Jodhpur Group - Malani Igneous Suite Contact
Encyclopedia
Jodhpur Group-Malani Igneous Suite Contact is a unique geological feature representing the last phase of igneous activity of Precambrian
age in the Indian Subcontinent
at the foot of the picturesque Mehrangarh Fort
in Jodhpur
city, the second largest city in Rajasthan
after Jaipur
.
Malani
was the name of a district in the former state of Marwar
(Jodhpur) where volcanic rocks were found and thus named as Malani beds (1877). This name underwent several changes over the years, known as Malani Volcanics Series (1902), Malani System (1933), the Malani Granite and Volcanic Suite(1968). Finally, the complete magmatic sequence has been named as the Malani Igneous Suite. The igneous suite marks the last phase of igneous activity of Precambrian age in the Indian subcontinent. The uniqueness of the geological feature at Jodhpur prompted the Geological Survey of India
(GSI) to declare the site as a National Geological Monument.
in Rajasthan, extends at the periphery of the desert, to an area of 44500 square kilometre covering parts of Pali
, Sirohi
, Jodhpur, Barmer
, Jaisalmer
, Jalore
and Siwana
districts of western Rajasthan. In particular, a rhyolite
rock exposure in a hillock of 120 metres (394 ft) height, originally called the "Mountain of Birds", forms the foundation for the imposing Mehrangarh Fort in Jodhpur.
The climate here is of extreme desert condition of scorching summer with hot dry winds and arid conditions. The winters are quite chilly. The rainfall is scanty and occurs during late June to September. The average rainfall is reported to be 360 millimetres (36 cm); extremely variable with a minimum recorded of 24 millimetres (2 cm) during the famine
year of 1899 and a maximum of 1178 millimetres (118 cm) during the floods of 1917.
, limestone
and shales
. Igneous activity preceded the deposition of these rocks in western Rajasthan in the form of a thick pile of lava
, mostly of an acidic nature. These lava and its plutonic equivalent have been noted in the form of granite
bosses and sills in Jalor, Siwana
, Mokalsar and Jodhpur areas and designated as Erinpura granite
and Malani Igneous Suite (pictured).
Mehrangarh Fort section in Jodhpur exposes the best Jodhpur Malani Suite contact. This erosional contact is between the underlying youngest Igneous suite of rocks of Precambrian age and overlying oldest sedimentary sequence of late Proterozoic
to Eocene
age. Its geological significance led to it being declared a National Geological Monument.
The igneous cycle has three phases namely, the volcanic, plutonic and hypabyssal. The eruption is reported to be of fissure
type. The pyroclastic exposed in a thickness of 40 metres (131 ft) to 50 metres (164 ft) is followed by rhyolite
flows of 50 metres (164 ft) to 60 metres (197 ft) thickness.
Sandstones of Jodhpur Group form the basal part of the Marwar Supergroup and the upper boundary of these volcanics is considerably eroded. The two formations called the Sonia Formation (sandstones) and the Girbhakar Formation (sandstones) occur unconformably over the eroded surface of Malani Volcanic rocks at the top, which comprise the Pokhran Boulder Bed (developed locally around Pokhran
) with the Jodhpur Group as the basal part. The sandstones are creamy (reddish maroon upwards), and widely used as building stones.
Further classification of the Malani Igneous Suite has been done by Bhushan (1991) as Granite Plutons (at least 15 varieties including the Jodhpur Rhyolites), the Siwana Granites (several plutons covering an area of 1100 square kilometre within the Malani Igneous Suite) and the Jalore Granite (covers an area of 7600 square kilometre including 3700 square kilometre of Sankara pluton).
Geological age
The geological age of the Malani Igneous Suite assessed by several geologists vary. Crawford and Compston (1970) assessed the age by Rb-Sr classification as 745 ± 10 Ma. They also reported, in 1975, that the Isochron age was 735 Ma which was less than the age of 840 Ma for Sandra Granite, 830 Ma for Erinpara Granites and 820 Ma for the Pali Granites. But the Geological Survey of India in its publication National Geological Monuments (2001) has given the age as 600±70 Ma.
named Cheeria Nathji, the Lord of the Bird
s. The hill and now the fort is habitat to thousands of birds, particularly the Cheel or Kite
, the sacred bird of the Rathore
s. When Maharana
Jodha wanted to build a fort on top of this hill, the irate hermit cursed him for intruding into his solitary cave; the curse "Jodha! May your citadel ever suffer a scarcity of water!", is true to this day as there is no water on the hill. The King, while continuing to build his fort, also appeased the hermit by building a temple
and a pond for the hermit to reside and meditate. The fort called the Mehrangarh Fort (etymology: 'Mihir' (Sanskrit
)–Sun
or Sun–deity; 'garh' (Sanskrit)–fort), located at the center of the Jodhpur city, thus known as the citadel of the Sun, and the Malani Igneous Suite hill are both famous now - the fort for its grandeur and the rock for its unique geological formation spread over an area of 5 square kilometre of the hill.
Another folk legend about the formation of the Thar Desert region, with the Malani Igneous Suit as an integral component, is of Lord Rama
, the hero of the Hindu epic
Ramayana
. In order to rescue his wife Sita
, who was abducted by the demon–king Ravana
, he attempted to cross the ocean but was turned back by the Sea–God. In a fit of fury, he raised his arrow to empty the ocean and force the Lord of the Sea to retreat, but discharged the arrow into another body of water located in western Rajasthan that resulted in its drying up. This is the area known as Marwar (former Jodhpur State) or Marusthali (desert region) or the land of the dead.
and air with the rest of the country. It is 343 kilometres (213 mi) SW of Jaipurcity. by the State Highway. The Northern Railway
Main Line and Northern Railway Phalodi
Branch passes through Jodhpur Town. The Fort is 5 kilometres (3 mi) away from the Jodhpur airport.
Precambrian
The Precambrian is the name which describes the large span of time in Earth's history before the current Phanerozoic Eon, and is a Supereon divided into several eons of the geologic time scale...
age in the Indian Subcontinent
Indian subcontinent
The Indian subcontinent, also Indian Subcontinent, Indo-Pak Subcontinent or South Asian Subcontinent is a region of the Asian continent on the Indian tectonic plate from the Hindu Kush or Hindu Koh, Himalayas and including the Kuen Lun and Karakoram ranges, forming a land mass which extends...
at the foot of the picturesque Mehrangarh Fort
Mehrangarh Fort
Mehrangarh Fort, located in Jodhpur city in Rajasthan state, is one of the largest forts in India.The fort is situated 400 feet above the city and is enclosed by imposing thick walls. Inside its boundaries there are several palaces known for their intricate carvings and expansive courtyards. A...
in Jodhpur
Jodhpur
Jodhpur , is the second largest city in the Indian state of Rajasthan. It is located west from the state capital, Jaipur and from the city of Ajmer. It was formerly the seat of a princely state of the same name, the capital of the kingdom known as Marwar...
city, the second largest city in Rajasthan
Rajasthan
Rājasthān the land of Rajasthanis, , is the largest state of the Republic of India by area. It is located in the northwest of India. It encompasses most of the area of the large, inhospitable Great Indian Desert , which has an edge paralleling the Sutlej-Indus river valley along its border with...
after Jaipur
Jaipur
Jaipur , also popularly known as the Pink City, is the capital and largest city of the Indian state of Rajasthan. Founded on 18 November 1727 by Maharaja Sawai Jai Singh II, the ruler of Amber, the city today has a population of more than 3.1 million....
.
Malani
Malani
Roko Malani was the eldest son of Rasolo, the first Tui Nayau , and of Laufitu a high-ranking lady of Totoya and Tongan descent. He succeeded to the title Roko Sau, after engineering a successful coup d'état and slaying his uncle, Matawalu, the fourth Roko Sau, in battle...
was the name of a district in the former state of Marwar
Marwar
Marwar is a region of southwestern Rajasthan state in western India. It lies partly in the Thar Desert. In Rajasthani dialect "wad" means a particular area. The word Marwar is derived from Sanskrit word 'Maruwat'. English translation of the word is 'The region of desert'., The Imperial Gazetteer...
(Jodhpur) where volcanic rocks were found and thus named as Malani beds (1877). This name underwent several changes over the years, known as Malani Volcanics Series (1902), Malani System (1933), the Malani Granite and Volcanic Suite(1968). Finally, the complete magmatic sequence has been named as the Malani Igneous Suite. The igneous suite marks the last phase of igneous activity of Precambrian age in the Indian subcontinent. The uniqueness of the geological feature at Jodhpur prompted the Geological Survey of India
Geological Survey of India
Geological Survey of India , established in 1851 is a government organization in India which is an attached office to the Ministry of Mines of Union Government of India for conducting geological surveys and studies. It is one of the oldest of such organizations in the world and the second oldest...
(GSI) to declare the site as a National Geological Monument.
Topography and geography
Malani Igneous Suite, an integral component of the Thar DesertThar Desert
The Thar Desert |Punjab]] province. The Cholistan Desert adjoins the Thar desert spreading into Pakistani Punjab province.-Location and description:...
in Rajasthan, extends at the periphery of the desert, to an area of 44500 square kilometre covering parts of Pali
Páli
- External links :* *...
, Sirohi
Sirohi
Sirohi is a city in southern Rajasthan state in western India. It is the administrative headquarters of Sirohi District, and was formerly the capital of the princely state of the same name. Nearest railway station to Sirohi is Sirohi Road station.-Geography:...
, Jodhpur, Barmer
Barmer district
Barmer is a district of Rajasthan state, India. Barmer is the district headquarters. Balotra, Guda Malani, Baytoo, Siwana, Jasol and Chohatan are other major towns.-Geography:...
, Jaisalmer
Jaisalmer
Jaysalmer , nicknamed "The Golden City", is a town in the Indian state of Rajasthan. It is located west from the state capital Jaipur. It was once known as Jaisalmer state. The town stands on a ridge of yellowish sandstone, crowned by a fort, which contains the palace and several ornate Jain...
, Jalore
Jalore
Jalor, also known as Jalore , is a city in Rajasthan state of western India. It is the administrative headquarters of Jalor District.- Geography :...
and Siwana
Siwana
Siwana is a Tehsil - in Barmer district in Indian state of Rajasthan, located 151 km from Barmer. The place is known for its fort. SIVANA having 129 villages total Population as per 2001 cencus is 213648, male is 111155 female is 102493....
districts of western Rajasthan. In particular, a rhyolite
Rhyolite
This page is about a volcanic rock. For the ghost town see Rhyolite, Nevada, and for the satellite system, see Rhyolite/Aquacade.Rhyolite is an igneous, volcanic rock, of felsic composition . It may have any texture from glassy to aphanitic to porphyritic...
rock exposure in a hillock of 120 metres (394 ft) height, originally called the "Mountain of Birds", forms the foundation for the imposing Mehrangarh Fort in Jodhpur.
The climate here is of extreme desert condition of scorching summer with hot dry winds and arid conditions. The winters are quite chilly. The rainfall is scanty and occurs during late June to September. The average rainfall is reported to be 360 millimetres (36 cm); extremely variable with a minimum recorded of 24 millimetres (2 cm) during the famine
Famine
A famine is a widespread scarcity of food, caused by several factors including crop failure, overpopulation, or government policies. This phenomenon is usually accompanied or followed by regional malnutrition, starvation, epidemic, and increased mortality. Every continent in the world has...
year of 1899 and a maximum of 1178 millimetres (118 cm) during the floods of 1917.
Geology
The lithological formations of the region classified as upper and lower Vindhyans in the east and Marwar in the west, have been recorded as consisting of a thick series of sedimentary rocks comprising sandstoneSandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...
, limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
and shales
Shalës
Shalës is a municipality in the Elbasan District, Elbasan County, central Albania. The municipality consists of the villages Shalës, Licaj, Kurtalli, Xibrake, Xherie and Kodras....
. Igneous activity preceded the deposition of these rocks in western Rajasthan in the form of a thick pile of lava
Lava
Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. When first erupted from a volcanic vent, lava is a liquid at...
, mostly of an acidic nature. These lava and its plutonic equivalent have been noted in the form of granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...
bosses and sills in Jalor, Siwana
Siwana
Siwana is a Tehsil - in Barmer district in Indian state of Rajasthan, located 151 km from Barmer. The place is known for its fort. SIVANA having 129 villages total Population as per 2001 cencus is 213648, male is 111155 female is 102493....
, Mokalsar and Jodhpur areas and designated as Erinpura granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...
and Malani Igneous Suite (pictured).
Mehrangarh Fort section in Jodhpur exposes the best Jodhpur Malani Suite contact. This erosional contact is between the underlying youngest Igneous suite of rocks of Precambrian age and overlying oldest sedimentary sequence of late Proterozoic
Proterozoic
The Proterozoic is a geological eon representing a period before the first abundant complex life on Earth. The name Proterozoic comes from the Greek "earlier life"...
to Eocene
Eocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...
age. Its geological significance led to it being declared a National Geological Monument.
The igneous cycle has three phases namely, the volcanic, plutonic and hypabyssal. The eruption is reported to be of fissure
Fissure
In anatomy, a fissure is a groove, natural division, deep furrow, elongated cleft, or tear in various parts of the body.-Brain:...
type. The pyroclastic exposed in a thickness of 40 metres (131 ft) to 50 metres (164 ft) is followed by rhyolite
Rhyolite
This page is about a volcanic rock. For the ghost town see Rhyolite, Nevada, and for the satellite system, see Rhyolite/Aquacade.Rhyolite is an igneous, volcanic rock, of felsic composition . It may have any texture from glassy to aphanitic to porphyritic...
flows of 50 metres (164 ft) to 60 metres (197 ft) thickness.
Sandstones of Jodhpur Group form the basal part of the Marwar Supergroup and the upper boundary of these volcanics is considerably eroded. The two formations called the Sonia Formation (sandstones) and the Girbhakar Formation (sandstones) occur unconformably over the eroded surface of Malani Volcanic rocks at the top, which comprise the Pokhran Boulder Bed (developed locally around Pokhran
Pokhran
Pokhran is a city and a municipality located in Jaisalmer district in the Indian state of Rajasthan. It is a remote location in the Thar Desert region and served as the test site for India's first underground nuclear weapon detonation.-Geography:Pokhran http://marupradesh.org/ located at...
) with the Jodhpur Group as the basal part. The sandstones are creamy (reddish maroon upwards), and widely used as building stones.
Further classification of the Malani Igneous Suite has been done by Bhushan (1991) as Granite Plutons (at least 15 varieties including the Jodhpur Rhyolites), the Siwana Granites (several plutons covering an area of 1100 square kilometre within the Malani Igneous Suite) and the Jalore Granite (covers an area of 7600 square kilometre including 3700 square kilometre of Sankara pluton).
Geological age
The geological age of the Malani Igneous Suite assessed by several geologists vary. Crawford and Compston (1970) assessed the age by Rb-Sr classification as 745 ± 10 Ma. They also reported, in 1975, that the Isochron age was 735 Ma which was less than the age of 840 Ma for Sandra Granite, 830 Ma for Erinpara Granites and 820 Ma for the Pali Granites. But the Geological Survey of India in its publication National Geological Monuments (2001) has given the age as 600±70 Ma.
Legend
The lone human occupant of the hill before the Mehrangarh Fort was built, was an old hermitHermit
A hermit is a person who lives, to some degree, in seclusion from society.In Christianity, the term was originally applied to a Christian who lives the eremitic life out of a religious conviction, namely the Desert Theology of the Old Testament .In the...
named Cheeria Nathji, the Lord of the Bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s. The hill and now the fort is habitat to thousands of birds, particularly the Cheel or Kite
Kite
A kite is a tethered aircraft. The necessary lift that makes the kite wing fly is generated when air flows over and under the kite's wing, producing low pressure above the wing and high pressure below it. This deflection also generates horizontal drag along the direction of the wind...
, the sacred bird of the Rathore
Rathore
The Rathore is a Suryavanshi Rajput clan same caste as Lohana. Their Kuldevi is Nagnechiya Mata and "Karani Mata". Rathores are originally from Kannauj in Uttar Pradesh. Rathores are historically considered the samurais of India...
s. When Maharana
Maharana
Maharana is a variation on the Indian royal title Maharaja, also meaning 'Great king' in Hindi. It is composed of Maha- 'great' and the royal title Rana, a variation on Raja.-Salute states :...
Jodha wanted to build a fort on top of this hill, the irate hermit cursed him for intruding into his solitary cave; the curse "Jodha! May your citadel ever suffer a scarcity of water!", is true to this day as there is no water on the hill. The King, while continuing to build his fort, also appeased the hermit by building a temple
Temple
A temple is a structure reserved for religious or spiritual activities, such as prayer and sacrifice, or analogous rites. A templum constituted a sacred precinct as defined by a priest, or augur. It has the same root as the word "template," a plan in preparation of the building that was marked out...
and a pond for the hermit to reside and meditate. The fort called the Mehrangarh Fort (etymology: 'Mihir' (Sanskrit
Sanskrit
Sanskrit , is a historical Indo-Aryan language and the primary liturgical language of Hinduism, Jainism and Buddhism.Buddhism: besides Pali, see Buddhist Hybrid Sanskrit Today, it is listed as one of the 22 scheduled languages of India and is an official language of the state of Uttarakhand...
)–Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
or Sun–deity; 'garh' (Sanskrit)–fort), located at the center of the Jodhpur city, thus known as the citadel of the Sun, and the Malani Igneous Suite hill are both famous now - the fort for its grandeur and the rock for its unique geological formation spread over an area of 5 square kilometre of the hill.
Another folk legend about the formation of the Thar Desert region, with the Malani Igneous Suit as an integral component, is of Lord Rama
Rama
Rama or full name Ramachandra is considered to be the seventh avatar of Vishnu in Hinduism, and a king of Ayodhya in ancient Indian...
, the hero of the Hindu epic
Indian epic poetry
Indian epic poetry is the epic poetry written in the Indian subcontinent, traditionally called Kavya . The Ramayana and Mahabharata, originally composed in Sanskrit and translated thereafter into many other Indian languages, are some of the oldest surviving epic poems on earth and form part of...
Ramayana
Ramayana
The Ramayana is an ancient Sanskrit epic. It is ascribed to the Hindu sage Valmiki and forms an important part of the Hindu canon , considered to be itihāsa. The Ramayana is one of the two great epics of India and Nepal, the other being the Mahabharata...
. In order to rescue his wife Sita
SITA
SITA is a multinational information technology company specialising in providing IT and telecommunication services to the air transport industry...
, who was abducted by the demon–king Ravana
Ravana
' is the primary antagonist character of the Hindu legend, the Ramayana; who is the great king of Lanka. In the classic text, he is mainly depicted negatively, kidnapping Rama's wife Sita, to claim vengeance on Rama and his brother Lakshmana for having cut off the nose of his sister...
, he attempted to cross the ocean but was turned back by the Sea–God. In a fit of fury, he raised his arrow to empty the ocean and force the Lord of the Sea to retreat, but discharged the arrow into another body of water located in western Rajasthan that resulted in its drying up. This is the area known as Marwar (former Jodhpur State) or Marusthali (desert region) or the land of the dead.
Access
The Geological monument is located in the heart of Jodhpur city, at the Mehrangarh fort hill range, which is connected by road, railRail transport
Rail transport is a means of conveyance of passengers and goods by way of wheeled vehicles running on rail tracks. In contrast to road transport, where vehicles merely run on a prepared surface, rail vehicles are also directionally guided by the tracks they run on...
and air with the rest of the country. It is 343 kilometres (213 mi) SW of Jaipurcity. by the State Highway. The Northern Railway
Northern Railway (India)
The Northern Railways is one of the 16 zones and the northernmost zone of the Indian Railways. Its headquarters is in Delhi at New Delhi Railway Station....
Main Line and Northern Railway Phalodi
Phalodi
Phalodi is a city and a municipality in Jodhpur district in the Indian state of Rajasthan. It is situated between latitude 27°-06 to 27°-09 north and 72°-20 to 72°-23east. It has an average elevation of 303 metres...
Branch passes through Jodhpur Town. The Fort is 5 kilometres (3 mi) away from the Jodhpur airport.