STRUCTURAL GEOLOGY HATCHER 11 Flashcards
Belt of thrust faults occuring between underformed craton and metamorphic core of nearly every mountain
Foreland Fold-Thrust Belt
Zones of weak rocks (shale , coal or strong unit suscpetible to strain softening) where thrusts generaly propagates. French for “Ungluing”
Detachment or Decollements or Bedding thrusts
A high angle segment which may exist where thrust cuts across a strong unit from one detachment to another
Ramp (High Angle Decollement)
Thickness of strong units
Strut
Formed by faulting the CONNECTING LIMB of a anticline and syncline pair overthrowing the haging wall anticline and preserving footwall syncline
Break Thrust/Fold Thrust
A Break Thrust formed independently of folding but not having a footwall syncline
Shear Thrust/Fracture Thrust
Formed as the THRUST SURFACE CHANGES from steeper dip to shallower in an up-dip direction (Surface)
Steeply dipping sa ilalim tapos biglang naging gentle sa ibabaw *Hanging wall anticline NO FOOT WALL Syncline
Nagchange lang yung steepnes ng dip and nagterminate sa surface
Fault Bend Fold
(ShearThrust/Fracture Thrust)
Formed as layers of a Sed Sequence fold during propagation of thrust (Hanging Wall Anticline plus Footwall Syncline
Nagfold yung sed layers nung nag thrust faulting nagterminate sa fault ramp
Fault Progation Fold
(Break Thrust/Fold Thrust)
Fault Bend Fold: Shear Thrust: Fault Propagation fault:
Break Thrust
Folds that form near the thrust sruface due to friction wherein the footwall are deformed to synclines and the hanging wall to antilines
Drag Folds
Materials that have been grinded due to faulting and may be transported within the fault zone under the thrust sheet
Mga fragments of rocks or asperities na naerode due to faulting at natrap sa gitna ng footwall and hanging wall
Horses (Hanging Wall Fragments)
Slices (Footwall Fragmets)
Whats the age of the horses?
intermediate between the ages of the hanging and footwall
Smaller faults in a group of thrust faults
Imbricate Thrusts
Series of thrusts making up the entire foreland thrust belt
Imbricate Zone
Strutures bounded by two thrust fault of approx equal displacement separated by deformed interval that is thin relative to its total area and the Upper an Lower Master fault connected by imricates
Duplex
Upper Master fault
Roof Thrust
Lower Master Fault
Floor Thrust
Line of intersection of two fault surfaces
Branch Line
A thrust that terminates at the surface
Erosion or Emergent Thrust
A thrust that was aborted within the sedimentary section and never reached the surface
Blind Thrust
Ends of thrust sheets that terminate in strike slop faults
Tear Faults
When there’s a hole in the thrust sheet/hanging wall formed during folding, the footwall rocks are exposed surrounded by steeply dipping haging wall rocks such hole is called
Simple window or Fenster
An erosional feature formed by renewed movement in an foled thrust sheet which creates an opening along the fault surface and will appear to be partly closed because the elongate outcrop pattern prallels tha fault trace
Eyelid Windows
If an exposed footwall is exposed surrounded by the rocks of the hanging wall and the contact is an unconformity it is called
Inlier
Disemembered part of a thrust sheet (Iniwan at nahiwalay na part ng thrust sheet).
Erosional Outliers
Klippe
Larger separated remnant of a thrust sheet
Allochton
Thrusts that involves transport of basement metamorphic and igneous rocks or both as part of the thrust sheet (Hanging Wall)
Crystalline Thrust
