deformation

Question 1

study of deformed rocks

Answer 1

structural geology

Question 2

transformation from an initial to a final geometry in the means of:

Answer 2

translation
rotation
distortion (strain)
dilation (volume change)

Question 3

distortion that is expressed in a deformed rock

Answer 3

deformation

Question 4

movement of particles in the same direction and distance;

change in position or location

Answer 4

translation

Question 5

example of translation

Answer 5

faults

Question 6

change in shape

Answer 6

distortion

Question 7

example of distortion

Answer 7

folding

Question 8

non rigid body formation is also known as

Answer 8

strain

Question 9

rigid body deformation eg.

Answer 9

translation and rotation

Question 10

non rigid body formation eg.

Answer 10

dilation and distortion

Question 11

deforming rock system

Answer 11

hawaii emperor volcanic chain

Question 12

processes that permit rocks to deform at the microscopic and atomic scale

Answer 12

microstructures

Question 13

it is accomodated through the activation of one or more microscale deformation mechanics

Answer 13

strain

Question 14

it influences the strength of minerals leading to deformed rocks

Answer 14

crystalline structure and interatomic bonding

Question 15

6 factors of deformation mechanics

Answer 15

1. mineralogy
2. temperature
3. confining pressure
4. fluid pressure
5. differential stress
6. strain rate

Question 16

microscopic to sub microscopic cracks and surfaces

Answer 16

microcracks

Question 17

the formation of small, microscopic cracks and fractures within a rock due to applied stresses and differential pressures

Answer 17

microfracturing

Question 18

types of microcracks

Answer 18

Intragranular
Intergranular
transgranular

Question 19

occur within a single grain

along a cleavage plane

fracture strength of the grain < grain boundaries

Answer 19

intragranular

Question 20

exploit grain boundaries

indicate that boundaries are easier to crack.

less common in coarse grained rocks

Answer 20

Intergranular

Question 21

cut across adjacent grains and their mutual grain boundaries
* strong grain boundaries and similar orientations of cleavage in neighboring grains

Answer 21

Transgranular

Question 22

pervasive brittle fracturing and granulation of rocks

aggregate of highly fractured grains and rock fragments

Answer 22

cataclasis

Question 23

mapping of stress and strain associated with folded layers

most common in plagioclase and calcite

Answer 23

mechanical twinning

Question 24

migration of vacancies in crystallographic lattices

Answer 24

diffusion creep

Question 25

types of diffusion creep

Answer 25

volume diffusion (nabaro herring creep) grain boundary diffusion (cobble creep)

Question 26

vacancies move through crystals (temperature and stress controlled). requires high energy; **occur in the lower part of the crust and in the mantle.** smaller grains = higher strain rate. material failure over time under constant, high-temperature, low-stress conditions.

Answer 26

volume diffusion (nabaro herring creep)

Question 27

vacancies move along grain boundaries (temperature and stress controlled). less energy demanding; **occur in the plastic crust.** understanding the deformation of fine-grained rocks, such as in shear zones, and its role in contributing to the overall weakening and failure of rock bodies over geological time.

Answer 27

grain boundary diffusion (cobble creep)

Question 28

* Ions move in fluid films and pore fluid (chemically and stress controlled). **Occur at very low (even diagenetic) temperatures.** * Mineral is dissolved and the ions are carried with the fluid to be precipitated some other place.

Answer 28

Dissolution Creep (Pressure Solution

Question 29

Processes of dissolution creep depends on:

Answer 29

1.) dissolution at the source 2.) diffusion or migration of the dissolved material along some pathway 3.) reprecipitation

Question 30

* **Change in shape** by a combination of very localized, temporary distortion of the lattice and shearing of the lattice along a slip plane. * Formation, motion and destruction of dislocations in a crystal.

Answer 30

Dislocation Creep

Question 31

are line defects in the crystal lattice where the regular arrangement of atoms is **disrupted.**

Answer 31

dislocation

Question 32

2 types of dislocation creep

Answer 32

edge dislocation screw dislocation

Question 33

* Perpendicular to the direction of slip. * Edge of an extra half-plane in the crystal lattice.

Answer 33

Edge Dislocation

Question 34

process by which edge dislocation move.

Answer 34

Dislocation glide

Question 35

* Dislocation line is oriented parallel to the slip direction. **A bit like tearing a piece of paper.**

Answer 35

Screw Dislocation

Question 36

what are the 6 types of deformation mechanism

Answer 36

microfracturing cataclasis or catacastic flow mehcanical twinning diffusion creep disolution creep dislocation creep