OPHIOLITES OPHIOLITES OF PAKISTANOF PAKISTAN

PRESENTED BYPRESENTED BY

JAWAD BASHIR JAWAD BASHIR (Thunder bird)(Thunder bird)

OPHIOLITEOPHIOLITE► The characteristic assemblage The characteristic assemblage

of rocks which form at of rocks which form at spreading ridges is called spreading ridges is called an an ophiolites sequence. ophiolites sequence. which laterally emplaced on which laterally emplaced on continental lithospherecontinental lithosphere..

► The typical rock types are The typical rock types are ocean sediments, mafic ocean sediments, mafic extrusive and intrusive extrusive and intrusive igneous rocks, and ultramafic igneous rocks, and ultramafic rocks. rocks.

► These sequences are These sequences are commonly revelaled in areas commonly revelaled in areas characterized by accretionary characterized by accretionary tectonics, such as the western tectonics, such as the western margin of North America. margin of North America.

OPHIOLITES OF OPHIOLITES OF PAKISTANPAKISTAN

1.1. MUSLIM BAGH OPHIOLITES.MUSLIM BAGH OPHIOLITES.

2.2. ZHOB OPHIOLITES.ZHOB OPHIOLITES.

3.3. WAZIRISTAN(KHOST OPHIOITES).WAZIRISTAN(KHOST OPHIOITES).

4.4. RASKOH OPHIOLITES.RASKOH OPHIOLITES.

5.5. INDUS SUTURE OPHIOLITES.INDUS SUTURE OPHIOLITES.

6.6. MALAKAND OPHIOITE.MALAKAND OPHIOITE.

7.7. SWAT OPHIOLITESWAT OPHIOLITE

8.8. BELA OPHIOLITES.BELA OPHIOLITES.

TECTONIC SETTINGS AND TECTONIC SETTINGS AND ENVIROMENTS.ENVIROMENTS.

1.1. Along Chaman Transform fault (Bela, Along Chaman Transform fault (Bela, Zhob,Bagh & Waziristan)Zhob,Bagh & Waziristan)

2.2. Along Chagai magmatic arc formed Along Chagai magmatic arc formed by the subduction of Indian plate by the subduction of Indian plate (Raskoh ophiolites)(Raskoh ophiolites)

3.3. Along Indus suture zone. In north of Along Indus suture zone. In north of Pakistan developed along thrust Pakistan developed along thrust faults along with subduction of Indian faults along with subduction of Indian plate. (Swat and Malakand)plate. (Swat and Malakand)

MUSLIM BAGH OPHIOLITES.MUSLIM BAGH OPHIOLITES.

► Located in Zhob valley in Northeast of Located in Zhob valley in Northeast of Quetta.Quetta.

► Consisting of two main blocks.Consisting of two main blocks.

1.1. Jhang Tor Ghar(West).Jhang Tor Ghar(West).

2.2. Saplai Tor Ghar(East).Saplai Tor Ghar(East).► Smaller massifs in zazghai and khanozoi Smaller massifs in zazghai and khanozoi

are found.are found.► Consists sedimentary and igneous rocks of Consists sedimentary and igneous rocks of

Neo-Tethys ocean.Neo-Tethys ocean.

SYNONAMY AND CONTACTS.SYNONAMY AND CONTACTS.

►Abbas and Rossman(1970).Abbas and Rossman(1970).►Moores(1980).Moores(1980).►Mahmood(1994).Mahmood(1994).

►CONTACTS:CONTACTS:► Underlying masstrichtian limestone turbidities.Underlying masstrichtian limestone turbidities.► Overlying lower Eocene transgression.Overlying lower Eocene transgression.

Ophiolitic Complex sequence. Ophiolitic Complex sequence.

► Banded dunites and harzburgites. Banded dunites and harzburgites. ►Green schist to granulatic facies. assemblage Green schist to granulatic facies. assemblage

found.found.► Transition from mantle to crustal sequence is Transition from mantle to crustal sequence is

only exposed in saplai Tor Ghar and Kanozai only exposed in saplai Tor Ghar and Kanozai area(Mark by dunite rich zone).area(Mark by dunite rich zone).

►Gabbros are layered, foliated or isotropic.Gabbros are layered, foliated or isotropic.► Sheeted dyke complex forms the core of 4km Sheeted dyke complex forms the core of 4km

wide synform in saplai tor Ghar massifs.wide synform in saplai tor Ghar massifs.

ZHOB OPHIOLITES.ZHOB OPHIOLITES.

► Located in north east of the muslim bagh Located in north east of the muslim bagh ophiolites.ophiolites.

► Located b/t Chaman transform fault & Indian Located b/t Chaman transform fault & Indian shield.shield.

► Large section of it is covered by pillow lavas.Large section of it is covered by pillow lavas.► It forms the core of four synclines.It forms the core of four synclines.► Best exposures are found at Muslim Bagh-Best exposures are found at Muslim Bagh-

Nasai area as Sapli Tor Ghar –Nasai Massif & Nasai area as Sapli Tor Ghar –Nasai Massif & Jang Tor Ghar Massif.Jang Tor Ghar Massif.

SYNONAMY AND CONTACTSYNONAMY AND CONTACT

► SYNONAMY:SYNONAMY:

1.1. Hunting survey of Pakistan(1960).Hunting survey of Pakistan(1960).

2.2. Assrarullah(1979).Assrarullah(1979).

► CONTACTS:CONTACTS:

1.1. Over lain by the sediments of unknown Over lain by the sediments of unknown age.age.

2.2. Under lain by marine sediments of upper Under lain by marine sediments of upper cretaceous.cretaceous.

Rocks of Zhob ophioliteRocks of Zhob ophiolite

► Ultrmafic tectonites contain of Ultrmafic tectonites contain of Lherzolite ,Hurzbrgite and Dunite(Jang Tor Lherzolite ,Hurzbrgite and Dunite(Jang Tor Ghar Massif)and Dunite enrich tectonites are Ghar Massif)and Dunite enrich tectonites are associated with Sapli Tor Ghar-Nasai Massif.associated with Sapli Tor Ghar-Nasai Massif.Ultramafic to mafic cumulates consist of Ultramafic to mafic cumulates consist of Olivine at base and Wehrlite pyroxinite at Olivine at base and Wehrlite pyroxinite at top,top,

►Mafic-trojdhjemitic dyke complex contain Mafic-trojdhjemitic dyke complex contain Dolerite gabbro,plagiogranite (Greenschist Dolerite gabbro,plagiogranite (Greenschist to Amphibolite facies).to Amphibolite facies).

COMPLEX SEQUENCE.COMPLEX SEQUENCE.

►The harzburgite gabbro section were The harzburgite gabbro section were thrust upon pillow lavas forming the thrust upon pillow lavas forming the central part of synclines with dunite central part of synclines with dunite veins.veins.

► Contain doleritic dikes and granitoid Contain doleritic dikes and granitoid intrusions.intrusions.

►Most of upper section is covered by Most of upper section is covered by pillow lavas.pillow lavas.

WAZIRISTAN OPHIOLITESWAZIRISTAN OPHIOLITES

► SYNONMAY:SYNONMAY:1.1. Khan(1982).Khan(1982).2.2. Jan(1985).Jan(1985).3.3. Beck(1996).Beck(1996).

► CONTACTS:CONTACTS: Overlain by red to Greyish radiolarian Overlain by red to Greyish radiolarian

cherts.cherts. Underlain by the sediments of upper Underlain by the sediments of upper

masstrichtian limestone and shales.masstrichtian limestone and shales.

Waziristan ophiolites.Waziristan ophiolites.

►Third largest ophiolites sequence in Third largest ophiolites sequence in Pakistan.Pakistan.

►Emplaced during Tertiary period.Emplaced during Tertiary period.►Also named as Khost Ophiolites.Also named as Khost Ophiolites.►About 50% of outcrop is pillow basalts About 50% of outcrop is pillow basalts

and sheeted dikes.and sheeted dikes.

OPHIOLITIC SEQUENCEOPHIOLITIC SEQUENCE

► Complete but strongly dismembered sequence.Complete but strongly dismembered sequence.► Mantle section consist of harzburgites and Mantle section consist of harzburgites and

dunite(contain chromite deposits).dunite(contain chromite deposits).► Massive ore of chromites with pull a part texture Massive ore of chromites with pull a part texture

found found ► Gabbros occur along with anarthosite in crustal Gabbros occur along with anarthosite in crustal

sequence.sequence.► Blue schist facie also found in some parts of Blue schist facie also found in some parts of

sequence.sequence.► Most of sequence is dominated by pillow basalts and Most of sequence is dominated by pillow basalts and

sheeted dikes.sheeted dikes.► Some parts of sequence are more than 90ma years Some parts of sequence are more than 90ma years

older.older.

Rocks of Waziristan Rocks of Waziristan ophiolitesophiolites

►Ultramafic rocks contain Ultramafic rocks contain Hurzburgite,Dunite,Pyroxinite .Hurzburgite,Dunite,Pyroxinite .

►Sheeted dykes contains Sheeted dykes contains labradorite,augite,pleochroic labradorite,augite,pleochroic hornblende,ilminite,actinolite,chlorite,alhornblende,ilminite,actinolite,chlorite,albite ,epidote,quartz and carbonates.bite ,epidote,quartz and carbonates.

►Volcanic rocks contains pillow Volcanic rocks contains pillow lava,tuff,agglomerate,breccia,dolerite,dlava,tuff,agglomerate,breccia,dolerite,diorite,actionolite,epidote,calcite,ironoxiiorite,actionolite,epidote,calcite,ironoxide.de.

Dunite(contain chromite Dunite(contain chromite deposits).deposits).

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Raskoh ophioliteRaskoh ophiolite

► Located in between chagai mamatic arc and Located in between chagai mamatic arc and chaman transform fault.chaman transform fault.

► Present in raskoh range Balouchistan.Present in raskoh range Balouchistan.►Height of about 3000m.Height of about 3000m.► Two main areas can be distinguished in Ras Two main areas can be distinguished in Ras

koh range.koh range.► Ras Koh and Chagai region is seprated by Ras Koh and Chagai region is seprated by

Dalbandin.Dalbandin.► Sequence disappears in Hamun 1 musakhel Sequence disappears in Hamun 1 musakhel

dipression in its west.dipression in its west.

Rocks in Ras Koh.Rocks in Ras Koh.

►Ultramafic contains serpentininized Ultramafic contains serpentininized dunite,peridotite and pyroxinite.dunite,peridotite and pyroxinite.

►Dolerit dykes intruded in the granitoids Dolerit dykes intruded in the granitoids and rhyolitic flowand rhyolitic flow

►Volcanic rocks consist of Volcanic rocks consist of diorite,gabbro,norite,monzonite & diorite,gabbro,norite,monzonite & apliteaplite

Complex sequence.Complex sequence.

► Serpentized harzburgite outcrops are widely Serpentized harzburgite outcrops are widely spread in the Bunap area.spread in the Bunap area.

► Red conglomerates containing basalts and Red conglomerates containing basalts and chert pebbles occur with serpentinites.chert pebbles occur with serpentinites.

►Metamorphic soles contain hornblendes Metamorphic soles contain hornblendes which formed in initial stage.which formed in initial stage.

► Alkaine pillow lavas are found exposed in Alkaine pillow lavas are found exposed in some places.some places.

Indus suture ophiolitesIndus suture ophiolites

► Indus suture zone is tectonic Indus suture zone is tectonic melange between Kohistan island arc melange between Kohistan island arc and Indian plate.and Indian plate.

1.1. Malakand mohmmand Malakand mohmmand ophioliteophiolite

2.2. Swat ophioliteSwat ophiolite

Malakand mohmmand Malakand mohmmand ophioliteophiolite

►Greenschist to amphiobolite facies Greenschist to amphiobolite facies during early Tertiary period.during early Tertiary period.

► ultramafic rocks contain (talc ultramafic rocks contain (talc tremolite,talc carbonatewith green beryl tremolite,talc carbonatewith green beryl & emerald)& emerald)

►Mafic rocks consist of Mafic rocks consist of saussurite,chlorite,uralite & rodingite.saussurite,chlorite,uralite & rodingite.

►Volcanic rocks consist of Volcanic rocks consist of chlorite,epidote,quartz,albite,amphibolitchlorite,epidote,quartz,albite,amphibolites,mica and pelites.es,mica and pelites.

Swat ophiolitesSwat ophiolites

►Ultramafic rocks consist of Ultramafic rocks consist of hurzburgite,dunite ,lherzolite ,websterihurzburgite,dunite ,lherzolite ,websterite,diopsidite.te,diopsidite.

►Mafic rocks consist of gabbro with Mafic rocks consist of gabbro with albite ,clinozoisite,amphibolite,with albite ,clinozoisite,amphibolite,with augite.augite.

►Plagiogranite,quartz,actinoite,pargasitPlagiogranite,quartz,actinoite,pargasiteepidote.eepidote.

BELA OPHIOLITESBELA OPHIOLITES

►Largest & most complete sequenceLargest & most complete sequence►Appear as large nappe over mesozoic Appear as large nappe over mesozoic

sequence of lover indus basin.sequence of lover indus basin.►Forms 10-60 km wide and 300 km long Forms 10-60 km wide and 300 km long

belt between karachi and Khuzdar.belt between karachi and Khuzdar.►Northern part offset along a sinistral Northern part offset along a sinistral

fault and continues in south to Arabian fault and continues in south to Arabian sea.sea.

SYNONAMYSYNONAMY

►Vrendenburg(1909).Vrendenburg(1909).►Hunting Corpertion(1960).Hunting Corpertion(1960).►Ahsan(1979).Ahsan(1979).►Sarwar(1992).Sarwar(1992).

BELA OPHIOLITESBELA OPHIOLITES

TWO MAIN UNITS.TWO MAIN UNITS.

►Upper Unit:Upper Unit:

The true ophiolite sequence found in The true ophiolite sequence found in the sunaro region in north.the sunaro region in north.

►Lower Unit:Lower Unit:

Mainly southern area of tectonically Mainly southern area of tectonically lower accretionary wedge .lower accretionary wedge .

Upper UnitUpper Unit► Mainly most of remanents found are located in northern Mainly most of remanents found are located in northern

part of belt.part of belt.

► Most complete sequence is found between villages of wad Most complete sequence is found between villages of wad and Sunaro.and Sunaro.

► Section Exposed containsSection Exposed contains::1.1. A metamorphic SoleA metamorphic Sole2.2. <2Km of serpentinized harzburgite mantle sequence<2Km of serpentinized harzburgite mantle sequence3.3. 1.5 to 2km of layered peridotites/gabbros,layered,foliated 1.5 to 2km of layered peridotites/gabbros,layered,foliated

and isotropic gabbros.and isotropic gabbros.4.4. 0.5 to 1 km of sheeted dikes.0.5 to 1 km of sheeted dikes.5.5. <100m of an extrusive sequenc.<100m of an extrusive sequenc.

LOWER UNITLOWER UNIT► It consists of imbricated sheets that dip 45-50 It consists of imbricated sheets that dip 45-50

degree west to north west.degree west to north west.► Imbrication is consist of partial or complete Imbrication is consist of partial or complete

sequence of oceanic lithosphere.sequence of oceanic lithosphere.► The micro gabbroic intrusions and sills cover The micro gabbroic intrusions and sills cover

larger sequence of about 30%.larger sequence of about 30%.► Red granitoides and dacites are also observed.Red granitoides and dacites are also observed.► Three sedimentary units found here(Red Three sedimentary units found here(Red

sediments, blackish sediments and yellow sediments, blackish sediments and yellow sediments).sediments).

► LOWER UNIT MAINLY CONTAINSLOWER UNIT MAINLY CONTAINS::1.1. Pillow lavas.Pillow lavas.2.2. Sedimentary rocks Sedimentary rocks 3.3. Serpentinites.Serpentinites.4.4. Dolerits.Dolerits.

THE END THE END

►ANY QUESTIONSANY QUESTIONS