ofiolit - Zenodo

OFIOLIT ?v Ofiolit adalah sisa kerak samudra purba dan

mantel atas yang alih tempat / penempatannyake tepian benua secara tektonik ;

v Berumur maksimum 170jt th

v Ophios : ular ;lithos :batu -à batu ular

Alexandre Brongniart (1740 – 1847)1813 : ofiolit adalah serpentinit di mélange1821 : redefinisi ofiolit mencakup himpunan batuan ultramafik,

gabbro, diabas, dan batuan volkanik (di Peg.Alpen)

Gustav Steinmann (1856–1929)1927 : - Ofiolit adalah himpunan batuan beku intrusi insitu

di sumbu geosinklin.

- Kehadiran himpunan batuan peridotit (serpentinit), gabbro,dan diabas-spilit (spilit : lava dengan albitisasi plagioklas),berasosiasi dengan batuan sedimen laut dalam (rijang,batulumpur serta batugamping) di Rangkaian PegununganMediteran,diinterpretasikan sebagai hasil diferensiasimagma di lantai samudra.

- Ko magmatik.

Steinmann Trinity : serpentinit, diabas -spilit, rijang

- "Ofiolit Semail" di Oman (Mesozoikum), Ofiolit Troodos di Siprus

(Mesozoikum), “Ofiolit Papua " di Papua Nugini (Mesozoikum), dan

“Ofiolit Bay of Islands " di Newfoundland (Paleozoic) ; lain-lain

di Jepang ofiolit Yakuno (Paleozoic), Hirakanai (Mesozoikum) dan

Poroshiri (Mesozoikum) , di Indonesia Meratus-Bobaris Kalimantan,

Bantimala Sulawesi Selatan, lengan timur Sulawesi, Halmahera,

Ciletuh, Karangsambung, Talaud, Timor, dll.

Penrose Conference 1972 Terdiri dari pseudo stratigrafi batuan beku

v basalt (di bagian atas), v anggota gabbro (diabas dan gabbro) dibagian tengah

danv anggota peridotit (lersolit, serpentin, harsburgit) dibagian

bawah.

Klasifikasi, macam-macam ofiolit

Miyashiro, 1975

KLASIFIKASI BERDASARKAN TATANAN TEKTONIK

Terbentuk di MOR (divergent plate boundaries) - lersolitTerbentuk di Supra subduction zone (SSZ) : busur kepulauan dantepian cekungan (marginal basins) --- convergent plate boundaries- Harsburgit

Data kimia dari batuan dan mineral

Akira ISHIWATARI,2001

There are incompatible-rich and incompatible-poor mantle source regions for MORB magmas

– N-MORB (normal MORB)

§ Mg# > 65: K2O < 0.10 TiO2 < 1.0

§ Depleted in LREE, Low LILE e.g. K+

– E-MORB (enriched MORB, P-MORB for plume)

§ Mg# > 65: K2O > 0.10 TiO2 > 1.0

§ Rich in LREE, higher in LILE e.g. K+

E-MORBs (squares) enriched in LREE over N-MORBs (red triangles): regardless of Mg#

Lack of distinct break suggests three MORB types

E-MORBs La/Sm > 1.8N-MORBs La/Sm < 0.7

T-MORBs (transitional) intermediate values

Manfaat ofiolit

v Mekanisme “pertemuan” lempeng----à geodinamika

v Ofiolit : endapan mineral logam dan non logamlogam mulia : emas,peraklogam berat : besi, kromit, nikel,grup platinummineral non logam : jade, asbes

OFIOLIT KARANGSAMBUNG UTARA

Distribution of Cretaceous accretionary-collision complexes. 1 = Ciletuh, 2 = Karangsambung, 3 = Jiwo Hills, 4 = Meratus, 5 = Pulau Laut, 6 = Bantimala, 7 = Barru, 8 = latimojong, 9 Pompangeo, 10 = Palu

( modified from Metcalf, 1990; Wakita, 2000)

Sumatra

Java

Kalimantan

SulawesiPapua

Jakarta

Bandung

Yogyakarta

Luh Ulo

Semarang

Java Sea

INDONESIA

MALAYSIA

AUSTRALIA

PHILIPINES

Surabaya

Luh Ulo area, Central Java

TATANAN GEOLOGI REGIONAL

Katili, 1974

Hamilton (1979)

GEOLOGI DAERAH LUH ULO

Waturanda Fm.

Totogan Fm.

Karangsambung Fm.

Black clay

Graywacke

Meta graywace/Meta arkose ?

Schist

a. Diabasb. Basalt

Gabbro, peridotite

Serpentinite

Detail observation

PETA GEOLOGI DAERAH LUH ULO (Sukendar,1974)

STRATIGRAFI DAN TATANAN TEKTONIK LUH ULO(Sukendar, 1974)

Pemetaan lintasan

Pillow basalt and radiolarian chert

Diabase

Massive gabro

Cummulate gabro

HarsburgiteSerpentinite

Dacite

Sediments

Melange

Milonites and breciatedrock

Faults

Pakuruhan River Section

Sediments (chert)Pillow lava

Diabase

Massive gabro

Cummulate gabro

HarburgiteSerpentinite

LEGEND :

Scale 1:12.500

CurugdawaRiver Section

Pillow basalt

Diabase

Massive gabro

Cummulate gabro

HarsburgiteSerpentinite

Metamorphic rocks

Sediments

Melange

Milonites

Faults

Basalt

Diabase

Massive gabro

Cummulate gabro


LEGEND :

Scale 1:12.500

Basalt

Diabase

Massive gabro


LEGEND :

Basalt and chert

Diabase

Massive Gabbro

Metamorphic rocks

Mylonite and Brecciated rocks

Harzburgite, Serpentinite

ParakansubahRiver Section

Scale 1:12.500

Massive gabbro outcrops showing some blocks of diabase . (Loc : Medana River)

Diabase outcrop showing white spotted plagioclase phenocrysts(Loc : Medana River)

Altered &deformed gabbro. Notes the presence of veins of quartz or carbonate, and epidote veins . (Loc : Medana River)

a. b.

epidotequartz or carbonate

a. b.

a). Fine grained Gabbro b. Coarse grained Gabbro

Location : Medana River

Boulder basalt in diabase outcrop (a); commonly show mixing of diabase, gabbro and basalt (Loc : Lokidang River)

a. b.

Basalt lava with pillow structures; close up photograph of outcrop (b); (Loc : Lokidang River)

a. b.

Lava bantal K.Muncar

Pillow Lava

Diabase

Massive gabbro

Cummulategabbro

HarzburgiteSerpentinite

Pelagic Sediments

Pillow Lava

Pelagic Sediments

Pillow Lava

Pelagic Sediments

Pillow Lava

Pelagic Sediments

Pillow Lava

Pelagic Sediments

Massive gabro Massive gabro Massive gabbro Massive gabbro

Diabase Diabase Diabase Diabase

Cummulategabro

Cummulategabbro

Cummulategabbro

Cummulategabbro

HarzburgiteSerpentiniteLherzolite


HarzburgiteSerpentiniteLherzolite

Pakuruhan River Curug Dawa River Medana River Lokidang River Parakan Subah River

Pseudostratigraphic Column of the Cretaceous Ophiolite Complex of Luh Ulo area

Pillow Lava

Diabase

Massive gabro

Cummulategabro


Sediments

Pillow Lava

Sediments

Pillow Lava

Sediments

Pillow Lava

Sediments

Pillow Lava

Sediments

Massive gabro Massive gabro Massive gabro Massive gabro

Diabase Diabase Diabase Diabase

Cummulategabro

Cummulategabro

Cummulategabro

Cummulategabro

HarburgiteSerpentiniteLersolit


HarburgiteSerpentiniteLersolit

Pakuruhan River Curug Dawa River Medana River Lokidang River Parakan Subah River

Pillow Lava

Sediments

Trondhjemite

Diabase dike

Olivine gabro


Trondhjemite &

Quartz diorite

Unconformity

Schisst & serpentinite

Gabro

Peridotite

Imbricated peridotite

Pillow Lava

Sediments

Massive gabro

Diabase

Cummulategabro

Harburgite

Serpentinite

Lersolit

Gabro

Piroxenite

Peridotite

OPHIOLITES

(Penrose, 1972)

Meratus Ophiolites(Sikumbang, 1986)

Luh Ulo Ophiolites(Suparka, 1988)

OPHIOLITE

(Penrose, 1972)

MERATUSSoutheast Kalimantan

(Sikumbang, 1986)

LUH ULONorth Karangsambung

(Suparka, 1989)

SedimentsSediments

Pillow Lava

Diabase dike

Trondhjemite

Gabbro

Olivine gabro

Pyroxenite

Peridotite

Peridotite

HarzburgiteSerpentinite

Trondhjemite &

Quartz diorite

Gabbro

Peridotite

Imbricated Peridotite,

Peridotite

Schisst & serpentinite

Pillow Lava

Diabase

Massive Gabbro

CummulateGabbro

Penampang kolom ofiolit daerah penelitian dibandingkan dengan penampang kolom ofiolit Semailmenurut Boudier dan Nicolas (1985)

Litologi dan ketebalan ofiolit pada ofiolitSemail menurut Boudier dan Nicolas(1985)

PERBANDINGAN OFIOLIT DAERAH PENELITIAN VSMODEL OFIOLIT SEMAIL

PETROGRAPHY AND MINERALOGY

a. b.

Lerzolite, consist of pyroxene and olivine. (x nicol)

a. b.

Lerzolite, showing exsolution intergrowth between opx & cpx (X-Polar)

a. b.

Non cummulate gabbro, ophitic-sub ophitic texture ( X nicol)

Gabbro, showing intercalation of plagioclase and pyroxene lamination(X nicol)

Gabbro, plagioclase as intercumulate crystals altered to sericite, where pyroxene represent as cumulate crystals.(X nicol)

Gabbro, display recrystalization as the result of alteration and deformation. Prenhite aggregate filled along the fracture (a) or partly replaced the plagioclase. Carbonate also occurred. (X nicol).

a. b.

Diabase, medium grain with ophitic / diabasic texture (a)Basalt, fine grain with intergranular – intersertal texture (b)

a. b.

a. b.

Diabase, showing deformation and alteration; prenhite cross cutting the rocks (b). (X nicol)

Normalized by chondrite (Sun & McDonough (1989)) Normalized by average N-type MORB-(Saunders & Tarney (1984);Sun (1980))

100

101

102

10-1

Rb Ba Th U K Nb Ta La Ce Sr Nd P Hf Zr Sm Ti Tb Y

100

101

102

10-1

La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

10-1

100

101

102

10-2


101

102

100


100

101

10-1


Basalt DiabaseGabbro

101

102

100


10^ 0

10^ 1

10^ 2

10^-1

Rb Ba Th U Ta Nb K La Ce Pb Sr Nd Zr Hf Sm Ti Tb Y

Primitive mantle by Sun and McDonough (1992)

BasaltDiabaseGabbro

Ba La Ba Nd Sm Eu Gd Dy Er Yb Lu

50

10

2

North Karangsambung

Mid Oceanic Ridge

BASALT

Fractionation REE pattern of basalt from Karangsambung compare to REE pattern of common basalt from Mid Oceanic Rigde (MORB)

10x chondrites; flat pattern; depleted in LREE

Mode of emplacement

Eurasia Continental Plate

Hindia Oceanic Crust

North Karangsambung Ophiolite

Cartoon diagram for showing emplacement of ophiolite in North Karangsambung

(Suparka, 1988)

(A) Emplacement of North Karangsambung Ophiolites ( Suparka,E., 1988).(B) Geologic section along N-S trend of Seboro Melange based on gravity anomaly (Kamtono et.al, 1996)

Ophiolite complexMid Oceanic Ridge relict

Melange Luh Ulo

Metamorphic rocks sequent (Melange complex)

Oceanic crust sequent

Melange Luh Ulo

Geological setting of the Luh Ulo , Karangsambung area at present day

(Suparka, 1988)

Recent 90-70 MA

33 b

120 – 90 MA

M O

Continental crust

Oceanic crust

Slice of Islands arc ophiolite

Melange wedge

Ophiolites

Islands Arc

Subduction zone

Mid Oceanic Ridge(Age 82-112 ma)

Mid Oceanic Ridge(Age 70-82 ma)33 b

M O

LEGEND :

THE DEVELOPMENT SCENARIO OF JAWA AND KALIMANTAN ISLAND BASE ON BASEMENT ROCKS

recent 90-70jt

Kesimpulan

v Himpunan batuan mafik – ultramafic Karangsambung Utarav adalah kompleks Ofiolit (ko genetic / ko magmatik)

v Terdiri dari harsburgit ,lersolit,gabbro (kumulat & non kumulat),v Diabas, lava bantal

v Kelas II (Myashiro,1975)

v Ofiolit terpisah-pisah, termetamorfisme

v Basalt : tipe N (normal)

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