Basalt is a mafic extrusive igneous rock formed from the rapid cooling of magnesium-rich and iron-rich lava exposed at or near the surface of a terrestrial planet or a moon. More than 90% of all volcanic rock on Earth is basalt. Basalt lava has a low viscosity, due to its low silica content, resulting in rapid lava flows that can spread over great areas before cooling and solidification. Flood basalt describes the formation in a series of lava basalt flows. By definition, basalt is an aphanitic igneous rock with 45–53% silica and less than 10% feldspathoid by volume, where at least 65% of the rock is feldspar in the form of plagioclase; this is as per definition of the International Union of Geological Sciences classification scheme. It is the most common volcanic rock type on Earth, being a key component of oceanic crust as well as the principal volcanic rock in many mid-oceanic islands, including Iceland, the Faroe Islands, Réunion and the islands of Hawaiʻi. Basalt features a fine-grained or glassy matrix interspersed with visible mineral grains.
The average density is 3.0 g/cm3. Basalt is defined by its mineral content and texture, physical descriptions without mineralogical context may be unreliable in some circumstances. Basalt is grey to black in colour, but weathers to brown or rust-red due to oxidation of its mafic minerals into hematite and other iron oxides and hydroxides. Although characterized as "dark", basaltic rocks exhibit a wide range of shading due to regional geochemical processes. Due to weathering or high concentrations of plagioclase, some basalts can be quite light-coloured, superficially resembling andesite to untrained eyes. Basalt has a fine-grained mineral texture due to the molten rock cooling too for large mineral crystals to grow; these phenocrysts are of olivine or a calcium-rich plagioclase, which have the highest melting temperatures of the typical minerals that can crystallize from the melt. Basalt with a vesicular texture is called vesicular basalt, when the bulk of the rock is solid; this texture forms when dissolved gases come out of solution and form bubbles as the magma decompresses as it reaches the surface, yet are trapped as the erupted lava hardens before the gases can escape.
The term basalt is at times applied to shallow intrusive rocks with a composition typical of basalt, but rocks of this composition with a phaneritic groundmass are referred to as diabase or, when more coarse-grained, as gabbro. Gabbro is marketed commercially as "black granite." In the Hadean and early Proterozoic eras of Earth's history, the chemistry of erupted magmas was different from today's, due to immature crustal and asthenosphere differentiation. These ultramafic volcanic rocks, with silica contents below 45% are classified as komatiites; the word "basalt" is derived from Late Latin basaltes, a misspelling of Latin basanites "very hard stone", imported from Ancient Greek βασανίτης, from βάσανος and originated in Egyptian bauhun "slate". The modern petrological term basalt describing a particular composition of lava-derived rock originates from its use by Georgius Agricola in 1556 in his famous work of mining and mineralogy De re metallica, libri XII. Agricola applied "basalt" to the volcanic black rock of the Schloßberg at Stolpen, believing it to be the same as the "very hard stone" described by Pliny the Elder in Naturalis Historiae.
Tholeiitic basalt is rich in silica and poor in sodium. Included in this category are most basalts of the ocean floor, most large oceanic islands, continental flood basalts such as the Columbia River Plateau. High and low titanium basalts. Basalt rocks are in some cases classified after their titanium content in High-Ti and Low-Ti varieties. High-Ti and Low-Ti basalts have been distinguished in the Paraná and Etendeka traps and the Emeishan Traps. Mid-ocean ridge basalt is a tholeiitic basalt erupted only at ocean ridges and is characteristically low in incompatible elements. E-MORB, enriched MORB N-MORB, normal MORB D-MORB, depleted MORB High-alumina basalt may be silica-undersaturated or -oversaturated, it has greater than 17% alumina and is intermediate in composition between tholeiitic basalt and alkali basalt. Alkali basalt is poor in silica and rich in sodium, it may contain feldspathoids, alkali feldspar and phlogopite. Boninite is a high-magnesium form of basalt, erupted in back-arc basins, distinguished by its low titanium content and trace-element composition.
Ocean island basalt Lunar basalt The mineralogy of basalt is characterized by a preponderance of calcic plagioclase feldspar and pyroxene. Olivine can be a significant constituent. Accessory minerals present in minor amounts include iron oxides and iron-titanium oxides, such as magnetite and ilmenite; because of the presence of such oxide minerals, basalt can acquire strong magnetic signatures as it cools, paleomagnetic studies have made extensive use of basalt. In tholeiitic basalt and calcium-rich plagioclase are common phenocryst minerals. Olivine may be a phenocryst, when
The Stone Age was a broad prehistoric period during which stone was used to make implements with an edge, a point, or a percussion surface. The period lasted 3.4 million years and ended between 8700 BCE and 2000 BCE with the advent of metalworking. Stone Age artifacts include tools used by modern humans and by their predecessor species in the genus Homo, by the earlier contemporaneous genera Australopithecus and Paranthropus. Bone tools were used during this period as well but are preserved in the archaeological record; the Stone Age is further subdivided by the types of stone tools in use. The Stone Age is the first period in the three-age system of archaeology, which divides human technological prehistory into three periods: The Stone Age The Bronze Age The Iron Age The Stone Age is contemporaneous with the evolution of the genus Homo, the only exception being the early Stone Age, when species prior to Homo may have manufactured tools. According to the age and location of the current evidence, the cradle of the genus is the East African Rift System toward the north in Ethiopia, where it is bordered by grasslands.
The closest relative among the other living primates, the genus Pan, represents a branch that continued on in the deep forest, where the primates evolved. The rift served as a conduit for movement into southern Africa and north down the Nile into North Africa and through the continuation of the rift in the Levant to the vast grasslands of Asia. Starting from about 4 million years ago a single biome established itself from South Africa through the rift, North Africa, across Asia to modern China, called "transcontinental'savannahstan'" recently. Starting in the grasslands of the rift, Homo erectus, the predecessor of modern humans, found an ecological niche as a tool-maker and developed a dependence on it, becoming a "tool equipped savanna dweller"; the oldest indirect evidence found of stone tool use is fossilised animal bones with tool marks. Archaeological discoveries in Kenya in 2015, identifying the oldest known evidence of hominin use of tools to date, have indicated that Kenyanthropus platyops may have been the earliest tool-users known.
The oldest stone tools were excavated from the site of Lomekwi 3 in West Turkana, northwestern Kenya, date to 3.3 million years old. Prior to the discovery of these "Lomekwian" tools, the oldest known stone tools had been found at several sites at Gona, Ethiopia, on the sediments of the paleo-Awash River, which serve to date them. All the tools come from the Busidama Formation, which lies above a disconformity, or missing layer, which would have been from 2.9 to 2.7 mya. The oldest sites containing tools are dated to 2.6–2.55 mya. One of the most striking circumstances about these sites is that they are from the Late Pliocene, where previous to their discovery tools were thought to have evolved only in the Pleistocene. Excavators at the locality point out that: "...the earliest stone tool makers were skilled flintknappers.... The possible reasons behind this seeming abrupt transition from the absence of stone tools to the presence thereof include... gaps in the geological record."The species who made the Pliocene tools remains unknown.
Fragments of Australopithecus garhi, Australopithecus aethiopicus and Homo Homo habilis, have been found in sites near the age of the Gona tools. In July 2018, scientists reported the discovery in China of the oldest stone tools outside Africa, estimated at 2.12 million years old. Innovation of the technique of smelting ore began the Bronze Age; the first most significant metal manufactured was bronze, an alloy of copper and tin, each of, smelted separately. The transition from the Stone Age to the Bronze Age was a period during which modern people could smelt copper, but did not yet manufacture bronze, a time known as the Copper Age, or more technically the Chalcolithic, "copper-stone" age; the Chalcolithic by convention is the initial period of the Bronze Age. The Bronze Age was followed by the Iron Age; the transition out of the Stone Age occurred between 6000 BCE and 2500 BCE for much of humanity living in North Africa and Eurasia. The first evidence of human metallurgy dates to between the 5th and 6th millennium BCE in the archaeological sites of Majdanpek and Pločnik in modern-day Serbia, though not conventionally considered part of the Chalcolithic or "Copper Age", this provides the earliest known example of copper metallurgy.
Note the Rudna Glava mine in Serbia. Ötzi the Iceman, a mummy from about 3300 BCE carried with him a flint knife. In regions such as Sub-Saharan Africa, the Stone Age was followed directly by the Iron Age; the Middle East and southeastern Asian regions progressed past Stone Age technology around 6000 BCE. Europe, the rest of Asia became post-Stone Age societies by about 4000 BCE; the proto-Inca cultures of South America continued at a Stone Age level until around 2000 BCE, when gold and silver made their entrance. The Americas notably did not develop a widespread behavior of smelting Bronze or Iron after the Stone Age period, although the technology existed. Stone tool manufacture continued after the Stone Age ended in a given area. In Europe and North America, millstones were in use until well into the 20th century, still are in many parts of the world; the terms "Stone Age", "Bronze Age", "Iron Age" were never meant to suggest that advancement and time periods in prehistory are only measured by the type of tool material, rather than, for
Turmeric is a flowering plant of the ginger family, the roots of which are used in cooking. The plant is rhizomatous and perennial, is native to the Indian subcontinent and Southeast Asia, requires temperatures between 20 and 30 °C and a considerable amount of annual rainfall to thrive. Plants are gathered each year for their rhizomes, some for propagation in the following season and some for consumption; when not used fresh, the rhizomes are boiled in water for about 30–45 minutes and dried in hot ovens, after which they are ground into a deep orange-yellow powder used as a coloring and flavoring agent in many Asian cuisines for curries, as well as for dyeing. Turmeric powder has a warm, black pepper-like flavor and earthy, mustard-like aroma. Although long used in Ayurvedic medicine, where it is known as haridra, no high-quality clinical evidence exists for use of turmeric or its constituent, curcumin, as a therapy. Turmeric has been used in Asia for thousands of years and is a major part of Ayurveda, Siddha medicine, traditional Chinese medicine and the animistic rituals of Austronesian peoples.
It was first used as a dye, later for its supposed properties in folk medicine. Although the precise origin of turmeric is not known, it appears to have originated from tropical Southeast Asia, it is most associated with India today. The greatest diversity of Curcuma species by number alone is at around 40 to 45 species. Thailand is much smaller than India. Other countries in tropical Asia have numerous wild species of Curcuma. Recent studies have shown that the taxonomy of Curcuma longa is problematic, with only the specimens from South India being identifiable as C. longa. The phylogeny, relationships and interspecific variation, identity of other species and cultivars in other parts of the world still need to be established and validated. Various species utilized and sold as "turmeric" in other parts of Asia have been shown to belong to several physically similar taxa, with overlapping local names. Furthermore, in the case of the use and spread of turmeric by the Austronesian peoples into Oceania and Madagascar, there is strong linguistic and circumstantial evidence that it pre-dated contact with India.
The populations in Polynesia and Micronesia, in particular, never came into contact with India, but use turmeric for both food and dye. Thus independent domestication events are likely; the origin of the name is Indian. It derives from Middle English or Early Modern English as turmeryte or tarmaret, it may be of terra merita. The name of the genus, Curcuma, is derived from the Sanskrit kuṅkuma, referring to both turmeric and saffron, used in India since ancient times. Turmeric is a perennial herbaceous plant. Branched, yellow to orange, aromatic rhizomes are found; the leaves are arranged in two rows. They are divided into leaf sheath and leaf blade. From the leaf sheaths, a false stem is formed; the petiole is 50 to 115 cm long. The simple leaf blades are 76 to 115 cm long and up to 230 cm, they are oblong to elliptical, narrowing at the tip. At the top of the inflorescence, stem bracts are present on; the hermaphrodite flowers are threefold. The three sepals are 0.8 to 1.2 cm long and white, have fluffy hairs.
The three bright-yellow petals are fused into a corolla tube up to 3 cm long. The three corolla lobes have a length of 1.0 to 1.5 cm and are triangular with soft-spiny upper ends. While the average corolla lobe is larger than the two lateral, only the median stamen of the inner circle is fertile; the dust bag is spurred at its base. All other stamens are converted to staminodes; the outer staminodes are shorter than the labellum. The labellum is yellowish, with a yellow ribbon in its center and it is obovate, with a length from 1.2 to 2.0 cm. Three carpels are under a constant, trilobed ovary adherent, sparsely hairy; the fruit capsule opens with three compartments. In East Asia, the flowering time is in August. Terminally on the false stem is an inflorescence; the bracts are ovate to oblong with a blunt upper end with a length of 3 to 5 cm. Turmeric powder is about 60–70% carbohydrates, 6–13% water, 6–8% protein, 5–10% fat, 3–7% dietary minerals, 3–7% essential oils, 2–7% dietary fiber, 1–6% curcuminoids.
Phytochemical components of turmeric include diarylheptanoids, a class including numerous curcuminoids, such as curcumin, demethoxycurcumin, bisdemethoxycurcumin. Curcumin constitutes up to 3.14% of assayed commercial samples of turmeric powder. Some 34 essential oils are present in turmeric, among which turmerone, germacrone and zingiberene are major constituents. Turmeric is one of the key ingredients in many Asian dishes, imparting a mustard-like, earthy aroma and pungent bitter flavor to foods, it is used in savory dishes, but is used in some sweet dishes, such as the cake sfouf. In India, turmeric leaf is used to prepare special sweet dishes, patoleo, by layering rice flour and coconut-jaggery mixture on the leaf closing and steaming it in a special u
A tool is an object used to extend the ability of an individual to modify features of the surrounding environment. Although many animals use simple tools, only human beings, whose use of stone tools dates back hundreds of millennia, use tools to make other tools; the set of tools needed to perform different tasks that are part of the same activity is called gear or equipment. While one may apply the term tool loosely to many things that are means to an end speaking an object is a tool only if, besides being constructed to be held, it is made of a material that allows its user to apply to it various degrees of force. If repeated use wears part of the tool down, it may be possible to restore it, thus tool falls under the taxonomic category implement, is on the same taxonomic rank as instrument, device, or ware. Anthropologists believe; because tools are used extensively by both humans and wild chimpanzees, it is assumed that the first routine use of tools took place prior to the divergence between the two species.
These early tools, were made of perishable materials such as sticks, or consisted of unmodified stones that cannot be distinguished from other stones as tools. Stone artifacts only date back to about 2.5 million years ago. However, a 2010 study suggests the hominin species Australopithecus afarensis ate meat by carving animal carcasses with stone implements; this finding pushes back the earliest known use of stone tools among hominins to about 3.4 million years ago. Finds of actual tools date back at least 2.6 million years in Ethiopia. One of the earliest distinguishable stone tool forms is the hand axe. Up until weapons found in digs were the only tools of “early man” that were studied and given importance. Now, more tools are recognized as culturally and relevant; as well as hunting, other activities required tools such as preparing food, “…nutting, grain harvesting and woodworking…” Included in this group are “flake stone tools". Tools are the most important items that the ancient humans used to climb to the top of the food chain.
“Man the hunter” as the catalyst for Hominin change has been questioned. Based on marks on the bones at archaeological sites, it is now more evident that pre-humans were scavenging off of other predators' carcasses rather than killing their own food. Mechanical devices experienced a major expansion in their use in Ancient Greece and Ancient Rome with the systematic employment of new energy sources waterwheels, their use expanded through the Dark Ages with the addition of windmills. Machine tools occasioned a surge in producing new tools in the industrial revolution. Advocates of nanotechnology expect a similar surge. One can classify tools according to their basic functions: Cutting and edge tools, such as the knife, scythe or sickle, are wedge-shaped implements that produce a shearing force along a narrow face. Ideally, the edge of the tool needs to be harder than the material being cut or else the blade will become dulled with repeated use, but resilient tools will require periodic sharpening, the process of removing deformation wear from the edge.
Other examples of cutting tools include gouges and drill bits. Moving tools move tiny items. Many are levers. Examples of force-concentrating tools include the hammer which moves a nail or the maul which moves a stake; these operate by applying physical compression to a surface. In the case of the screwdriver, the force called torque. By contrast, an anvil concentrates force on an object being hammered by preventing it from moving away when struck. Writing implements deliver a fluid to a surface via compression to activate the ink cartridge. Grabbing and twisting nuts and bolts with pliers, a glove, a wrench, etc. move items by some kind of force. Tools that enact chemical changes, including temperature and ignition, such as lighters and blowtorches. Guiding and perception tools include the ruler, set square, straightedge, microscope, clock, printer Shaping tools, such as molds, trowels. Fastening tools, such as welders, rivet nail guns, or glue guns. Information and data manipulation tools, such as computers, IDE, spreadsheetsSome tools may be combinations of other tools.
An alarm-clock is for example a combination of a perception tool. This enables the alarm-clock to be a tool. There is some debate on whether to consider protective gear items as tools, because they do not directly help perform work, just protect the worker like ordinary clothing, they do meet the general definition of tools and in many cases are necessary for the completion of the work. Personal protective equipment includes such items as gloves, safety glasses, ear defenders and biohazard suits. A simple machine is a mechanical device that changes the magnitude of a force. In general, they are the simplest mechanisms; the six classical simple machines which were defined by Renaissance scientists are: Lever Wheel and axle Pulley Inclined plane Wedge Screw Often, by design or coincidence, a tool may share key functional attributes with one or more other tools. In this case, s
The Maya civilization was a Mesoamerican civilization developed by the Maya peoples, noted for its logosyllabic script—the most sophisticated and developed writing system in pre-Columbian Americas—as well as for its art, mathematics and astronomical system. The Maya civilization developed in an area that encompasses southeastern Mexico, all of Guatemala and Belize, the western portions of Honduras and El Salvador; this region consists of the northern lowlands encompassing the Yucatán Peninsula, the highlands of the Sierra Madre, running from the Mexican state of Chiapas, across southern Guatemala and onwards into El Salvador, the southern lowlands of the Pacific littoral plain. The Archaic period, prior to 2000 BC, saw the first developments in agriculture and the earliest villages; the Preclassic period saw the establishment of the first complex societies in the Maya region, the cultivation of the staple crops of the Maya diet, including maize, beans and chili peppers. The first Maya cities developed around 750 BC, by 500 BC these cities possessed monumental architecture, including large temples with elaborate stucco façades.
Hieroglyphic writing was being used in the Maya region by the 3rd century BC. In the Late Preclassic a number of large cities developed in the Petén Basin, the city of Kaminaljuyu rose to prominence in the Guatemalan Highlands. Beginning around 250 AD, the Classic period is defined as when the Maya were raising sculpted monuments with Long Count dates; this period saw the Maya civilization develop a large number of city-states linked by a complex trade network. In the Maya Lowlands two great rivals, the cities of Tikal and Calakmul, became powerful; the Classic period saw the intrusive intervention of the central Mexican city of Teotihuacan in Maya dynastic politics. In the 9th century, there was a widespread political collapse in the central Maya region, resulting in internecine warfare, the abandonment of cities, a northward shift of population; the Postclassic period saw the rise of Chichen Itza in the north, the expansion of the aggressive Kʼicheʼ kingdom in the Guatemalan Highlands. In the 16th century, the Spanish Empire colonized the Mesoamerican region, a lengthy series of campaigns saw the fall of Nojpetén, the last Maya city, in 1697.
Classic period rule was centred on the concept of the "divine king", who acted as a mediator between mortals and the supernatural realm. Kingship was patrilineal, power would pass to the eldest son. A prospective king was expected to be a successful war leader. Maya politics was dominated by a closed system of patronage, although the exact political make-up of a kingdom varied from city-state to city-state. By the Late Classic, the aristocracy had increased, resulting in the corresponding reduction in the exclusive power of the divine king; the Maya civilization developed sophisticated artforms, the Maya created art using both perishable and non-perishable materials, including wood, obsidian, sculpted stone monuments and finely painted murals. Maya cities tended to expand haphazardly, the city centre would be occupied by ceremonial and administrative complexes, surrounded by an irregular sprawl of residential districts. Different parts of a city would be linked by causeways; the principal architecture of the city consisted of palaces, pyramid-temples, ceremonial ballcourts, structures aligned for astronomical observation.
The Maya elite were literate, developed a complex system of hieroglyphic writing, the most advanced in the pre-Columbian Americas. The Maya recorded their history and ritual knowledge in screenfold books, of which only three uncontested examples remain, the rest having been destroyed by the Spanish. There are a great many examples of Maya text found on stelae and ceramics; the Maya developed a complex series of interlocking ritual calendars, employed mathematics that included one of the earliest instances of the explicit zero in the world. As a part of their religion, the Maya practised human sacrifice; the Maya civilization developed within the Mesoamerican cultural area, which covers a region that spreads from northern Mexico southwards into Central America. Mesoamerica was one of six cradles of civilization worldwide; the Mesoamerican area gave rise to a series of cultural developments that included complex societies, cities, monumental architecture and calendrical systems. The set of traits shared by Mesoamerican cultures included astronomical knowledge and human sacrifice, a cosmovision that viewed the world as divided into four divisions aligned with the cardinal directions, each with different attributes, a three-way division of the world into the celestial realm, the earth, the underworld.
By 6000 BC, the early inhabitants of Mesoamerica were experimenting with the domestication of plants, a process that led to the establishment of sedentary agricultural societies. The diverse climate allowed for wide variation in available crops, but all regions of Mesoamerica cultivated the base crops of maize and squashes. All Mesoamerican cultures used Stone Age technology. Mesoamerica lacked draft animals, did not use the wheel, possessed few domesticated animals. Mesoamericans viewed the world as hostile and governed by unpredictable deities; the ritual Mesoamerican ballgame was played. Mesoamerica is linguistically diverse, with most languages falling within a small number of language families—the major families are Mayan, Mixe–Zoquean and Uto-Aztecan.
Pakistan the Islamic Republic of Pakistan, is a country in South Asia. It is the world’s sixth-most populous country with a population exceeding 212,742,631 people. In area, it is the 33rd-largest country. Pakistan has a 1,046-kilometre coastline along the Arabian Sea and Gulf of Oman in the south and is bordered by India to the east, Afghanistan to the west, Iran to the southwest, China in the far northeast, it is separated narrowly from Tajikistan by Afghanistan's Wakhan Corridor in the northwest, shares a maritime border with Oman. The territory that now constitutes Pakistan was the site of several ancient cultures and intertwined with the history of the broader Indian subcontinent; the ancient history involves the Neolithic site of Mehrgarh and the Bronze Age Indus Valley Civilisation, was home to kingdoms ruled by people of different faiths and cultures, including Hindus, Indo-Greeks, Turco-Mongols and Sikhs. The area has been ruled by numerous empires and dynasties, including the Persian Achaemenid Empire, Alexander III of Macedon, the Seleucid Empire, the Indian Maurya Empire, the Gupta Empire, the Arab Umayyad Caliphate, the Delhi Sultanate, the Mongol Empire, the Mughal Empire, the Afghan Durrani Empire, the Sikh Empire and, most the British Empire.
Pakistan is the only country to have been created in the name of Islam. It is an ethnically and linguistically diverse country, with a diverse geography and wildlife. A dominion, Pakistan adopted a constitution in 1956, becoming an Islamic republic. An ethnic civil war and Indian military intervention in 1971 resulted in the secession of East Pakistan as the new country of Bangladesh. In 1973, Pakistan adopted a new constitution which stipulated that all laws are to conform to the injunctions of Islam as laid down in the Quran and Sunnah. A regional and middle power, Pakistan has the sixth-largest standing armed forces in the world and is a nuclear power as well as a declared nuclear-weapons state, the second in South Asia and the only nation in the Muslim world to have that status. Pakistan has a semi-industrialised economy with a well-integrated agriculture sector and a growing services sector, it is ranked among the emerging and growth-leading economies of the world, is backed by one of the world's largest and fastest-growing middle class.
Pakistan's political history since independence has been characterized by periods of military rule, political instability and conflicts with India. The country continues to face challenging problems, including overpopulation, poverty and corruption. Pakistan is a member of the UN, the Shanghai Cooperation Organisation, the OIC, the Commonwealth of Nations, the SAARC and the Islamic Military Counter Terrorism Coalition; the name Pakistan means "land of the pure" in Urdu and Persian. It alludes to the word pāk meaning pure in Pashto; the suffix ـستان is a Persian word meaning the place of, recalls the synonymous Sanskrit word sthāna स्थान. The name of the country was coined in 1933 as Pakstan by Choudhry Rahmat Ali, a Pakistan Movement activist, who published it in his pamphlet Now or Never, using it as an acronym referring to the names of the five northern regions of British India: Punjab, Kashmir and Baluchistan; the letter i was incorporated to ease pronunciation. Some of the earliest ancient human civilisations in South Asia originated from areas encompassing present-day Pakistan.
The earliest known inhabitants in the region were Soanian during the Lower Paleolithic, of whom stone tools have been found in the Soan Valley of Punjab. The Indus region, which covers most of present day Pakistan, was the site of several successive ancient cultures including the Neolithic Mehrgarh and the Bronze Age Indus Valley Civilisation at Harappa and Mohenjo-Daro; the Vedic period was characterised by an Indo-Aryan culture. Multan was an important Hindu pilgrimage centre; the Vedic civilisation flourished in the ancient Gandhāran city of Takṣaśilā, now Taxila in the Punjab, founded around 1000 BCE. Successive ancient empires and kingdoms ruled the region: the Persian Achaemenid Empire, Alexander the Great's empire in 326 BCE and the Maurya Empire, founded by Chandragupta Maurya and extended by Ashoka the Great, until 185 BCE; the Indo-Greek Kingdom founded by Demetrius of Bactria included Gandhara and Punjab and reached its greatest extent under Menander, prospering the Greco-Buddhist culture in the region.
Taxila had one of the earliest universities and centres of higher education in the world, established during the late Vedic period in 6th century BCE. The school consisted of several monasteries without large dormitories or lecture halls where the religious instruction was provided on an individualistic basis; the ancient university was documented by the invading forces of Alexander the Great, "the like of which had not been seen in Greece," and was recorded by Chinese pilgrims in the 4th or 5th century CE. At its zenith, the Rai Dynasty of Sindh ruled the surrounding territories; the Pala Dynasty was the last Buddhist empire, under Dharmapala and Devapala, stretched across South Asia from what is now Bangladesh through Northern India to Pakistan. The Arab conqueror Muhammad bin Qasim conquered Sindh in 711 CE; the Pakistan government's official chronol