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The Earth Story

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This is the blog homepage of the Facebook group "The Earth Story" (Click here to visit our Facebook group). “The Earth Story” are group of volunteers with backgrounds throughout the Earth Sciences. We cover all Earth sciences - oceanography, climatology, geology, geophysics and much, much more. Our articles combine the latest research, stunning photography, and basic knowledge of geosciences, and are written for everyone!
We hope you find us to be a unique home for learning about the Earth sciences, and we hope you enjoy!
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Chernobyl’s Trees

The disaster at the Chernobyl Nuclear Power Plant in Ukraine was one of the worst nuclear catastrophes of all time. This 1986 explosion contaminated the surrounding area with 20 times more radiation than was released in Hiroshima. Part of the tragedy is that now, 29 years later, the risk of harmful radioactive exposure still lives on—and some of it is hidden in the trees.

After the explosion, an “exclusion zone”, encompassing everything within a 30 km radius of the site, was designated as an unsafe, evacuated, do-not-enter zone. Many trees in this area died immediately following the explosion, but many forests are still alive. Oddly enough, the exclusion zone became an unintentional nature preserve—human interference is minimal and many unaware animals have made this their home. However, the dangers of radiation are still very real. The trees surrounding Chernobyl contain harmful amounts of cesium-137, a radioactive nuclide. The real threat lies in forest fires that could potentially send plumes of radioactive ash around Europe (radioactive particles from the initial explosion were found as far away as Sweden). A recent study found that forest fires in 2002, 2008, and 2010, displaced the equivalent of 8% of the Cs-137 that was released in 1986.

Although forest fires are a natural, and somewhat expected, occurrence, these forests are actually at much higher risk for igniting…thanks again to radiation. Plant litter generally decays fairly rapidly, thanks to our trusty decomposers—mushrooms, lichens, bacteria, etc. However, many of these decomposers cannot survive in this toxic environment, so they aren’t around to break down organic material. The dead trees here don’t decay; many of them have been lying around for years, perhaps even since the explosion. This means there is quite a bit of kindling, ready to catch fire at the slightest spark.

This is a clear problem without an easy solution. Setting off small, controlled fires (a commonly-used fire prevention technique) would still release the noxious nuclides. Furthermore, many local firefighters aren’t fully aware or fully prepared for the danger of the situation. With wildfire season coming soon, this is definitely something that will be on the environmental radar.

-CM

Photo credit: http://bit.ly/1E0IYIP

The abstract of a recent publication on this: http://bit.ly/1ypHKV1

For more information: http://bbc.in/1ECAV3R

Source: facebook.com
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alandhart
Great excitement a few years ago (Nov 2002) when a new ‘caesium rich beryl’ was discovered in a granitic pegmatite at Ambatovita, Madagascar. The Sakalavana pegmatite main find was a large zone ~6 metres below surface, containing numerous vugs with an estimated 40Kg of material recovered (with smoky quartz, spodumene, tourmaline), mainly fragments and masses of a few grams of low quality and often very corroded. Analysis showed that the mineral was actually a new species of the Beryl group with high caesium (11-15%) and lithium content, and was named Pezzottaite. Rarest of all the specimens are good quality crystals with much of the find being corroded or suitable only for carving or cabochons. This piece is just crazy huge and at 814 carats the largest I have seen! An almost solid ‘plate’ of Pezzottaite crystals over 10cm long, showing typical ‘hexagonal’ form although the species is actually trigonal. The crystals are distinctive with large flat pinacoid faces with smaller modifications and although hard to see on small specimens, with this it is easy to pezzottaite’s great pleochroism. As you look straight down the ‘c-axis’ a bright peachy-raspberry red is revealed, however as I slightly turn the specimen it changes to a more violet hue as we approach the side (the prism direction). The colour has been shown to be caused by radiation induced colour centres involving Mn3+, the radiation most probably derived from 40K in the K-Feldspars in the pegmatite and could account for the smoky quartz and morganite found as associated minerals. I am slightly(!) envious of my friend Dr Federico Pezzotta whom after the species is named 😎. Unlike most new species discovered, it is truly rare to find one that occurs in such large crystals and even more so one that can be used as a gem material! There has been a number of smaller discoveries elsewhere, but none come close to this deposit which is apparently worked-out. This great specimen is just phenomenal and am glad I was able to share it! Thanks
@granada.gallery
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Superb Vorobyevite

Beryl comes in many forms, including some rarities such as the caesium rich variant in the photo, also known as Rosterite. While there is a caesium rich cousin of beryl called Pezzotaite (see http://on.fb.me/15DU72Z), Vorobyevite was deemed by those in charge of naming as not containing enough of it to be distinguished as a separate mineral. The name was applied to colourless material from the Urals mountains in Russia and rosy crystals from Madagascar until a stunning find of deep blue material in the Badakhshan province of Afghanistan. The blue crystals sit on a quartz matrix, and the piece measures 3.5 x 2.7 x 2.0 cm.

Loz

Image credit: Spirifer Minerals

Source: facebook.com
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Vorobyevite

Beryl comes in many forms, including some rarities such as the caesium rich variant in the photo, also known as Rosterite. While there is a caesium rich cousin of beryl called Pezzotaite (see http://on.fb.me/15DU72Z), Vorobyevite doesn't contain enough of it to be distinguished as a separate mineral. The name was applied to colourless material from the Urals mountains in Russia and rosy crystals from Madagascar until this stunning find of deep blue material. They turned up in a single pocket in the Badakhshan province of Afghanistan. The short hexagonal prisms with an undeveloped long axis bowed in towards the centre are its characteristic habit. The near perfect single crystal in the photo measures 3.0 x 2.6 x 1.5 cm

Loz

Image credit: Rob Lavinsky/iRocks.com

http://www.mindat.org/min-4208.html http://www.gemdat.org/gem-4208.html

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