pendekatan tektonik indonesia Geologi Pngea UPN

PENDEKATAN TEKTONIK INDONESIA

1. Teori TEKTONIK LEMPENG

2. Litologi Basement: Komposisi & Konfigurasi

3. Tektonostratigrafi4. Polyhistory

PENDEKATAN TEKTONIK INDONESIA

PLATE TECTONIC & SEDIMENTARY BASIN FORMATION

CONTINENTAL CRUST

TRANSITIONALCRUST

OCEANIC CRUST

SUTURE

CONTINENTAL CRUST

CONTINENTAL CRUST

TRANSITIONALCRUST

OCEANIC CRUST

SUTURE

CONTINENTAL CRUST

TYPES OF CRUST – INDONESIA REGION

BASEMENT COMPOSITIONBASEMENT COMPOSITION

Indonesia Position Global Plate-Tectonics

• The pacific oceanic plate in the E & NE

• The Australian continental plate in the SE

• The Indian oceanic plate in the W&SW

• The Asian continental plate in the NW

• Continental landmass: continental islands and sea shelf: < 200 m

• Oceanic Islands and Oceanic Deeps :>200 m

INDONESIA: BATHYMETRY

INDONESIA: Continental Landmass

• SUNDA SHELF with:• Sumatra, • Java and • Kalimantan

• ARAFURA CONTINENTAL SHELF :• Australian

continent• Irian Jaya New

Guinea

TECTONIC PLATES & CRUSTS IN INDONESIA

• WESTERN INDONESIA: STABLE SUNDA CONTINENT

• CENTRAL INDONESIA: MICRO-CONTINENTS AND OCEANIC BASINS

• EAST INDONESIA: STABLE SAHUL/AUSTRALIAN CONTINENT

• Convergence, (collisions, subduction and obduction).

• Divergence (rifting, break-up and subsequent seafloor spreading).

• Transvergence (wrench faulting); involving translatation and rotation.

PLATE TECTONICS MOVEMENT IN INDONESIA involves:

PLATE BOUNDARIES

• ACTIVE MARGINS– SUBDUCTION

ZONES– OBDUCTION

ZONES– TRANSDUCTION

ZONES (Sorong Fault zone)

• PASSIVE MARGINS (Eastern Kalimantan)

–Delta Basin–Carbonate

Platform• COLLISION

ZONES & OROGENIC BELTS (Papua & Sulawesi)

ACTIVE MARGINS

• SUBDUCTION ZONES: – CONTINENTAL ISLAND ARC:

Western Sumatra Sunda Arc, Southern Java Sunda Arc

– OCEANIC ISLAND ARC: Nusatenggara Sunda Arc

• OBDUCTION/COLLISION ZONES: Banda Arc-Australian continent being subducted under Banda Sea oceanic crust; Banggai-Sula colliding Eastern Sulawesi

• TRANSDUCTION ZONES: Sorong Faultzone

• Zona subduksi: •   CONTINENTAL ISLAND ARC: Barat

Sumatra Sunda Arc, Jawa Southern Arc Sunda

•   OCEANIC ISLAND ARC: Nusatenggara Sunda Arc

• OBDUCTION / TUBRUKAN ZONA: benua Banda Arc-Australia sedang subduksi di bawah Laut Banda kerak samudera; Banggai-Sula bertabrakan Sulawesi Timur

• ZONA TRANSDUKSI: Sorong Faultzone

PASSIVE MARGINS

NW BORNEO PASSIVE MARGIN

• East Natuna basinal area, Baram Delta

• EASTERN KALIMANTAN PASSIVE MARGINS

• MICROCONTINENT PASSIVE MARGINS

• Southwest Sulawesi Basinal area

COLLISION ZONES & OROGENIC BELTS

• Kuching Zone

• Meratus Mts Belt

• Central Sulawesi Collision Belt

• Central Irian Jaya Mt Range

Tectonic Framework of Indonesia

• West Indonesia with Sunda Platform acting as a continental core• Central Indonesia consising of fragmented microcontinents represented

by Sulawesi and the Banda Arc• East Indonesia with the Arafura Platfrom acting as continental core• Barat Indonesia dengan Sunda Landasan bertindak sebagai inti benua • Indonesia consising pusat microcontinents terfragmentasi diwakili oleh

Sulawesi dan Banda Arc • Indonesia Timur dengan Arafura platfrom bertindak sebagai inti benua

(Koesoemadinata, 2008)

West Indonesia: ACTIVE MARGINS

• To the W and S the Sundaland is bordered by an active margin; consisting of an island arc system with fore arc, interarc and back-arc basins, as the result of a convergence with the Indo-Australia oceanic plate in which the oceanic plate is subducted under the continental plate.

• Untuk W dan S Sundaland berbatasan dengan margin aktif; terdiri dari sistem busur kepulauan dengan busur muka, interarc dan back-arc basins, sebagai hasil dari konvergensi dengan lempeng samudera Indo-Australia di mana lempeng samudera yang menunjam di bawah lempeng benua.

(Koesoemadinata, 2008)

West Indonesia: PASSIVE MARGINS

• The E Sundaland margin, rifting, break-up and sea-floor spreading of the Makassar Strait, and the formation of : Aulocogene basins followed by deltaic deposition of the Mahakan Delta and

Tarakan Delta. Paternoster Carbonate Platform.

• The NW Sundaland margin; resulted from rifting and opening of the S China Sea and associated rifting in the Gulf of Thailand and W Natuna basin. Rifting of the S China sea results in a collision in NW Borneo.

CENTRAL INDONESIA: Fragmented microcontinents between Oceanic basins

Consisting of assorted microcontinents, mainly broken off from the Australian Continent, but some belong to the Asian Continent : SW Sulawesi

Sulawesi Island Banggai-Sula Islands West Nusa Tenggara Island Arc

Central Indonesia: an assortment or conglomeration of contental fragments oceanic basins

and oceanic troughs

• Sulawesi Island: an conglomeration of Australian and Asian continental fragments and island arc

• Sula-Banggai Island• Halmahera Island-arc• Lesser Sunda Islands, and island-arc as the eastern continuation of the

Sunda island arc• Oceanic Basins of Flores sea, Banda sea and Celebes seaPulau Sulawesi: sebuah konglomerasi fragmen benua Australia dan Asia dan

busur kepulauan Pulau Sula-Banggai Pulau Halmahera-arc Kepulauan Sunda Kecil, dan pulau-arc sebagai kelanjutan timur Sunda busur

kepulauan Cekungan samudera Flores laut, Laut Banda dan Sulawesi laut

Eastern Indonesia: Major Tectonic Elements

• Arafura Shelf: Stable Shelf• Banda Island Arc: Passive to Active Margin

(Subduction/Obduction)• Jaya Wijaya Central Range: Orogenic Mountain

Range• Sorong Fault Zone: Active wrench fault

(transduction)

POLYHISTORY

BASIN EVOLUTION

• Sedimentary basins evolved from one to another type• Superimposition of various type of basin on top of the

other occurs• Sedimentary sequences of various types of basin can be

analysed in tectono-stratigraphical sequences:Cekungan sedimen berevolusi dari satu ke jenis lainSuperimposisi berbagai jenis cekungan di atas yang lain

terjadiUrutan sedimen dari berbagai jenis cekungan dapat

dianalisis dalam urutan tektono - stratigrafi

EXTENSIONAL BASIN DEVELOPMENT

• Rifting ----> grabens, half graben basins ---->synrift sedimentation

• Break-up -----> aulacogene basins -------> deltaic sedimentation

• Drifting -----> passive margin basins ------> passive margin sedimentation

• Spreading (oceanic) -----> oceanic basins ----> deep marine sedimentation

EVOLUTION OF RIFT – TO –PASSIVE MARGIN BASINRIFT-DRIFT

PASSIVE MARGIN BASINdeveloping into a

CARBONATE PLATFORM

Contoh: Indonesia Timur –Australian continental margin

EXTENSIONAL TO COMPRESSIONAL REGIME

• Drifting -------> passive margin basin sedimentation• Subduction -----> back-arc, inter-arc and fore-arc basins• Obduction --------->foreland basins & fore deeps• Continent to continent collision------> Suture related foreland

and fore deep basinsMelayang ------- > passive margin cekungan sedimentasiSubduksi ----- > back- arc , antar - busur dan kedepan - busur

cekungan Obduction --------- > tanjung cekungan & Deeps kedepanBenua ke benua tabrakan ------ > Jahitan terkait tanjung dan

cekungan kedepan dalam

EVOLUTION OF A PASSIVE MARGIN BASIN

TECTONIC INVERSION.• During the transition from extensional to compressional tectonic regime

a tectonic inversion, often takes place • Faults are reactivated with inversion of direction of movement• Lower parts of the basin e.g. ‘graben’ are inverted into highs within the

sedimentary basin• Inversion is a common feature in Tertiary sedimentary basin on the

Sunda Shelf Selama transisi dari rezim tektonik ekstensional ke compressional inversi

tektonik , sering terjadiKesalahan yang diaktifkan dengan inversi arah gerakanBagian bawah cekungan misalnya ' graben ' terbalik ke tertinggi dalam

cekungan sedimenInversi adalah fitur umum di Tersier sedimen basin di Paparan Sunda

TECTONO-STRATIGRAPHY:

• To arrange sedimentary strata in its tectonic environment• Tectono-stratigraphic sequences are separated by unconformities

which reflects a tectonic event• The tectonics event caused a change in the tectonic environment are

e.g. rifting, sagging, collision, uplift, dsb.• Each tectonic environment is characterized by a certain facies

associationUntuk mengatur sedimen strata dalam lingkungan tektonik yangUrutan tektono - stratigrafi yang dipisahkan oleh bidang ketidakselarasan

yang mencerminkan peristiwa tektonikAcara tektonik menyebabkan perubahan dalam lingkungan tektonik

adalah misalnya rifting , kendur , tabrakan , mengangkat, dsb .Setiap lingkungan tektonik ditandai oleh asosiasi fasies tertentu

TECTONO-STRATIGRAPHIC TERMS

• Pre-Rift• Syn-Rift• Post-Rift, Sag• Passive Margin Deposition (Syn-drift?)• Pre-Orogenic (Pre-Collision)• Syn-Orogenic (Syn-Collision)• Post Orogenic (Post Collision)

EXTENSIONAL TO COMPRESSIONAL REGIME

• Drifting -------> passive margin basin sedimentation

• Subduction -----> back-arc, inter-arc and fore-arc basins

• Obduction --------->foreland basins & fore deeps

• Continent to continent collision------> Suture related foreland and fore deep basins

EVOLUTION OF A PASSIVE MARGIN BASIN

PASSIVE MARGIN BASINdeveloping into a

CARBONATE PLATFORM

Contoh: Indonesia Timur –Australian continental margin

EVOLUTION OF BASINS RIFT –

TO- BACK-ARC BASIN

??

(Koesoemadinata, 2008)

Evolution of a Back-arc Basin Model

(Koesoemadinata, 2008)

PRE-RIFT

Evolution of a Back-arc Basin

(Koesoemadinata, 2008)

SYN-RIFT

Evolution of a Back-arc Basin Model

(Koesoemadinata, 2008)

POST-RIFT

Evolution of a Back-arc Basin Model

(Koesoemadinata, 2008)

INVERSION: Syn & Post orogenic deposition

EVOLUTION OF BASINS:

FROM RIFT – TO –

FORELAND BASIN

RIFT-DRIFT-COLLIDE

(Koesoemadinata, 2008)

Evolution of the Rift-Drift-Collision Model

(Koesoemadinata, 2008)

SYN-RIFT

Evolution of the Rift-Drift-Collision Model

(Koesoemadinata, 2008)

POST-RIFT

Evolution of the Rift-Drift-Collision Model

(Koesoemadinata, 2008)

Evolution of the Rift-Drift-Collision Model

(Koesoemadinata, 2008)

Evolution of the Rift-Drift-Collision Model

INVERSION: Syn & Post orogenic deposition

EVOLUTION OF BASINS:

FROM RIFT – TO –

FORELAND BASIN

RIFT-DRIFT-COLLIDE

(Koesoemadinata, 2008)

Western Indonesia Paleogene Rift-Basins

Western Indonesia Neogene Sedimentary Basins

Western Indonesia Tertiary Stratigraphy