STRUCTURAL GEOLOGY HATCHER 7 Flashcards
imperfectios in crystal lattice
Defects
involves a foreign ion or atom in a lattice site or a normal atom out of its proper place, may be introduced while the crystal is forming
Substitution or Interstitial Defects
defects when an unoccupied site is produced due to irradiation by high energy particles and by sudden cooling of a crystal from high temp
Vacancies
A line on a crystallograhic slip plane that separates the slipped from the unslipped portion of a crystal
Dislocation
Lines dislocation in w/c slip sense across the crystalloraphic slip plane is normal to the dislocation
Edge Dislocation
Lines dislocation in w/c slip sense across the crystalloraphic slip plane is parallell to the dislocation
Screw Disolications
Describing edge or screew dislocations
Burgers Vectors or Circuit
Consist of irregularities in the repeat order of unit cells in a series of layers in a lattice
Stacking Faults (As in pagkakamali)
A deformation that occur in a crystal by HOMOGENOUS SIMPLE SHEAR that causes movement of a dislocation located parallel to an existing crystallographic plane thus having an offset planes called slip systems
Dislocation or Translational Gliding
aka Mechanical Crystal Plasticity
A defomration by Homogenous simple shear that produces DEFLECTION SLIP of less than 1 repeat interval along crystallographic planes thus producing Shear induced twinning of the crystal
Twin Gliding
Brittle deformation concentrated on movement surfaces that have NO COHESION which produces granulation of rock at LOW T and P with high strain rate
Cataclasis
Cohesive rocks produced by this brittle granulation of rocks mostly angular
Cataclasite
Ductilely formed fault rocks which iccurs under conditions of moderate to low strain rate and high temp
Mylonite
Brittle deformation (microscopic) which produces apparent flow of fine grain material.
Ductile sa labas pero net effect lang ng cataclasis
Cataclastic Flow
Behavior that shows apparent megascopic ductile behaviour but is shown to be brittle in microscopic scale
Triboplastic
Indication of Cataclasis
Megascopic Breccia
Gouge, Fault and Fractures
Microbreccia and Microfarctures
aka steady state deformation mechanisms
Creep Processes
Dissolution under stress of soluble constituents particularly qtz and calcite and is generally active at LOW to MOD Temp<350 in THE PRESENCE OF WATER
Pressure Solution
What makes a rock more susceptible to pressure solution?
Fine Grains sizes and presnce of impurities
Irregular surface coated with insoluble minerals parallel to the bedding formed during diaganeses
Stylolites
what distinguishes a diagenetic stylolite to a tectonic stylolite?
Diagenetic sub parallel
Tectonic High angles ot the bedding
Processes that dominate at Temp >400 where there is a THERMALLY DRIVE DIFFUSION MASS TRANSFER along grain boundaries especially when water from pressure solution becomes less efficient and there is an additional heat energy acceleration
Cobble Creep or
Grain boundary Diffusion Creep
A two step process that includes both strain (Glide) and accomodation of the lattice (Climb) to such strain driven by Mod to High Temp and Pressure
Glide - the movement of Edge Dislocation
Creep - the recovery of the lattice form the glide
Dislocation Creep
This involves diffusion of point defects particularly vacancies through crystals toward points of high stress.
Mapuputa ung vacanies sa region of high stress
Volume -Diffusion Creep
Nabarro-Herring Creep
