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Latest Petrology Stories

Iceland's Basalt Pillars Not From Warring Trolls, As Folk Legend Has It
2014-02-04 13:18:11

[ Watch the Video: Trolls Not Responsible For Iceland's Basalt Pillars ] Lee Rannals for redOrbit.com - Your Universe Online Icelandic trolls are not responsible for shaping the basalt pillars found on the island, according to a study recently published in the Journal of Volcanology and Geothermal Research. Folklore says that mysterious basalt pillars found in Iceland were created by a pair of angry trolls who hurled rocks at one another. However, the new study says that these...

Large Magma Chamber Sits Below World’s Most Active Volcano
2014-01-29 13:29:50

[ Watch the Video: What's Bubbling Below The Kilauea Volcano? ] Lee Rannals for redOrbit.com - Your Universe Online University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science researchers have discovered a large magma chamber below the world’s most active volcano. The new discovery is the first geophysical observation that large magma chambers exist in the deeper parts of Kilauea. For the study, the team analyzed the seismic waves that travel through the volcano....

2014-01-07 08:35:08

SAN FRANCISCO, January 7, 2014 /PRNewswire/ -- Elsevier [http://www.elsevier.com/wps/find/homepage.cws_home ], a world-leading provider of scientific, technical and medical information products and services, and IEDA [http://www.iedadata.org ] (Integrated Earth Data Applications), an NSF-funded data facility in the geosciences at the Lamont-Doherty Earth Observatory of Columbia University, announced the winner of the 2013 International Data Rescue Award in the Geosciences at...

Supervolcanoes And Volcanic Activity
2014-01-06 03:54:43

redOrbit Staff & Wire Reports - Your Universe Online One team of researchers has uncovered the factors that determine the frequency and magnitude of volcanic activity, while another has identified the triggers for the rare and explosive eruptions experienced by supervolcanoes, according to studies currently appearing in the advanced online edition of the journal Nature Geoscience. In one paper, ETH-Zurich professor Carmen Sanchez-Valle and her colleagues used an X-ray beam at the...

2013-12-20 10:18:03

GSA Bulletin articles posted online ahead of print on 6 and 13 December 2013 cover earthquake hazards of the Santa Barbara suburban area; apatite and the skeletons of early animals; the peculiar geological features of Faial (Azores, Portugal); the nature of Mount Rainier; the origin of Pearya terrane, Canada; a re-interpretation of the Chilhowee Group of the Appalachian Blue Ridge; and more. Authors hale from the U.S., Italy, South Africa, and Canada. GSA Bulletin articles published ahead...

Geoscientist Leads International Drilling Mission To Lower Crust Of Pacific
2013-12-04 11:33:49

University of Houston A University of Houston (UH) geoscientist and his colleagues are revealing new discoveries about the Earth's development, following a major international expedition that recovered the first-ever drill core from the lower crust of the Pacific Ocean. Co-chief scientists Jonathan Snow from UH and Kathryn Gillis from University of Victoria in Canada led a team of 30 researchers from around the world on the $10 million expedition, finding a few surprises upon...

Volcanic Rock Research Sheds New Light On Earth’s Formation
2013-11-08 12:29:31

redOrbit Staff & Wire Reports - Your Universe Online By analyzing basalt, a substance formed from cooling lava, a team of European scientists have gained new insight into how the Earth’s core, crust and atmosphere formed, as well as how volcanic activity originated. According to UPI, the researchers recreated the conditions of the Earth approximately 4.5 billion years ago, when much of the world was molten and the crust formed as lava cooled. Their goal was to develop a...

Ancient Syrians Chose Buying Local Instead Of Importing
2013-10-16 15:02:48

University of Sheffield An archaeologist at the University of Sheffield has found evidence that, contrary to a widely held theory, ancient Syrians made their stone tools locally instead of importing finished tools from Turkey. The discovery, newly published online in Journal of Archaeological Science, has implications for our understanding of how early cities developed in these regions and how the geographic origins of raw materials affect developing states. During the Early Bronze...

Iceland's Basalt Pillars Formed By Slow Lava And Water
2013-10-09 15:55:39

Brett Smith for redOrbit.com - Your Universe Online Icelandic folk legend has it that the rocky pillars in the country’s Skaelingar Valley were projectiles fired into the ground by armies of warring trolls. However, a new study in Journal of Volcanology and Geothermal Research indicates that these hollow pillars of basalt were formed by a very slow lava flow oozing from Iceland's volcanoes and interacting with water. The researchers’ conclusion is unusual because the mixing of water...

New Evidence Gives New Life To ‘Percolation’ Theory For Earth’s Core
2013-10-08 17:23:32

Lee Rannals for redOrbit.com – Your Universe Online Scientists writing in the journal Nature Geoscience say that a similar process to that which allows water to yank oils from ground coffee  in order to make a cup of joe in the morning, could be how the Earth's core formed. Stanford University scientists recreated the intense pressures and temperatures inside Earth and found that an iron melt network may have helped grow the Earth's core. The finding revisits a theory first proposed...


Latest Petrology Reference Libraries

28_e9750264d5476c85f9be09d17bc6fd51
2005-05-26 12:03:39

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...

28_56635877b282726a86b25cf3e98722c2
2005-05-26 11:30:45

Chert is a fine-grained silica-rich cryptocrystalline sedimentary rock that may contain small fossils. It varies greatly in color from white to black, but most often manifests as gray, brown, grayish brown and light green to rusty red; its color is an expression of trace elements present in the rock, and both red and green are most often related to traces of iron (in its oxidized and reduced forms respectively). It outcrops as nodules in limestone, chalk, and dolostone formations as a...

28_42121cee4c09c0898f52263bea588d54
2005-05-26 11:26:59

Chromite, iron magnesium chromium oxide: (Fe,Mg)Cr2O4, is an oxide mineral belonging to the spinel group. Magnesium is always present in variable amounts, also aluminium and iron substitute for chromium. Chromite is found in peridotite and other layered ultramafic intrusive rocks and also found in metamorphic rocks such as serpentinites. Ore deposites of chromite form as early magmatic differentiates. It is commonly associated with olivine, magnetite, serpentine, and corundum. Chromite is...

28_b760796d3dace508242e89fc53d49081
2005-05-26 11:13:08

In geology, a conglomerate is a rock consisting of other stones that have been cemented together. Conglomerates are sedimentary rocks consisting of subangular clasts and are thus differentiated from breccias, which consist of angular clasts. Both conglomerates and breccias are characterized by clasts larger than sand (>2 mm). There are two varieties of conglomerate, defined by texture: paraconglomerates and orthoconglomerates. Paraconglomerates are one of two varieties of conglomerate...

28_0d277ca2b0d8b8cd79fb9cfa322f77e1
2005-05-26 11:01:52

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...

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Word of the Day
mallemaroking
  • Nautical, the visiting and carousing of sailors in the Greenland ships.
This word is apparently from a confusion of two similar Dutch words: 'mallemerok,' a foolish woman, and 'mallemok,' a name for some persons among the crew of a whaling vessel.