Himalayan
Geology, Vol.21 (1), 2000, pp.1-11, Printed in India
Influence
of Delhi-Hardwar-Harsil Ridge (DHHR) on Basin Configuration in Himalayan
Foothills Belt during Tertiary
DEVENDRA
PAL, R.A.K. SRIVAST AVA
AND N.S. MATHUR
Wadia Institute of Himalayan Geology. Dehradun
248001, India
Abstract: The lower Tertiary
successions extend from northwest to southeast along the Sub Himalaya, the
Lesser Himalaya, the Zanskar and the Indus belts. However, in the Sub Himalaya
these successions are not exposed east of thc Delhi-Hardwar-Harsil Ridge
(DHHR), which is a NNE-SSW trending basement ridge of the Aravallis and
Delhis. In the Sub Himalaya, the lower
Tertiary successions were deposited in a linear foredeep that was formed to the
south of the Himalaya during the late Mesozoic Orogeny and was restricted by
the DHHR to its west.
Taking all the
facts and field relations into account the authors have interpreted that: (a)
the Main Boundary Thrust (MBT) of the western Sub Himalaya cannot be equated
with the MBT of central parts; (b) the DHHR controllcd the Maastrichtian-lower
Tertiary sedimentation and restricted it to the west of the DHHR in the Sub
Himalaya; (c) the lower horizons of the Siwalik succession (the Kamlial) are
not exposed east of Nahan; and (d) the Paleocene-Eocene successions of Rajpur
(the Tethyan sequence towards north of the Pir Panjal Range) and Garhwal (the
Lesser Himalayan sequence) are parts of totally different setups which are
neither in continuity of the Sub Himalaya. nor are parts of these setups. In
fact, these are only time equivalents.
Palaeogeographic
reconstruction, based on faunal and sedimentological studies and geomorphic
controls besides the tectonic set up, has led the authors to redefine the
existing model pertaining to basin development of the Sub Himalaya. In the first part only basement rocks of the
Vaishnodevi Limestone and the Aravalli of the DHHR existed. Marine transgression from west to east took
place immediately after the late Mesozoic orogeny. The sea was nearly 80-100 km
wide in the western part and 10-15 km in the Sataun-Nahan peripheral area,
where the Kakara-Subathu Sea was deposited. Thc Lower Murree (= Dagshai/Lower
Dharmsala) was deposited when the Subathu Sea regressed. Monsoon conditions
commenced with deposition of the Kasauli (Upper Murree/Upper Dharmsala). At
this stage another basin came into existence south of Vaishnodevi and Bilaspur
where fluvial conditions led to deposition of the Lower Siwalik to north of
Ramnagar and Jogindernagar. Next stage was marked by deposition of the Middle
and Upper Siwalik not only to the west of the DHHR (the Delhi-Aravalli and
Vindhyan) but also to the east in the central part of Himalaya. The Middle and Upper Siwalik successions arc
much richer in mammalian fossils in the western part than in the east.
Introduction
The Himalayan mountain chain
runs from Nanga Parbat in the northwest to Namche Barwa in the east along the
northern region of India and passes through Pakistan, India. Nepal, Bhutan and
Tibet. This chain runs in a NNW-SSE direction from Poonch to Paonta Sahib and
then abruptly swings in a WNW-ESE direction in Uttar Pradesh (U.P.) and becomes
E-W in eastern Nepal. It is generally believed that various geological
formations are continuous, running as linear belts from west to east all
through the length of the Himalaya.
Gansser (1964) recognised five lithotectonic units (from south to north)
in the Himalayan orogenic belt that runs for a strike length of over 2400 km
and has a width varying from 230 to 320 km; these units from south to north
are: Sub Himalaya (zone I), Lesser Himalaya (zone 2), Higher Himalaya (Zone 3).
Tethys Himalaya (zonc 4) and Indus Suture (= ophnolite zone; zone 5).
Out of these five
lithotectonic units the Sub Himalaya, which is constituted by the Siwalik Hills
all along the foothills belt of the Himalaya, stands abruptly in the backdrop
of the Indo-Gangetic Plains towards the south. This belt comprises rocks of
Tertiary and Quaternary ages with a few inliers of older sedimentaries.
However, no crystallines or their nappes occur in this belt which are otherwise
common in the Lesser Himalaya. The thrusts recognised by several workers in
this belt arc basically high angle reverse faults. Normal faults that
occasionally occur on dip slopes are of no regional importance as compared to
reverse faults.
In the Sub Himalayan belt of
Jammu and Himachal Pradesh, the Paleogene successions are better developed than
those of Uttar Pradesh and Nepal, where only the Maastrichtian to lower Paleogene
sediments were deposited. It has also been observed that the upper Paleogcne
and lower Neogene successions, which are best developed in this zone in Jammu
and Himachal Pradesh gradually pinch out at Kalsi (cast of Paonta Sahib) and
are not observed east of this place (Figs. 1 and 2). It is, therefore, interpreted that there must have been a
physical barrier at Kalsi which restricted the basin to the west. This physical
barrier is recognised as the Delhi-Hardwar-Harsil Ridgce(DHHR), which trends in
a NNE-SSW direction (Pal, 1993; Pal et al., 1998).
Delhi-Hardwar-Harsil
Ridgc (DHHR)
The DHHR is a northerly
extension of the Aravalli Mountain Belt, which also trends in a NNE-SSW
direction and stretches from Amba Mata-Deri (Gujarat-Rajasthan) to Delhi via
Ajmer and Jaipur. Its northernmost outcrop is exposed on the right bank of the
river Yamuna at Wazirabad Bridge in Delhi. Its further northward extension
below the Indo-Gangetic Plains at Panipat and Saharanpur has been confirmed by
the ONGC. The DHHR comprises quartzite, slate and basic rocks, which belong to
the Delhi Group. From Delhi this ridge gradually slopes down in northerly
direction below the Indo-Gangetic Plains. Therefore, it deepens northwards.
This ridge occurs in the form of scattered outcrops in the southern, middle and
northern parts of the Aravalli. The discontinuous nature of exposures of the
Aravalli Mountain Belt in Rajasthan can be attributed to either denudation or
structural complexities.
Supporting
facts
A DHHR-like feature was also
noticed by Arora et al. (1993 who
described a Trans-Himalayan conductor right through Mohand and Dehra Dun which
almost overlaps the DHHR an d may be synonymous with the DHHR. The authors have
described two different crusts on either side of this conductor, their density,
conductivity and rigidity being totally contrasting. Raiverman (1992) worked out sedimentation history during the
Cenozoic times and showed several trans-Asiatic lineaments including the Astin
Tagh-Yamuna-Aravalli curved lineament, which runs across the ". Himalaya.
Misra (1996) brought out a geological map showing localities of tin, tungsten
and lead mineralisation in Debari, Khetri, Degana (Rajasthan), Tosham (Haryana)
and Purbani (Kinnaur), which fall in a straight line and almost coincide with
the western flank of the DHHR.
Physical
extensions of the DHHR
The DHHR is 65-70 km wide
between Kalsi (Paonta Sahib) and Chilla (Hardwar). It is estimated to exist at
a depth of 2 km at Dehra Dun and becomes gradually deeper when followed
northward in Mussoorie and Uttarkashi. The DHHR is bounded by faults on its
western and eastern sides, which are known as the Yamuna Tear Fault and Ganga
Tear Fault, respectively. The Yamuna
and Ganga rivers follow traces of these faults while flowing down from the
Lesser Himalaya into the Indo-Gangetic Plains. The existence of the DHHR is
supported by the presence of a 1600 Ma old volcano-sedimentary sequence, which
is supposed to be continuation of Bijawar (Vindhyan) below it (Qureshy, 1998).
The DHHR has attained a
primary importance as far as sedimentation control of the Sub Himalaya is
concerned. This ridge also controlled the basin configuration in the Lesser and
Tethys Himalayas marked by pinching out of various geological formations on either
side of it. The regions lying to the east and west of the DHHR have been
grouped under segments I and 2, respectively.
Main
Boundary Thrust (MBT) and Main Boundary Fault (MBF)
The Main Boundary Thrust
(MBT)… separates the Sub Himalaya from the Lesser Himalaya. It is believed that
large scale movement took place along the MBT Main Boundary Thrust bringing the
Lesser Himalayan metasedimentaries over the Sub Himalayan successions. In Uttar
Pradesh (eastern part of DHHR), the MBT is known as the Krol Thrust as it has
brought the Krol belt of the Lesser Himalaya over the Siwalik
(Auden,1934,1937). This means that the Krol Thrust in segment I overlaps the
MHT. In segment 2 further to the west in Jammu, the 'MBF' is equated with the
Murree Thrust (MT) which brings the Tethyan succession (Baila-(Gamir-Panjal
Traps-Mandi-Rajpur) over the Murree Group (late Paleogene-Early Miocene) of the
Sub Himalaya. It may be pointed out that this thrust has erroneously been named
as the 'Main Boundary Fault' by some workers. The MHF Was originally defined as
a tectonic contact separating the upper Tertiaries (Neogene) from the lower
Tertiaries (Paleogene), a definition followed by Wadia ( 1928, 1931, 1966 ). In
the Jammu region the MBF is much to the south of the MBT, the latter being
manifested at Peeda (Nasri Nala) and slightly north of Poonch in the western part, whi1e the former
is observed to the south of Rajauri, Kalakot, Riasi, Katra and to north of
Udhampur, where Kishanpur Thrust (Karunakaran and RangaRao, 1979) merges with
the MBF. As the KT(=MHT) has brought
Krol Thrust sheet over the Siwalik in segment 1, the age of thrusting has to be
younger than the Upper Siwalik, i.e -0.20 Ma (Late Pleistocene), while the MBF
(='Riasi Thrust') in segment 2 is a fault plane that developed after deposition
of the Upper Murree (=Upper Dharmsala/ Kasauli) sediments, which were uplifted
and southern margin of the sediments was faulted and became the MBF. Therefore,
the age of MBF has to be early Miocene, i.e. ~18 Ma (before deposition of the
Lower Siwalik to the south of this fault). So, it is clear that the MBF is much
older than the Krol Thrust/Murree Thrust/MBT.
Contrasting
Geological setting on either side of the DHHR
The geological setups (Table
1) in the Sub Himalaya, Lesser Himalaya and Tethys Himalaya of segments I and 2
are different (Fig. 3). In the following paragraphs, the geographical extent of
various formations in these lithotectonic zones on the eastern (segment 1) and
western (segment 2) sides of the DHHR is discussed briefly.
Table
1.
Tectonostratigraphic sequence in the two
segments (west and east of the DHHR) of the
Himalaya
SEGMENT
2 SEGMENT
I
(west
of DHHR in J & K, (east or DHHR in
Garhwal)
H.P.
and Haryana)
TETHYS
HIMALAYA LESSER
HIMALAYA
Rajpur Fm. (Hazara facies) Subathu
Fm.
(Subathu facies)
Kakara
Fm.
Mandi Fm. ______Unconformity______
Panjal Volcanics Tal
Fm
Agglomeratic Slates Fm. Krol
Fm.
Blaini
Fm.
Gamir Fm. ______Unconformity______
Baila Fm. Nagthat Fm.
Chandpur
Fm.
Mandhali
Fm.
Krol Thrust in south______Unconformity in
north______
Deoban
Gr. ---
__________________Murree
Thrust_________________
SUB
HIMALAYA
Inner
Belt
Upper Murree Fm.
(Upper Dharmsala Fm.= Kasauli Fm.)
Lower Murree Fm.
(Lower Dharmsala Fm.= Dagshai Fm.)
Subathu Fm.
(Subathu facies)
Kakara Fm.
____________Unconformity____________
Vaishnodevi
Limestone (=Sirban/Riasi/Great/
Jammu/Dharamkot/Bandla/Tundapathar
Lime-stone)
Outer
Belt Outer
Belt
Upper Siwalik
Subgroup Upper
Siwalik Subgroup
Middle Siwalik
Subgroup Lower
/Middle Siwalik
Lowcr Siwalik
Subgroup transition
and
Middle
Siwalik Subgroup
Sub
Himalaya
There are two linear belts
of sedimentary successions within the Sub Himalaya: the Inner and Outer
(Fig.4}. The Inner Belt comprises the Kakara-Subathu-Murree/Dharmsala/Dagshai-Kasauli
succession overlying the Vaishnodevi (Riasi/Sirban) Limestone and the Outer
Belt consists of the Neogene (Siwalik Group) sediments. The two are separated
by the MBF.
Inner
Belt or Sub Himalaya
In segment 2, within the
inner belt of the Sub Himalaya, there are several exposures of older basement
rocks in thc Jammu area represented by the Vaishnodevi Limestone (= Sirban
Limestone/Great Limestone/Riasi Limestone/Jammu Limestone), and its equivalents
(Dharamkot Limestone in Dharmsala area, Bandla Limestone in Bi1a.spur area and
Tundapathar Limestone in Shimla area) in Himachal Pradesh and Haryana. These
lithounits occur in the form of inliers in this belt.
Thc
Vaishnodevi Limestone is made up of thickly bedded, highly jointed, hard,
siliceous, dark grey commonly oolitic limestone showing algal mats and
stromatolites (Rao and Rao, 1979). Due to hardness of the rock type, it is quite
resistant to erosion and physical weathering, and therefore stands out in
relief to the low-lying topography. This unit has yielded a rich microbiota
indicative of late Proterozoic to Vendian age (Venkatachala and Kumar, 1996)
thereby corroborating the age assigned by Raha et al. (1978) and Raha (1980). The Vaishnodevi Limestone is
autochthonous and is exposed south of the Main Boundary Thrust and forms the
base of the Sub Himalayan rocks. As a result of it, its geological equivalents
are situated in the southern parts.
Therefore, the only possibility is that the Precambrian-Cambrian
limestone of the Salt Range (Hazara/Abbottabad Formation) could be continuing north-eastwards
in Muzaffarabad-Poonch, Kalakot-Metka-Mohgala, Vaishnodevi-Trikuta Hills (Riasi
inlier), Dhansal-Sawalkot, Dharamkot-(Dharmsala)-Bandla
(Bilaspur)-Kakarhatti-Tundapathar upto the western flank of the DHHR. Out of these, the Riasi inlier is thr
largest in its extent and Dhansal-Sawalkot inlier is the second largest. Though
the Vaishnodevi Limestone belt is in juxtaposition with the calcareous
sequences of the Himalaya, the former cannot be in strike continuity of
Himalayan sequence. They represent
extrabasinal sediments in the Himalaya and obviously are part of basement of
the Peninsular India and could be extending in Himalaya also as MBT and MBF are
post- depositional. The landforms in the Vaishnodevi Limestone were partially
submerged in the Subathu Sea of the Sub Himalaya (Inner Belt) and partially
remained above water (positive areas). This is evident from the unconformity
exposed between the limestone and the Kakara-Subathu succession. A rich fauna
has been recorded from the Subathu sediments of the Jammu region (Singh, 1980a;
Kumar and Sahni, 1985; Juyal and Mathur, 1992). Higher peaks of Vaishnodevi Limestone have remained positive area
during
Cretaceous
and Cenozoic times. In segment 2, the Late Cretaceous to Palaeocene
(Quaker-Sabbath/Murray/ Dharmsala/Dagshai-Kasauli) succession was deposited
unconformably over various Precambrian lithounits and is more than 200 km wide
in Jammu, but becomes narrower eastwards in the Kalka-Subathu section with its
width varying from 100-120 km before the succession finally pinches out at
Kalsi (west of DHHR). In Himachal Pradesh, the Subathu Formation has yielded a
rich foraminiferal assemblage indicative of Ypresian-Early Lutetian age. The
assemblage comprises Nummulites burd.
burdigalensis de la Harpe, N.
beaumonti d' Archiac and Haime, N. .
praediscorbinus Schaub, N. discorbinus (Schlotheim), N. subramondi de la Harpe. Assilina plana Schaub, A. placentula grande Schaub, A. laxispira de la Harpe and A. spira abrardi Schaub (Mathur, 1997;
Juyal, 1997). The Inner Belt of the Sub Himalaya does not continue to the east
of the DHHR in segment 1.
Outer Belt of Sub
Himalaya
The Murree/Dharmsala/Dagshai-Kasauli succession so
well developed in Jammu (3500 m) and Himachal Pradcsh (3000 m) (segment 2) was
not deposited in Garhwal (east of the DHHR i.e. segment 1) (Agarwal et al., 1994). Similarly the Siwalik
succession is well devclopcd in Outer Belt of segment 2 and is represented by
the Lower, Middle and Upper Siwalik. The Lower Siwalik comprises red clay and
sandstone with reddish brown marl and siltstone, whereas the Middle Siwalik
consists of sandstone and variegated clay with conglomerate towards the top,
and the Upper Siwalik is composed of sandstone and conglomerate with reddish
brown silt and clay. From the Lower Siwalik of Ramnagar (Jammu). Sehgal (1998)
has reported charophytes, gastropods, pisces, crocodiles, turtles, primates,
carnivores, proboscideans, suids, anthracotheres, tragulids, giraffids and
bovids. Based on this biota, he assigned a middle Miocene age to the Lower
Siwalik. The fossil assemblages of Ramnagar are referred to three ecological
communities, namely aquatic and semiaquatic community represented by stream,
stream bank and pond populations; the abroreal by primates; and the terrestrial
by other mammals (Sehgal, 1998). According to Sehgal (1998), the bulk of the
mammalian assemblage is indicative of tropical rain forest environment with
swampy conditions. The Middle Siwalik in Himachal Pradcsh is characterised by
thickly bedded multi-storeyed, grey sheet sandstone showing salt and pepper
texture with minor mudstone deposited by erstwhile south-easterly flowing axial
drainage (Ghosh et al., 1998). According to Ghosh et al. ( 1998) the Upper
Siwalik has varied lithofacies association. It comprises buff, ribbon shaped,
fine grained. matrix-rich sandstone within the grey sandy domain. These
sandstone bodies, which are bound by overbank deposits and without any lateral
accretionary features, represent laterally fixed channel of south-south-east
flowing piedmont drainage originating from the proximal part of the foreland
basin. The Middle and Upper Siwalik have yielded a rich vertebrate fauna
(Nanda. 1976, 1978. J 998). In Jammu and western Himachal Pradesh regions, the
Kamlial and Chinji formations of the Lower Siwalik can be recognised. There is
so much difference in lithology of the Lower Siwalik of these regions from
eastern Himachal Pradesh that their equivalent in the latter region has been
named as the Nahan.
In segment I, the extent of
the Siwalik exposures is much reduced and is not more than 30 km in
Mohand-Rajpur (Mussoorie) section of the Doon Valley and is minimum (3- 4 km)
at Kotdwar in the Khoh Valley between Sidhbali temple and Haldwani Bridge
(south of Dugadda). In Garhwal region (segment I ), only the upper part of
Lower Siwalik, and the Middle and Upper Siwalik have been reported (Ranga Rao et al., 1979; Tiwari, 1981 ). In this
region, repetition of beds is due to Mohand Anticline, Doon Syncline and Malsi
Anticline (from S to N). The total thickness of the Siwalik succession is
around 4000 m in the Mohand-Rajpur section. The Middle Siwalik near Mohand
consists of micaceous, fine to medium grained, grey, multistoried sandbodies
and grey mudstone which changes to red in the younger horizons. According to
Tandon et al. ( 1988), the occurrence
of red mudstone in the top part of the Middle Siwalik suggests oxidising
conditions and relatively well drained flood plains. The Upper Siwalik
comprises conglomerate (cobbles and pebbles), its provenance being from the
Himalayan metamorphics like granites, gneisses, schists, quartzites, slates,
etc. (Kumar and Srivastava, 1995). It is very important to note that rich and
well preserved vertebrate fauna recorded from the Middle and Upper Siwalik of
segment 2 (Jammu and western Himachal Pradesh) has not been found in segment I
(Garhwal region), or its presence is negligible (Sahni and Tiwari, 1979; Tandon
et al., 1988). It has, therefore,
been inferred that the DHHR hindered the movement of vertebrates from west to
east. The richer yield of Tertiary vertebrate fauna in the areas to the west of
the DHHR is a consequence of role played by the manifestation of the DHHR in
controlling the configuration of the foreland basin on either side of it. For
smaller vertebrate fauna, it might have acted as a physical barrier, which
seems to be well reflected in the composition of larger vertebrates and in
their food- , web. It further supports the contention that the DHHR, which
formed a physical barrier, not only limited the sedimentary basins but also
controlled the physical movement of vertebrates. Therefore, the lithologies of
the Middle and Upper Siwalik are also markedly different on either side of the
DHHR.
Lesser
Himalaya
Almost all the workers took
it for granted that the Krol Belt extending from the Krol Hill in Solan to
Nainital in Kumaun is a single belt ignoring completely the absence of Krol
Sandstone and Tal Phosphorite (two
economic deposits) on eastern and
western sides of the DHHR. The Krol Sandstone (50-60m) is remarkably uniform
and occurs persistently at the base of the Krol Limestone (Member A) in the
Outer Krol Belt. It comprises compact orthoquartzite and friable sandstone. It
has highly rounded, coarse grained and well sorted quartz grains with little or
no matrix. This unit is completely missing in the Inner Krol Belt of Mussoorie,
Garhwal and Nainital. It was Bhargava (1972), who clearly established that the
two successions in the Krol Hill and Nainital areas are neither in strike
continuity nor were deposited in a single basin. He grouped the Krol succession
of the Simla and Nainital areas under the Outer and Inner Krol belts,
respectively. The Nainital, Garhwal and Mussoorie synclines fall In the Inner
Krol Belt, whereas the Krol, Pachmunda and Sain Dhar Synclines are in the Outer
Krol Belt. The Krol Sandstone is found in the Outer Krol Belt while the Tal
Phosphorite is restricted to the Inner Krol Belt. Similarly, the volcanic rocks
are quite common in the Inner Krol Belt, whereas basic volcanic rocks are
absent in the Outer Krol Belt.
To the north of the MBT
(=Krol Thrust), which is a sharp line from Kalsi to Rajpur, Rishikesh, Dugadda
and Rathwadhab, a prominent and well marked sequence of the Krol Belt is
exposed in a linear form almost parallel to the Sub Himalayan trend. This is in
sharp contrast to what is observed in the west (Outer Krol Belt). East of the
DHHR, the Lesser Himalayan sequence comprising Jaunsar and Krol groups is
thrust over the Siwalik. The Kakara (= Bansi)- Subathu Dagshai succession lies
unconformably over the Krol- Tal succession and occupies the youngest position
in the Inner Krol Belt. The Jaunsar Group, represented by the Mandhali,
Chandler and Nagthat formations, forms the base of this sedimentary belt and is
overlain by rocks of the Krol Group. The Blaini Formation is the oldest unit of
the Krol Group and is represented by pebbly quartzite and turbidites (Blaini
Member) grading upwards into the Infra-Krol Member. The latter unit is overlain
by the Krol Formation, which contains limestone in great abundance and forms
higher ranges in the Lesser Himalaya due to its resistence to physical
weathering. The overlying Tal Formation comprises carbonaceous shale,
phosphorite and chert at its base followed upwards by shale and quartzite. This
unit has yielded Cambrian fauna (Azmi et
al., 1981; Rai and Singh, 1983; Kumar et
al.. 1983 ). The Kakara Formation lies unconformably over the Tal
Formation. It comprises hard grey, massive, oolitic shelly limestone. It has
been assigned varying ages in the Maastrichtian-Thanetian interval based on
various taxa: a Maastrichtian-Danian age by Mathur (1977) (cerioporids and
molluscs) and Bhatia (1980) (cerioporid bryozoan -Diplocavae calcareous algae and hydrozoan); a late Cretaceous age
(Coniacian) by Singh (1980b) ( Globotruncana);
and a Maastrichtian- Thanetian age by Juyal and Mathur (1990) ( Diplocava
nilkanthi (Singh) and Phafcocythere
rete Siddiqui - a Thanetian ostracode species and several other long
ranging nlanetian-Lutetian ostracode taxa recovered from the upper part of this
unit). This shelly limestone of Garhwal region (=Nilkanth Formation of Singh,
1979/Bansi Formation of Valdiya, 1980) has been equated with the Kakara
Formation of the Shimla region based on lithology and sedimentology, thereby
supporting the views held by Valdiya ( 1980). The succeeding Subathu Formation
consists mainly of grey, green to red shalc with subordinate siltstone,
sandstonc and limcstone which is frequcntly fossiliferous. The Subathu Formation
has been assigned a Ypresian to an Early Lutetian age based on the occurrcnce
of a rich fauna (Mathur, 1997; Juyal, 1997). The Dagshai Formation is the
youngest unit in this belt of which only the basal part, comprising green
sandstone and red shale, is present at Dugadda (segment ] ).In segment 2, the
Subathu Formation occurs in the form of tectonic windows north of the Krol
Thrust at SoJan. In this segment in the Shali area, north of Solan, the Subathu
Formation rests unconformably over the Shali-Madhan succession. Further in
Mussoorie-Chakrata area the KroJ- Tal succession along with the Deoban is
exposed right from the MBTto the Main Central Thrust (MCT). This itself is a
unique setting confirming existence of the DHHR. Further the rocks of the Krol-
Tal succession show very gentle dips and beds are even horizontal at Chakrata.
Auden ( 1933) had interpreted strike continuity of the Aravallies across the
Himalaya in the Chakrata area. In a later work, Rupke ( 1974) gave a detailed
account of rocks of the Damta Group in western Garhwal, whcre he proposed a new
name -Damta High -a basinal high which effectively controlled sedimentation on
its peripheries in the Chakrata-Nagthat area. This almost coincides with the
DHHR, which passes through this area and has controlled the sedimentation.
Tethys
Himalaya
The succession to
the north of the MBT ('Murree Thrust') in the Poonch area has been considered
by some workers to fall in the Lesser Himalaya. The authors interpret that this
succession represented by the Gamir-Baila-Panjal Trap-Mandi-Rajpur succession
is a part and parcel of the Tethys Himalaya. The litho-and biostratigraphy of
this succession has been outlined by Verma et
al. ( 1981 ). The Rajpur Formation, the youngest unit of the succession, is
best exposed at Rajpur village, north of Poonch. It is divisible into two
distinct members, the lower Nummulitic Limestone Member and the upper
Variegated Shale Member. The lower member has yielded several species of Daviesina. Nummulites and Assilina indicative of
Thanetian-Ypresian age. The Rajpur Formation which is exposed in the western
part of Kashmir has earlier been designated as' Hazara facies’ (Wadia, 1966).
The above Tethyan sequence
continues eastwards in the Zanskar and Spiti regions. The Permo-Triassic
limestone and Chikkim Formation pinches out to the west of the river Satluj
near where a Trans-Himalayan granite (Leopargil Granite) is emplaced along the
DHHR which is almost perpendicular to the Himalayan strike, as if it restricted
basins on either side of it, as the Malla Johar Basin of Kumaun does not cross
this granite mass.
Basin
Development history during Cenozoic
A model of basin
development for the Sub Himalaya based on physical discontinuity across the
DHHR and geological setting of various successions to the east and west of this
ridge (segments I and 2) is given in Figure 5. In the first stage of basin development, the Sub Himalayan basin
extended from Poonch in the west to Paonta Sahib in the east, where the DHHR
formed its eastern limit and the Panjal
Traps formed the northern limit. It has many exposures probably in geological
continuity of the Vaishnodevi Limestone at Kalakot, Metka, Mohgala, Riasi,
Dhansal- Sawalkot, Dharamsala, Bilaspur, Kakarhatti and Tundapathar areas. This basin was formed during the Late
Cretaceous times (Mathur, 1990, 1997; Mathur and Juyal, 1996). The
Maastrichtian-lower Paleogene marine
sediments, represented by the Kakara-Subathu succession, were deposited in this
basin. The marine sedimentation was replaced by fluviodeltaic system as the
basin was partially filled up and partly became positive. The rivers started
flowing down from higher areas ill the north and the rock.-; of the overlying
Murree were deposited in the Inner Belt, their provenance was both from north
and south.
In the second stage, the basin got uplifted and a
newer landscape in the Paleogene-Early Miocene sediments also came into
existence. The southern border of this landscape became the MBT and the Lower
Siwalik \vas deposited to south of it in the Outer Belt. An estuary of brackish
water stretched towards north from Ramnagar to Udhampur, and another from
Sundarnagar to Jogindernagar. The eastern limit was restricted to the DHHR.
Nahan lying on the peripheral area of the ridge gave rise to slightly different
lithology due to its location on the edge of the ridge.
In the third stage, the DHHR got partly
submerged due to some tectonic movement. As a result of it two different
lithofacics developed on either side of the DHHR. It can be assumed that a
single basin existed from the Middle Siwalik onwards and finally the entire
succession got uplifted in the Early Quaternary and gave rise to landscape of
present day. A situation similar to original MBF is further developing in the
form of Himalayan Frontal Fault (HFF) in the Indus and Gangetic Plains.
Acknowledgements: The
authors are grateful to the Director of the Wadia Institute of Himalayan
Geology, Dehradun for providing various facilities.
References
AGARWAL. R.P..
PRASHAD, D.N., SAMANTA, U., BERRV, C.M. and SHARMA. J., 1994. Hydrocarbon
potential of Siwalik Basin. Him. Geol.,
IS, 30 1-320.
ARORA. B.R.,
MAHASHABDE, M.V. and SIVAJI, Ch., 1993. Geophysical appraisal of the crust
break the Indo-Gangetic Plains and contiguous frontal belt of Himalaya. Sem. Him. Geol. & Geophysics, Wadia Institute of Himalayan
Geology. Dehra Dun. Abstract. p. 89.
AUDEN. J.B. 1933.
On the age of certain Himalayan granites. Rec.
Geol. Surv. India, 66 (4), 461-471.
____________1934.
The geology of the Krol Belt. Rec. Geol.
Surv. India, 67 (4), 357-454.
____________1937.
The structure of the Himalaya in Garhwal. Rec.
Geol. Surv. India, 71 (4),407-433.
AZMI R.J., JOSHI,
M.N. and JUYAL, K.P., 1981. Discovery of Cambro-Ordovician conodonts from the
Mussoorie Tal Phosphorite : its significance in correlation of Lesser Himalaya.
In SINHA, A.K. (ed.). Cotlemp. Geo.sci.
Res. in Himalaya. Bishen Singh Mahendra Pal Singh, Dehra Dun, 1, 245-250.
BHARGVA, O.N.,
1972. A reinterpretation of the Krol Belt. Him.
Geol.,2,47-81.
BHATIA. S.B.
1980. The Tal Tangle. In Valdiya, K.S. and Bhatia, S.B. (eds), Stratigraphy and correlation of Lesser
Himalayan formations. Hindustan Publ. Corp., Delhi, 79-96
GANSSER, A.,
1964. Geology of the Himalayas. Wiley
interscience Publ., London, 1-289.
GHOSH, S.K..
KUMAR, R. and SSNGODE, S.J., 1998. Sequential variation of Mio-Pleistocene
palaeodrainage in a part of the Himalayan Foreland Basin, India. Workshop on Himalayan Foreland Basin with
special reference to pre-Siwalik Tertiaries, Jammu Univ., Jammu, 28-29 (abstract).
JUYAL, K.P.,
1997. Faunal communities of the Kakara-Subathu sequence (Maastrichtian-lower
Lutetian) of western Himalayan foothills. In SINHA. A.K., SASSI, F.P. AND
PAPANIKOLEAU, D. (eds), Geodynamic
Domains in Alpine Himala.van Tethys : Speciall
Publ. IGCP Project 276. Oxford and IBH Publishing Co. Pvt. Ltd, New Delhi
and A.A. Balkema, Rotterdam, 159-192.
_______and
MATHUR, N.S., 1990. Ostracodasfrom the Kakara and Subathu Formations of
Himachal Pradesh and Garhwal Himalaya, India, Jour. Him. Geol., 1 (2), 209-233.
_________and____________,
1992. Ostraeodes from the Subathu Formation of Jammu region, Jammu and Kashmir
State. India. Jour.Him. Geol., 3 (I),
21-35.
KARUNAKARAN, C. and RANGA
RAO, A., 1979. Status of exploration for hydrocarbons in the Himalayan region .
Contributions to stratigraphy and structure. Him. Geol. Sem, Geol.Surv. India. 41 (5) 1-68.
KUMAR. and
JANGPANGI, B.S.,1983. Lower Cambrian body and trace fossils from the Tal
Formalion, Garhwal Synform. Uttar Pradesh, India. Jour. Palaeont. Soc India, 28, 106-111.
KUMAR, K. and
SAHANI, A., 1985. Eocene mammals from the Subathu Group. Jour. Vert. Paleont., 5 (2), 153-168.
KUMAR, R. and SRIVASTAVA,
R.A.K., 1995. Mio-Pliocene multistoried sandstone complex exposed in Mohand
area, Dehra Dun ; palaeo-current analysis of megafans. Vigyan Garima Sindhu, Commission
for Scientific and Technical Terminology, New Delhi, 19, 128-141.
MATHUR, N.S.,
1977. Age of the Tal and Subathu Formation in the Garhwal region, Uttar
Pradesh. India. Bull. Indian Geol.
Assoc., 10 (2), 21-27.
_______________1990. Tethyan
Cretaceous sediments in the northwest Himalaya. Cretaceous Res., II, 289-305.
_______________1997.
A comparative study of lower Tertiary bio-stratigraphic sequences in the
northwest Hiimalaya and their palaeogeographic significance. In SINHA A.K.,
SASSI. F.P. and PAPANIKOLEAU, D. (eds),Geodynamic
Domains in Alpine-Himalayan Tethys : Special
Publ. IGCP Project 276 Oxford and 1BH Publishing Co. Pvt. Ltd., New Delhi
and A.A. Balkema, Rotterdam, 126-158.
________and
JUVAL. K.P. 1996, Time of emplacement of ophiolitic melange in Indus Suture
zone, Ladakh Himalaya; a paleonlological approach. Contrs XV Indian Colloq. Micropal. Strat. Dehra Dun. 169-176.
MISRA, S.P..
1996. Tin-Tungsten Line of western India. Proc
.Sy'mp. NW Himalaya and Foredeep (1995), Geo{ .Surv. India. Special Publication, 21 ( 1 ), 455-457 ,
NANDA, A.C..
1976. Some proboscidean fossils from the Upper Siwalik Subgroup of Ambala. Him. Geol., 6. 1-26
_____________1978. Fossil
equids, from the Upper Siwalik Subgroup of Ambala, Haryana. Him.Geol., 8, 149-177.
______________1998.
Siwalik stratigraphy and vertebrate palaeontology of northwest Himalaya :
recent advances. Workshop on Himalayan
Foreland basin with special reference to pre-Siwalik Tertiaries. Jammu Univ.
Jammu. 45-47 (abstract).
PAL, D., 1993.
India and China forming a single plate - evidenccs from Himalaya, Arabian Sea
and China. Bull. Oil and Natural Gas
Commission, Dehra Dun, 30 (2)
19-25.
________SHARMA,
B.P. and LAI., A.K.. 1998. Degradation of land resources in MBT and MCT zones
as a result of NNE- SSW trending linear Aravalli basement in Garhwal Himalaya. National Seminar on
Him.Env.&Sust.Development, Dehra
Dun (1995). In SAXENA, P.B. (ed.), Recern
Trends in Biosphere and Env Series, 1, 284-302.
QURESHY, M.N.,
1998. The presumed transverse ridges in the Ganga Foredeep and Peninsular
India: an appraisal from isostatic anomalies and related tectono-physical data.
Workshop 0f Himalayan Foreland Basin with
special reference to pre-Siwalik Tertiaries, Jammu Univ., Jammu. 56-59
(abstract).
RAHA, P.K.. 1980.
Proterozoic microbiota from stromatolitic black chert of Jammu Limestone,
Udhampur District, Jammu and Kashmir. India. Jour. Geol. Soc. India, 21, 572-574.
___________,
CHANDY, K.C. and BALASUBRAMANY AN, M.N., 1978. Geochronology of the Jammu
Limestone, Udhampur, Jammu, India. Jour.
Geol. Soc~ India, 19 (5), 221-223.
RAIVERMAN, V.,
1992. Trans-Asiatic lineaments and Himalayan orogeny. In SINHA, A.K. (ed.), Himalayan Orogen and Global Tectomcs. Oxford
& IBH Publishing Co. LId, New Delhi, 121-155.
RAI V. and SINGH,
I.B., 1983. Discovery of trilobite impressions in the Arenaceous Member of the
Tal Formation, Mussoorie area, India. Jour.
Palaeont. Soc. India, 28, 114-117.
RANGA RAO A.
KHAN, N.N., VENKATACHALA, B.S. and SASTRI, V. V., 1979. Neogene/Quaternary Boundary and the Siwalik. Review Papers. Field
Conference. Neogene/Quaternary Boundary , India, 1-36.
RAO. V. V.K. and
RAO. R.P.. 1979. Geology of Tertiary belts of north- west Himalaya, Jammu &
Kashmir State. India. Him. Geol. Seminar.
Geol.Surv. India, 41 (5), 149-182.
RUPKE, J., 1974.
Stratigraphic and structural evolution of the Kumaun Lesser Himalaya. Sedimentary Geology, II, 81-265.
SAHNI. A. and
TIWARI, B.N., 1979. Lower Siwalik vertebrates from Kalagarh area, District
Pauri Garhwal. Him.Geol., 9 ( 1 ),
339- 347.
SEHGAl. R.K.,
1998. Palaeoecology of the Lower
Siwalik sediments of Ramnagar (J
& K). Workshop on Himalayan Foreland
Basin with special reference to pre-Siwalik Tertiaries Jammu Univ., Jammu, 66-67
(abstract).
SINGH, I.B., 1979.
Environment and age of the Tal Formation of Mussoorie and Nilkanth areas of
Garhwal Himalaya. Jour. Geol. Soc. India,
20, 214-225.
SINGH, P, 1980a. The Subathu Group o)f India. Nav Jyoti
Scientific Publications, Lucknow, Prof. Paper I, 1-92.
__________1980b.
Microfauna, age, palacoenvironment and palaeobiogeography of the Tal Formalion
of Lesser Himalaya, Garhwal, Uttar Pradesh, India. Current Science, 49 (7}, 255- 261.
TANDON, S.K.
THAKUR, V.C., NANDA, A.C. AZMI, R.J., BAGATI,T.N. TEWARI, V .C. AND KUMAR, R.. 1988. Excursion Guide
: Himalayan sequence of Dehra Dun-Mussoorie Sector. Special Publication. Geol. Soc. India, 1-90.
TIWARI, B.N.,
1981. Lower Siwalik faunas of the Indian Subcontinent, with special reference
to Kalagarh fauna. Pub Centre o)f
Advanced Study in Geology. Punjab Univ., Chandigarh. 13, 98~ 12.
VALDIYA, K.S.,
1980. Geology of Kuauun Lesser
Himalaya. Wadia Institute of
Himalayan Geology, Dehra Dun, 1-291.
VENKATACHALA,
B.S. and KUMAR, A., 1996. Significant microbiota from the Great Limestone of
Jammu, Lesser Himalaya. Contrs. XV, Indian Colloq. Micropaleont. Strat.,Dehra
Dun, 551-557
VERMA, S.N.,
SINGH, R.P. and SHIVAJI, K., 1981. On the Upper Paleozoic, Mesozoic and Eocene
rocks of the para-autochthonous belt in Mandi Valley of Poonch District, J
& K. Him Geol.,11,91- 102.
W ADIA, D.N.,
1928. The geology of Poonch State (Kashmir} and the adjacent portions of
Punjab. Mem. Geol. Surv. India, 51
(2), 185-370.
_____________,1931.
Thc syntaxis of northwest Himalaya: its rocks, tectonics and orogeny. Rec. Geo. Surv. India, 55 (2). 189-220.
______________1966, Geology of
lndia, . McMillan and Co., 1-536.