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Latest Petrology Stories

2012-01-23 14:03:33

Kimberlites are magmatic rocks that form deep in the Earth’s interior and are brought to the surface by volcanic eruptions.

Iberian Coast Ocean Drilling Expedition Reports Early Findings
2012-01-23 12:10:57

Mediterranean bottom currents and the sediment deposits they leave behind offer new insights into global climate change, the opening and closing of ocean circulation gateways and locations where hydrocarbon deposits may lie buried under the sea.

2012-01-13 08:00:00

The biological and geographical website EurekaMag.com publishes reviews of specific subjects of all areas of biological and geographical science.

Moon Mineral Discovered In Western Australia
2012-01-09 09:40:57

An Australian paleontologist has discovered a mineral, long thought to be found only on the moon, in a billion-year-old rock formation in Western Australia.

NASA Missing Hundreds Of Moon Rocks
2011-12-09 12:07:29

An audit of NASA has turned up evidence that hundreds of moon rocks and other space matter are apparently missing, many of which have been loaned out by the space agency.

2011-11-16 08:00:00

Adya Inc., a Coldwater, Michigan company providing mineral waters with extraordinary properties, has a new website, found at adyaclarity.com.

Geologists Assess Deep Impacts Of Near-Earth Object Strikes
2011-10-18 08:03:44

Volcanologists from the Universities of Leicester and Durham have forensically reconstructed the impact of a meteorite on Earth and how debris was hurled from the crater to devastate the surrounding region.

The Cause Of Earth's Largest Environmental Catastrophe
2011-09-15 08:14:44

Siberian traps and their relation to the mass extinction 250 million years ago.


Latest Petrology Reference Libraries

Chaitén
2014-08-28 10:38:21

Chaitén is a volcanic caldera that is located in southern Chile that reaches an elevation of 3,681 feet. It is thought that this volcano once held a rhyolite obsidian lava dome that reached 3,156 in height, but this was destroyed after its most recent eruption in 2008. In the past, this volcano has released grey obsidian, which was used by pre-Columbian cultures to make many objects, some of which have been found 250 miles away from the volcano. Chaitén experienced the beginning of a new...

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...

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Word of the Day
postliminy
  • In Roman antiquity, the return of a person who had been banished, or taken prisoner by an enemy, to his old condition and former privileges.
  • In international law, that right by virtue of which persons and things taken by an enemy in war are restored to their former status when coming again under the power of the nation to which they belonged.
The word 'postliminy' comes from a Latin word meaning 'threshold'.