Salt Range geology

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Carnets de Gologie / Notebooks on Geology Book 2009/03 (CG2009_B03), Chapter 6

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The Salt Range:Pakistan's unique field museum

of geology and paleontology

[Le Salt Range :un muse de gologie et de palontologie

ciel ouvert au Pakistan]

Shahid Jamil SAMEENI1

Citation: SAMEENIS.J. (2009).- The Salt Range: Pakistan's unique field museum of geology andpaleontology.- In: LIPPSJ.H. & GRANIERB.R.C. (eds.), PaleoParks - The protection and conservation offossil sites worldwide.- Carnets de Gologie / Notebooks on Geology, Brest, Book 2009/03, Chapter 6(CG2009_BOOK_03/06)

Abstract: The Salt Range contains the most important geologic and paleontologic localities in Pakistan,and is one of the outstanding field areas in the entire world. Despite its easy accessibility, it has awealth of geological and paleontological features. In fact, it represents an open book of geology where

various richly fossiliferous stratified rocks are very well exposed due to lack of vegetation. Theseinclude the Permian carbonate succession with its outstanding brachiopod fauna, Lower Triassicammonoid beds (the Mianwali Formation, formerly known as "Ceratite Beds"), and Lower Tertiarymarine strata with age diagnostic foraminifera. These rocks also provide an excellent opportunity forappreciation of tectonics in the field. In addition to the easily available roadside geology, someprominent gorges provide fantastic locations to study the sedimentary succession. Older strata areexposed in the eastern Salt Range between the Khewra-Choa Saidan Shah and Fort Kussak includingthe famous Khewra Gorge. In the west, beyond Kallar Kahar, are younger strata such as in theNilawahan Gorge at Nurpur, the Nammal Gorge near Mianwali, the Chichali Gorge near Kalabagh, andfurther west the Lumshiwal Nala at Makerwal. This succession has been rightly called a Field Museum ofGeology and Paleontology and can be classified as one of the great paleontological areas of the world,fully worthy of conservation and protection efforts.

Key Words: Pakistan; Salt Range; geology; paleontology; stratigraphy.

Rsum : Le Sa l t Rang e : un m use d e go log i e e t de pa lon to l o g i e c ie l ou ve r t au

P a k i s t a n . - Le Salt Range hberge les plus remarquables sites gologiques et palontologiques duPakistan, voire mme du monde. D'accs facile, sans vgtation gnante, ces sites aux thmatiquesvaries sont comme un livre ouvert sur la gologie des roches sdimentaires et leurs fossiles. On yobserve une srie de carbonates permiens et leur remarquable faune de Brachiopodes, un Triasinfrieur Ammonodes (les clbres "couches Cratites" de la formation de Mianwali) et un Tertiaireinfrieur riche en associations de Foraminifres de rfrence. La tectonisation de ces couches permet,en prime, d'observer de belles figures de dformation. Prcisons que l'observation de ces faitsgologiques se fait par de bonnes routes au cur de gorges trs impressionnantes. Les plus anciennessries sont observables dans la partie orientale du Salt Range entre Khewra-Choa Saidan Shah et FortKussak en passant par les gorges de Khewra. A l'ouest, prs de Kallar Kahar, les couches les plusrcentes s'observent dans les gorges de Nilawahan prs de Nurpur, de Nammal prs de Mianwali, deChichali prs de Kalabagh. Plus l'ouest, on visite le Lumshiwal Nala prs Makerwal. Ces sites

judicieusement appels "Muse en plein air de Gologie et Palontologie" sont reconnus comme l'unedes plus importantes zones d'intrt palontologique du monde, et mritent tous les efforts possiblesde conservation et de dveloppement.

Mots-Clefs : Pakistan ; chane du Salt Range ; gologie ; palontologie ; stratigraphie.

1 Institute of Geology, Punjab University, Lahore-54590 (Pakistan)

Manuscript online since September 17, 2009

1. Introduction

The Salt Range forms the southern border ofthe hydrocarbon-bearing Potowar Basin innorthern Pakistan, along the northwestern mar-gin of the Indo-Pakistani Plate (Fig. 1). Itderives its name from the occurrence ofgigantic deposits of rock salt embedded in thePrecambrian bright red marls of the Salt RangeFormation (formerly known as the "PunjabSaline Series").

Strata in the Salt Range dip northwards intothe Potowar Basin where non-marine Tertiary

sediments, collectively known as the Siwaliks,are exposed with a wealth of vertebrate fossils.The southern face of the Salt Range is anescarpment that rises abruptly from the PunjabPlains with a junction marked by the FrontalThurst. Block faulting is the most characteristictectonic style within the Salt Range.

The Salt Range is essentially an East-Westtrending elongated narrow trough bounded onthe east by the River Jhelum and on the westby the River Indus. Beyond the River Indus atKalabagh, it takes a sharp turn to run almost ina North-South direction (Fig. 1). The entire


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mountainous belt has, therefore, previouslybeen differentiated into the Cis-Indus SaltRange and Trans-Indus Salt Range now known

as The Salt Range and Trans-Indus SurgharRange, respectively.

Figure 1:Map of the Salt Range, Pakistan (after E.H. PASCOE, 1919).

The Salt Range is one of the most importantgeological regions in Pakistan. It is easily acces-

sible and displays a wide variety of geologicalfeatures and paleontological remains. It has,therefore, been rightly called a field museum ofgeology and paleontology. It represents anopen book of geology with richly fossiliferousstratified rocks that include a Permian carbo-nate succession with brachiopods, LowerTriassic ammonite bearing beds (the MianwaliFormation, formerly known as "Ceratite Beds")and Lower Tertiary marine strata composed ofage diagnostic foraminifera. All the strata areexcellently exposed due to lack of vegetation.The quality of the exposure also providesexcellent opportunities to appreciate tectonicfeatures in the field. The Salt Range is,therefore, of international scientific and educa-tional value, and is highly worthy ofconservation and preservation.

2. Previous work

In the past, the Salt Range has attractedgeologists from all over the world to studyCambrian stratigraphy, the Permian-Triassicboundary, and Lower Tertiary foraminiferalbiostratigraphy. Of particular note is thepioneering work of E.R. GEE(1935, 1945), whodedicated almost his entire geological career to

the study of the Salt Range. His initial workrelated to solving the controversy regarding theage of the "Saline Series", a burning topic ofthat time, and he made a great contribution by

producing a geological map (more recently sixsheets on a scale 1:50,000 have been published

by the Geological Survey of Pakistan excludingthe Trans-Indus Surghar Range).

DAVIES and PINFOLD (1937) completed acomprehensive study of Lower Tertiary largerforaminifera of the Salt Range. WAAGEN (1882-1885, 1895) worked on the brachiopods of thePermian of the Salt Range and FATIMI (1973)studied the ceratitids of the Triassic of the SaltRange and Trans-Indus Surghar Range. He alsoworked on stratigraphic nomenclature on theSalt Range as did SHAH (1977). KUMMEL andTEICHERT (1966, 1970) illustrated Permianbrachiopods and described the detailed strati-

graphy of the Permian rocks while GRANT(1966)described trilobites. HAQUE(1956) described thesmaller foraminifera from the Tertiaryformations of the western Nammal Gorge, SaltRange. AFZAL (1997) completed his doctoralthesis on the planktonic foraminifera of thePaleogene and established a planktonicbiostratigraphy for the Patala Formation of theSalt Range and Surghar Range (AFZAL & vonDANIELS, 1991; AFZAL & BUTT, 2000). SAMEENI(1997) completed his doctoral thesis on thePaleogene biostratigraphy of the Salt Rangeunder UNESCO IGCP-286, headed by Prof.Lukas HOTTINGER of Basel University, Switzer-

land, and established an alveolinid bio-stratigraphy for the Eocene succession of theSalt Range (SAMEENI & BUTT, 1996, 2004;SAMEENI& HOTTINGER, 2003). ASHRAF and BHATTI


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(1991) worked on the nannofossils of the Patalaand Nammal formations of the Khairabad areaof the western Salt Range.

3. Geology and Paleontology

PRECAMBRIAN ROCKS

The Precambrian rocks exposed in the SaltRange belong to the Salt Range Formation,which contains the thickest (approximately5000 feet) seams of rock salt in the world. TheSalt Range Formation is widely exposed alongthe southern edge of the Salt Range from eastto west and in the Trans Indus Surghar Range.It is also recognized in the subsurface atDhullian 200 km north of the Salt Range and atKarampur, approximately 500km south of theSalt Range. The Salt Range Formation is dividedinto three members:

3- Sahwal Marl Member

2- Bandarkas Gypsum Member

1- Billianwala Salt Member

Figure 2: Salt Range Formation and KhewraSandstone exposed in the Khewra Gorge.

Figure 3:Diamond-like salt crystals of the BillianwalaMember, Salt Range Formation.

All three members are well exposed on bothsides of the Khewra Gorge (Fig. 2). TheBillianwala Member contains ferruginous marl

and thick seams of rock salt (Fig. 3). One of thelargest mines in the world is situated in thetown of Khewra (Fig. 4) in the eastern SaltRange, where salt is mined by the room andpillar method from 17 floors of the mine. The

Figure 4:Entrance to the Khewra Salt Mine, one ofthe largest in the world.

Figure 5: Bandarkas Gypsum member of the SaltRange Formation.

Figure 6:Kewra Gorge.


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Bandarkas Gypsum Member contains marland huge deposits of crystalline and non-crystalline gypsum (Fig. 5). The Sahwal MarlMember contains marl along with 8-10 feetthick seams of rock salt. At the top of thismember in the Khewra area, an igneous volca-nic body is exposed known as Khewrite', whichresembles an igneous body that occurs with thePre-Cambrian Harmuz Salt of Iran. The sharpcontact between the Salt Range Formation andthe overlying Cambrian Khewra Sandstone(Figs. 2 & 6) can also be observed in the gorge.

PALEOZOIC ROCKS

The Paleozoic rocks exposed in the the SaltRange are of Cambrian and Permian age, withno strata representing the Ordovician toCarboniferous systems. The Cambrian sequencecomprises four formations:

4- Baghanwala Formation

3- Jutana Formation

2- Kussak Formation

1- Khewra Sandstone

Figure 7: Roadside geology showing the contactbetween the Baghanwala and Tobra Formations inroad cuts.

Figure 8: Contact between Baghanwala Formation(with salt pseudomorphs) and the overlying Permianglacial Tobra Formation.

These Cambrian formations contain (apartfrom other fossils) a wealth of trace fossils,

including trails of trilobites and worm tracks.The Khewera Sandstone shows honeycombweathering, cross-bedding and intera-formational folds. The Baghanwala Formation(Figs. 7-8), which contains salt pseudo-

Figure 9: Salt pseudomorphs in the BaghanwalaFormation.

Figure 10: The Permian Warchha Sandstone

overlying the Dandot Formation exposed along theKhewra-Choa Saidan Shah road.

Figure 11:Permian Amb Formation, Pail Area.


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morphs (Fig. 9), is well exposed along theroadside and displays a sharp unconformableupper contact with the overlying Permian glacialdeposits.

Figure 12: Fusulinids beds the Amb Formation, PailArea.

Figure 13: Fusulinids in the Amb Formation, PailArea.

Figure 14:A view of Nammal Gorge.

The Permian strata of the Salt Range areassigned to two groups, the Nilawan Group andthe Zaluch Group. The oldest formation of thePermian, the Tobra Formation of the NilawanGroup, is a non-marine deposit that showsdifferent facies across the region. In the eastern

Salt Range, it is tillitic (glacially deposited),grading into a marine sandstone; in the centralSalt Range it incorporates lacustrine deposits;in the western Salt Range and Trans Indusranges it displays a complex facies of

alternating glacial and stream (ice melt water)deposits. The other formations of the group, theDandot Formation and Warchha Sandstone, arealso well exposed along the Khewra-ChoaSaidan Shah road with a sharp contact betweenthem (Fig. 10).

Figure 15: Middle Productus Limestone in NammalGorge.

Figure 16: Productus exposed in the limestone inNammal Gorge.

In the central Salt Range near Pail the AmbFormation, the youngest formation of theZaluch Group, is very well exposed along theroadside, where it contains numerous fusulinid-bearing beds (Figs. 11-13). Further west in theNammal Gorge (Fig. 14), the Wargal Formation(formerly known as the Middle ProductusLimestone) and the Chhidru Formation (for-merly known as the Upper ProductusLimestone) are exposed, and bear abundantspecimens of Productus and other brachiopods(Figs. 15-16). The Permian rocks have a sharpupper contact with Triassic rocks, marking aparaconformity. The Permian rocks aredistinguished by the presence of Productus,whereas the Triassic rocks contains Ceratites.

MESOZOIC ROCKS

The Triassic Mianwali Formation is very wellexposed in the Nammal Gorge as well as in theDhak Pass, where beautiful Ceratitesspecimenscan be found along the roadside (Figs. 17-19).The lower contact of the Mianwali Formation


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with the Permian Chhidru Formation is aparaconformity. The Triassic and Jurassic suc-cession contains both marine and non-marinestrata. Amongst Cretaceous rocks, the ChichaliFormation (formerly known as the "BelemniteBeds") is very well exposed (Fig. 20) in theChichali Gorge (Trans-Indus Surghar Range)where it bears a wealth of belemnites in theform of a "graveyard"; this formation is alsoexposed in other parts of the Kohat-Potowarbasin.

Figure 17: Road cuts containing abundant Ceratitesat Dhak Pass.

Figure 18: Numerous Ceratites exposed on theoutcrop.

Figure 19:A well-preserved Ceratites.

Figure 20:Abundant Cretaceous belemnites, knownas a "belemnite graveyard", in the Chichali Formationin the Surghar Range.

CENOZOIC ROCKS

Paleogene rocks are mostly exposed in thecentral and western Salt Range (Fig. 21) as wellas in the Trans-Indus Surghar Range. Theserocks are oil bearing in the adjacent Kohat-Potowar basin, where the Paleocene LockhartLimestone (Fig. 22) acts as a reservoir rock, thePatala Formation as source rock and theNammal Formation and Sakesar Limestone ascap rocks. The Lockhart Limestone wasdeposited in a shallow-shelf, marine carbonateenvironment inhabited by abundant shallowbenthic larger foraminifera (Fig. 23), includingguide fossils for the Upper Paleocene such asMiscellanea miscellaand Lockhartia haimei. The

Patala Formation, of Upper Paleocene andLower Eocene age, also contains larger fora-minifera. The Lower Eocene Nammal Formationand Sakesar Limestone (Fig. 24) are exposedthroughout the Salt Range and Surghar Range,and are rich in age diagnostic largerforaminifera, including Nummulites, alveolinidsand assilinids.

The Choegali Formation (formerly known as"Bhadrar Beds"), of Lower Eocene age, is onlyexposed in the central Salt Range, where itbears age-diagnostic larger foraminifera likeNummulites(Fig. 25) and alveolinids.

Figure 21:Paleogene formations exposed in NammalGorge.


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The non-marine Miocene-Pliocene rocksknown as the Lower and Upper Siwaliks (Figs.26-28) are famous for their vertebrate faunaincluding mammals (among which is the largestmammal), birds and reptiles.

Figure 22: The Paleogene Lockhart Limestoneexposed along a road side near Nammal Gorge.

Figure 23: Nodular foraminiferal limestone beds in

the Lockhart Limestone.

Figure 24:Sakesar Limestone.

Figure 25: The Choegali Formation of Eocene agecontains numerous Nummulites, shown in this image.

Figure 26: The Lower and Upper Siwaliks, non-marine Miocene-Pliocene rocks, occur in the SaltRange.

Figure 27: Differential weathering and badlandsexposures in the Siwaliks.


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Figure 28:Vertebrate fossils are well preserved andabundant at localities in the Siwaliks.

4. Recommendations

The Salt Range contains a number of unique

fossil occurrences and many occurrences thatare useful in research and education. It shouldbe considered carefully by local paleontologistsfor the preservation and conservation of theseresources. Those sites (of any geographicextent) that are deemed worthy of preservationshould be designated a potential PaleoPark andlocal efforts to preserve them should ensue.This will require significant efforts because ofthe numerous sites, and the size andpaleontological fame of the Salt Range.

Acknowledgements

The author is grateful to Prof. Jere H. LIPPS

for encouragement, guidance and editing, andto Prof. Richard J. ALDRIDGEfor editing the text.

Bibliographic references

AFZAL J. (1997, unpublished).- Foraminiferalbiostratigraphy and paleoenvironments ofthe Patala and Nammal formations at thePaleocene-Eocene boundary in the SaltRange and Surgar Range, Pakistan.- Ph.D.Thesis, Punjab University, Lahore, 155 p.

AFZAL J. & BUTT A.A. (2000).- Lower Tertiaryplanktonic biostratigraphy of the Salt Range,Northern Pakistan.- Neues Jahrbuch frGeologie und Palontologie, Monatshefte,Stuttgart, Heft 12, p. 721-747.

AFZAL J. & DANIELS C.H. von (1991).-Foraminiferal biostratigraphy and paleo-environmental interpretation of the Paleo-ceneEocene Patala and Nammal formationsKhairabad East, Western Salt Range.-Pakistan Journal of Hydrocarbon Research,Islamabad, vol. 3, n 2, p. 61-79.

ASHRAF M. & BHATTI M. (1991, unpublished).-Nannofossil biostratigraphy of the Patala andNammal Formations of Khairabad East,Western Salt Range, Pakistan.- Hydrocarbon

Development Institute of Pakistan (HDIP),unpublished report.ASRARULLAH P. (1967).- Geology of the Khewra

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Conference, University of Sind, Hyderabad,Part-III, Abstracts, F3-F4.

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CHEEMAM.R. (1974).- Bauxite and clay depositsof a part of Katha-Arara area, KhushabTehsil, Sargodha Dist. Punjab, WestPakistan.- Pakistan Geological Survey,Information Release, Quetta, n 76, 21 p.

COLBERTE.H. (1935).- Siwalik (India) mammalsin the American Museum of Natural History.-Transactions of the American PhilosophicalSociety, Philadelphia, (new ser.), vol. XXVI,401 p.

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Kohat-Potwar Province, Indus basin.- Geolo-gical Survey of Pakistan, Memoirs, Quetta,vol. 10, 80 p.

GEE E.R. (1935).- The saline series of north-western India.- Current Science, Bangalore,vol. II, p. 460-463.

GEEE.R. (1945).- The age of saline series of thePunjab and Kohat.- Proceedings of the Natio-nal Academy of Sciences of India, Calcutta,(Section B), vol. 14, n 6, p. 269-312.

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the Salt Range, West Pakistan.- Palaeon-tology, Oxford, vol. 9, Part 1, p. 64-73.

HAQUEA.F.M. (1956).- The smaller foraminiferaof the Ranikot and Laki of the NammalGorge, Salt Range.- Geological Survey ofPakistan, Memoirs, Quetta, vol. 1, 300 p.

KUMMEL B. & TEICHERT C. (1966).- Relationsbetween the Permian and Triassic formationsin the Salt Range and Trans-Indus ranges,West Pakistan.- Neues Jahrbuch fr Geologieund Palontologie, Abhandlungen, Stuttgart,Band 125, p. 297-333.

KUMMEL B. & TEICHERT C. (1970).- Stratigraphyand paleontology of the Permian-Triassicboundary beds, Salt range and trans-Indusranges, West Pakistan. In: KUMMEL B. &TEICHERT C. (eds.), Stratigraphic boundaryproblems: Permian and Triassic of WestPakistan.- University of Kansas, SpecialPublication, Lawrence, n 4, p. 1-110.

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Punjab University, Lahore, 64 p.SAMEENIS.J. & BUTTA.A. (1996).- Use of alveo-linids for the recognition of the Paleocene-Eocene boundary in the Salt Range,Northern Pakistan.- In: DROBNE K., GORIAN


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