Introduce the crucial basic terminology of structural geology

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Introduce the crucial basic terminology of structural geology

Содержание

2. This Lecture Purpose: Introduce the crucial basic terminology of Structural Geology Outline: Orientation of planes and
3. Analysis Levels Geometrical shape and body’s relations Kinematical motions Geomechanical stress/strain relations (incl. ductile/brittle type of
4. Strike Geographical North Pole 0/3600 East / 900 West / 2700 South / 1800 True (Geographical)
5. Line Orientation West / 2700 South / 1800 Magnetic Strike Direction is: 350-70 = 280, so
6. Planes Orientation Contour Lines 300 200 100 Structure Contour Map projection Multiple “rules” exist… True for
7. Orientation of Lines Again, multiple “rules” exist… «plunge» = «погружение»
8. Faults More-or-less planar surface along which there has been relative displacement of the two sides? OR
9. Fault Names Normal Fault = «сброс» Reverse Fault = «взброс» Strike Slip Fault = «сдвиг»
10. Slip Direction The rock layers continue beyond the ends of the drawing! Strike Slip Direction: opposite
11. Naming the Blocks Old mining terms Hangingwall = «висячее крыло» Footwall = «лежачее крыло»
12. Recognizing Faults on Structural Maps Naming the blocks and recognizing fault’ types Kisimbay Oilfield, Western Kazakhstan
13. Anderson’ Faults Concept σ1 is vertical, σ2 and σ3 are horizontal σ1 and σ2 are horizontal,
14. Fault’s dip angle Hubbert & Willis, 1957 potential hydro fracture orientation Strain ellipse (for reverse fault
15. Stress Trajectory Variations Even “simple” loadings cause stress trajectories to curve, so the vertical stress is
16. Fault Sets - Extension Horst = горст Graben = грабен Half Graben = полуграбен Listric Fault
17. Fault Sets – Extension: a bit more about growing faults After Mitchum et al., 1990
18. Fault Sets - Shortening 1 2 3 4 5 6 7 Duplex Zone = дуплекс Imbicate
19. What is a fold? And Fold Names Anticlines are a major trap type Feature where rock
20. Hinge lines Crestline and Trough line are the lines of maximum and minimum elevation respectively Hinge
21. Symmetry Symmetric folds (equal limb lengths) Asymmetric folds (unequal limb lengths) Limbs usually have different dips
22. Multi-layers Axial surface (not always plane) connects multiple hinge lines (that is a difference with Russian
23. Fold Names
24. Measuring Folds
25. Thickness changes? Isogone – line connected points with same dip angle Similar Folds are more “popular”
26. Causes? складки продольного изгиба складки поперечного изгиба
27. Fault-Bend Interaction: Folds
28. Detached Folds Zagros
29. Rollover Structures
30. Rollover Structures
31. Rollover Structures
32. rollover anticline: ductile scenario Rollover Structures
33. rollover anticline: brittle scenario, antithetic faults development Rollover Structures antithetic faults
34. rollover anticline: brittle + overlaid Rollover Structures
35. Inversion Early: extension, with sediments thickening across faults Later: shortening, re-use of previous faults
36. Fractures Fractures vs Faults: almost invisible (not more then few mm) lateral motion along fracture surface
37. Fractures Some extension (if big enough difference between principle stresses) may exist producing “open” fractures with
38. Fractured Reservoirs (joints only!) Nelson (1992): I – essential contribution in reservoir’ porosity & permeability; deplete
39. Fault-Associated Fractures what tends to be open? simple shear
40. Fracturing associated with faults Twiss & Moores, 1992 Fault-Associated Fractures
41. Fold-Associated Fractures Simple view
42. Fold-Associated Fractures Scheme described by Stearns, 1968 Classification relates fractures and bedding orientation, plus curvature, with
43. Cooling Magmatic – both plutonic and volcanic - rocks cooling (columnar basalts are good example) Twiss
44. High Differential Stress Fracturing because of general strain (big enough differential stress) Bekker & Gross, 1992
45. Tectonic Uplifting Fracturing because of tectonic uplifting – sure should be initiated by other processes (like
46. Natural Hydrofracturing Twiss & Moores, 1992
48. Скачать презентацию

Слайд 2

This Lecture
Purpose: Introduce the crucial basic terminology of Structural Geology
Outline:
Orientation of

planes and lines
Faults
Folds
Faults/Fold relationships
Fractures
Typical Features for shortening/extention environments

Слайд 3

Analysis Levels
Geometrical
shape and body’s relations
Kinematical
motions
Geomechanical
stress/strain relations (incl. ductile/brittle type of deformation)
Increasing

level of complexity

More Interpretative

More descriptive

Слайд 4

Strike
Geographical North Pole
0/3600
East / 900
West / 2700
South / 1800
True (Geographical)

Strike Direction (“Strike”) is: 350

Rules:
always measure clockwise,
may be measured with two results with 1800 difference:
350 or 2150 – both are correct

350

2150

Слайд 5

Line Orientation
West / 2700
South / 1800
Magnetic Strike Direction is: 350-70 =

280, so correction +70 has to be made for compass

350

2150

Magnetic North Pole

magnetic declination (some 70 in West Siberia)

Слайд 6

Planes Orientation
Contour Lines
300
200
100
Structure Contour Map
projection
Multiple “rules” exist…
True for the Left-Hand Rule.

Basically dip should be noted: 22SW/105.
Alternatively Dip direction (Instead of Strike) may be noted.

Слайд 7

Orientation of Lines
Again, multiple “rules” exist…
«plunge» = «погружение»

Слайд 8

Faults
More-or-less planar surface along which there has been relative displacement of

the two sides?
OR
Process zone (finite thickness) in which fault-rock materials are created and altered?

(Hooper, Hatcher, 1988)

Слайд 9

Fault Names
Normal Fault = «сброс»
Reverse Fault = «взброс»
Strike Slip Fault =

«сдвиг»

Слайд 10

Slip Direction
The rock layers continue beyond the ends of the drawing!
Strike

Slip Direction:
opposite block moves to the left: Sinistral Strike Slip = «левосторонний сдвиг»
opposite block moves to the right: Dextral Strike Slip = «правосторонний сдвиг»

Слайд 11

Naming the Blocks
Old mining terms
Hangingwall = «висячее крыло»
Footwall = «лежачее крыло»

Слайд 12

Recognizing Faults on Structural Maps
Naming the blocks and recognizing fault’ types
Kisimbay

Oilfield, Western Kazakhstan (Bisengalieva et al., 2002)

Слайд 13

Anderson’ Faults Concept
σ1 is vertical, σ2 and σ3 are horizontal
σ1 and

σ2 are horizontal, while σ3 is vertical

σ1 and σ3 are horizontal, while σ2 is vertical

σ1 ≥ σ2 ≥ σ3

Слайд 14

$Fault’s dip angle Hubbert & Willis, 1957 potential hydro fracture orientation$

Fault’s dip angle
Hubbert & Willis, 1957
potential hydro fracture orientation
Strain ellipse (for

reverse fault area)

were
φ is a internal friction angle. For sand/sandstones within elastic behavior φ ≈ 300 (and strongly depends on Poisson ratio)

Слайд 15

Stress Trajectory Variations
Even “simple” loadings cause stress trajectories to curve, so

the vertical stress is not a principal stress.
And complex loadings cause considerable spatial (and temporal) variations in the stress field.

Слайд 16

Fault Sets - Extension
Horst = горст
Graben = грабен
Half Graben = полуграбен
Listric

Fault = листрический разлом

σ1 is vertical, σ2 and σ3 are horizontal

Слайд 17

Fault Sets – Extension: a bit more about growing faults
After

Mitchum et al., 1990

Слайд 18

Fault Sets - Shortening
1
2
3
4
5
6
7
Duplex Zone = дуплекс
Imbicate Fan = чешуйчатый надвиг
Detachment

= детачмент

Слайд 19

What is a fold? And Fold Names
Anticlines are a major trap

type

Feature where rock layers or other markers become non-planar due to deformation

Слайд 20

Hinge lines
Crestline and Trough line are the lines of maximum and

minimum elevation respectively
Hinge Line traces points with maximum curvature (doesn’t necessary coincide with Crest/Trough lines)
Inflection Line (i) separates adjacent folds and traces area with minimal curvature (points of changing curvature sign)
Limb (or Flank) is low-curvature area between hinges (крыло складки)
Closure is an hight-curvature area around (or between) hinges (замок складки)

Describing Surfaces

Twiss & Moores, 1992

Слайд 21

Symmetry
Symmetric folds (equal limb lengths)
Asymmetric folds (unequal limb lengths)
Limbs usually have

different dips

Limbs usually have same dip

симметричные прямые

наклонные (косые)

Слайд 22

Multi-layers
Axial surface (not always plane) connects multiple hinge lines (that is

a difference with Russian terminology)
Inflection surface include inflection lines

Слайд 23

Fold Names

Слайд 24

Measuring Folds

Слайд 25

Thickness changes?
Isogone – line connected points with same dip angle
Similar Folds

are more “popular” in nature: mass flow exist from high-stress areas (limbs) to low-stress (closures)

Слайд 26

Causes?
складки продольного изгиба
складки поперечного изгиба

Слайд 27

Fault-Bend Interaction: Folds

Слайд 28

Detached Folds
Zagros

Слайд 29

Rollover Structures

Слайд 30

Rollover Structures

Слайд 31

Rollover Structures

Слайд 32

rollover anticline: ductile scenario
Rollover Structures

Слайд 33

rollover anticline: brittle scenario, antithetic faults development
Rollover Structures
antithetic faults

Слайд 34

rollover anticline: brittle + overlaid
Rollover Structures

Слайд 35

Inversion
Early: extension, with sediments thickening across faults
Later: shortening, re-use of previous

faults

Слайд 36

$Fractures Fractures vs Faults: almost invisible (not more then few mm) lateral motion along fracture surface$

Fractures
Fractures vs Faults: almost invisible (not more then few mm) lateral

motion along fracture surface

Слайд 37

Fractures
Some extension (if big enough difference between principle stresses) may exist

producing “open” fractures with definite aperture and spacing that, being unfilled by secondary minerals, increase reservoir’ permeability greatly – as cube of joint aperture

shear fractures

extensional fracture (real joint)

flattening fractures

Слайд 38

Fractured Reservoirs (joints only!)
Nelson (1992):
I – essential contribution in reservoir’ porosity

& permeability; deplete rapidly, basically not economic,
II – essential permeability; matrix porosity support fluid flow to fractures; good reserves,
III – fractures add to reservoir’ permeability, improving otherwise poor-quality reservoir,
IV – regular matrix reservoir, where fractures add permeability anysotropy/compartmentalisation.

Слайд 39

Fault-Associated Fractures
what tends to be open?
simple shear

Слайд 40

Fracturing associated with faults
Twiss & Moores, 1992
Fault-Associated Fractures

Слайд 41

Fold-Associated Fractures
Simple view

Слайд 42

$Fold-Associated Fractures Scheme described by Stearns, 1968 Classification relates fractures and$

Fold-Associated Fractures
Scheme described by Stearns, 1968
Classification relates fractures and bedding orientation,

plus curvature, with some aspects of a “process model”

Type 1

Type 2

Types 3a, 3b

Слайд 43

Cooling
Magmatic – both plutonic and volcanic - rocks cooling (columnar basalts

are good example)

Twiss & Moores, 1992

Слайд 44

High Differential Stress
Fracturing because of general strain (big enough differential stress)
Bekker

& Gross, 1992

S/T ≈ 0.7…1.2
where:
S – fracture spacing,
T – bed thickness

Слайд 45

Tectonic Uplifting
Fracturing because of tectonic uplifting – sure should be initiated

by other processes (like cooling)

Twiss & Moores, 1992

Слайд 46

Introduce the crucial basic terminology of structural geology

Содержание

This LecturePurpose: Introduce the crucial basic terminology of Structural GeologyOutline:Orientation of

Analysis LevelsGeometricalshape and body’s relationsKinematicalmotionsGeomechanicalstress/strain relations (incl. ductile/brittle type of deformation)Increasing

StrikeGeographical North Pole 0/3600East / 900West / 2700South / 1800True (Geographical)

Line OrientationWest / 2700South / 1800Magnetic Strike Direction is: 350-70 =

Planes OrientationContour Lines300200100Structure Contour MapprojectionMultiple “rules” exist…True for the Left-Hand Rule.

Orientation of LinesAgain, multiple “rules” exist…«plunge» = «погружение»

FaultsMore-or-less planar surface along which there has been relative displacement of

Fault NamesNormal Fault = «сброс»Reverse Fault = «взброс»Strike Slip Fault =

Slip DirectionThe rock layers continue beyond the ends of the drawing!Strike

Naming the BlocksOld mining termsHangingwall = «висячее крыло»Footwall = «лежачее крыло»

Recognizing Faults on Structural MapsNaming the blocks and recognizing fault’ typesKisimbay

Anderson’ Faults Conceptσ1 is vertical, σ2 and σ3 are horizontalσ1 and

Fault’s dip angleHubbert & Willis, 1957potential hydro fracture orientationStrain ellipse (for

Stress Trajectory VariationsEven “simple” loadings cause stress trajectories to curve, so

Fault Sets - ExtensionHorst = горстGraben = грабенHalf Graben = полуграбенListric

Fault Sets – Extension: a bit more about growing faults After

Fault Sets - Shortening1234567Duplex Zone = дуплексImbicate Fan = чешуйчатый надвигDetachment

What is a fold? And Fold NamesAnticlines are a major trap

Hinge linesCrestline and Trough line are the lines of maximum and

SymmetrySymmetric folds (equal limb lengths)Asymmetric folds (unequal limb lengths)Limbs usually have

Multi-layersAxial surface (not always plane) connects multiple hinge lines (that is

Fold Names

Measuring Folds

Thickness changes?Isogone – line connected points with same dip angleSimilar Folds

Causes?складки продольного изгибаскладки поперечного изгиба

Fault-Bend Interaction: Folds

Detached FoldsZagros

Rollover Structures

Rollover Structures

Rollover Structures

rollover anticline: ductile scenarioRollover Structures

rollover anticline: brittle scenario, antithetic faults developmentRollover Structuresantithetic faults

rollover anticline: brittle + overlaidRollover Structures

InversionEarly: extension, with sediments thickening across faultsLater: shortening, re-use of previous

FracturesFractures vs Faults: almost invisible (not more then few mm) lateral

FracturesSome extension (if big enough difference between principle stresses) may exist

Fractured Reservoirs (joints only!)Nelson (1992):I – essential contribution in reservoir’ porosity

Fault-Associated Fractureswhat tends to be open?simple shear

Fracturing associated with faultsTwiss & Moores, 1992Fault-Associated Fractures

Fold-Associated FracturesSimple view

Fold-Associated FracturesScheme described by Stearns, 1968Classification relates fractures and bedding orientation,

CoolingMagmatic – both plutonic and volcanic - rocks cooling (columnar basalts

High Differential StressFracturing because of general strain (big enough differential stress)Bekker

Tectonic UpliftingFracturing because of tectonic uplifting – sure should be initiated

Natural HydrofracturingTwiss & Moores, 1992

Похожие презентации

This Lecture
Purpose: Introduce the crucial basic terminology of Structural Geology
Outline:
Orientation of

Analysis Levels
Geometrical
shape and body’s relations
Kinematical
motions
Geomechanical
stress/strain relations (incl. ductile/brittle type of deformation)
Increasing

Strike
Geographical North Pole
0/3600
East / 900
West / 2700
South / 1800
True (Geographical)

Line Orientation
West / 2700
South / 1800
Magnetic Strike Direction is: 350-70 =

Planes Orientation
Contour Lines
300
200
100
Structure Contour Map
projection
Multiple “rules” exist…
True for the Left-Hand Rule.

Orientation of Lines
Again, multiple “rules” exist…
«plunge» = «погружение»

Faults
More-or-less planar surface along which there has been relative displacement of

Fault Names
Normal Fault = «сброс»
Reverse Fault = «взброс»
Strike Slip Fault =

Slip Direction
The rock layers continue beyond the ends of the drawing!
Strike

Naming the Blocks
Old mining terms
Hangingwall = «висячее крыло»
Footwall = «лежачее крыло»

Recognizing Faults on Structural Maps
Naming the blocks and recognizing fault’ types
Kisimbay

Anderson’ Faults Concept
σ1 is vertical, σ2 and σ3 are horizontal
σ1 and

Fault’s dip angle
Hubbert & Willis, 1957
potential hydro fracture orientation
Strain ellipse (for

Stress Trajectory Variations
Even “simple” loadings cause stress trajectories to curve, so

Fault Sets - Extension
Horst = горст
Graben = грабен
Half Graben = полуграбен
Listric

Fault Sets – Extension: a bit more about growing faults
After

Fault Sets - Shortening
1
2
3
4
5
6
7
Duplex Zone = дуплекс
Imbicate Fan = чешуйчатый надвиг
Detachment

What is a fold? And Fold Names
Anticlines are a major trap

Hinge lines
Crestline and Trough line are the lines of maximum and

Symmetry
Symmetric folds (equal limb lengths)
Asymmetric folds (unequal limb lengths)
Limbs usually have

Multi-layers
Axial surface (not always plane) connects multiple hinge lines (that is

Thickness changes?
Isogone – line connected points with same dip angle
Similar Folds

Causes?
складки продольного изгиба
складки поперечного изгиба

Detached Folds
Zagros

rollover anticline: ductile scenario
Rollover Structures

rollover anticline: brittle scenario, antithetic faults development
Rollover Structures
antithetic faults

rollover anticline: brittle + overlaid
Rollover Structures

Inversion
Early: extension, with sediments thickening across faults
Later: shortening, re-use of previous

Fractures
Fractures vs Faults: almost invisible (not more then few mm) lateral

Fractures
Some extension (if big enough difference between principle stresses) may exist

Fractured Reservoirs (joints only!)
Nelson (1992):
I – essential contribution in reservoir’ porosity

Fault-Associated Fractures
what tends to be open?
simple shear

Fracturing associated with faults
Twiss & Moores, 1992
Fault-Associated Fractures

Fold-Associated Fractures
Simple view

Fold-Associated Fractures
Scheme described by Stearns, 1968
Classification relates fractures and bedding orientation,

Cooling
Magmatic – both plutonic and volcanic - rocks cooling (columnar basalts

High Differential Stress
Fracturing because of general strain (big enough differential stress)
Bekker

Tectonic Uplifting
Fracturing because of tectonic uplifting – sure should be initiated

Natural Hydrofracturing
Twiss & Moores, 1992