Canggaan, Sesar dan LipatanCanggaan, Sesar dan Lipatan(Deformation, Faults and (Deformation, Faults and

Folds)Folds)

CANGGAAN

PENGARUH TEGASAN &TERIKAN

SESAR

LIPATAN

JENIS2

JENIS2

PETA GEOLOGIKAJIAN TAPAK

KEKAR

PROSES GEOLOGI

objektifobjektifMemberi takrifan jenis2 tegasan yang boleh dialami Memberi takrifan jenis2 tegasan yang boleh dialami batuanbatuanMemberi takrifan ragam (behaviour) batuan bila Memberi takrifan ragam (behaviour) batuan bila dikenakan tegasandikenakan tegasanMembandingkan pelbagai jenis lipatan (folds) seperti Membandingkan pelbagai jenis lipatan (folds) seperti sinklin, antiklin, monoklin, dom (dome) dan empangan sinklin, antiklin, monoklin, dom (dome) dan empangan (basin)(basin)Membandingkan pelbagai jenis sesar (normal, Membandingkan pelbagai jenis sesar (normal, songsang, thrust, gelincir jurus) dan tegasan yang songsang, thrust, gelincir jurus) dan tegasan yang menghasilkan sesarmenghasilkan sesarMemahami penggunaan jurus dan sudut miring (dip Memahami penggunaan jurus dan sudut miring (dip and strike) atau sudut miring dan arah sudut miring and strike) atau sudut miring dan arah sudut miring (dip/dip direction)(dip/dip direction)Melihat kejadian kekar dan pengaruhnya terhadap Melihat kejadian kekar dan pengaruhnya terhadap pembinaan strukturpembinaan struktur

Deformation refers to the changes in Deformation refers to the changes in volume or shape of a body of rock volume or shape of a body of rock

(canggaan merujuk kepada perubahan (canggaan merujuk kepada perubahan isipadu atau bentuk sesuatu jasad batuan)isipadu atau bentuk sesuatu jasad batuan)

Bumi kita adalah dinamik => senantiasa Bumi kita adalah dinamik => senantiasa berubah, dan berubah dalam bentuk yg berubah, dan berubah dalam bentuk yg tertib dan mengikut hukum tertentutertib dan mengikut hukum tertentuBumi dikelilingi dengan daya; ada yang Bumi dikelilingi dengan daya; ada yang dapat dirasa dan dilihat, dan sebaliknya. dapat dirasa dan dilihat, dan sebaliknya. Contoh: daya magnet, daya tektonikContoh: daya magnet, daya tektonikKita lebih berminat dgn apa yang boleh kita Kita lebih berminat dgn apa yang boleh kita kawal walaupun kadangkalanya tak dapat kawal walaupun kadangkalanya tak dapat kita fahami, terutama di permukaan bumikita fahami, terutama di permukaan bumiKadang2 kita berminat benda yg di luar Kadang2 kita berminat benda yg di luar kawalan kita….kawalan kita….

mineral

batuan

airsuhu

tekanan tanah

INTERAKSI PELBAGAI FAKTOR => MENGHASILKAN PELBAGAI PRODUK

Tegasan-Terikan Tegasan-Terikan (Stress-Strain)(Stress-Strain)

Cause-and-effectCause-and-effect

Stress Stress is the FORCE acting on a body of is the FORCE acting on a body of rock. Stress = Force / area = daya/luas rock. Stress = Force / area = daya/luas

Strain Strain is the response of a rock to stress. is the response of a rock to stress. It generally involves a change in shape or It generally involves a change in shape or volume of the rock volume of the rock

Strain = change in shapeStrain = change in shape

Strain Strain = change in length = change in length

= volume change = volume change

==> result in being shortened/elongated==> result in being shortened/elongated

STRAIN => DAPAT KITA LIHAT

STRESS => TAK DAPAT KITA LIHAT TETAPI LEBIH PADA APA MINDA KITA DAPAT RASA DAN BAYANGKAN (mental learning?)

Types of stressTypes of stress

1.1. Compressional Compressional

2.2. Tensional Tensional

3.3. ShearShear

Hubungan tegasan-terikanHubungan tegasan-terikan

deformationdeformation

deformationdeformation

Types of strainTypes of strain

Elastic deformation (Canggaan kenyal)Elastic deformation (Canggaan kenyal) - changes in - changes in shape of rock are reversible. Deform it, remove the shape of rock are reversible. Deform it, remove the stress, and it returns to its original shape (like a rubber stress, and it returns to its original shape (like a rubber band or a piece of elastic) band or a piece of elastic) Plastic deformation (Canggaan plastik)Plastic deformation (Canggaan plastik) - changes in - changes in shape of rock are permanent and not reversible (like shape of rock are permanent and not reversible (like folding). folding). Rock Behavior (Ragam batuan)Rock Behavior (Ragam batuan)– Brittle - the rock breaks Brittle - the rock breaks – Ductile - the rock flows or bends (folds are produced) Ductile - the rock flows or bends (folds are produced)

Once the elastic limit is surpassed, rocks will deform Once the elastic limit is surpassed, rocks will deform plastically if the rock is ductile (mulur) or they will fracture plastically if the rock is ductile (mulur) or they will fracture (rupture) if the rock is brittle (rapuh). (rupture) if the rock is brittle (rapuh).

San Andreas FaultSan Andreas Fault

SESAR/FAULTSSESAR/FAULTS

TERHASIL DRPD CANGGAAN KENYAL TERHASIL DRPD CANGGAAN KENYAL (ELASTIC DEFORMATION) BAHAN YG (ELASTIC DEFORMATION) BAHAN YG RAPUH (BRITTLE)RAPUH (BRITTLE)

Jenis2 sesarJenis2 sesar

faultfault

Retak pd batuan yg ada pergerakan yg jelas

Dinding kaki & dinding gantung Dinding kaki & dinding gantung (Hanging & footwall)(Hanging & footwall)

Normal & reverse faultNormal & reverse fault

Oblique slipOblique slip

Strike slipStrike slip

grabengraben

Normal faultsNormal faults

Thrust faultThrust fault

faultfault

faultfault

faultfault

Describing the orientation of layers of rockDescribing the orientation of layers of rock

When we describe the orientation of When we describe the orientation of sedimentary rock units, we must keep in mind sedimentary rock units, we must keep in mind that these rocks were originally deposited as that these rocks were originally deposited as sediment in horizontal (flat) layers (Remember sediment in horizontal (flat) layers (Remember from geologic time: Law of original horizontality)from geologic time: Law of original horizontality)

Tectonic forces cause the rock layers to be Tectonic forces cause the rock layers to be folded and uplifted, and sedimentary rocks can folded and uplifted, and sedimentary rocks can be in any orientation, including vertical. be in any orientation, including vertical.

Cara memperihalkan orientasi sesar dan lipatan

Law of horizontalityLaw of horizontality

If we examine a small area of a layer of rock, we If we examine a small area of a layer of rock, we can describe its orientation in space using two can describe its orientation in space using two directional components: directional components:

The angle at which the rock "dips" (with respect to The angle at which the rock "dips" (with respect to the horizontal) - called the horizontal) - called dip (sudut miring)dip (sudut miring)

The compass direction along which the bed of rock The compass direction along which the bed of rock trends (with respect to north) - called trends (with respect to north) - called strikestrike(Jurus)(Jurus)

Jurus dan sudut miring (Strike and dip)

Strike dipStrike dip

Rocks dipping to the right 45Rocks dipping to the right 45oo

Ahli geologi gemar menggunakan jurus Ahli geologi gemar menggunakan jurus (strike) dan sudut miring (dip) sementara(strike) dan sudut miring (dip) sementara

Jurutera lebih suka menggunakan sudut Jurutera lebih suka menggunakan sudut miring (dip) dan arah sudut miring (dip miring (dip) dan arah sudut miring (dip direction)direction)

Rocks dip to the right 45 degreesRocks dip to the right 45 degrees

45o

Strike and dip & soil failure as creep

LIPATAN/FOLDLIPATAN/FOLD

TERHASIL DRPD CANGGAAN PLASTIK TERHASIL DRPD CANGGAAN PLASTIK BAHAN MULUR (DUCTILE)BAHAN MULUR (DUCTILE)

Types of folds (formed as a Types of folds (formed as a result of plastic deformation)result of plastic deformation)

During mountain building or compressional During mountain building or compressional stress, rocks may deform plastically to stress, rocks may deform plastically to produce folds. produce folds.

The up-folds and the down-folds are The up-folds and the down-folds are adjacent to one another, and grade into adjacent to one another, and grade into one another. In geology each is given a one another. In geology each is given a separate descriptive name. separate descriptive name.

Basic types of foldsBasic types of folds

anticlines - upfolds anticlines - upfolds

synclines - downfolds synclines - downfolds

Types of foldsTypes of folds

foldfold

foldfold

foldfold

foldfold

fold

lineationlineation

Vertical fold – Vertical fold – after weathering after weathering

and erosionand erosionoriginal fold original fold

cannot be seen cannot be seen anymore. This anymore. This

is based on field is based on field observationobservation

Plunging foldPlunging fold

Mountains and the ContinentsMountains and the Continents

Stress and tectonic setting Stress and tectonic setting

Building continents: Orogenic belts vs. Building continents: Orogenic belts vs. cratons cratons

Fault block ranges Fault block ranges

Fold and thrust ranges Fold and thrust ranges

Volcanic rangesVolcanic ranges

Akan dibincang sekali lagi bersamadgn topik Tektonik Keping

Syncline Late Paleozoic strata, Syncline Late Paleozoic strata, MarylandMaryland

FoldsFoldsChilhowee Group QuartziteChilhowee Group Quartzite

Mountain City WindowMountain City Window

Chevron folds in shaleChevron folds in shaleNorth Carolina or TennesseeNorth Carolina or Tennessee

Wills Creek Formation (Silurian)Wills Creek Formation (Silurian)North of Hancock, Maryland,North of Hancock, Maryland,

SynclineSyncline Eastern Eastern

TennesseeTennessee

Axial planeAxial planeParts of a fold: fold axis axial plane limb

Fold shapesFold shapes

symmetrical symmetrical

asymmetrical asymmetrical

overturned - tipped in one direction so that overturned - tipped in one direction so that one of the limbs is overturned one of the limbs is overturned

recumbent - lying on its side recumbent - lying on its side

dome dome

basin basin

Fold shapesFold shapes

Orientation of the axis of the fold: Orientation of the axis of the fold:

plunging - the axis of the fold dips plunging - the axis of the fold dips

non-plunging - the axis of the fold is non-plunging - the axis of the fold is horizontal horizontal

Joints-Changkat Jering, K KangsarJoints-Changkat Jering, K Kangsar

Joints- Pos Slim, Simpang PulaiJoints- Pos Slim, Simpang Pulai

Kekar di Changkat Jering, K Kekar di Changkat Jering, K KangsarKangsar

fracturefracture

Lineation: bukti yg terdapat pd batuan Lineation: bukti yg terdapat pd batuan metamorfik menandakan tegasan yg dialami metamorfik menandakan tegasan yg dialami

amat hebat sekali (UCS berapa?)amat hebat sekali (UCS berapa?)

foliationfoliation

Apa itu foliasi?Apa itu foliasi?

Apa kepentingannya?Apa kepentingannya?

Di mana berlaku?Di mana berlaku?

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