Latest Igneous rocks Stories
Lee Rannals for redOrbit.com - Your Universe Online Scientists analyzing data from NASA's MESSENGER spacecraft say that Mercury once harbored an ancient magma ocean. An MIT team of scientists say that Mercury may have had a large ocean of magma very early in its history, shortly after its formation about 4.5 billion years ago. A group of scientists analyzed X-ray fluorescence data from MESSENGER collected back in 2011. They were able to identify two distinct compositions of rocks on...
Lee Rannals for redOrbit.com – Your Universe Online University of Michigan scientists have found traces of water from a lunar sample brought back during the Apollo 15 mission. The lunar sample, known as "Genesis Rock," was thought to be a piece of the moon's primordial crust, and researchers writing in Nature Geoscience are now reporting they have found traces of water in the rock. The traces of water were detected within the crystalline structure of mineral samples taken from...
Brett Smith for redOrbit.com - Your Universe Online Neither explosive nor effusive—there’s a new type of volcanic eruption that was recently described in the latest edition of Nature Geoscience. According to the U.K. and New Zealand scientists who authored the description, volcanic pumice produced by the Macauley volcano in the southwest Pacific is the result of a previously unarticulated type of eruption. “By documenting the shape and density of bubbles in pumices generated by...
April Flowers for redOrbit.com - Your Universe Online Even though two-thirds of the Earth's solid surface is covered with oceanic crust, scientists still do not entirely understood the process by which it is made. But a recent study from the Carnegie Institution for Science, which analyzed more than 600 samples of oceanic crust, reveals a systemic pattern that alters long-held beliefs about how the process works. Findings of this study, published in the journal Nature, explain a...
Lee Rannals for redOrbit.com – Your Universe Online Scientists have identified a trigger for the largest explosive volcanic eruptions on Earth, according to a report published in the journal Scientific Reports. University of Southampton researchers investigated crystal cumulate nodules and their trapped magma to see what caused eruptions at the Las Cañadas volcanic caldera on Tenerife, in the Canary Islands. This volcano has generated at least eight major eruptions during the last...
Lawrence LeBlond for redOrbit.com - Your Universe Online New scientific data from the Greek isle of Santorini has shown signs of unrest for the first time in more than 50 years, and could be evidence of an impending eruption similar to the one that last struck in 1950, but far less catastrophic than the one that wiped out Minoan settlements on the island of Crete some 3,600 years ago. The Santorini volcanic eruption circa-1650 BC formed a large crater, or caldera, which is now flooded...
April Flowers for redOrbit.com - Your Universe Online How often have you wished you could safely see a lava flow, like the one that destroyed Pompeii? Did you ever wish you could see it in Syracuse, New York? Professors, students, visiting volcanologists and passing spectators are now seeing lava flows in a campus parking lot at Syracuse University and have been since January 2010. The Syracuse University Lava Project has created a unique blending of science, art, and education to...
Lee Rannals for redOrbit.com - Your Universe Online A long-dormant New Zealand volcano erupted on Monday, spewing an ash cloud that disrupted flights and closed highways. The Mount Tongariro volcano located in the middle of the North Island erupted for the first time after lying dormant for more than a century. The last activity the volcano had shown at the site was in 1897, officials said. Witnesses in the area reported seeing "flame-like explosions and a cloud of ash coming from a...
Brett Smith for redOrbit.com - Your Universe Online In addition to being fairly unpredictable, volcanoes can eject a wide range of material, from mile-high plums of black ash to a deadly hail of fist-sized pumice. These ejections travel extremely fast and can reach internal temperatures between 750 to 1,500 degrees Fahrenheit. The prevailing theory has been that the difference in particle size determined when bubbling magma deep below the volcano converts into a rising stream of gas and...
Brett Smith for redOrbit.com - Your Universe Online Although volcanic scientists are able to approximate the age of lava flows, determining the exact timing of each of a volcano’s eruptions has proved difficult in the past. A joint research team from the Universitat Autònoma de Barcelona, University of Girona, the Catalan Institute of Human Paleoecology and Social Evolution (IPHES) and other organizations has looked to establish a chronology of eruptions in the volcanic region of La...
Latest Igneous rocks Reference Libraries
Biotite is a common phyllosilicate mineral that contains potassium, magnesium, iron and aluminium. It is sometimes called "iron mica" and is found in granitic rocks, gneisses, and schists. Like other mica minerals, biotite has a highly perfect basal cleavage, its flexible sheets easily flaking off. It has a hardness of 2.5 - 3, a specific gravity of 2.7 - 3.1, is colored greenish to brown or black, and can be transparent to opaque. Biotite is occasionally found in large sheets, especially in...
Diorite is a grey to dark grey intermediate intrusive igneous rock composed principally of plagioclase feldspar (typically andesine), hornblende, and/or pyroxene. Varieties deficient in hornblende and other dark minerals are called leucodiorite. It is often described as "salt and pepper" when composed largely of light-colored minerals randomly interspersed with dark minerals. When olivine and more iron-rich augite are present, the rock grades into ferrodiorite, which is transitional to...
Gabbro is a dark, coarse-grained, intrusive igneous rock chemically equivalent to basalt. It is a plutonic rock, formed when molten magma is trapped beneath the Earth's surface and cools slowly into a hard, coarsely crystalline mass. It is dense, greenish or dark-colored and contains varied percentages of plagioclase feldspar, pyroxene, amphibole, and olivine (called olivine gabbro when olivine is present in large quantities). Quartz gabbros are also known to occur and are probably derived...
Peridotite is a dense, coarse grained ultrabasic rock, consisting mainly of the minerals olivine and pyroxene. Peridotite is also a group of mantle derived igneous rocks. They all are ultramafic or ultrabasic meaning they contain less than 45% silica and are high in iron and magnesium. Members of the peridotite family include: Dunite - predominately composed of olivine, with minor enstatite pyroxene and chromite. Harzburgite - composed of olivine, enstatite, and minor chromite....
Rhyolite is an igneous, volcanic (extrusive) rock, of felsic composition, with aphanitic to porphyritic texture. Mineral assembly is usually quartz, alkali feldspar and plagioclase (in a ratio > 1:2). Biotite and pyroxene are common accessory minerals. Rhyolite can be considered as the extrusive equivalent to the plutonic granite rock. Due to their high content of silica, rhyolite form highly viscous lavas. They can also occur as breccias or in volcanic necks and dikes. Like obsidian,...
