Structural Geology Flashcards
A rule that states that microstructures are keys to mimic the styles and orientation of macrostructures of the same generation within a particular area.
Pumpelly’s rule
An isostasy hypothesis which accounts for regional isostasy created due to flexural folding of the lithosphere. When load on the crust causes downward flexural folding of the crust, with buoyancy forces acting opposite of it, and can possibly create bulging around the load.
Vening Meinesz’ Hypothesis
also called “Uniform pressure”
Hydrostatic pressure
It measures the stiffness or stretcheability of a material, defined as the ratio of stress over strain.
Young’s Modulus
It expresses the relationship between volume change and stress. The ratio of lateral change due to compression or tension.
Poisson’s Ratio
The study of the ability of stressed solid materials, as well as fluids, to flow or deform due to strain rate, elasticity, and viscosity.
a. Speleology
b. Pedology
c. Rheology
d. Palynology
a. Speleology - caves
b. Pedology - soils
c. Rheology - solids/fluids ability to flow due to strain
d. Palynology - nanometer-sized organic-walled fossils
occurs where two subparallel thrusts of approximately equal displacement are separated by a deformed interval that is thin relative to its total area extent.
Duplex
A fault surface parallel to a mechanically weak horizon or layer, or parallel to bedding, that detaches or separates deformed rocks above from undeformed or differently deformed rocks below.
Decollements
Differentiate buckling and bending
Bending - force is applied not parallel to the layer, results in folding
Buckling - force applied is parallel to the layer, resulting in folds
Joints that exhibit feathered structure
a. nonsystematic
b. pinnate
c. plumose
d. Griffith
a. nonsystematic (no common orientation)
b. pinnate (merges with the fault at 30-45-degrees angle)
c. plumose (feathered structure)
d. Griffith (pre-existing microcracks/flaws in a rock)
