2 Type-movement-boundary of Plates

Modul 2

-Type of lithosphere (type of plate)

-Movement of plates

-Type of plate boundaries

BUMI DALAM PERSPEKTIF RUANG ANGKASA

* ATMOSFER & HIDROSFER

* BIOSFER

* KONTINEN & SAMUDERA

GAMBARAN PERMUKAAN BUMI

MEMBERIKAN REKAMAN DARI DINAMIKA BUMI

GAMBARAN UTAMA

PERMUKAAN BUMI

KONTINEN

Shield, Stable platform,

Folded mountain

SAMUDERA

Oceanic Ridge, Abyssal,

Seamounts, Trench,

Continental Margin

Evidence on Seafloor

Seafloor Age Map

Deformation history of the Eastern Belt,

Peninsular Malaysia

Ibrahim Abdullah

Program Geologi, Fakulti Sains dan Teknologi

Universiti Kebangsaan Malaysia

Bangi, 43600, Selangor DE.

Malaysia

Tree Belts:Western,Central,

Eastern

Originally proposed by

Scrivenor (1928)

Western boundary:

- Connecting serpentinite bodies

- Known as Bentung Line,

Hutchison ((1975)

- Could extend southwards,

> Across straits of Malacca

> Through Lalang Fault Zone

> Known as Bentung Suture

(Tjia, 1987)

Eastern boundary-Lebir Fault zone

TE CTO N IC B E LTS

O F MALAYS IA PE N IN S U LA

EA

STE

RN

BELT

CEN

TRA

L BELT

WESTE

RN

BELT

2. General Geology of the Eastern Belt

= Oldes sediment-Carboniferous and Permian

> Clastic, volcanic and minor lst.

> Plant fossils ( Chand, 1978; Jennings, 1985)

> Fauna (trilobites, brachiopod, bryozoans, bivalves

(Idris and Zaki, 1986)

Plant

fossils

Clastic

- Linear belt of Triassic-Jurassic (Chung1973)

- Late Permian-tuffaceous sst., slst. And

mst.+cgl. (Tiemoko et.al, 1992)

- Jurassic-Cretaceous continental deposits-

Gagau group (Rishworth, 1974)

Pulau

Redang

STRUKTUR BUMI : C-M-C(compositionally)

Inti Bumi (Core)

Selubung (Mantle)

Kerak (Crust)

STRUKTUR BUMI

STRUKTUR INTERNAL BUMI

PENJALARAN GELOMBANG SEISMIK DIDALAM BUMI

STRUKTUR BUMI

PERUBAHAN KECEPATAN GEL. P & S PADA KEDALAMAN

LITHOSFER & ASTENOSFER(mechanical properties)

LITHOSFER

Lapisan terluar (100 km) kuat,

kaku (rigid), terdiri dari kerak

bumi & sebagian mantel atas

ASTENOSFER

Lapisan lunak pada mantel

atas (100-200 km), dibawah

litosfer, dekat titik lebur batuan

De

pth

(k

m)

cold, rigid, brittle

hot, plastic

hot, high pressure,rigid, brittle

liquid

solid

rocks

ultrabasicigneous rocks

Fe, Ni

Kerak bumi merupakan lapisan paling luar: keras,

padat, relatif dingin, ketebalan 70 - 100 km,

tersusun dari batuan beku, batuan sedimen, dan

batuan ubahan.

Kerak bumi dibedakan menjadi dua:

Kerak Samudra danKerak Benua

KERAK BUMI

STRUKTUR BUMI

LITHOSFER & ASTENOSFER - KERAK & MANTEL

GAMBARAN PERMUKAAN BUMI

RANGKAIAN PEGUNUNGAN

JALUR STRUKTUR UTAMA

GAMBARAN PERMUKAAN BUMI

STRUKTUR BUMI

DISTRIBUSI PUSAT GEMPA

GAMBARAN PERMUKAAN BUMI

STRUKTUR BUMI

RANGKAIAN GUNUNG API

GAMBARAN PERMUKAAN BUMI

KONFIGURASI (MOSAIK) LEMPENG

Plate Tectonics

What drivesPlate Tectonics???

GEODYNAMICS

TektonikLempeng 36

GERAK LEMPENG

DAYA PENGGERAK (Driving Forces)

- Slab Pull

- Push Ridge

- Basal (mantle) Drag

What drives plate motions Forces that drive plate motion

Slab-pull

Cold, dense slabs of subducted oceanic lithosphere pull the plate towards the subduction zone

Ridge-push

The higher elevation of spreading centers result in oceanic lithosphere wanting to move downhill, away from the ridge

Far less important than slab-pull

Mantle drag and plate resistance

Can act to increase or decrease plate motion

GEODYNAMICS

TektonikLempeng 38

DAYA PENGGERAK

GEODYNAMICS

TektonikLempeng 39

DAYA PENGGERAK

GEODYNAMICS

TektonikLempeng 40

DAYA PENGGERAK

PUSH RIDGE

Internal Heat

Plate Tectonics

Basal / Mantle drag

GEODYNAMICS

TektonikLempeng 42

3 KEMUNGKINAN KONVEKSI PADA MANTEL

3 KEMUNGKINAN KONVEKSI

MANTEL

- Pada Astenosfer

- Pada keseluruhan Mantel

- Timbul dari Batas Inti-Mantel

(Mantel Plume)

Models of plate-mantle convection Any model must be consistent with

observed physical and chemical properties of the mantle

Horizontal movement of plates causes mantle upwelling

Models Layering at 660 km Explains why basalts erupted at

mid-ocean ridges are different (more evolved, relatively shallow source) compared to those erupted at hot-spots (more primitive, deeper source).

We know that subducting slabs descend beneath 660 km

What drives plate motions

Model of Whole-mantle convection

Would mix the entire mantle in the space of a few hundred million years, removing heterogeneities

What drives plate motions

Deep-layer model

Lava lamp model

Two layers swell and shrink in a complex fashion in response to heat from the Earths interior

What drives plate motions

GEODYNAMICS

TektonikLempeng 46

KECEPATAN GERAK LEMPENG

GERAK RELATIF LEMPENG

- Paleomagnetisme

- Studi Mekanisme Fokus Gempa

GERAK ABSOLUT LEMPENG

- Hot Spot

- GPS

GEODYNAMICS

(Kearey et al 2009)

GEODYNAMICS

TektonikLempeng 48

KECEPATAN GERAK LEMPENG

PENENTUAN UMUR DAN PERTUMBUHAN

SAMUDERA DARI PALEOMAGNETISME

Evidence on Seafloor

PENENTUAN UMUR DAN PERTUMBUHAN SAMUDERA DARI PALEOMAGNETISME

Evidence on Seafloor

Seafloor Age Map

GEODYNAMICS

TektonikLempeng 51

KECEPATAN GERAK LEMPENG (relatif)

PENENTUAN KECEPATAN DARI GERAK LEMPENG (FOKUS GEMPA & GPS)

GEODYNAMICS

(Kearey et al 2009)

Mantle Plume Hot Spot Tracks

Evidence on Seafloor

(Kearey et al 2009)

GEODYNAMICS

TektonikLempeng 55

KECEPATAN GERAK LEMPENG (absolut)

PENENTUAN KECEPATAN GERAK LEMPENG DARI SEAMOUNTS (ABSOLUT)

HOTSPOTS

GEODYNAMICS

TektonikLempeng 59

KECEPATAN GERAK LEMPENG

KECEPATAN GERAK LEMPENG DAN PERTUMBUHAN SAMUDERA

Directions of Motion and Plate Velocities Determined by

Mantle Plume Hot Spot Tracks and Age-Dating of Rocks

Plate Tectonics

Directions of Motion and Plate Velocities Determined by GPS

(Global Positioning System) Satellites

Plate Tectonics

Directions of Motion and Plate Velocities Determined

by GPS (Global Positioning System) Satellites

(Kearey et al 2009)

(Kearey et al 2009)

Plate boundaries

BASIC PLATE TECTONICS Revised

Earths lithosphere is broken into 12-24 rigid

plates

Plates move about 1-10 cm/yr on the plastic

Asthenosphere

Geology happens where the plates

interact with one another along Divergent,

Transform, Subduction and Collisional

Boundaries

Results in the formation of Oceanic Crust

Plate Tectonics

Divergent Boundary

Transform Boundary

Plate Tectonics

Results in the formation & growth of Continental Crust

and destruction of Oceanic Crust

Melting

Produces

More

Felsic

Magma

Plate Tectonics

Convergent Boundary: Subduction

Results in the growth of Continental Crust

Convergent Boundary: Collision

Plate Tectonics

TEKTONIK LEMPENG (PLATE TECTONICS)

BATAS DIVERGEN, KONVERGEN & STRIKE-SLIP

GERAK DIVERGEN, KONVERGEN & STRIKE-SLIP

TEKTONIK LEMPENG

TEKTONIK LEMPENG

CONTINENTAL MARGIN SREADING CENTER

TEKTONIK LEMPENG

SPREADING CENTER (PUSAT PEMEKARAN)

TEKTONIK LEMPENG

PERTUMBUHAN SAMUDERA

TEKTONIK LEMPENG

CONVERGENT, CONTINENT-OCEAN,

OCEAN-OCEAN, CONTINENT-CONTINENT

TEKTONIK LEMPENG

SUBDUCTION &VOLCANISM

TEKTONIK LEMPENG

SUBDUCTION & EARTHQUAKE

TEKTONIK LEMPENG : polyhistory

COLLISION & STRIKE-SLIP

INTRAPLATE VOLCANISM

GEODYNAMICS

TERIMAKASIH

TektonikLempeng 83