Types of Brittle Deformation

Pelatnas IESO Geologi Struktur 2013 Pelatnas IESO Geologi Struktur 2013

Deformasi Rapuh Deformasi Rapuh

Salahuddin Husein Salahuddin Husein Jurusan Teknik Jurusan Teknik Geologi Geologi Fakultas Teknik Fakultas Teknik Universitas Universitas Gadjah Gadjah Mada Mada

Types of Brittle Deformation common during shallow deformation of occurs during deformation of well- porous rocks and sediments consolidated sedimentary rocks and non-porous rocks

Intergranular fractures (extend across a Intragranular fractures (restricted to number of grains) in metamorphic rock single grains) in cataclastically deformed porous sandstone

Tensile Cracks

A crack in a crystal lattice. The crack is a plane of finite extent across which all atomic bonds are broken.

The importance of preexisting cracks in creating stress concentrations.

Tensile Cracks

Development of a throughgoing crack in a block under tension.

) is applied, When tensile stress (σ • Griffith cracks open up. _t

The largest, properly oriented cracks propagate to form a throughgoing crack. Pluijm & Marshak (2004)

Modes of Crack Displacement

Extension fractures:

Joints; have little or no macroscopically detectable displacement.
Fissure; when filled with air or fluid.
Veins; mineral-filled extension fractures.
Dikes; magma-filled fractures.

Stylolites: contraction

fractures or closing fractures

(anticracks) _{Fossen (2010)}

Fault Surface Veins

Stepped calcite slip fibers on a fault surface; pencil indicates displacement direction.

Pluijm & Marshak (2004)

Joints Joints

The dimple of a joint origin, controlled by an inclusion.

Straight plume Curvy plume

Multiple arrest _{Pluijm & Marshak (2004)}

Joints form in a random sequence, but with regular spacing.

Stress Shadow Stress shadow defines the joint interval.

Stress shadow formation.

Joint Origins: Fault-related Joints

Formation of joints in the hanging-wall block of a region in which normal faulting is taking place.

Formation of joints above an irregularity in a (reverse) fault surface.

Pinnate joints along a fault. _{Pluijm & Marshak (2004)}

Horsetailing at the end of a shear

fracture in gneiss.

Compressive stress Extenxional stress

Joint Termination

Joints terminating without curving when they approach one another.

Joints curving into each other and linking.

Map view sketch illustrating how joint spacing is fairly constant because joints that grow too close together cannot pass each other. _{Pluijm & Marshak (2004)} Vein Arrays ^{shddin © 2012} Pluijm & Marshak (2004) Simple en echelon array.

Sigmoidal en echelon veins.

Cataclastic deformation band, Navajo Sandstone Cataclastic deformation band, Nubian Sandstone

Develop by shear-related disaggregation of
grains by means of grain rolling, grain

boundary sliding and breaking of grain
bonding cements.
Disaggregation bands can be almost invisible in clean sandstones, but may be detected
where they cross and offset laminae.

Conjugate (simultaneous and oppositely dipping) sets of cataclastic deformation bands in Entrada Sandstone, Utah.

Fault Terminology

Fault splay Fault Anastomosing fault

Fault zone Shear zone _{Pluijm & Marshak (2004)}

Normal Fault Characteristics

Older rocks in HW over younger rocks in the FW.
Stratigraphic omission

Hangingwall Footwall

Reverse (Thrust) Fault Characteristics

Younger rocks in HW over older rocks in the FW.
Stratigraphic repetition

Footwall Hangingwall

Reverse (thrust fault)

Slip and Separation

Slip - actual relative displacement between two points that occupied the same location before faulting
Separation - apparent relative displacement between two points that may have occupied the same location before faulting

Reverse/thrust faults

Map symbols:

Normal faults Strike- slip faults

Profile symbols:

Normal Fault Zone

Normal fault sense of drag

Duplexes are imbricate fault systems linked on both sides by major faults, all faults must have been active synchronously

Restraining bend Releasing bend

Fault Anatomy D=1000CT and D=10CT, meaning that the fault core is statistically around 1/100 of the fault displacement for faults with displacements up to 100 meters

Stick-Slip Behaviour Laboratory frictional sliding experiment on granite, showing stick-slip behavior. The stress drops (dashed lines) correspond to slip events.

A. Fault merging

B. Fault horsetailing

C. Transfer onto ductile deformation

Tip line: boundary between the slipped and unslipped region at the end of a fault. _{Pluijm & Marshak (2004)}

Fossen (2010) shddin © 2012 Damage Zone Hanging-wall rollover (fault-bend fold) related to bend in the main fault. The damage zone is unusually wide due to the complications posed by the fault bend. Synthetic and antithetic shear bands are separated by color.

Damage Zone Schematic illustration of how a damage zone can grow periodically. This repeats itself as the fault grows.

Imbricate Duplex

The Wasatch fault zone near Salt Lake City, Utah, crudely indicated by white dashed line.
Note the curved fault geometry, indicating a history of segment linkage.
Sketches of various stages of plaster extension experiment indicate how such fault zones can form.

Overlap Zones Fossen (2010)

Change with Depth Pluijm & Marshak (2004)

Anderson’s theory of faulting

Listric Faults Listric Faults

Faulting preferentially initiated in sandstone unit.
Mechanical contrasts due to changes in lithology are enormously important to understanding structural style in numerous ways.

Two end members for fault growth:

Radial tip propagation (a)
Segment linkage (b) early stage and (c) late stage

Types of Brittle Deformation

Deformasi Rapuh Deformasi Rapuh

Modes of Crack Displacement

Modes of Crack Displacement

Joints Joints

Joint Origins: Fault-related Joints

Joint Termination

Fault Terminology

Normal Fault Characteristics

Reverse (Thrust) Fault Characteristics

Slip and Separation

Listric Faults Listric Faults

Dokumen yang terkait

The Influence of HEdPERF and Student Satisfaction Against Perceived Service Value and Implication In Institutional Image

Analysis of Human Resource Competency as Effort to Increase SMEs Economic Sector Productivity with Gender as Differentiating Variable

Quality Service Strategy In Improving Performance of Puskesmas Service Area of Mranggen District

Exploring Goal Commitment Predictors of Boundary Role Persons (BRP)

Role of Reference Group in Winning Banten Higher Education Service Market

The Segmentation of Visitor Tanah Lot Tourism Attraction

Influence of Styles of Women Leadership and Organization Culture on Locus of Control and Job Satisfaction of UIN Alauddin Makassar Lecturer

Insulin-like Growth Factor-1 Receptor (IGF-1R), Epidermal Growth Factor Receptor (EGFR), dan Mammalian Target of Rapamycin (mTOR) pada Kemoterapi Kanker Paru

The Neuropharmacogenomical Perspectives of

Clinical Manifestations of Ocular Tuberculosis

Dukungan

Links

Types of Brittle Deformation

Deformasi Rapuh Deformasi Rapuh

Modes of Crack Displacement

Modes of Crack Displacement

Joints Joints

Joint Origins: Fault-related Joints

Joint Termination

Fault Terminology

Normal Fault Characteristics

Reverse (Thrust) Fault Characteristics

Slip and Separation

Listric Faults Listric Faults

Dokumen yang terkait

The Influence of HEdPERF and Student Satisfaction Against Perceived Service Value and Implication In Institutional Image

Analysis of Human Resource Competency as Effort to Increase SMEs Economic Sector Productivity with Gender as Differentiating Variable

Quality Service Strategy In Improving Performance of Puskesmas Service Area of Mranggen District

Exploring Goal Commitment Predictors of Boundary Role Persons (BRP)

Role of Reference Group in Winning Banten Higher Education Service Market

The Segmentation of Visitor Tanah Lot Tourism Attraction

Influence of Styles of Women Leadership and Organization Culture on Locus of Control and Job Satisfaction of UIN Alauddin Makassar Lecturer

Insulin-like Growth Factor-1 Receptor (IGF-1R), Epidermal Growth Factor Receptor (EGFR), dan Mammalian Target of Rapamycin (mTOR) pada Kemoterapi Kanker Paru

The Neuropharmacogenomical Perspectives of

Clinical Manifestations of Ocular Tuberculosis

Dokumen yang Anda mencari sudah siap untuk unduhkan