Pakistan's Highway of Marvels (Urdu) by dawn-news
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Applied geophysics by: W.M.Tellford, L.P.Geldart, R.E.Sheriff
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Thursday, 23 October 2014
Super Continent Pangea,Himalayas, Boundary Fault,Main Karakoram Thrust (MKT),Main Mantle Thrust ( MMT),Main Central Thrust (MCT),Main Boundary Thrust (MBT),Salt Range Thrust (SRT) and Trans Indus Ranges Thrust (TIRT) ,Subdivision of Himalaya,1Trans Himalaya,Higher Himalaya,Lesser Himalaya,Sub Himalaya,Tectonic Settings of Salt Range,Central Salt Range
Super Continent Pangea
A large super continent Pangea (Searle, 1991) existed till the end of Proterozoic era (Piper, 1982). The single enormous ocean which surrounded Pangea is known as Panthalassa (Nield, 1998). Before Pangea, the supercontinent, Rodinia, formed about 1.1 billion years ago during the Proterozoic era, and lasted until 700-750 Ma (Dalziel, 1995). Breakup of super continent initiated in Carboniferous to early Permian (Searle, 1991) and it result super continent divide in two parts, Gondwanaland (Suess, 1885) in south and Laurasia in north and a new ocean Neo Tethys between them (Searle, 1991: Powell, 1979). Among the Gondwana continents, India started to move rapidly northwest relative to Australia and Antarctica during Late Cretaceous.
As a consequence, the Neo-Tethys that was located between the Indian continent and Asian plate started shrinking and this continental drift was facilitated by the consumption of Neo-Tethys and opening up of the Indian ocean behind. Eventually India collided with Kohistan Island arc at 67+2 Ma (Chaudhry et al., 1994; Valdiya, 2002) and the Kohistan Island Arc with southern margin of Eurasia (Powell, 1979) at 65 Ma prior to this collision (Searle, 1991). Propelled by the geodynamic forces, the Indian plate traveled 5000 km northward (Powell 1979).
After the collision, Indian continental crust started to subducted beneath Eurasia and northward movement of Indian plate slowdown and continuous up to present (Powell, 1979).The subduction of the northern margin of the Indian plate finally closed the Neo-Tethys and the Indian Ocean assumed its present widespread expanse (Treloar and Izatti, 1993). This collision is characterized by deformation, crustal thickening and surface uplift. The ongoing convergence caused the development of Himalayas along the northwestern margin of Indian Plate (Spencer, 1993).
: Pangea after break up HimalayasAs a consequence, the Neo-Tethys that was located between the Indian continent and Asian plate started shrinking and this continental drift was facilitated by the consumption of Neo-Tethys and opening up of the Indian ocean behind. Eventually India collided with Kohistan Island arc at 67+2 Ma (Chaudhry et al., 1994; Valdiya, 2002) and the Kohistan Island Arc with southern margin of Eurasia (Powell, 1979) at 65 Ma prior to this collision (Searle, 1991). Propelled by the geodynamic forces, the Indian plate traveled 5000 km northward (Powell 1979).
After the collision, Indian continental crust started to subducted beneath Eurasia and northward movement of Indian plate slowdown and continuous up to present (Powell, 1979).The subduction of the northern margin of the Indian plate finally closed the Neo-Tethys and the Indian Ocean assumed its present widespread expanse (Treloar and Izatti, 1993). This collision is characterized by deformation, crustal thickening and surface uplift. The ongoing convergence caused the development of Himalayas along the northwestern margin of Indian Plate (Spencer, 1993).
The Himalayan ranges of south Asia are a dilemma due to their complex geology in modern plate tectonic theory. The process of sea floor spreading and subduction together leads to drift of lower density buoyant continents and island arcs, which can eventually, collided against each other, leading to thrusting. Thrusting builds up a stack of lower density crustal sheets involving deformation and leading to metamorphism and magmatism. This deformed metamorphosed and intruded stock eventually starts rising to achieve new isostatic equilibrium giving rise to linear collision mountains or orogenic belts. Tectonically the Himalayas are recognized as young collisional orogen and mountain belt formed as result of collision at about 55 Ma or 65 Ma between north moving Indian plate to south and Asian plate to the north (Lillie, 1988).
The tectonic elements of NW Himalayas (Fig. 3.2) include from north to south as Asian Plate (Brad et al., 1976: Ghazanfar et al., 1991), Main Karakoram Thrust, MKT (Ghazanfar, 1993), Kohistan Island Arc Complex (Brad et al., 1976: Ghazanfar et al., 1991; Tahirkheli et al., 1979; Trelor et al., 1989; Chaudhry et al., 1984), Indus suture or MMT (Ashraf et al., 1991; Tahirkheli et al., 1979) and Indian Plate margin (Chaudhry and Ghazanfar, 1987; Ghazanfar, 1993).
Boundary Faults
On the basis of four regional faults systems, Pakistani Himalayas can be divided into five litho-tectonic terrains, which are characterized by distinctive stratigraphy and physiography. From north to south these gross geological belts and the major faults systems separating them are as given and described respectively below.
Main Karakoram Thrust (MKT)
The Main Karakoram Thrust (MKT) zone marks the contact between the Eurasian Plate in the north and the Indian Plate in the south (Coward et al. 1982). The Main Karakoram Thrust (MKT) is major tectonic feature in northern Pakistan formed as a result of the collision between the Karakoram block in the north and the Kohistan Island Arc in the south (Gansser 1980). The MKT was previously named as the Northern Suture (Pudsey et al,. 1986).
Main Mantle Thrust (MMT)
The MMT is marked by the mantle related ultra-mafics, metavolcancis, metagabbros, phylitic sediments, blueschists, and garnet granulites (Jan, 1980, Jan and Howie, 1981). The MMT bounds the Kohistan Island Arc (KIA) to the south and the Indian Plate to the north. It formed as a result of collision and subduction of Indian Plate underneath the KIA during Eocene time. It is the southernmost thrust involving lower-crust crystalline rocks of the Indo-Pakistani shield (Desio, 1974 b).
Main Central Thrust (MCT)
This thrust was initially defined by the Auden (1937) and Heim et al. (1939) as a thrust fault which has brought the high grade crystalline rocks over the low grade meta-sediments (Kazmi, 1997). The main central thrust (MCT) is an intracontinental thrust that separates the Higher and Lesser Himalayas. It was first described by the Heim and Gansser (1939) as a tectonic boundary between the Himalayan autochthonous sedimentary sequence and the overlying crystalline complex. It has been traced from Nepal and up to Southern Kashmir (Gansser, 1964). In NW Himalayas, It is north dipping, generally 5 to 20 Km thick, low to high angle shear zone associated with mylonization, strong stretching lineation and strong foliation. It is also marked by inverse metamorphism and sudden jump in metamorphic grade from greenschist to upper amphibolite facies with different tectonic style on either side of the shear zone. This ductile shear zone develops in the turbidites of Kaghan as well as Malakand area (Ghazanfar and Chaudhry, 1999).
Main Boundary Thrust (MBT)
MBT is hairpin-shaped system of faults that can be followed around the Hazara Kashmir Syntaxis. It truncates the Murree Formation on the east, north and west (Treloar et al., 1989 a, 1990, Chaudhry et al., 1997a). It abuts the Mesozoic and the earlier rocks against the Murree Formation. The Main Boundary Thrust (MBT) represents the southward migration of Himalayan deformation from the site of MMT. From northeast to southwest, it extends along the front of the northern fold and thrust belt around Hazara-Kashmir Syntaxes (Calkins et al., 1975). The MBT zone is comprised of a series of parallel or en-echelon thrust faults dividing the northwest Himalayan sequence into a deformed sedimentary southern zone or foreland zone, and a deformed and metamorphosed northern zone or the hinterland zone (Di Pietro et al., 1996).
Salt Range Thrust (SRT) and Trans Indus Ranges Thrust (TIRT)
Salt Range Thrust (SRT) / Himalayan Frontal Thrust (HFT) or the Main Frontal Thrust (MFT) runs along western margin of Salt Range between Jhelum and Indus River in NW Himalayas of Pakistan. It is low angle fault or sub horizontal fault and throw of the fault is good enough to expose Pre-Cambrian strata (Salt Range Formation). In northern Pakistan most of the youngest thrusting has occurred along frontal thrust system in Salt Range along Salt Range Thrust (SRT) in the east and in Trans-Indus Ranges Thrust (TIRT) in the West (Blisniuk et al., 1998). The frontal thrust system has accommodated about ≥ 20 km of shortening in Salt Range (Lillie et al., 1987) and ~ 10 km in Trans Indus Ranges. Along this thrust front Eo-Cambrian Salt Range Formation in the Salt Range (Gee, 1980); Permian rocks in the Surghar Range and the Cambrian Jhelum Group rocks in the Khisor Range are Thrusted over the Punjab Fore-deep in the South (Kidwai, 1973).
Salt Range Thrust (SRT) and Trans Indus Ranges Thrust (TIRT)
Salt Range Thrust (SRT) / Himalayan Frontal Thrust (HFT) or the Main Frontal Thrust (MFT) runs along western margin of Salt Range between Jhelum and Indus River in NW Himalayas of Pakistan. It is low angle fault or sub horizontal fault and throw of the fault is good enough to expose Pre-Cambrian strata (Salt Range Formation). In northern Pakistan most of the youngest thrusting has occurred along frontal thrust system in Salt Range along Salt Range Thrust (SRT) in the east and in Trans-Indus Ranges Thrust (TIRT) in the West (Blisniuk et al., 1998). The frontal thrust system has accommodated about ≥ 20 km of shortening in Salt Range (Lillie et al., 1987) and ~ 10 km in Trans Indus Ranges. Along this thrust front Eo-Cambrian Salt Range Formation in the Salt Range (Gee, 1980); Permian rocks in the Surghar Range and the Cambrian Jhelum Group rocks in the Khisor Range are Thrusted over the Punjab Fore-deep in the South (Kidwai, 1973).
Subdivision of Himalaya
With the demarcation of basement of Indian plate and boundary faults, now it is possible to divide NW Himalayas into four tectonic units of Gansser (1964), as in Eastern and Central Himalayas. NW Himalayas are enumerated from north to south as Tethyan Himalaya, Higher Himalaya, Lesser Himalaya and Sub Himalaya.
Trans Himalayas
Trans Himalaya or Tibetan-Tethyan Himalaya occur north of Higher Himalaya and consists of Proterozoic to Eocene siliciclastic and carbonate sedimentary rocks inter-bedded with Paleozoic and Mesozoic volcanic rocks resting over Pre-Cambrian higher Himalayan basement with tectonized unconformity (Baud et al., 1984; Garzanti et al., 1986, 1987). Tethyan sequence has developed as continental margin shelf deposit on the northern edge of Indian plate which occurs as low grade meta-sediments (Ghazanfar and Chaudhry, 1999).The Tethyan Himalayas are limited to north by Indus Tsangpo Suture Zone in NW Himalaya and this zone also acts as the northern most boundery of the Indian plate. Indus suture or MMT demarcate boundary between Indian plate and Kohistan island arc and comprised of dismembered ophiolites (Tahirkheli et al., 1979). MMT is the true extension of Indus-Tsangpo Suture Zone which occurs at 65 Ma (Spencer, 1993; Chaudhry et al., 1994; Smith et al., 1994). Until very recently the Tibetan-Tethys zone of Himalaya was considered absent in the Pakistan. Mapping in Kaghan and Swat however, have indicated that the Tibetan-Tethys zone of Himalaya is indeed present in Pakistan, though much attenuated and discontinuous (Chaudhry and Ghazanfar, 1987; Chaudhry et al., 1992, 1993, Ghazanfar and Chaudhry, 1999).
Higher Himalayas
With the delineation of Main Central Thrust or MCT in (Chaudhry et al., 1997b; Ghazanfar and Chaudhry, 1986, 1990; Chaudhry et al., 1994a, 1994b), now it is possible to establish the different tectono-stratigraphic regions of Himalaya, such as Higher Himalaya, Lesser Himalaya and Sub Himalaya in Pakistan. Higher Himalayas are limited by MMT in north and MCT in south. MCT is intracontinental thrust which demarcates the boundery between the Lesser and Higher Himalayas (Brunel, 1986; Valdiya, 1984; Ghazanfar and Chaudhry, 1986).
In Pakistan, the Higher Himalayas includes the Nanga Parba-Haramosh massif (Yeats and Lawerence, 1984).It extends from Bajaur on the Pakistan Afghanistan border in the west to the Neelum valley of Kashmir in the east. Higher Himalaya comprised of Proterozoic to Late Proterozoic basement and Phanerozoic to Mesozoic cover in Pakistan (Ghazanfar, 1993; Chaudhry and Ghazanfar, 1987). Basement rock represents the oldest exposed rocks of Pakistan and composed of lower autochthonous to Para-autochthonous granitoid-migmatite complex, pelite-psamites with turbidites and associated minor quartzite and marble horizons. Basement is overlained by cover sequence which is composed of calc-pelites and marbles with some garnetiferous calc-pelites, amphibolites and pelites (Ghazanfar, 1993; Chaudhry and Ghazanfar, 1987; Ghazanfar and Chaudhry, 1985; Chaudhry et al., 1994a, 1997; Ghazanfar et al., 1983, 1999a).
Basement and cover sequence rocks are grouped in different areas of Higher Himalaya. Kel Group, Purbinar Group and Pacha Group constitutes the basement rock in Neelum Valley, western Kashmir, Upper Kaghan Valley and Swat area respectively and Sharda Group, Burawai Group and Alpuri group represent cover sequence respectively. The rocks of Higher Himalaya are metamorphosed to upper amphibolites facies and kyanite-silliminite grades just north of Batal area in Naran area of Kaghan (Ghazanfar et al., 1983, 1999a; Ghazanfar and Chaudhry, 1985, 1987; Chaudhry et al., 1994a, 1997).
Lesser Himalayas
Lesser Himalaya is confined between MCT and MBT in north and south respectively. MBT formed due to compressional deformation. In Pakistan, Lesser Himalayaextends in Lower Neelum Valley, Lower Kaghan Valley, Hazara area and Swat area across the Indus River. Lesser Himalaya has biotite-garnet grade rocks (Chaudhry et al., 1997a).
The Lesser Himalayas division in NW Himalayas includes Hill Ranges (including Margala, Kala Chitta, Attock, Kohat Hills and Safed Koh), Plio-Pleistocene basins (Peshawar and Campbellpur basin) and the Lower Kohistan (Yeats and Lawerence, 1984). Lesser Himalayas are divisible into two distinct units, Northern metamorphic Zone and Southern Sedimentary Zone, and Panjal fault marks boundary between them (Ghazanfar, 1993; Ghazanfar et al., 1999a).
Northern Metamorphic Zone represents a terrain of meta pelite-psamite sequence which are intruded by Cambrian granites and some younger ones, and overlained by younger rocks including slates, phyllites, meta conglomerates, graphitic schist, limestone, marble, agglomeratic schist and basic volcanics of Kashmir basin and Peshawar basin. This meta pelite-psamite sequence is designated as Kundalshahi Group in Neelum Valley, Kaghan Group in Kaghan Valley and Tanawal Formation in Hazara area (Chaudhry et al., 1992; Ghazanfar and Chaudhry, 1985; Chaudhry and Ghazanfar, 1987; Ghazanfar et al., 1983). Kundalshahi Group is intruded by Jura granite of Cambrian age in southern parts and younger Neelum granite in north (Ghazanfar et al., 1983). Southern Sedimentary zone is characterized by the Pir Panjal ranges in east and Attock Hazara Fold and Thrust Belt, AHFTB, in west of Hazara Kashmir Syntaxis and south of Kashmir basin and Peshawar basin (Ghazanfar et al., 1999a). AHFTB is possible continuation of parautochthonous folded belt (Wadia, 1931) or Panjal Imbricate zone or Pir Panjal Range of Kashmir.
Sub Himalaya
Murree Fault or Main Boundary Thrust (MBT) and Salt Range Thrust (SRT) act as northern and southern boundaries of Sub-Himalaya respectively. The Himalayan foot hills form the Sub-Himalayan zone from the Punjab to Assam. These hills are comprised of a narrow belt of folded Neogene Murree and Siwalik red colored molasse type sediments.
The Sub Himalayas of Pakistan in the longitudnal sense can be subdivided into Azad Kashmir Zone in the east and the Punjab Zone or Punjab foreland in the west. In a transverse sense the Punjab foreland can be subdivided into North Potwar or Rawalpindi Zone (a fold and thrust belt culminating in the Khair-e-Murat structure and intensity of deformation increases northward), the Soan Zone (comprising a broad syncline under the plateau in the east and Kohat Basin in the west), the upthrusted inlier of Salt Range and Trans Indus Range and the only slightly deformed Punjab Plateform further to south (Ghazanfar and Chaudhry, 1999). Simply to say, Sub Himalayas subdivision includes Potwar Plateau, Kohat Plateau, Salt Range and Trans Indus Salt Ranges (Yeats and Lawerence, 1984). The Salt Range Fold and thrust belt gives way northward in the Potwar plateau to a broad syncline, the axis of which is followed by Soan River. This syncline is asymmetric and verges south further north. The intensity of folding increases and north dipping thrust fault appeared (Pinfold, 1980; Gill, 1953), culminating in the faults Kala Chitta and Margalla Hills along the Northern margin of Potwar Plateau.
Fig 4.2: Tectonic map of North Western Himalayas of Pakistan by Chaudhry et al (1992).
West of Potwar plateau, Eocene through Siwaliks strata are involved in complex folding, in which Eocene salt occupies the core of many of the anticlines (DeJong and Qayum, 1981). The Kohat plateau structure differs from that of Potwar plateau largely because of this higher salt detachment horizon in Kohat area (Yeats and Lawerence, 1984).
4.4 Tectonic Settings of Salt Range
Salt Range and Trans-Indus Salt Range represent the surface expression of up thrusting of a decollement in which basement is not involved and decollement exists in Cambrian to Eocambrian evaporites (Seeber and Armbuster, 1981; Crawford, 1974). Strata in the Salt Range generally dip northwards into the Potwar Basin (Sameeni, 1997). Structurally, the Salt Range is the result of tectonic forces imposed during the later phases of the Himalayan Orogeny in Late Cenozoic time, the occurrence of thick, incompetent Salt Range Formation at the base of sedimentary sequence has strongly influenced the structure). After the MBT zone under the Kala Chitta Range to the north was locked some 2 Ma ago compression was transferred to the plateform sequence to the south of MBT, as the result of which Salt Range thrust developed and Salt Range rises to surface (Yeats et al; 1984) .
Salt Range rises as 180 km (roughly ENE-WSW trending) long range at the southern edge of Potwar Plateau, making an abrupt escarpment against the Punjab plains in south. Its width is 150 km (Sameeni, 1997). The Salt Range forms an isolated E-W trending arc across the Indus River. It is a discrete structural zone bounded in north by north-dipping Main Boundary Thrust (Sarwar et al. 1979, Yeats et al. 1984, Coward et al. 1985), in south by the Salt Range Thrust, in west by Kalabagh fault and in East by Jhelum fault (Fig. 3.3). Tectonically, the Salt Range is the Himalayan equivalent of the Jura Mountains in the Alps and the Pine Mountains of the Appalachians (Qayyum, 1991). Salt Range is thin-skinned fold-and-thrust belt (Lillie et al., 1987; Butler et al., 1987 and Baker, 1987).
The allochthonous nature of the Salt Range, with a detachment in the Eocambrian Salt Range Formation, was recognized by many earlier workers (e. g., Wynne, 1878; Wadia, 1945 a, 1945 b, 1957; Gee, 1945, 1947, 1980; Voskresenskiy, 1978).
This range is essentially a complex salt anticlinorium with a series of salt anticlines. The structure along its northern slope is comprised of simple, broad, shallow folds followed by a gentle monocline. Southward the folding becomes tighter and the folds are commonly faulted (Gee, 1989). The Eocambrian evaporites are exposed in some of these overfolded and faulted anticlines (Qayyum, 1991).
Because the Salt Range formation is easily eroded, horsts form deep gorges, in which some of the classic stratigraphic section of Salt Range are found (Khewra, Nilawahan and Warchha gorges) (Yeats and Lawrence, 1984).
The overall structure of the Salt Range, except the easternmost part of the Eastern Salt Range, involves basically a fault bend fold geometry modified due to the presence of the underlying ductile salt. The roof sequence has been folded into sharp, salt cored anticlines and broad, flat synclines, which in its southernmost part frequently have been disrupted by forward and back verging thrusts and almost vertical dipping apparent normal faults (Qayyum, 1991).
Longitudinally, Salt Range is divided from East to West into the Eastern, Central and Western Salt Range. The Salt Range thrust is strongly emergent in its Central and Western parts, whereas in the east it is entirely a buried thrust (terminology of Morley, 1986) and folding predominates (Lillie et al., 1987). Davis & Engelder (1985) suggested that the difference in the structural style between East and West is the result of eastward thinning of the evaporites.
4.4.1 Central Salt Range
The surface geology across the Central Salt Range manifests the gradual exposure of older platform strata toward the South. The basement normal fault has acted as a buttress against which the salt has thickened. It also constitutes the lower part of the northern ramp and brings the older platform sequence to the surface. As the roof sequence rides over the northern ramp due to the basement normal fault, the strata become almost horizontal. The roof sequence is very gently folded into a series of small salt-cored anticlines near the leading edge. These anticlines are generally bounded by minor normal faults. Near the leading edge, there is a back thrust that brings Salt Range Formation over either the Jhelum Group or the Nilawahan group. This back thrust may have developed late in the geological history to build topography in order to maintain the forward motion of the roof sequence. The back thrust results in a total shortening of 27 km in the Central Salt Range (Qayyum, 1991).
Westward near to Sakesar peak, the range widens to some 30 km. In the north, the Eocene formations, capped in places by sandstone and clay-shales of the Early Miocene and overlain unconformably by Late Pliocene-Pleistocene Kalabagh Conglomerates, occur as broad, east and west plunging anticlines and synclines of varying wavelengths. The plunge variation results in large domes and basins e.g. between Dhariala and Kallar Kahar and westward via Vasnal and Khabakki in the approach to Sakesar (Gee, 1989). Several of these folds are faulted.
A concealed duplex structure is newly recognized in central Salt Range. It was evolved along a décollement with two ramps and extends more than 40 km along strike. The first ramp is within the Salt Range Formation. The second ramp crosses the platform sequence and follows shaley horizons of the overlying Murree Formation near the contact. The duplex structure is only present in the Central Salt Range, which implies that the décollement at its base must step down section and join the main décollement both in the west and the east. Further west along the duplex edge the platform sequence is flat and has not yet ramped upward. This implies that the décollement at the base of the duplex structure steps down along a Lateral ramp to join the main décollement (Qayyum, 1991).
In Pakistan, the Higher Himalayas includes the Nanga Parba-Haramosh massif (Yeats and Lawerence, 1984).It extends from Bajaur on the Pakistan Afghanistan border in the west to the Neelum valley of Kashmir in the east. Higher Himalaya comprised of Proterozoic to Late Proterozoic basement and Phanerozoic to Mesozoic cover in Pakistan (Ghazanfar, 1993; Chaudhry and Ghazanfar, 1987). Basement rock represents the oldest exposed rocks of Pakistan and composed of lower autochthonous to Para-autochthonous granitoid-migmatite complex, pelite-psamites with turbidites and associated minor quartzite and marble horizons. Basement is overlained by cover sequence which is composed of calc-pelites and marbles with some garnetiferous calc-pelites, amphibolites and pelites (Ghazanfar, 1993; Chaudhry and Ghazanfar, 1987; Ghazanfar and Chaudhry, 1985; Chaudhry et al., 1994a, 1997; Ghazanfar et al., 1983, 1999a).
Basement and cover sequence rocks are grouped in different areas of Higher Himalaya. Kel Group, Purbinar Group and Pacha Group constitutes the basement rock in Neelum Valley, western Kashmir, Upper Kaghan Valley and Swat area respectively and Sharda Group, Burawai Group and Alpuri group represent cover sequence respectively. The rocks of Higher Himalaya are metamorphosed to upper amphibolites facies and kyanite-silliminite grades just north of Batal area in Naran area of Kaghan (Ghazanfar et al., 1983, 1999a; Ghazanfar and Chaudhry, 1985, 1987; Chaudhry et al., 1994a, 1997).
Lesser Himalayas
Lesser Himalaya is confined between MCT and MBT in north and south respectively. MBT formed due to compressional deformation. In Pakistan, Lesser Himalayaextends in Lower Neelum Valley, Lower Kaghan Valley, Hazara area and Swat area across the Indus River. Lesser Himalaya has biotite-garnet grade rocks (Chaudhry et al., 1997a).
The Lesser Himalayas division in NW Himalayas includes Hill Ranges (including Margala, Kala Chitta, Attock, Kohat Hills and Safed Koh), Plio-Pleistocene basins (Peshawar and Campbellpur basin) and the Lower Kohistan (Yeats and Lawerence, 1984). Lesser Himalayas are divisible into two distinct units, Northern metamorphic Zone and Southern Sedimentary Zone, and Panjal fault marks boundary between them (Ghazanfar, 1993; Ghazanfar et al., 1999a).
Northern Metamorphic Zone represents a terrain of meta pelite-psamite sequence which are intruded by Cambrian granites and some younger ones, and overlained by younger rocks including slates, phyllites, meta conglomerates, graphitic schist, limestone, marble, agglomeratic schist and basic volcanics of Kashmir basin and Peshawar basin. This meta pelite-psamite sequence is designated as Kundalshahi Group in Neelum Valley, Kaghan Group in Kaghan Valley and Tanawal Formation in Hazara area (Chaudhry et al., 1992; Ghazanfar and Chaudhry, 1985; Chaudhry and Ghazanfar, 1987; Ghazanfar et al., 1983). Kundalshahi Group is intruded by Jura granite of Cambrian age in southern parts and younger Neelum granite in north (Ghazanfar et al., 1983). Southern Sedimentary zone is characterized by the Pir Panjal ranges in east and Attock Hazara Fold and Thrust Belt, AHFTB, in west of Hazara Kashmir Syntaxis and south of Kashmir basin and Peshawar basin (Ghazanfar et al., 1999a). AHFTB is possible continuation of parautochthonous folded belt (Wadia, 1931) or Panjal Imbricate zone or Pir Panjal Range of Kashmir.
Sub Himalaya
Murree Fault or Main Boundary Thrust (MBT) and Salt Range Thrust (SRT) act as northern and southern boundaries of Sub-Himalaya respectively. The Himalayan foot hills form the Sub-Himalayan zone from the Punjab to Assam. These hills are comprised of a narrow belt of folded Neogene Murree and Siwalik red colored molasse type sediments.
The Sub Himalayas of Pakistan in the longitudnal sense can be subdivided into Azad Kashmir Zone in the east and the Punjab Zone or Punjab foreland in the west. In a transverse sense the Punjab foreland can be subdivided into North Potwar or Rawalpindi Zone (a fold and thrust belt culminating in the Khair-e-Murat structure and intensity of deformation increases northward), the Soan Zone (comprising a broad syncline under the plateau in the east and Kohat Basin in the west), the upthrusted inlier of Salt Range and Trans Indus Range and the only slightly deformed Punjab Plateform further to south (Ghazanfar and Chaudhry, 1999). Simply to say, Sub Himalayas subdivision includes Potwar Plateau, Kohat Plateau, Salt Range and Trans Indus Salt Ranges (Yeats and Lawerence, 1984). The Salt Range Fold and thrust belt gives way northward in the Potwar plateau to a broad syncline, the axis of which is followed by Soan River. This syncline is asymmetric and verges south further north. The intensity of folding increases and north dipping thrust fault appeared (Pinfold, 1980; Gill, 1953), culminating in the faults Kala Chitta and Margalla Hills along the Northern margin of Potwar Plateau.
Fig 4.2: Tectonic map of North Western Himalayas of Pakistan by Chaudhry et al (1992).
West of Potwar plateau, Eocene through Siwaliks strata are involved in complex folding, in which Eocene salt occupies the core of many of the anticlines (DeJong and Qayum, 1981). The Kohat plateau structure differs from that of Potwar plateau largely because of this higher salt detachment horizon in Kohat area (Yeats and Lawerence, 1984).
4.4 Tectonic Settings of Salt Range
Salt Range and Trans-Indus Salt Range represent the surface expression of up thrusting of a decollement in which basement is not involved and decollement exists in Cambrian to Eocambrian evaporites (Seeber and Armbuster, 1981; Crawford, 1974). Strata in the Salt Range generally dip northwards into the Potwar Basin (Sameeni, 1997). Structurally, the Salt Range is the result of tectonic forces imposed during the later phases of the Himalayan Orogeny in Late Cenozoic time, the occurrence of thick, incompetent Salt Range Formation at the base of sedimentary sequence has strongly influenced the structure). After the MBT zone under the Kala Chitta Range to the north was locked some 2 Ma ago compression was transferred to the plateform sequence to the south of MBT, as the result of which Salt Range thrust developed and Salt Range rises to surface (Yeats et al; 1984) .
Salt Range rises as 180 km (roughly ENE-WSW trending) long range at the southern edge of Potwar Plateau, making an abrupt escarpment against the Punjab plains in south. Its width is 150 km (Sameeni, 1997). The Salt Range forms an isolated E-W trending arc across the Indus River. It is a discrete structural zone bounded in north by north-dipping Main Boundary Thrust (Sarwar et al. 1979, Yeats et al. 1984, Coward et al. 1985), in south by the Salt Range Thrust, in west by Kalabagh fault and in East by Jhelum fault (Fig. 3.3). Tectonically, the Salt Range is the Himalayan equivalent of the Jura Mountains in the Alps and the Pine Mountains of the Appalachians (Qayyum, 1991). Salt Range is thin-skinned fold-and-thrust belt (Lillie et al., 1987; Butler et al., 1987 and Baker, 1987).
The allochthonous nature of the Salt Range, with a detachment in the Eocambrian Salt Range Formation, was recognized by many earlier workers (e. g., Wynne, 1878; Wadia, 1945 a, 1945 b, 1957; Gee, 1945, 1947, 1980; Voskresenskiy, 1978).
This range is essentially a complex salt anticlinorium with a series of salt anticlines. The structure along its northern slope is comprised of simple, broad, shallow folds followed by a gentle monocline. Southward the folding becomes tighter and the folds are commonly faulted (Gee, 1989). The Eocambrian evaporites are exposed in some of these overfolded and faulted anticlines (Qayyum, 1991).
Because the Salt Range formation is easily eroded, horsts form deep gorges, in which some of the classic stratigraphic section of Salt Range are found (Khewra, Nilawahan and Warchha gorges) (Yeats and Lawrence, 1984).
The overall structure of the Salt Range, except the easternmost part of the Eastern Salt Range, involves basically a fault bend fold geometry modified due to the presence of the underlying ductile salt. The roof sequence has been folded into sharp, salt cored anticlines and broad, flat synclines, which in its southernmost part frequently have been disrupted by forward and back verging thrusts and almost vertical dipping apparent normal faults (Qayyum, 1991).
Longitudinally, Salt Range is divided from East to West into the Eastern, Central and Western Salt Range. The Salt Range thrust is strongly emergent in its Central and Western parts, whereas in the east it is entirely a buried thrust (terminology of Morley, 1986) and folding predominates (Lillie et al., 1987). Davis & Engelder (1985) suggested that the difference in the structural style between East and West is the result of eastward thinning of the evaporites.
4.4.1 Central Salt Range
The surface geology across the Central Salt Range manifests the gradual exposure of older platform strata toward the South. The basement normal fault has acted as a buttress against which the salt has thickened. It also constitutes the lower part of the northern ramp and brings the older platform sequence to the surface. As the roof sequence rides over the northern ramp due to the basement normal fault, the strata become almost horizontal. The roof sequence is very gently folded into a series of small salt-cored anticlines near the leading edge. These anticlines are generally bounded by minor normal faults. Near the leading edge, there is a back thrust that brings Salt Range Formation over either the Jhelum Group or the Nilawahan group. This back thrust may have developed late in the geological history to build topography in order to maintain the forward motion of the roof sequence. The back thrust results in a total shortening of 27 km in the Central Salt Range (Qayyum, 1991).
Westward near to Sakesar peak, the range widens to some 30 km. In the north, the Eocene formations, capped in places by sandstone and clay-shales of the Early Miocene and overlain unconformably by Late Pliocene-Pleistocene Kalabagh Conglomerates, occur as broad, east and west plunging anticlines and synclines of varying wavelengths. The plunge variation results in large domes and basins e.g. between Dhariala and Kallar Kahar and westward via Vasnal and Khabakki in the approach to Sakesar (Gee, 1989). Several of these folds are faulted.
A concealed duplex structure is newly recognized in central Salt Range. It was evolved along a décollement with two ramps and extends more than 40 km along strike. The first ramp is within the Salt Range Formation. The second ramp crosses the platform sequence and follows shaley horizons of the overlying Murree Formation near the contact. The duplex structure is only present in the Central Salt Range, which implies that the décollement at its base must step down section and join the main décollement both in the west and the east. Further west along the duplex edge the platform sequence is flat and has not yet ramped upward. This implies that the décollement at the base of the duplex structure steps down along a Lateral ramp to join the main décollement (Qayyum, 1991).
Friday, 22 August 2014
We shall Fight On Beaches A Historical Speech by Winston Churchill
“We Shall Fight on the Beaches” by Winston Churchill
June 4, 1940
House of Commons
From the moment that the French defenses at Sedan and on the Meuse were broken at the end of the second week of May, only a rapid retreat to Amiens and the south could have saved the British and French Armies who had entered Belgium at the appeal of the Belgian King; but this strategic fact was not immediately realized. The French High Command hoped they would be able to close the gap, and the Armies of the north were under their orders. Moreover, a retirement of this kind would have involved almost certainly the destruction of the fine Belgian Army of over 20 divisions and the abandonment of the whole of Belgium. Therefore, when the force and scope of the German penetration were realized and when a new French Generalissimo, General Weygand, assumed command in place of General Gamelin, an effort was made by the French and British Armies in Belgium to keep on holding the right hand of the Belgians and to give their own right hand to a newly created French Army which was to have advanced across the Somme in great strength to grasp it.
However, the German eruption swept like a sharp scythe around the right and rear of the Armies of the north. Eight or nine armored divisions, each of about four hundred armored vehicles of different kinds, but carefully assorted to be complementary and divisible into small self-contained units, cut off all communications between us and the main French Armies. It severed our own communications for food and ammunition, which ran first to Amiens and afterwards through Abbeville, and it shore its way up the coast to Boulogne and Calais, and almost to Dunkirk. Behind this armored and mechanized onslaught came a number of German divisions in lorries, and behind them again there plodded comparatively slowly the dull brute mass of the ordinary German Army and German people, always so ready to be led to the trampling down in other lands of liberties and comforts which they have never known in their own.
I have said this armored scythe-stroke almost reached Dunkirk-almost but not quite. Boulogne and Calais were the scenes of desperate fighting. The Guards defended Boulogne for a while and were then withdrawn by orders from this country. The Rifle Brigade, the 60th Rifles, and the Queen Victoria’s Rifles, with a battalion of British tanks and 1,000 Frenchmen, in all about four thousand strong, defended Calais to the last. The British Brigadier was given an hour to surrender. He spurned the offer, and four days of intense street fighting passed before silence reigned over Calais, which marked the end of a memorable resistance. Only 30 unwounded survivors were brought off by the Navy, and we do not know the fate of their comrades. Their sacrifice, however, was not in vain. At least two armored divisions, which otherwise would have been turned against the British Expeditionary Force, had to be sent to overcome them. They have added another page to the glories of the light divisions, and the time gained enabled the Graveline water lines to be flooded and to be held by the French troops.
Thus it was that the port of Dunkirk was kept open. When it was found impossible for the Armies of the north to reopen their communications to Amiens with the main French Armies, only one choice remained. It seemed, indeed, forlorn. The Belgian, British and French Armies were almost surrounded. Their sole line of retreat was to a single port and to its neighboring beaches. They were pressed on every side by heavy attacks and far outnumbered in the air.
When, a week ago today, I asked the House to fix this afternoon as the occasion for a statement, I feared it would be my hard lot to announce the greatest military disaster in our long history. I thought-and some good judges agreed with me-that perhaps 20,000 or 30,000 men might be re-embarked. But it certainly seemed that the whole of the French First Army and the whole of the British Expeditionary Force north of the Amiens-Abbeville gap would be broken up in the open field or else would have to capitulate for lack of food and ammunition. These were the hard and heavy tidings for which I called upon the House and the nation to prepare themselves a week ago. The whole root and core and brain of the British Army, on which and around which we were to build, and are to build, the great British Armies in the later years of the war, seemed about to perish upon the field or to be led into an ignominious and starving captivity.
That was the prospect a week ago. But another blow which might well have proved final was yet to fall upon us. The King of the Belgians had called upon us to come to his aid. Had not this Ruler and his Government severed themselves from the Allies, who rescued their country from extinction in the late war, and had they not sought refuge in what was proved to be a fatal neutrality, the French and British Armies might well at the outset have saved not only Belgium but perhaps even Poland. Yet at the last moment, when Belgium was already invaded, King Leopold called upon us to come to his aid, and even at the last moment we came. He and his brave, efficient Army, nearly half a million strong, guarded our left flank and thus kept open our only line of retreat to the sea. Suddenly, without prior consultation, with the least possible notice, without the advice of his Ministers and upon his own personal act, he sent a plenipotentiary to the German Command, surrendered his Army, and exposed our whole flank and means of retreat.
I asked the House a week ago to suspend its judgment because the facts were not clear, but I do not feel that any reason now exists why we should not form our own opinions upon this pitiful episode. The surrender of the Belgian Army compelled the British at the shortest notice to cover a flank to the sea more than 30 miles in length. Otherwise all would have been cut off, and all would have shared the fate to which King Leopold had condemned the finest Army his country had ever formed. So in doing this and in exposing this flank, as anyone who followed the operations on the map will see, contact was lost between the British and two out of the three corps forming the First French Army, who were still farther from the coast than we were, and it seemed impossible that any large number of Allied troops could reach the coast.
The enemy attacked on all sides with great strength and fierceness, and their main power, the power of their far more numerous Air Force, was thrown into the battle or else concentrated upon Dunkirk and the beaches. Pressing in upon the narrow exit, both from the east and from the west, the enemy began to fire with cannon upon the beaches by which alone the shipping could approach or depart. They sowed magnetic mines in the channels and seas; they sent repeated waves of hostile aircraft, sometimes more than a hundred strong in one formation, to cast their bombs upon the single pier that remained, and upon the sand dunes upon which the troops had their eyes for shelter. Their U-boats, one of which was sunk, and their motor launches took their toll of the vast traffic which now began. For four or five days an intense struggle reigned. All their armored divisions-or what Was left of them-together with great masses of infantry and artillery, hurled themselves in vain upon the ever-narrowing, ever-contracting appendix within which the British and French Armies fought.
Meanwhile, the Royal Navy, with the willing help of countless merchant seamen, strained every nerve to embark the British and Allied troops; 220 light warships and 650 other vessels were engaged. They had to operate upon the difficult coast, often in adverse weather, under an almost ceaseless hail of bombs and an increasing concentration of artillery fire. Nor were the seas, as I have said, themselves free from mines and torpedoes. It was in conditions such as these that our men carried on, with little or no rest, for days and nights on end, making trip after trip across the dangerous waters, bringing with them always men whom they had rescued. The numbers they have brought back are the measure of their devotion and their courage. The hospital ships, which brought off many thousands of British and French wounded, being so plainly marked were a special target for Nazi bombs; but the men and women on board them never faltered in their duty.
Meanwhile, the Royal Air Force, which had already been intervening in the battle, so far as its range would allow, from home bases, now used part of its main metropolitan fighter strength, and struck at the German bombers and at the fighters which in large numbers protected them. This struggle was protracted and fierce. Suddenly the scene has cleared, the crash and thunder has for the moment-but only for the moment-died away. A miracle of deliverance, achieved by valor, by perseverance, by perfect discipline, by faultless service, by resource, by skill, by unconquerable fidelity, is manifest to us all. The enemy was hurled back by the retreating British and French troops. He was so roughly handled that he did not hurry their departure seriously. The Royal Air Force engaged the main strength of the German Air Force, and inflicted upon them losses of at least four to one; and the Navy, using nearly 1,000 ships of all kinds, carried over 335,000 men, French and British, out of the jaws of death and shame, to their native land and to the tasks which lie immediately ahead. We must be very careful not to assign to this deliverance the attributes of a victory. Wars are not won by evacuations. But there was a victory inside this deliverance, which should be noted. It was gained by the Air Force. Many of our soldiers coming back have not seen the Air Force at work; they saw only the bombers which escaped its protective attack. They underrate its achievements. I have heard much talk of this; that is why I go out of my way to say this. I will tell you about it.
This was a great trial of strength between the British and German Air Forces. Can you conceive a greater objective for the Germans in the air than to make evacuation from these beaches impossible, and to sink all these ships which were displayed, almost to the extent of thousands? Could there have been an objective of greater military importance and significance for the whole purpose of the war than this? They tried hard, and they were beaten back; they were frustrated in their task. We got the Army away; and they have paid fourfold for any losses which they have inflicted. Very large formations of German aeroplanes-and we know that they are a very brave race-have turned on several occasions from the attack of one-quarter of their number of the Royal Air Force, and have dispersed in different directions. Twelve aeroplanes have been hunted by two. One aeroplane was driven into the water and cast away by the mere charge of a British aeroplane, which had no more ammunition. All of our types-the Hurricane, the Spitfire and the new Defiant-and all our pilots have been vindicated as superior to what they have at present to face.
When we consider how much greater would be our advantage in defending the air above this Island against an overseas attack, I must say that I find in these facts a sure basis upon which practical and reassuring thoughts may rest. I will pay my tribute to these young airmen. The great French Army was very largely, for the time being, cast back and disturbed by the onrush of a few thousands of armored vehicles. May it not also be that the cause of civilization itself will be defended by the skill and devotion of a few thousand airmen? There never has been, I suppose, in all the world, in all the history of war, such an opportunity for youth. The Knights of the Round Table, the Crusaders, all fall back into the past-not only distant but prosaic; these young men, going forth every morn to guard their native land and all that we stand for, holding in their hands these instruments of colossal and shattering power, of whom it may be said that
Every morn brought forth a noble chance
And every chance brought forth a noble knight,
deserve our gratitude, as do all the brave men who, in so many ways
and on so many occasions, are ready, and continue ready to give life and
all for their native land.And every chance brought forth a noble knight,
I return to the Army. In the long series of very fierce battles, now on this front, now on that, fighting on three fronts at once, battles fought by two or three divisions against an equal or somewhat larger number of the enemy, and fought fiercely on some of the old grounds that so many of us knew so well-in these battles our losses in men have exceeded 30,000 killed, wounded and missing. I take occasion to express the sympathy of the House to all who have suffered bereavement or who are still anxious. The President of the Board of Trade [Sir Andrew Duncan] is not here today. His son has been killed, and many in the House have felt the pangs of affliction in the sharpest form. But I will say this about the missing: We have had a large number of wounded come home safely to this country, but I would say about the missing that there may be very many reported missing who will come back home, some day, in one way or another. In the confusion of this fight it is inevitable that many have been left in positions where honor required no further resistance from them.
Against this loss of over 30,000 men, we can set a far heavier loss certainly inflicted upon the enemy. But our losses in material are enormous. We have perhaps lost one-third of the men we lost in the opening days of the battle of 21st March, 1918, but we have lost nearly as many guns — nearly one thousand-and all our transport, all the armored vehicles that were with the Army in the north. This loss will impose a further delay on the expansion of our military strength. That expansion had not been proceeding as far as we had hoped. The best of all we had to give had gone to the British Expeditionary Force, and although they had not the numbers of tanks and some articles of equipment which were desirable, they were a very well and finely equipped Army. They had the first-fruits of all that our industry had to give, and that is gone. And now here is this further delay. How long it will be, how long it will last, depends upon the exertions which we make in this Island. An effort the like of which has never been seen in our records is now being made. Work is proceeding everywhere, night and day, Sundays and week days. Capital and Labor have cast aside their interests, rights, and customs and put them into the common stock. Already the flow of munitions has leaped forward. There is no reason why we should not in a few months overtake the sudden and serious loss that has come upon us, without retarding the development of our general program.
Nevertheless, our thankfulness at the escape of our Army and so many men, whose loved ones have passed through an agonizing week, must not blind us to the fact that what has happened in France and Belgium is a colossal military disaster. The French Army has been weakened, the Belgian Army has been lost, a large part of those fortified lines upon which so much faith had been reposed is gone, many valuable mining districts and factories have passed into the enemy’s possession, the whole of the Channel ports are in his hands, with all the tragic consequences that follow from that, and we must expect another blow to be struck almost immediately at us or at France. We are told that Herr Hitler has a plan for invading the British Isles. This has often been thought of before. When Napoleon lay at Boulogne for a year with his flat-bottomed boats and his Grand Army, he was told by someone. “There are bitter weeds in England.” There are certainly a great many more of them since the British Expeditionary Force returned.
The whole question of home defense against invasion is, of course, powerfully affected by the fact that we have for the time being in this Island incomparably more powerful military forces than we have ever had at any moment in this war or the last. But this will not continue. We shall not be content with a defensive war. We have our duty to our Ally. We have to reconstitute and build up the British Expeditionary Force once again, under its gallant Commander-in-Chief, Lord Gort. All this is in train; but in the interval we must put our defenses in this Island into such a high state of organization that the fewest possible numbers will be required to give effective security and that the largest possible potential of offensive effort may be realized. On this we are now engaged. It will be very convenient, if it be the desire of the House, to enter upon this subject in a secret Session. Not that the government would necessarily be able to reveal in very great detail military secrets, but we like to have our discussions free, without the restraint imposed by the fact that they will be read the next day by the enemy; and the Government would benefit by views freely expressed in all parts of the House by Members with their knowledge of so many different parts of the country. I understand that some request is to be made upon this subject, which will be readily acceded to by His Majesty’s Government.
We have found it necessary to take measures of increasing stringency, not only against enemy aliens and suspicious characters of other nationalities, but also against British subjects who may become a danger or a nuisance should the war be transported to the United Kingdom. I know there are a great many people affected by the orders which we have made who are the passionate enemies of Nazi Germany. I am very sorry for them, but we cannot, at the present time and under the present stress, draw all the distinctions which we should like to do. If parachute landings were attempted and fierce fighting attendant upon them followed, these unfortunate people would be far better out of the way, for their own sakes as well as for ours. There is, however, another class, for which I feel not the slightest sympathy. Parliament has given us the powers to put down Fifth Column activities with a strong hand, and we shall use those powers subject to the supervision and correction of the House, without the slightest hesitation until we are satisfied, and more than satisfied, that this malignancy in our midst has been effectively stamped out.
Turning once again, and this time more generally, to the question of invasion, I would observe that there has never been a period in all these long centuries of which we boast when an absolute guarantee against invasion, still less against serious raids, could have been given to our people. In the days of Napoleon the same wind which would have carried his transports across the Channel might have driven away the blockading fleet. There was always the chance, and it is that chance which has excited and befooled the imaginations of many Continental tyrants. Many are the tales that are told. We are assured that novel methods will be adopted, and when we see the originality of malice, the ingenuity of aggression, which our enemy displays, we may certainly prepare ourselves for every kind of novel stratagem and every kind of brutal and treacherous maneuver. I think that no idea is so outlandish that it should not be considered and viewed with a searching, but at the same time, I hope, with a steady eye. We must never forget the solid assurances of sea power and those which belong to air power if it can be locally exercised.
I have, myself, full confidence that if all do their duty, if nothing is neglected, and if the best arrangements are made, as they are being made, we shall prove ourselves once again able to defend our Island home, to ride out the storm of war, and to outlive the menace of tyranny, if necessary for years, if necessary alone. At any rate, that is what we are going to try to do. That is the resolve of His Majesty’s Government-every man of them. That is the will of Parliament and the nation. The British Empire and the French Republic, linked together in their cause and in their need, will defend to the death their native soil, aiding each other like good comrades to the utmost of their strength. Even though large tracts of Europe and many old and famous States have fallen or may fall into the grip of the Gestapo and all the odious apparatus of Nazi rule, we shall not flag or fail. We shall go on to the end, we shall fight in France, we shall fight on the seas and oceans, we shall fight with growing confidence and growing strength in the air, we shall defend our Island, whatever the cost may be, we shall fight on the beaches, we shall fight on the landing grounds, we shall fight in the fields and in the streets, we shall fight in the hills; we shall never surrender, and even if, which I do not for a moment believe, this Island or a large part of it were subjugated and starving, then our Empire beyond the seas, armed and guarded by the British Fleet, would carry on the struggle, until, in God’s good time, the New World, with all its power and might, steps forth to the rescue and the liberation of the old.
General Data about Earth
Earth Data
Surface Area : 510,100,500 Sq.Kms.Land Surface : 148,950,800 Sq.Kms. (29.08%)
Water Surface : 361,149,700 Sq.Kms. (70.92%)
Equatorial circumference : 40,075 Kms.
Polar circumference : 40,008 Kms
Equatorial radius : 6,377 Kms.
Equatorial Diameter : 1,22,756 Kms.
Polar radius : 6,357 Kms.
Polar Diameter : 12,714 Kms.
Mean distance from the Sun : 14,95,97,900 Kms.
Period of revolution : 365 days 5 hours 48 mts. 45.51 Sec.
Period of rotation : 23 hrs. 56 mts. 4.091 Sec.
Escape Velocity from the earth : 11 Km per Sec. (minimum)
Vocablary For GAT Students Special
Aberration
Unusual and unacceptable, oddness, deviation from standard, irregularity. For example, He was not normal at that time. His act was aberrational.
Abstruse
Hidden, difficult to understand, deep
Accumulation
Gather, collect
Acrimonious
Angry and bitter feelings / words
Affection
Love
Affront
To insult
Aggravate
To make worse
Alleviate
To make sth less severe. Synonym: Ease
Ameliorate
Improve
Amenable
Agreeable
Anomaly
Irregularity. For example, A man ordered 5kg rice, but the shopkeeper sent 4kg. So, there is anomaly in supply.
Apart
Away, separate, distant
Archipelago
A group of islands. Few islands make archipelago.
Argumentative
A person who argues, Not willing to obey sth
Arrogant
Behaving in a proudy way, that is unpleasant for others, Considering oneself superior than others
Auspicious
Favourable, Likely to be successful, Promising
Baleful
Harmful and damaging
Beget
To make sth happen, cause to exist
Bevy
Large group
Brook
Tolerate
Cacophony
A mixture of unpleasant sounds, noice
Cajole
Deceive. Synonym: Coax
Candid
Honest, saying as it is. (2) A candid photo is one that is taken without knowledge of the person
Capricious
Shaky, uncertain
Carnivorous
Any animal that eats meat
Cautious
Careful in what you say or do
Chary
Not taking risks, cautious. Synonym: Wary
Chide
To criticize or blame sb because they have done sth wrong
Coax
Deceive. Synonym: Cajole
Congnizant
Aware
Compliant
(1) Willing or ready to obey. Synonym: Submissive. (2) Agreement
Concealed
Hidden, difficult to understand, deep
Confront
To face
Conjoin
Join together
Consensus
Agreement
Console
to give comfort or sympathy to somebody who is unhappy or disappointed
Consul
A government official who is the representative of his/her country in a foreign city
Contraction
becoming smaller
Council
Ruling body, committee
Counsel
(1). advice (2). Lawer on behalf of somebody
Crestfallen
Sad and disappointed
Curtail
To limit something OR to shorten something
Deleterious
harmful and damaging
Demise
Death
Deteriorate
To become worse. Antonym: Improve
Detraction
Making something less good/enjoyable/important
Disavow
Deny
Distraction
Disturbance
Doctrine
Established belief
Doting
Liking/Loving sth very much
Eclected
Drawn from many sources, wisely chosen
Elated
Very happy and excited
Eminent
Famous
Enamoured
Liking something a lot
Enigma
A person, place or thing that is mysterious and difficult to understand. Mystery, Riddle
Entail
To involve something that cannot be avoided
Erudite
Deeply learned, Scholarly learned
Euphony
Pleasant sounds
Evanescent
Disapperaing quickly, short lived, fleeting
Evasive
Wordy, Not up to the point, using too much words than necessary
Exigent
Urgent
Fallow
Not used
Feckless
Careless
Feeble
Weak, Inefficient
Fleeting
Disappearing quickly, short lived
Foe
Enemy
Fond
Liking/Loving sb/sth
Frightened
Afraid, feeling of fear
Gloomy
Sad and without hope, No hope of success or happiness in future
Herbivorous
Any animal that eats only plants
Hone
(1) To sharp, sharpen. (2) To develop and improve sth
Imminent
About to happen
Impartial
Neutral
Impecunious
Poor, penny less
Indifferent
not interested OR no concern
Integrity
(1) Honesty (2) Whole, Not devided
Intrinsic
Inherent, belonging to sb/sth
Later
At a time in future. Antonym: Earlier
Levy
Government taxes
Melancholy
A deep feeling of sadness, very sad
Mercy
A kind and forgiving attitude
Minatory
Threatening
Morose
Extremely sad, depressed. Synonym: Gloomy
Mulish
Not changing opinion/attitude, stick to his own opinion
Mystery
A person, place or thing that is mysterious and difficult to understand. Enigma, Riddle
Naive
(1) Inexperienced, Lacking knowledge. (2) Innocent and simple
Narrate
Tell
Neophyte
Beginner
Nepotism
Favoritism
Obstinate
Not changing opinion/attitude, stick to his own opinion, Stubborn
Offensive
rude and annoying
Pragmatic
Practical
Precede
Before, happen before of sth
Probity
Honesty
Ratify
to make an agreement officially valid by voting for or singning it
Ravenous
Starving, extremely hungry
Skeptical
Unbelievable
Static
Not moving
Strut
Walk proudly
Stubborn
Not changing opinion/attitude, stick to his own opinion
Stuffed
Full
Sunninct
Concise
Partisan
Showing support to a person/group/idea, not nuetral, biased
Pillory
To criticize sb strongly in public
Touchstone
Criteria
Tractable
Easy to deal/control, Easily handled
Tranquil
Quite and peaceful
Transient
Disappearing quickly, short lived, fleeting
Trepidation
Fear
Urbane
Wise
Vacous
Stupid
Vindictive
Trying to harm sb
Volatile
Changing easily/suddenly
Vouch
To say that somebody will behave well, and you are responsible for his actions
Vow
a formal and serious promise
Wary
Not taking risks, cautious. Synonym: Chary
Formulas For GAT Test Maath
FORMULA SHEET
Math Topics
Age problems
Work hours problems
Clock angles and Sector area
Algebraic expressions
Speed distance problems
Fractions & Percentages
Range, mean, Mod, Median
Simple Geometry problems
Basic Arithmetic
Probability
Ratios
Profit, Discount problems
Equation solving for Variables
Basic Calculations
Square, Marble Size
Bridge Length
Fraction Based Gain, Loss
Finding Share
1.Mean
The mean average is not always a whole number.
The mean is the total of the numbers dividedby
how many numbers there are.
To work out the mean:
1.
Add up all the numbers.
7 + 9 + 11 + 6 + 13 + 6 + 6 + 3 + 11 = 72
7 + 9 + 11 + 6 + 13 + 6 + 6 + 3 + 11 = 72
2.
Divide the answer by how
many numbers there are.
There are 9 numbers.
72 ÷ 9 = 8
So the mean value is 8.
There are 9 numbers.
72 ÷ 9 = 8
So the mean value is 8.
2: Mode
The mode is the value that appears the most.
7 9 11 6 13 6 6 3 11
To work out the mode:
1.
Put the numbers in order:
3 6 6 6 7 9 11 11 13
3 6 6 6 7 9 11 11 13
2.
Look for the number that appears the most.
6 appears more than any other number.
So the mode value is 6.
6 appears more than any other number.
So the mode value is 6.
3.Median
The median is the middle value.
To work out the median:
1.
Put the numbers in
order:
3 6 6 6 7 9 11 11 13
3 6 6 6 7 9 11 11 13
2.
The number in the middle
of the list is the median.
So the median value is 7.
So the median value is 7.
If there are two middle values, the median is halfway between them. Work out the median for
this set of numbers:
3 6 6 6 7 8 9 11 11 13
There are two middle values, 7 and 8.
The median is halfway between 7 and 8, so the median is
The median is halfway between 7 and 8, so the median is
4.Range
The range is the difference between the biggest and the smallest
number.
To work out the range:
1.
Put the numbers in
order:
3 6 6 6 7 9 11 11 13
3 6 6 6 7 9 11 11 13
2.
Subtract the smallest
number from the biggest number:
13 - 3 = 10
So the range of this set of numbers is 10.
13 - 3 = 10
So the range of this set of numbers is 10.
5.Sum
of Series
Sum of an series =
Exp.what is the avg of first 20 multiples of 7?
7,14,21…….41
Sum=((7+140)/2)*20
Sum=73.5*20
We have to find
avg so
Avg=73.5*20/20=73.5 ans
6.Probability
Ten
coins are tossed simultaneously. In how many of the outcomes will the third
coin turn up a head?
A.
210
B.
29
C.
3 * 28
D.
3 * 29
E.
None of these
The correct choice is (B) and the correct answer is 29.
If two dice are thrown what is the probability of soming a
sum of 9.
(4,5)…(5,4)….(3,6)…..(6,3)
Total 4 ways to become 9
So 4/36=1/9 ans
Factorial:
N!=N.(N-1).(N-2)…….…2.1
7:PERMUTATION
If here are 5
student , in how many ways they can sit?
5!=5*4*3*2*1=120
8:COMBINITION
5 combinition
2 = 5!/2!(5-2)!= 5!/2!*3!=5*4*3*2*1/2*1*3*2*1=10
Exp. How many
different 4-person teams can b made from a group of 9 players?
=9!/5!(9-5)!=126
9:MARBLE
SIZE
Marble
size is 20cm*30cm. How many marbles are required to cover a square with side
3m?
3m=300cm
Area=300*300
No
of marbles=Area/Marble size
=300*300/20*30=150
12:
LENGTH OF BRIDGE
If
a man running at 15kmph passed a bridge in 9 seconds, what is the length of the
bridge?
Length
or Dist=speed * Time
15km=15000m
15000mpr=15000/3600
mps
So Length=15000*9/3600=37.5m
12: EQU MAKING
What
is the number 3 more than the double of specific value of x..?
2x-3
Similarly….
What
is the number 3 less than the double of specific value of x..?
2x+3
13:LOG
PROPERTIES
Log(x.y)=log
x+logy
Log(x/y)=logx-log
y
ln
e=1
ln x^2=2ln x
14: Clock Angles
Angle traced by hour hand in 12 hrs = 360°.
Angle traced by minute hand in 60 min. = 360°.
5:35 .. express
hour hand in degree?
As 12Sectors on clock=360 degree
5*30+30*35/60=150+17.5=167.5
14:WORK
SHARE
Amount
of Work/Time=Output(Rate)
A
can do a piece of work in 4 hours; B and C together can do it in 3 hours, while
A and C together can do it in 2 hours. How long will B alone take to do it?
A=1/4
B+C=1/3
A+C=1/2
C=1/2-1/4=1/4
B=1/3-1/4=1/12
So
B alone will do in 12 hours
15:
AREA & CIRCUMFERENCE OF CIRCLE
Area= pi*r^2
C=2*pi*r
16: AREA OF SQUARE,triangle,rectangle
Area
of square= s^2
Perimeter=4s
Area
of triangle= b*h/2
Perimeter=
sum of all sides
Area
of Equilateral triabgle=sqrt3 *s^2/4
Perimeter=3s
Area
of rectangle= L*W
Perimeter=2(L+W)
Volume
of cylinder = pi*r^2*h
Volume
of cube=a^3
Area
of a rectangle = (Length × Breadth).
|
Perimeter
of a rectangle = 2(Length + Breadth).
|
Area
of a square = (side)2 = 1 / 2
(diagonal)2
|
Area
of 4 walls of a room = 2 (Length + Breadth) × Height.
|
Area
of a triangle = 1 / 2 × Base × Height.
I).
Area of a triangle = √s(s-a)(s-b)(s-c) where a, b, c
are the sides of the triangle and s = 1/ 2 (a + b + c)
II).
Area of parallelogram = (Base x Height).
Area
of a rhombus = 1 / 2 (Product of diagonals).
III).
Area of a trapezium =1 / 2 (sum of parallel sides) x distance between them.
Iv).
Area of a circle = Î R2, where R is
the radius.
|
Circumference
of a circle = 2Î R.
I).
Circumference of a semi-circle = Î R.
II).
Area of semi-circle = Î R2 / 2.
|
Cube :
Let each edge of a cube be of length a. Then,
1. Volume = a3 cubic
units.
2. Surface area = 6a2 sq. units.
3.
Diagonal =√ 3a units.
Cylinder :
Let radius of base = r and Height (or length) = h. Then,
1. Volume = (∏r2h) cubic units.
2. Curved surface area = (2∏rh) sq. units.
3. Total surface area = 2∏r(h + r) sq. units.
17: i values
I=sqrt of -1
I^2=-1
I^4=1
18:
Average formula:
Let a1,a2,a3,......,an be a set of numbers, average = (a1 + a2 + a3,+......+ an)/n
Let a1,a2,a3,......,an be a set of numbers, average = (a1 + a2 + a3,+......+ an)/n
Average= sum of
elements/no of elements
19:
RATIO
3:b=x:c
X=?
3c=bx
X=3c/b
20:
Algebra
a^n*a^m=a^m+n
a^n/a^m=a^n-m
19:
If Given
Data is
Passed in 1st sub=x%.......Pass in
2nd sub=y%......failed in both sub=z%
Then we can find % of
passing students in both sub by this
formula
passed in both %= passed
in 1st sub+passed in 2nd sub+failed in both-100%.
Similarly
If given data is
Failed in 1st
sub=x%.......Failed in 2nd sub=y%....Passedin both sub=z%
Then we can find % of
students failed in both sub by this
formula
Failed in both
%=failed in 1st
sub+failed in 2nd sub+Passed
in both-100%.
Through these formulas
you can find % of failed or passed
students in only one subject or both
subjects
20:
If it is Sunday , what wil be after 100 days?
12*8=96=Sunday
so +4=Thursday
After
100 days it wll b Friday
20:AGE
PROBLEM
If
father is double the age of his son. 20 years ago he was 12 times that of son.
What is the age of father now?
F=2S
F-20=12(S-20)
2S-20=12S-240
10S=220
S=22
F=2S=44
21:
% SHARE
A
company sell three types of mobiles worth 100, 125, and 225. It sold equal no.
of all mobiles. What is the percent share of cheapest mobile?
Total=100+125+225=450
225=50%
100+125=225=50%
100*50/225=22.22%
Simple Interest (S.I.) :
If the interest on a sum borrowed for certain period is reckoned
uniformly, then it is called simple interest.
Let the principal = P, Rate = R% per annum (p.a)
and Time = T years. Then ,
1. S.I. = (P x R x T / 100)
2. P = (100 x S.I. / R x T)
3. R = (100 x S.I / P x T)
4. T = (100 x S.I. / P x R).
22:
SIMPLE EQU TO FIND
VALUE OV VARIABLE
If
a=3 find (a^2)^3-a=?
a^6-a=3^6-3=726
23: square root, perfect square
Find the square root
of 2809.
1) The last digit is ’9′…so the last digit of the answer is either ’3′ or ’7′.
2) Out of the perfect squares in the list, which ones straddle ’28′? In this case, ’25′ and ’36′.
3) Choose ’25′ since its the lower one. The square root of ’25′ is ’5′. ’5′ is the first digit of our answer.
4) Which number is ’28′ closer to…’25′ or ’36′? It’s closer to ’25′ in this case, so we choose the smaller of our choices for the second digit. Our choices are ’3′ and ’7′; so we choose ’3′.
1) The last digit is ’9′…so the last digit of the answer is either ’3′ or ’7′.
2) Out of the perfect squares in the list, which ones straddle ’28′? In this case, ’25′ and ’36′.
3) Choose ’25′ since its the lower one. The square root of ’25′ is ’5′. ’5′ is the first digit of our answer.
4) Which number is ’28′ closer to…’25′ or ’36′? It’s closer to ’25′ in this case, so we choose the smaller of our choices for the second digit. Our choices are ’3′ and ’7′; so we choose ’3′.
Answer: The square root of 2809 is 53.
Try for
6084…. Ans 78
24:
How much speed of train must be increased if time is reduced by 20% …
S=vt….suppose
s=100, t=10
V=100/10=10
20%
les time=10-2=8
V=100/8=12.5
12.5-10=2.5 hence
25%
25:
Largest of 13 consecutive intgrs
whose sum os 0 ? -6 to 6
Largest
=6
Leat no of
among three digits whose
sum is 18= 5..bcz
X+X+1+X+2=18………………3X=15X=5……… 5+6+7=18
26: Sum Of Series:
Sn=n(a1+an)/2
Example. Sum of numbers from 1,2,3……..100
a1=1;
an=100
n=100
Sn=100(1+100)/2=5050
27: Gain, Loss
Loss = (C.P.) - (S.P.).
|
||||
Gain Percentage: (Gain %)
Gain % = (Gain x 100 / C.P)
|
||||
|
Loss Percentage: (Loss %)
Loss % = (Loss x 100 / C.P )
28: Percentage:
Concept of
Percentage :
By a certain percent, we mean that many
hundredths. Thus, x percent means x hundredths, written as x%.
I. To express x% as a fraction: We have, x%
= x / 100.
Thus, 48% = 48 / 100 = 12 / 25.
II. To express a / b as a percent :
We have a / b = (a / b × 100)%.
Percent to fraction: x% =
x/100
Percentage formula: Rate/100 = Percentage/base |
Properties of Logarithms :
1. loga(xy) = loga x
+ loga y
2. loga(x / y) = loga x
- loga y
3. logx x = 1
4. loga 1 = 0
5. loga (xp)
= p(loga x )
6. loga x = 1 / logxa
Some Important Formulae :
I. ( 1 + 2 + 3 + .....+ n) = n (n + 1 ) / 2
II. (1 2 + 22 + 32 + ..... + n2) = n ( n + 1 ) (2n + 1) / 6
III. (1 3 + 23 + 33 + ..... + n3) = n2 (n + 1)2 / 4
Fractions formulas:
Consumer math formulas:
Discount = list price × discount rate
Sale price = list price − discount
Discount rate = discount ÷ list price
Sales tax = price of item × tax rate
Interest = principal × rate of interest × time
Tips = cost of meals × tip rate
Commission = cost of service × commission rate
Discount = list price × discount rate
Sale price = list price − discount
Discount rate = discount ÷ list price
Sales tax = price of item × tax rate
Interest = principal × rate of interest × time
Tips = cost of meals × tip rate
Commission = cost of service × commission rate
BY
Falak Sher Buzdar
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