural Geology. Sedimentary and volcanic rocks are originally deposited in sub-horizontal layers. Any deviation shown by rocks is considered a structural deformation and is found/shown on geologic maps.
v 0030 of 'Structural Geology' by Greg Pouch
at 2011-10-24 09:57:29
LastSavedBeforeThis 2011-09-07 16Structural.ppt
3 Rheology > Stress
4 Rheology > Strain
5 Rheology > Controls on Strain Style
6 Rheology on one slide
7 Rheology Images
8 Geologic maps (how we know about deformation)
Products (Geologic Structures)
9 Geologic Structures>Fractures
10 Geologic Structures>Fractures > Slides
11 Geologic Structures>Flexures
12 Geologic Structures>Flexures>Slides
13 Basins and Domes
Strain is the change in length divided by the initial length. (continuum replacement of displacement)
Many materials are linear-elastic (strain is proportional to stress)
Engineers consider elastic good in final products like buildings and roads.
Faults often occur alone, but frequently occur in sets with the same direction (fault zones). Faults are rarely seen, but are usually inferred based on differences in rock outcrop; when they are seen, they are not usually nice clean planes, but some ground up mess.
At high pressure and temperature, rock can behave plastically or viscously (ductilely) and accommodate compressive stresses by folding. Flexures (bends) can also occur in brittle rocks by movement along faults, with "hinges" at faults.. Ductile flexure results in smoothly curving shapes. Brittle flexure results in sharp, angular shapes.