Quantcast

Latest Petrology Stories

New Type Of Volcanic Eruption Described By Scientists
2013-01-21 10:41:33

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...

Earth’s Magma Mantle Melts Hotter Than Previously Thought
2013-01-10 10:10:41

April Flowers for redOrbit.com - Your Universe Online According to a new study by researchers at Rice University, the Earth's mantle magma melts far hotter and deeper in the Earth's core than previously thought, a discovery that will have lasting implications for our understanding of the planet's geophysical and geochemical properties. The research team, led by Rajdeep Dasgupta, put small amounts of peridotite under large pressures in a laboratory to determine that rock can and does...

New Test Helps With Understanding Earth’s History And Resources
2012-12-06 10:18:32

University of Florida A new study co-authored by a University of Florida researcher provides the first direct chronological test of sequence stratigraphy, a powerful tool for exploring Earth´s natural resources. The model allows geologists to better understand how sedimentary rocks are related to one another in time and space and predict what types of rocks are located in different areas. The information may help scientists more reliably interpret various aspects of Earth´s...

Breaking Through The Crust: Unraveling The Magma Mystery
2012-11-30 13:54:20

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...

Minnesota’s Apollo 11 Moon Rocks Found In National Guard Storage Unit
2012-11-27 08:17:26

Lawrence LeBlond for redOrbit.com - Your Universe Online Hundreds of moon rocks that have been handed out to state governments and foreign countries through the years have gone missing, according to a NASA audit last December. Though some have been recovered, most are still missing. On a good note, another set of lunar pebbles were found this week in a government storage area in St. Paul, Minnesota. The rocks were part of the Apollo 11 lunar landing mission on July 20, 1969 in which...

Volcanic Eruption Buried Ancient Rhino
2012-11-23 07:09:37

April Flowers for redOrbit.com - Your Universe Online Although less than two percent of the fossils on earth are preserved in volcanic rock, researchers from the University of Montpellier have identified a new one. They found the skull of a rhino that perished in a volcanic eruption 9.2 million years ago. Found in Turkey, the fossil is thought to be that of a large two-horned rhino (Ceratotherium neumayri) that was common in the Eastern Mediterranean during that period. The unusual...

2012-11-08 00:53:19

Rapid advances in the new and developing field of restoration sedimentology will be needed to protect the world's river deltas from an array of threats, Indiana University Bloomington geologist Douglas A. Edmonds writes in the journal Nature Geoscience. The commentary, published this week in the November issue, addresses the fact that land is disappearing from river deltas at alarming rates. And deltas are extraordinarily important: They are ecologically rich and productive, and they are...

Volcanic Eruptions Driven By Bubble Growth
2012-10-17 04:36:06

Alan McStravick for redOrbit.com - Your Universe Online From Pompeii to Mount St. Helens, we humans have watched in awe, and sometimes horror, the magnificence of volcanic eruptions. As detailed in a great article earlier this month by redOrbit´s own Lee Rannals, monogenetic volcanoes, volcanoes erupting due to the combination of water and magma, are driven by a rapid expansion of gas bubbles that form as the water, previously trapped in molten rock, rises beneath the volcano....

Trigger For Explosive Volcanic Eruptions Identified
2012-10-13 09:27:11

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...


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...

More Articles (18 articles) »
Word of the Day
virgule
  • A punctuation mark (/) used to separate related items of information.
  • A little rod; a twig.
This word comes from the Late Latin 'virgula,' accentual mark, a diminutive of 'virga,' rod.
Related