Arabic is a Central Semitic language that was first spoken in Iron Age northwestern Arabia and is now the lingua franca of the Arab world. Arabic is the language of 1.7 billion Muslims. It is one of six languages of the United Nations. The modern written language is derived from the language of the Quran and it is widely taught in schools and universities, and is used to varying degrees in workplaces and the media. The two formal varieties are grouped together as Literary Arabic, which is the language of 26 states. Modern Standard Arabic largely follows the standards of Quranic Arabic. Much of the new vocabulary is used to denote concepts that have arisen in the post-Quranic era, Arabic has influenced many languages around the globe throughout its history. During the Middle Ages, Literary Arabic was a vehicle of culture in Europe, especially in science, mathematics. As a result, many European languages have borrowed many words from it. Many words of Arabic origin are found in ancient languages like Latin.
Balkan languages, including Greek, have acquired a significant number of Arabic words through contact with Ottoman Turkish. Arabic has borrowed words from languages including Greek and Persian in medieval times. Arabic is a Central Semitic language, closely related to the Northwest Semitic languages, the Ancient South Arabian languages, the Semitic languages changed a great deal between Proto-Semitic and the establishment of the Central Semitic languages, particularly in grammar. Innovations of the Central Semitic languages—all maintained in Arabic—include, The conversion of the suffix-conjugated stative formation into a past tense, the conversion of the prefix-conjugated preterite-tense formation into a present tense. The elimination of other prefix-conjugated mood/aspect forms in favor of new moods formed by endings attached to the prefix-conjugation forms, the development of an internal passive. These features are evidence of descent from a hypothetical ancestor. In the southwest, various Central Semitic languages both belonging to and outside of the Ancient South Arabian family were spoken and it is believed that the ancestors of the Modern South Arabian languages were spoken in southern Arabia at this time.
To the north, in the oases of northern Hijaz and Taymanitic held some prestige as inscriptional languages, in Najd and parts of western Arabia, a language known to scholars as Thamudic C is attested
Trajan was Roman emperor from 98 to 117 AD. Born in the city of Italica in the province of Hispania Baetica, Trajans non-patrician family was of Italian, Trajan rose to prominence during the reign of emperor Domitian. Serving as a legatus legionis in Hispania Tarraconensis, in 89 Trajan supported Domitian against a revolt on the Rhine led by Antonius Saturninus, in September 96, Domitian was succeeded by Marcus Cocceius Nerva, an old and childless senator who proved to be unpopular with the army. After a brief and tumultuous year in power, culminating in a revolt by members of the Praetorian Guard, Nerva was compelled to adopt the more popular Trajan as his heir and he died on 27 January 98 and was succeeded by his adopted son without incident. Early in his reign, he annexed the Nabataean Kingdom, creating the province of Arabia Petraea and his conquest of Dacia enriched the empire greatly, as the new province possessed many valuable gold mines. However, its position north of the Danube made it susceptible to attack on three sides, and it was abandoned by Emperor Aurelian.
Trajans war against the Parthian Empire ended with the sack of the capital Ctesiphon and his campaigns expanded the Roman Empire to its greatest territorial extent. In late 117, while sailing back to Rome, Trajan fell ill and he was deified by the Senate and his ashes were laid to rest under Trajans Column. He was succeeded by his adopted son Hadrian, as an emperor, Trajans reputation has endured – he is one of the few rulers whose reputation has survived nineteen centuries. Every new emperor after him was honoured by the Senate with the wish felicior Augusto, among medieval Christian theologians, Trajan was considered a virtuous pagan. As far as ancient literary sources are concerned, an extant continuous account of Trajans reign does not exist, only fragments remain of the Getiká, a book by Trajans personal physician Titos Statilios Kriton. The Parthiká, a 17-volume account of the Parthian Wars written by Arrian, has met a similar fate, book 68 in Cassius Dios Roman History, which survives mostly as Byzantine abridgments and epitomes, is the main source for the political history of Trajans rule.
Besides this, Pliny the Youngers Panegyricus and Dio of Prusas orations are the best surviving contemporary sources and it is certain that much of text of the letters that appear in this collection over Trajans signature was written and/or edited by Trajans Imperial secretary, his ab epistulis. Therefore, discussion of Trajan and his rule in modern historiography cannot avoid speculation, as well as recourse to sources such as archaeology. Marcus Ulpius Traianus was born on 18 September 53 AD in the Roman province of Hispania Baetica, Trajans birthplace of Italica was founded as a Roman military colony in 206 BC, though it is unknown when the Ulpii arrived there. Trajan was the son of Marcia, a Roman noblewoman and sister-in-law of the second Flavian Emperor Titus, and Marcus Ulpius Traianus, Marcus Ulpius Traianus the elder served Vespasian in the First Jewish-Roman War, commanding the Legio X Fretensis. Trajan himself was just one of many well-known Ulpii in a line that continued long after his own death and his elder sister was Ulpia Marciana, and his niece was Salonina Matidia.
The patria of the Ulpii was Italica, in Spanish Baetica, as a young man, he rose through the ranks of the Roman army, serving in some of the most contested parts of the Empires frontier
Damascus is the capital and likely the largest city of Syria, following the decline in population of Aleppo due to the ongoing battle for the city. It is commonly known in Syria as ash-Sham and nicknamed as the City of Jasmine, in addition to being one of the oldest continuously inhabited cities in the world, Damascus is a major cultural and religious centre of the Levant. The city has an population of 1,711,000 as of 2009. Located in south-western Syria, Damascus is the centre of a metropolitan area of 2.6 million people. The Barada River flows through Damascus, first settled in the second millennium BC, it was chosen as the capital of the Umayyad Caliphate from 661 to 750. After the victory of the Abbasid dynasty, the seat of Islamic power was moved to Baghdad, Damascus saw a political decline throughout the Abbasid era, only to regain significant importance in the Ayyubid and Mamluk periods. Today, it is the seat of the government and all of the government ministries. The name of Damascus first appeared in the geographical list of Thutmose III as T-m-ś-q in the 15th century BC, the etymology of the ancient name T-m-ś-q is uncertain, but it is suspected to be pre-Semitic.
It is attested as Dimašqa in Akkadian, T-ms-ḳw in Egyptian, Dammaśq in Old Aramaic, the Akkadian spelling is found in the Amarna letters, from the 14th century BC. Later Aramaic spellings of the name include a intrusive resh, perhaps influenced by the root dr. Thus, the English and Latin name of the city is Damascus which was imported from originated from the Qumranic Darmeśeq, and Darmsûq in Syriac, meaning a well-watered land. In Arabic, the city is called Dimašqu š-Šāmi, although this is shortened to either Dimašq or aš-Šām by the citizens of Damascus, of Syria and other Arab neighbours. Aš-Šām is an Arabic term for Levant and for Syria, the latter, the Anti-Lebanon mountains mark the border between Syria and Lebanon. The range has peaks of over 10,000 ft. and blocks precipitation from the Mediterranean sea, however, in ancient times this was mitigated by the Barada River, which originates from mountain streams fed by melting snow. Damascus is surrounded by the Ghouta, irrigated farmland where many vegetables, maps of Roman Syria indicate that the Barada river emptied into a lake of some size east of Damascus.
Today it is called Bahira Atayba, the hesitant lake, because in years of severe drought it does not even exist, the modern city has an area of 105 km2, out of which 77 km2 is urban, while Jabal Qasioun occupies the rest. The old city of Damascus, enclosed by the city walls, to the south-east and north-east it is surrounded by suburban areas whose history stretches back to the Middle Ages, Midan in the south-west and Imara in the north and north-west. These neighbourhoods originally arose on roads leading out of the city and these new neighbourhoods were initially settled by Kurdish soldiery and Muslim refugees from the European regions of the Ottoman Empire which had fallen under Christian rule
In its many centuries of existence, the Roman state evolved from a monarchy to a classical republic and to an increasingly autocratic empire. Through conquest and assimilation, it came to dominate the Mediterranean region and Western Europe, Asia Minor, North Africa and it is often grouped into classical antiquity together with ancient Greece, and their similar cultures and societies are known as the Greco-Roman world. Ancient Roman civilisation has contributed to modern government, politics, art, architecture, warfare, religion and society. Rome professionalised and expanded its military and created a system of government called res publica, the inspiration for modern republics such as the United States and France. By the end of the Republic, Rome had conquered the lands around the Mediterranean and beyond, its domain extended from the Atlantic to Arabia, the Roman Empire emerged with the end of the Republic and the dictatorship of Augustus Caesar. 721 years of Roman-Persian Wars started in 92 BC with their first war against Parthia and it would become the longest conflict in human history, and have major lasting effects and consequences for both empires.
Under Trajan, the Empire reached its territorial peak, Republican mores and traditions started to decline during the imperial period, with civil wars becoming a prelude common to the rise of a new emperor. Splinter states, such as the Palmyrene Empire, would divide the Empire during the crisis of the 3rd century. Plagued by internal instability and attacked by various migrating peoples, the part of the empire broke up into independent kingdoms in the 5th century. This splintering is a landmark historians use to divide the ancient period of history from the pre-medieval Dark Ages of Europe. King Numitor was deposed from his throne by his brother, while Numitors daughter, Rhea Silvia, because Rhea Silvia was raped and impregnated by Mars, the Roman god of war, the twins were considered half-divine. The new king, feared Romulus and Remus would take back the throne, a she-wolf saved and raised them, and when they were old enough, they returned the throne of Alba Longa to Numitor. Romulus became the source of the citys name, in order to attract people to the city, Rome became a sanctuary for the indigent and unwanted.
This caused a problem for Rome, which had a large workforce but was bereft of women, Romulus traveled to the neighboring towns and tribes and attempted to secure marriage rights, but as Rome was so full of undesirables they all refused. Legend says that the Latins invited the Sabines to a festival and stole their unmarried maidens, leading to the integration of the Latins, after a long time in rough seas, they landed at the banks of the Tiber River. Not long after they landed, the men wanted to take to the sea again, one woman, named Roma, suggested that the women burn the ships out at sea to prevent them from leaving. At first, the men were angry with Roma, but they realized that they were in the ideal place to settle. They named the settlement after the woman who torched their ships, the Roman poet Virgil recounted this legend in his classical epic poem the Aeneid
Syrias capital and largest city is Damascus. Religious groups include Sunnis, Alawites, Mandeans, Salafis, Sunni Arabs make up the largest religious group in Syria. Its capital Damascus and largest city Aleppo are among the oldest continuously inhabited cities in the world, in the Islamic era, Damascus was the seat of the Umayyad Caliphate and a provincial capital of the Mamluk Sultanate in Egypt. The post-independence period was tumultuous, and a number of military coups. In 1958, Syria entered a union with Egypt called the United Arab Republic. Syria was under Emergency Law from 1963 to 2011, effectively suspending most constitutional protections for citizens, Bashar al-Assad has been president since 2000 and was preceded by his father Hafez al-Assad, who was in office from 1970 to 2000. Mainstream modern academic opinion strongly favours the argument that the Greek word is related to the cognate Ἀσσυρία, Assyria, in the past, others believed that it was derived from Siryon, the name that the Sidonians gave to Mount Hermon.
However, the discovery of the inscription in 2000 seems to support the theory that the term Syria derives from Assyria. The area designated by the word has changed over time, since approximately 10,000 BC, Syria was one of centers of Neolithic culture where agriculture and cattle breeding appeared for the first time in the world. The following Neolithic period is represented by houses of Mureybet culture. At the time of the pre-pottery Neolithic, people used vessels made of stone, finds of obsidian tools from Anatolia are evidences of early trade relations. Cities of Hamoukar and Emar played an important role during the late Neolithic, archaeologists have demonstrated that civilization in Syria was one of the most ancient on earth, perhaps preceded by only those of Mesopotamia. The earliest recorded indigenous civilisation in the region was the Kingdom of Ebla near present-day Idlib, gifts from Pharaohs, found during excavations, confirm Eblas contact with Egypt. One of the earliest written texts from Syria is an agreement between Vizier Ibrium of Ebla and an ambiguous kingdom called Abarsal c.2300 BC.
The Northwest Semitic language of the Amorites is the earliest attested of the Canaanite languages, Mari reemerged during this period, and saw renewed prosperity until conquered by Hammurabi of Babylon. Ugarit arose during this time, circa 1800 BC, close to modern Latakia, Ugaritic was a Semitic language loosely related to the Canaanite languages, and developed the Ugaritic alphabet. The Ugarites kingdom survived until its destruction at the hands of the marauding Indo-European Sea Peoples in the 12th century BC, Yamhad was described in the tablets of Mari as the mightiest state in the near east and as having more vassals than Hammurabi of Babylon. Yamhad imposed its authority over Alalakh, the Hurrians states, the army of Yamhad campaigned as far away as Dēr on the border of Elam
Syrian Civil War
The Syrian Civil War is an armed conflict taking place in Syria. Syrian opposition groups formed the Free Syrian Army and seized control of the area surrounding Aleppo, over time, some factions of the Syrian opposition split from their original moderate position to pursue an Islamist vision for Syria, joining groups such as al-Nusra Front and ISIL. In 2015, the Yekîneyên Parastina Gel joined forces with Arab, Armenian and Hezbollah militarily engaged in support of the Syrian government, while beginning in 2014, a coalition of NATO countries began launching airstrikes against ISIL. International organizations have accused the Syrian government, ISIL, and some groups of severe human rights violations. The conflict has caused a major refugee crisis, over the course of the war a number of peace initiatives have been launched, including the March 2017 Geneva peace talks on Syria led by the United Nations, but fighting continues. Syria became an independent republic in 1946, although democratic rule ended with a coup in March 1949, a popular uprising against military rule in 1954 saw the army transfer power to civilians.
From 1958 to 1961, a union with Egypt replaced Syrias parliamentary system with a highly centralized presidential government. The secular Baath Syrian Regional Branch government came to power through a successful coup détat in 1963, for the next several years Syria went through additional coups and changes in leadership. In March 1971, Hafez al-Assad, an Alawite, declared himself President, on 31 January 1973, Hafez al-Assad implemented a new constitution, which led to a national crisis. They labeled Assad the enemy of Allah and called for a jihad against his rule, the government survived a series of armed revolts by Sunni Islamists, mainly members of the Muslim Brotherhood, from 1976 until 1982. Upon Hafez al-Assads death in 2000, his son Bashar al-Assad was elected as President of Syria, Bashar al-Assad and his wife Asma, a Sunni Muslim born and educated in Britain, initially inspired hopes for democratic reforms. The Damascus Spring, a period of social and political debate, the Damascus Spring largely ended in August 2001 with the arrest and imprisonment of ten leading activists who had called for democratic elections and a campaign of civil disobedience.
In the opinion of his critics, Bashar al-Assad had failed to deliver on promised reforms, Syrian Arabs, together with some 600,000 Palestinian Arabs, make up roughly 74 percent of the population. Syria Muslims are 74 percent Sunnis, and 13 percent Shias,3 percent were Druze, not all of the Sunnis are Arabs. Bashar is married to a Sunni, with whom he has several children and he is affiliated with the sect that his parents belong to, the minority Alawite sect which comprises an estimated 8-12 percent of the total population. Assyrians, an indigenous Eastern Aramaic-speaking Christian Semitic people, numbering approximately 500,000, are mainly in northeast Syria. A larger population lives over the border in northern Iraq, other ethnic groups include Armenians, Turkmens, Mhallami, Yezidi and Mandeans. Socioeconomic inequality increased significantly after free market policies were initiated by Hafez al-Assad in his years, the country faced particularly high youth unemployment rates
Roman theatre (structure)
Roman theatres derive from and are part of the overall evolution of earlier Greek theatres. Indeed, much of the influence on the Romans came from the Greeks. However, Roman theatres have specific differences, such as generally being built upon their own instead of earthen works or a hillside. Roman theatres were built in all areas of the empire from Spain to the Middle East, because of the Romans ability to influence local architecture, we see numerous theatres around the world with uniquely Roman attributes. There exist similarities between the theatres and amphitheatres of ancient Rome/Italy and they were constructed out of the same material, Roman concrete, and provided a place for the public to go and see numerous events throughout the Empire. However, they are two different structures, with specific layouts that lend to the different events they held. Amphitheatres did not need superior acoustics, unlike those provided by the structure of a Roman theatre, while amphitheatres would feature races and gladiatorial events, theatres hosted events such as plays, choral events, and orations.
Their design, with its form, enhances the natural acoustics. These buildings were semi-circular and possessed certain inherent architectural structures, with minor differences depending on the region in which they were constructed, the scaenae frons was a high back wall of the stage floor, supported by columns. The proscaenium was a wall that supported the front edge of the stage with ornately decorated niches off to the sides, the Hellenistic influence is seen through the use of the proscaenium. The Roman theatre had a podium, which supported the columns of the scaenae frons. The theatre itself was divided into the stage and the seating section, vomitoria or entrances and exits were made available to the audience. The auditorium, the area in which people gathered, was constructed on a small hill or slope in which stacked seating could be easily made in the tradition of the Greek Theatres. The center of the auditorium was hollowed out of a hill or slope, while the outer radian seats required structural support and this was of course not always the case as Romans tended to build their theatres regardless of the availability of hillsides.
All theatres built within the city of Rome were completely man-made without the use of earthworks, the auditorium was not roofed, awnings could be pulled overhead to provide shelter from rain or sunlight. Some Roman theatres, constructed of wood, were torn down after the festival for which they were erected concluded. This practice was due to a moratorium on permanent theatre structures that lasted until 55 BC when the Theatre of Pompey was built with the addition of a temple to avoid the law, some Roman theatres show signs of never having been completed in the first place. Inside Rome, few theatres have survived the centuries following their construction, Theatre of ancient Greece Theatre of ancient Rome Amphitheatre Roman architecture
A citadel is the core fortified area of a town or city. It may be a fortress, castle, or fortified center, the term is a diminutive of city and thus means little city, so called because it is a smaller part of the city of which it is the defensive core. It is positioned to be the last line of defense, should the enemy breach the other components of the fortification system, a citadel is a term of the third part of a medieval castle, with higher walls than the rest. It was to be the last line of defense before the keep itself, some of the oldest known structures which have served as citadels were built by the Indus Valley Civilization, where the citadel represented a centralised authority. The main citadel in Indus Valley was almost 12 meters tall, the purpose of these structures, remains debated. Though the structures found in the ruins of Mohenjo-daro were walled, they may have been built to divert flood waters. The most well-known is the Acropolis of Athens, but nearly every Greek city-state had one – the Acrocorinth famed as a strong fortress.
In a much period, when Greece was ruled by the Latin Empire, rebels who took power in the city but with the citadel still held by the former rulers could by no means regard their tenure of power as secure. One such incident played an important part in the history of the Maccabean Revolt against the Seleucid Empire, the Hellenistic garrison of Jerusalem and local supporters of the Seleucids held out for many years in the Acra citadel, making Maccabean rule in the rest of Jerusalem precarious. When finally gaining possession of the place, the Maccabeans pointedly destroyed and razed the Acra, a city where the citadel held out against an invading army was not considered conquered. In the Philippines The Ivatan people of the islands of Batanes often built fortifications to protect themselves during times of war. They built their so-called idjangs on hills and elevated areas. These fortifications were likened to European castles because of their purpose. Usually, the entrance to the castles would be via a rope ladder that would only be lowered for the villagers.
In time of war the citadel in many cases afforded retreat to the living in the areas around the town. For example, during the Dutch Wars of 1664-67, King Charles II of England constructed a Royal Citadel at Plymouth, barcelona had a great citadel built in 1714 to intimidate the Catalans against repeating their mid-17th- and early-18th-century rebellions against the Spanish central government. A similar example is the Citadella in Budapest, the Citadelle of Québec still survives as the largest citadel still in official military operation in North America. It is home to the Royal 22nd Regiment of Canada, citadels since the mid 20th century, are commonly military command and control centres built to resist attack commonly aerial or nuclear bombardment. The Military citadels under London such as the underground complex beneath the Ministry of Defense called Pindar is one such example
Civil wars and executions continued, culminating in the victory of Octavian, Caesars adopted son, over Mark Antony and Cleopatra at the Battle of Actium in 31 BC and the annexation of Egypt. Octavians power was unassailable and in 27 BC the Roman Senate formally granted him overarching power, the imperial period of Rome lasted approximately 1,500 years compared to the 500 years of the Republican era. The first two centuries of the empires existence were a period of unprecedented political stability and prosperity known as the Pax Romana, following Octavians victory, the size of the empire was dramatically increased. After the assassination of Caligula in 41, the senate briefly considered restoring the republic, under Claudius, the empire invaded Britannia, its first major expansion since Augustus. Vespasian emerged triumphant in 69, establishing the Flavian dynasty, before being succeeded by his son Titus and his short reign was followed by the long reign of his brother Domitian, who was eventually assassinated.
The senate appointed the first of the Five Good Emperors, the empire reached its greatest extent under Trajan, the second in this line. A period of increasing trouble and decline began with the reign of Commodus, Commodus assassination in 192 triggered the Year of the Five Emperors, of which Septimius Severus emerged victorious. The assassination of Alexander Severus in 235 led to the Crisis of the Third Century in which 26 men were declared emperor by the Roman Senate over a time span. It was not until the reign of Diocletian that the empire was fully stabilized with the introduction of the Tetrarchy, which saw four emperors rule the empire at once. This arrangement was unsuccessful, leading to a civil war that was finally ended by Constantine I. Constantine subsequently shifted the capital to Byzantium, which was renamed Constantinople in his honour and it remained the capital of the east until its demise. Constantine adopted Christianity which became the state religion of the empire. However, Augustulus was never recognized by his Eastern colleague, and separate rule in the Western part of the empire ceased to exist upon the death of Julius Nepos.
The Eastern Roman Empire endured for another millennium, eventually falling to the Ottoman Turks in 1453, the Roman Empire was among the most powerful economic, cultural and military forces in the world of its time. It was one of the largest empires in world history, at its height under Trajan, it covered 5 million square kilometres. It held sway over an estimated 70 million people, at that time 21% of the entire population. Throughout the European medieval period, attempts were made to establish successors to the Roman Empire, including the Empire of Romania, a Crusader state. Rome had begun expanding shortly after the founding of the republic in the 6th century BC, then, it was an empire long before it had an emperor
According to the Syria Central Bureau of Statistics, Bosra had a population of 19,683 in the 2004 census. It is the center of the nahiyah of Bosra which consisted of nine localities with a collective population of 33,839 in 2004. Bosras inhabitants are predominantly Sunni Muslims, although the town has a small Shia Muslim community and it continued to be administratively important during the Islamic era, but became gradually less prominent during the Ottoman era. It became a Latin Catholic titular see and the see of a Melkite Catholic Archeparchy. Today, it is a archaeological site and has been declared by UNESCO as a World Heritage Site. The settlement was first mentioned in the documents of Thutmose III, Bosra was the first Nabatean city in the 2nd century BC. The Nabatean Kingdom was conquered by Cornelius Palma, a general of Trajan, under the Roman Empire, Bosra was renamed Nova Trajana Bostra and was the residence of the legio III Cyrenaica. It was made capital of the Roman province of Arabia Petraea, the city flourished and became a major metropolis at the juncture of several trade routes, namely the Via Traiana Nova, a Roman road that connected Damascus to the Red Sea.
It became an important center for production and during the reign of Emperor Phillip the Arab. The two Councils of Arabia were held at Bosra in 246 and 247 AD, by the Byzantine period which began in the 5th-century, Christianity became the dominant religion in Bosra. The city became a Metropolitan archbishops seat and a cathedral was built in the 6th-century. Bosra was conquered by the Sassanid Persians in the early 7th-century, Bosra played an important part in the early life of prophet Muhammad, as described in the entry for the Christian monk Bahira. The forces of the Rashidun Caliphate under general Khalid ibn Walid captured the city from the Byzantines in the Battle of Bosra in 634, throughout Islamic rule, Bosra would serve as the southernmost outpost of Damascus, its prosperity being mostly contingent on the political importance of that city. Bosra held additional significance as a center of the pilgrim caravan between Damascus and the Muslim holy cities of Mecca and Medina, the destinations of the hajj pilgrimage.
Early Islamic rule did not alter the general architecture of Bosra, as Bosras inhabitants gradually converted to Islam the Roman-era holy sites were utilized for Muslim practices. In the 9th-century Yaqubi wrote that Bosra was the capital of the Hauran province, after the end of the Umayyad era in 750, major activity in Bosra ceased for around 300 years until the late 11th-century. In the last years of Fatimid rule, in 1068, a number of building projects were commissioned, with the advent of Seljuk rule in 1076, increasing focus was paid to Bosras defenses. In particular, the Roman theater was transformed into a fortress, with the coming to power of the Burid dynasty in Damascus, the general Kumushtakin was allotted the entire Hauran plain as a fief by the atabeg Tughtakin
Basalt is a common extrusive igneous rock formed from the rapid cooling of basaltic lava exposed at or very near the surface of a planet or moon. Flood basalt describes the formation in a series of basalt flows. By definition, basalt is an igneous rock with generally 45-55% silica and less than 10% feldspathoid by volume. Basalt commonly features a very fine-grained or glassy matrix interspersed with visible mineral grains, the average density is 3.0 gm/cm3. Basalt is defined by its content and texture, and physical descriptions without mineralogical context may be unreliable in some circumstances. Basalt is usually grey to black in colour, but rapidly weathers to brown or rust-red due to oxidation of its mafic minerals into hematite, although usually 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 and these phenocrysts usually 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 texture is called vesicular basalt, when the bulk of the rock is mostly solid. Gabbro is often marketed commercially as black granite and these ultramafic volcanic rocks, with silica contents below 45% are usually classified as komatiites. Agricola applied basalt to the black rock of the Schloßberg at Stolpen. Tholeiitic basalt is relatively rich in silica and poor in sodium, included in this category are most basalts of the ocean floor, most large oceanic islands, and continental flood basalts such as the Columbia River Plateau. Basalt rocks are in some cases classified after their content in High-Ti and Low-Ti varieties. High-Ti and Low-Ti basalts have been distinguished in the Paraná and Etendeka traps and it has greater than 17% alumina and is intermediate in composition between tholeiite and alkali basalt, the relatively alumina-rich composition is based on rocks without phenocrysts of plagioclase. Alkali basalt is relatively poor in silica and rich in sodium and it is silica-undersaturated and may contain feldspathoids, alkali feldspar and phlogopite.
Boninite is a form of basalt that is erupted generally in back-arc basins. Ocean island basalt Lunar basalt On Earth, most basalt magmas have formed by melting of the mantle. Basalt commonly erupts on Io, the third largest moon of Jupiter, and has formed on the Moon, Venus. The crustal portions of oceanic tectonic plates are composed predominantly of basalt, produced from upwelling mantle below, the mineralogy of basalt is characterized by a preponderance of calcic plagioclase feldspar and pyroxene