), a volcanic caldera with 10 known

Agate has also been known to fill veins or cracks in volcanic or altered rock underlain by granitic intrusive masses.

Diamonds are brought close to the Earth ′ s surface through deep volcanic eruptions by a magma, which cools into igneous rocks known as kimberlites and lamproites.

El Salvador is known as the " Land of Volcanoes "; there are frequent and sometimes very destructive earthquakes and volcanic activity ; catastophic hurricanes are uncommon.

He went on to find a similar penetration of volcanic rock through sedimentary rock near the centre of Edinburgh, at Salisbury Crags, adjoining Arthur's Seat: this is now known as Hutton's Section.

An estimate of of dense-rock equivalent pyroclastic material, known the Youngest Toba tuff, was blasted from the youngest caldera during one of the largest single explosive volcanic eruptions in geologic history.

Similar climatic effects can be caused by comets or an asteroid impact, also sometimes termed an impact winter, or by a supervolcano eruption, known as a volcanic winter.

In June 1957, The Effects of Nuclear Weapons by Samuel Glasstone was published containing a section entitled " Nuclear Bombs and the Weather " ( pages 69 – 71 ), which states: " The dust raised in severe volcanic eruptions, such as that at Krakatoa in 1883, is known to cause a noticeable reduction in the sunlight reaching the earth ...

The Siberian Traps were formed by one of the largest known volcanic events of the last 500 million years of Earth's geological history.

The volcanic event is said to be the largest known volcanic eruption in Earth's history.

The high level gases reflect sunlight and cause the widespread cooling ( known as a volcanic winter ) and heavy rains of 1816, causes snows in June and July in the northern hemisphere, widespread crop failures, and subsequently famine, which is why 1816 is later known as the Year Without a Summer.

This year was known as the ' Year Without a Summer ' because of low temperatures in the northern hemisphere, the result of the Mount Tambora volcanic eruption in Indonesia in 1815.

There are two known processes by which magma ceases to exist: by volcanic eruption, or by crystallization within the crust or mantle to form a pluton.

Before and during volcanic eruptions, volatiles such as CO < sub > 2 </ sub > and H < sub > 2 </ sub > O partially leave the melt through a process known as exsolution.

By inputting data on the ratio of stable isotopes < sup > 18 </ sup > O :< sup > 16 </ sup > O into computer models, it has been shown that in conjunction with quick-weathering of volcanic rock, this increased rainfall may have reduced greenhouse gas levels to below the threshold required to trigger the period of extreme glaciation known as Snowball Earth.

Lavas, especially rhyolite and dacite flows, tend to form clastic volcanic rocks by a process known as autobrecciation.

It cannot be created by volcanic action ; the only known mechanism of creating it is through an impact event ( or artificially through a nuclear explosion ).

The Bushveld, like the Rand, houses a virtual treasure chest of minerals, one of the largest and best known layered igneous ( volcanic ) mineral complexes in the world.

An unmined copper and gold deposit known as " the Bend Project " lies north of Perkinstown, which geologists believe was formed up to two billion years ago by a black smoker, a volcanic vent under an ancient ocean.

It is believed that the anomaly was caused by a combination of a historic low in solar activity with a volcanic winter event, the latter caused by a succession of major volcanic eruptions capped by the 1815 eruption of Mount Tambora, in the Dutch East Indies ( Indonesia ), the largest known eruption in over 1, 300 years.

In the Cook Islands, for example, on the capital island of Rarotonga, northern facing volcanic rocks, tumbling onto the shore millennia ago and still set in place, are well known as the ancient departure point for souls bound for Avaiki-the afterworld or heaven.

The " Days of April " ( journées d ' avril ) is a name appropriated in French history to a series of insurrections at Lyons, Paris and elsewhere, against the government of Louis Philippe in 1834, which led to violent repressive measures, and to a famous trial known as the procès d ' avril.

Spalding was, however, known to aggrandise his role in the major moments in baseball's history.

According to Steven H Silver, alternate history requires three things: 1 ) the story must have a point of divergence from the history of our world prior to the time at which the author is writing, 2 ) a change that would alter history as it is known, and 3 ) an examination of the ramifications of that change.

Secret history, works that document things that are not known to have happened historically but would not have changed history had they happened, is also not to be confused with alternate history.

Amara Simhan ( c. AD 375 ) was a Sanskrit grammarian and poet, of whose personal history hardly anything is known.

The natural history of Africa encompasses some of the well known megafauna of that continent.

These include Hindu astrology ( also known as " Indian astrology " and in modern times referred to as " Vedic astrology ") and Chinese astrology, both of which have influenced the world's cultural history.

Well known armour types in European history include the lorica hamata, lorica squamata, and the lorica segmentata of the Roman legions, the mail hauberk of the early medieval age, and the full steel plate harness worn by later medieval and renaissance knights, and breast and back plates worn by heavy cavalry in several European countries until the first year of World War I ( 1914 – 15 ).

In ancient Cretan history Leto was worshipped at Phaistos and in Cretan mythology Leto gave birth to Apollo and Artemis at the islands known today as the Paximadia.

The 1924 town council elections in Cicero became known as one of the most crooked elections in the Chicago area's long history of rigged elections, with voters threatened by thugs at polling stations.

Although the New Synagogue is still an anchor for Jewish history and culture, Oranienburger straße and surrounding areas are increasingly known for the shopping and nightlife.

Its hydroxide was known in pre-modern history as baryta ; this substance does not occur as a mineral, but can be prepared by heating barium carbonate.

Almost everything that is known of Bede's life is contained in the last chapter of his Historia Ecclesiastica, a history of the church in England.

The standard theological view of world history at the time was known as the six ages of the world ; in his book, Bede calculated the age of the world for himself, rather than accepting the authority of Isidore of Seville, and came to the conclusion that Christ had been born 3, 952 years after the creation of the world, rather than the figure of over 5, 000 years that was commonly accepted by theologians.

No such person as Darius the Mede < sup ></ sup > is recorded in known history.

Little is known about Nahum ’ s personal history.

In American history, early gambling establishments were known as saloons.

This phenomenon, known as regulatory capture, has a long history.

The known history of the Central African Republic dates back to the 7th century AD.

The doctor Bernardo Vera, known in the history of the independence, was the author of the verses that were sung to Robles ' music.

The known history of Cuba predates Christopher Columbus ' landing on the island during his first voyage of discovery on 28 October 1492.