2. •Tectonic movements sometimes lead to the rupture of the
continuity of rock layers and the formation of faults or
disjunctive dislocations. There are faults without
displacement and with displacements.
•Displacement faults Based on direction of slip include
following faults:
•- dip-slip, offset is predominantly vertical and/or
perpendicular to the fault trace.
•- strike-slip, where the offset is predominantly horizontal,
parallel to the fault trace.
•- oblique-slip, combining strike and dip slip.
•- thrust faults
3. • The elements of tectonic faults are: fault plane, walls, tilt angle of fault
plane, offset amplitude.
• tilt angle - | tilt ˈæŋɡ(ə)l| -meyl bucağı
• offset amplitude -|ˈɒfset| |ˈæmplɪtjuːd| -yerdəyismə amplitudu
4. • walls - rock strata located on both sides of the fault.
• Hanging wall- |ˈhaŋɪŋ wɔːl | - asılı qanad
-When the fault plane is tilted, the wall above it is called the hanging wall
• Footwall- |fʊt wɔːl | yatıq qanad
• When the fault plane is tilted, the wall below it is called the footwall
• Fault plane –|fɔːlt pleɪn | qırılma müstəvisi
-The fault plane is the plane along which the displacement occurs. The tilt angle of
the fault plane can vary from several degrees to 80-90o.
• Fault trace or fault line –|fɔːlt treɪs| |fɔːlt laɪn| -qırılma oxu və ya qırılma xətti
• A fault trace or fault line is a place where the fault can be seen or mapped on the
surface. A fault trace is also the line commonly plotted on geologic maps to
represent a fault.
• Upthrown blok- |ˈʌpθrəʊn blɒk | yuxarıya yerini dəyişmiş blok
• Downthrown blok- |ˈdaʊnθrəʊn blɒk | aşağıya yerini dəyişmiş blok
• Fault scarp- |fɔːlt skɑːp | qırılma yamacı
5.
6. Dip-slip faults
• Dip-slip faults can occur either as "reverse" or as "normal" faults. A normal
fault occurs when the crust is extended. Alternatively such a fault can be
called an extensional fault. The hanging wall moves downward, relative to the
footwall
Normal fault |ˈnɔːrml fɔːlt | - fay tip qırılma
A reverse fault is the opposite of a normal fault—the hanging wall moves up relative to
the footwall. Reverse faults indicate shortening of the crust. The dip of a reverse fault is
relatively steep, greater than 45°.
Reverse fault- | rəˈvərs fɔːlt | - əks-fay tip qırılma
7. Strike-slip faults
• In a strike-slip fault (also known as a wrench fault, tear fault or transcurrent
fault), the fault surface (plane) is usually near vertical and the footwall moves
laterally either left or right with very little vertical motion. Strike-slip faults with
left-lateral motion are also known as sinistral faults. Those with right-lateral
motion are also known as dextral faults. Each is defined by the direction of
movement of the ground as would be seen by an observer on the opposite side
of the fault. A special class of strike-slip fault is the transform fault, when it
forms a plate boundary.
•
9. Oblique-slip faults
• A fault which has a component of dip-slip and a component of strike-slip is
termed an oblique-slip fault. Nearly all faults have some component of both
dip-slip and strike-slip, so defining a fault as oblique requires both dip and
strike components to be measurable and significant. Some oblique faults
occur within transtensional and transpressional regimes, and others occur
where the direction of extension or shortening changes during the
deformation but the earlier formed faults remain active. The hade angle is
defined as the complement of the dip angle; it is the angle between the fault
plane and a vertical plane that strikes parallel to the fault.
10. • transtensional -|trænz||ˈtenʃ(ə)n əl| - gərilmə təsiri altında yerdəyişmə
• Transpressional -|trænz presʃ(ə)n əl| - təzyiqin təsiri altında yerdəyişmə
• Oblique-slip faults- |əˈbliːk slɪp fɔːlts| -fay-əks-fay- uzununa sürüşmə
qırılmaları
• hade angle - |heɪd| |ˈæŋɡ(ə)l| - düşmə bucağı
• dip angle - |dɪp| |ˈæŋɡ(ə)l| - yarım bucağı
11. Thrust faults
• A thrust fault has the same sense of motion as a reverse
fault, but with the dip of the fault plane at less than 45°.
These structures are widespread in folded areas. Thrust
faults typically form ramps, flats and fault-bend (hanging
wall and foot wall) folds. Thrust faults form nappes and
klippes in the large thrust belts. A thrust with a large
horizontal displacement is called a nape, in which the
hanging wing can move for many kilometers and even
tens of kilometers.
• Fault-bend folds are formed by movement of the
hanging wall over a non-planar fault surface and are
found associated with both extensional and thrust faults
13. • Faults are often manifested with normal and reverse fault systems. In
this case, specific structures are formed.
• Graben |ˈɡrɑːb(ə)n| is a subsided area of the earth's crust bounded by
parallel normal faults of considerable length.
• Horst |hɔːst| is a raised area of the earth's crust, enclosed between
parallel faults.
• Graden /greiden/. When the blocks pushed upward or downward relative
to each other staircase is called graden.
• Several parallel, stepped grabens form a complex graben. This applies to
the structures of the Great African Lakes (Tanganyika, Albert, Rudolf), the
Red Sea rift, Lake Baikal rift, the Rhine graben, etc.
14.
15. • Faults without displacements are cracks |kræks| (fissure
['fɪʃə], joints [|dʒɔɪnts| ],
fractures ['frækʧəs]). They differ in width (from millimeters to several
meters), in length (from the first centimeters to tens of kilometers), in depth,
shape (linear, arc-shaped, etc.) and so on. In addition to cracks of tectonic
origin, there are cracks of exogenous |ɪkˈsɒdʒɪnəs| (non-tectonic) origin –
drought cracks |draʊt kræks |, landslide |ˈlæn(d)slæɪd| ,
avalanch |ˈævəlɑːnʃ|, rock extension |rɒk ɪkˈstɛnʃ(ə)n|, slacking |ˈslækɪŋ| ,
etc.
