Tectonic elements of pakistan

1. TECTONIC ELEMENTS OF
PAKISTAN
It includes:
 KOHISTAN-LADAKH MAGMATIC ARC
 INDUS PLATE FORM AND FOREDEEP
 EAST BALOCHISTAN FOLD-AND-THRUST BELT
 NORTHWEST HIMALAYAN FOLD-AND- THRUST BELT
 KARAKORAM BLOCK
 KAKAR KHORASAN FLYSCH BASIN AND
MAKRAN ACCRETIONARY ZONE
 CRAGAI MAGMATIC ARC
 PAKISTAN OFFSHORE

2. Kohistan-Ladakh Magmatic Arc
Ranges from Kohistan in Pakistan to Ladakh in india
The Northern boundary of belt is known as MKT or Shyok ophiolite
complex belt
The Southern boundary of belt is known as IYS ophiolite complex
belt
The area is divided into:
-Ladakh Massif
-Dras Volcanic arc

3. This island arc is formed within the Tethys ocean in Mesozoic times.
It formed when tethy sea thrust southward and sequezed between
converging indian and Asian plate.
Thickness of Arc is between 50 to 70 km.
Western Himalaya is an example of arc-continent collision.

5. Indus Plateform and Foredeep
• This zone extends over an area exceeding 250,000 km2 in
southeastern Pakistan
• It includes Indus Plain and Thar-Cholistan Deserts.
• It consists of more than 80% of the population of Pakistan
• It is also very valuable because of it,s coal deposits,valuable gas and
oil fields and vast groundwater reservoirs.
• Eastern side mainly composed of Marine and deltaic sediments of
Mesozoic and Cenozoic and also have Precambrian rocks.

6. There are 2 broad zones defined by gravity survey
1. Up warp
2. Down warp
• Sedimentary cover is thin in the upwarp zone
•Sedimentary cover is thick in the down warp zone
•In foredeep it is specially very thick upto 10,000 m
thick

8. EAST BALOCHISTAN FOLD-AND-THRUST BELT
• This zone of folds and thrusts is 60 to 150 km wide, with a strike
length of about 1,250 km.
• It extands from Waziristan through Loralai-Bugti area, around the
Quetta syntaxis, down south to Karachi and the Indus Delta
• The Sulaiman-Kirthar foredeeps lie on its eastern flank
• Ornach-Nal Transform Fault and Ghazaband Fault are truncated on
west.
• Himalayan fold and thrust belt are in faulted contact with its north
south structures.

9. • The East Balochistan fold-and-thrust belt is the product of transpression
and oblique collision of India-Pakistan plate with the Afghan block
• This belt is reportedly underlain by relatively thinner transitional or
oceanic crust at least in its northern part
• The basement is covered by a thick Phanerozoic sedimentary wedge
• Inward there is a broad folded zone with narrow anticlinal hills and wide
synclinal valleys.
• Magmatism is largely confined to basic dykes and sills in the Mesozoic
sequence.
• Metamorphism is restricted to ophiolite bearing sections of the thrust
belt

10. Stratigraphy and structure
• The East Balochistan fold-and-thrust belt contains more than 10 km
thick sequence of Permian
• Mesozoic shelf carbonates, neritic shales and volcanics
• Paleogene shallow-water interlayered marine and continental
deposits and Neogene molasse.
• There is an intimate relationship between the structure and
stratigraphy of this belt
• In India-Eurasia collision, the deposition centres and the deformation
have gradually migrated south and eastward towards the foreland.

11. • Towards the west, the outer part of the East Balochistan fold-and-
thrust belt is comprised of an over 550 km long and 20 to 40 km wide
imbricate zone of thrusts
This belt is divided into two parts
• Zhob ophiolite-and-thrust belt in the north
• Bela ophiolite-and-thrust belt in the south

12. NORTHWEST HIMALAYAN FOLD-AND- THRUST
BELT
• The Northwest Himalayan fold-and-thrust belt occupies a 250 km wide and
about 560 km long.
• These irregularly shaped mountainous region stretching from the Afghan
border near Parachinar up to the Kashmir Basin
• The Hazara-Kashmir and Nanga Parbat Syntaxes form its eastern margin.
• It covers all the terrain between the Main Mantle Thrust (MMT) in the
north and-the Salt Range Thrust in the south.
• This region is comprised of the mountain ranges of Nanga Parbat. Hazara,
southern Kohistan, Swat, Margalla, Kalachitta, KohaL Sufaid Koh, Salt Range
and its western extension.

13. A major thrust fault the Panjal-Khairabad Fault divides the NW
Himalayan sequence into
• Deformed southern zone often referred to as the external or
foreland zone
• Deformed and metamorphosed northern zone, also known as the
hinterland zone
Foreland Zone:
• The foreland zone is comprised of the Hazara-Kashmir Syntaxis, Salt
Range and Kohat-Potwar fold belt and the Kurram-Cherat-Margalla
thrust belt
Hinterland zone:
• Hinterland zone comprises the Himalayan crystalline nappe-and-
thrust belt

14. • The eastern margin of the NW Himalayan fold-and-thrust belt in
Pakistan comprises the north-south trending Hazara-Kashmir Syntaxis
• In Northeast it extends upto Nanga Parbat-Haramosh Massif.
Hazara-Kashmir Syntaxis:
• It lies on northern corner of Pakistan, between Mirpur and
Muzaffarabad and farther to the north and northeast
• It consists of geological formations and broader geological structures
of the Himalayas make an abrupt hairpin bend

15. On western side of Hazara-Kashmir Syntaxis there are several arcuate,
south verging thrust faults which terminate in the Jhelum Fault at an
acute angle between Balakot and Kohala
These are:
1. Main central thrust
2. Jhelum fault
3. Panjal thrust
4. Murree Fault

17. KARAKORAM BLOCK
Karakoram block is 70 to 120 km wide and 1,400 km long structural
zone
The Karakoram Batholith divides the region into a northern and
southern sedimentary belt
The western part of the region, the Tirich Mir zone, is separated from
the main body of the Karakoram belt by the Tirich Fault
Tirich Mir zone:
• This zone is largely comprised of the highly deformed and imbricated
metasediments of the Arkari Formation

18. • It mainly consists of dark grey phyllites with subordinate quartzites and marbles
Southern Sedimentary Belt:
• The Southern belt forms an belt of highly deformed and imbricated
metasediments thrust southward over the Kohistan-Ladakh sequence along the
Shyok Suture zone or MKT.
• In the western part of the belt, between Chitral town and Mastuj, Late Paleozoic
to Tertiary rocks are exposed.
• The Darkot Group is the oldest sedimentary unit with Carboniferous to Permian
fossils
• It also consists of slates, schists and quartzites intercalated with crystalline
limestones
• It has been intruded by granites and is unconformably overlain by the Tertiary

19. Northern Sedimentary Belt:
• The Northern sedimentary belt extends westward from Shaksgam,
through Upper Hunza and Chapursan Valleys, up to Baroghil Pass.
• It then bends southward and follows the Yarkhun Valley
• In the Upper Hunza region, it consists of three tectonostratigraphic
units separated by lwo major faults
• An E-W trending reverse fault the Upper Hunza Fault
• an antiformal stack and northward, across the Northern Fault, it is
structurally overlain by the Misghar Unit

20. KAKAR KHORASAN FLYSCH BASIN AND
MAKRAN ACCRETIONARY ZONE
• These two tectonic zones presently form separate and distinct
structural units northwest and west of the Sulaiman-Kirthar fold-and-
thrust belt
• both share a common depositional history and are comprised of
Cenozoic Khojak Flysch.
• They are separated by the Chaman Transform Fault Zone.
• The Kakar Khorasan Basin lies to the north of Zhob ophioliteand-
thrust belt
• As part of the large Katawaz Basin, it extends southward from near
Kabul to Zhob and links up with the Makran Basin

21. • The Kakar Khorasan Basin is bound to the south and east by the Zhob
and Shinghar-Chukhan Manda Faults respectively.
• On west it is terminated by the Chaman Fault
• It is filled by 4 to 6 km thick sequence offlysch, deltaic and molasse
type sediments
• Gravity modelling shows that the transitional crust of the Sulaiman
zone becomes thinner and deeper beneath Kakar Khorasan Basin and
is overlapped by oceanic crust
• Eocene Nisai Limestone and Oligocene to Miocene Khojak Flysch are
exposed in the Kakar Khorasan Basin.
• This sequence has been thrust southward over the Zhob Ophiolites.
• The flysch is capped by Pliocene or younger molasse

22. • This sequence forms broad synclines and tight anticlines cut by
reverse faults.
• The folds form a part of the Sulaiman oroclinal flexure.
• The structural trend changes from SW in the basin to NS near the
Chaman Fault.
• The Chaman Fault is a major left-lateral strike-slip active fault that has
been the site of moderate to large earthquakes
• This fault extends
• northward from Kharan to Kabul for 850 km and is considered as the
western transform boundary of the Indian plate
• It connects the Makran convergence zone with the Himalayan
convergence zone (where Indo-Pakistan plate is underthrusting
Eurasia).

23. CRAGAI MAGMATIC ARC
• the Chagai arc is an east-west-trending, arcuate, south-yerging
magmatic belt comprised of Cretaceous to Tertiary sediments and
volcanics.
• It is intruded by Tertiary granites, diorites and mafic dykes and sills.
Small tectonised blocks of ultramafic rocks occur in the southern part
• Quaternary volcanoes dot the landscape in the northwestern section
of the arc
• This magmatic arc forms a part of the Makran trench arc system on
the southern margin of the Afghan and Lut blocks

24. It comprises three main tectonic components:
1. the North Chagai calc-alkaline and magmatic belt
2. Mirjawa-Dalbandin trough
3. the Ras Koh uplift block
• Eastward the Chagai arc is abruptly truncated by the Chaman Fault
• the Kakarkhorasan, Makran and Chagai regions are all parts of
Makran-Chagai trench-arc system which developed in response to
northward movement of the Indian and Arabian plates and
subduction of the Neotethys under the southern margin of the
Afghan block
• Cretaceous submarine volcanism associated with periodic uplift
eventually led to the formation of Chagai andesitic volcanic arc.

25. PAKISTAN OFFSHORE
• The Pakistan Offshore extends for 700 km from Rann of Cutch to the
Iranian border (near Gwadar).
• It comprises two distinct structural and sedimentary basins, the Indus
and Makran Offshore Basins, which are separated by the Murray
Ridge.
• This ridge is an extension of the Owen Fracture Zone and forms the
boundary between Indian and Arabian plates
Makran Offshore:
• This zone is characterised by relatively narrow shelf and slope which
form the northern margin of the Gulf of Oman Abyssal Plain.

26. • In this region the Arabian plate is being Gubducted beneath Makran and
the subduction zone is located near the base of the
continental slope
• Seismic profiles indicate that the sediment pile on the Makran continental
margin is about 5 km thick
• In the abyssal plain these sediments are horizontally disposed but
shoreward they are abruptly deformed into an approximately 50 km wide
fold and thrust belt
• Only the upper 2.5 km of the sedimentary sequence is folded and forms a
decollement zone.
• As revealed by offshore drilling, most of this sequence consists of Early
Miocene and younger sediments

27. Indus Offshore:
• This region lies between the Murray Ridge and the Indian Coast.
• It is characterised by a wide shelf and slope comprised of the vast
Indus Fan
It is comprised of two main structural zones:
1. Indus platform zone to the east
2. Indus depression to the west
• The Indus Offshore basin contains a thick sedimentary sequence
ranging from Cretaceous to Recent
• Seismic profiles of this region indicate gently dipping structures with
abundant down-to-the basin type normal faults

28. REFERENCES:
• The geological characteristics of India Ladakh - Pakistan Kohistan
island arc and volcanic
• rock
Li Shanglinli, Ji Wenhua, Ma Boyong, Luo Yanjun
, Cao xin
Xi’an Center of Geological Survey· CGS. Xian 710054, Shaanxi, China
China Geological Library, Beijing 100083, China
and Li Guochun
Inner Mongolia Institute of Geology and Mineral Resources Exploration, Huhhot 010010,
Inner Mongolia, China
• GEOLOGY AND TECTONICS OF PAKISTAN
By A.H.KAZMI· andM.QASIMJAN
• TECTONIC MODEL OF NW HIMALAYAN FOLD AND THRUST BELT ON THE BASIS OF FOCAL MECHANISM STUDIES