The Earth Story

Amber fossils demonstrate ecological continuity Lizards in amber are very uncommon, since they are usually strong enough to not get stuck in the gooey tree resin, but small species do get entrapped and fossilised and a new set of finds has enriched our understanding of a poorly understood evolutionary radiation of species between 20-15 million years ago and the stability of this aspect of an ecosystem over a very long time, in fact up to the present day. The finds were preserved in Dominican amber from the Miocene.

Star twinned Cubanite

When crystals grow together in different orientations they are known as twins, sharing a common boundary or growth surface, and the bright golden copper iron oxide (aka Chalmersite) in the photo is a beautiful example of cyclic twinning, where several crystals have grown together to form a wheel shape . A rare mineral named after the Caribbean island where it was first found, it forms in high temperature veins from metal bearing hot brines circulating in the crust. It tends to precipitate at the same time as a closely related mineral called chalcopyrite. As the solution cools the two minerals that could previously coexist in solution in the hotter water separate and exsolve, each forming its own crystals, often interleaved.

Like most metal rich minerals it is dense, feeling hefty in the hand, and crystal faces are lined (called striations) in the long direction. As well as the type location, it has also been found in Brazil, the Harz Mountains of Germany and Quebec in Canada, from which this 1.9 x 1.4 x 1.0 cm specimen hails.

Loz

Image credit: Spirifer Minerals http://www.galleries.com/Cubanite http://www.mindat.org/min-1168.html

This storm was nicknamed “The Atlantic Ocean”

This satellite weather photo flashback is a marvel to behold. This was an amazing storm in 2013 - it was assembled out of several low pressure systems merging as they reached the Atlantic ocean. It stretched from Cuba in the Caribbean to Portugal, from Portugal north to Greenland, and from Greenland to Newfoundland.

In other words…this storm covered the entire Northern Atlantic Ocean.

-JBB

WaPo with image, credited to NASA: http://www.washingtonpost.com/blogs/capital-weather-gang/wp/2013/03/28/incredible-storm-spans-atlantic-ocean-coast-to-coast/

ABC: http://abcnews.go.com/blogs/headlines/2013/03/powerful-atlantic-coast-to-coast-storm-threatens-spring-break/

Weather Underground: http://www.wunderground.com/news/massive-atlantic-storm-20130329

Amber fossils demonstrate ecological continuity

Lizards in amber are very uncommon, since they are usually strong enough to not get stuck in the gooey tree resin, but small species do get entrapped and fossilised and a new set of finds has enriched our understanding of a poorly understood evolutionary radiation of species between 20-15 million years ago and the stability of this aspect of an ecosystem over a very long time, in fact up to the present day. The finds were preserved in Dominican amber from the Miocene.

The Anolis genus were previously only known from 3 specimens, which has now been extended to 20, giving us a baseline for comparison to the modern populations on the island of Hispaniola today. They found the same habitat niches being filled by very similar or identical species then and now, proving that the continuity of evolutionary pressures has resulted in ecological stability over long time scales, at least for these particular lizards. This is extraordinary, since mammals regularly come and go into the same niches, but seldom the same ones, and never for such a long time. The average lifetime of a mammalian species is more like 1-2 million years rather than 20. To cap it all the commiunity has survived through major ecological changes, including the gradual cooling of the world and the series of ice age oscillations over the last few million years.

They first appeared some 50 million years back on the main isles of the Antilles archipelago, and occupy a variety of ecological niches in trees, each species occupying a distinctive geographical region within the tree lizard habitat and community. The genus has been well studied in its present ecosystems, so the new data slots into a relatively understood ecology. The islands have similar environments, and the radiation of the lizards was mirrored between them, producing similar specialisations for the different niches within the tree environment over the archipelago, giving us a deeper idea of how the relationship between environment and evolution work.

Loz

Image credit: Kevin de Queiroz

http://s.si.edu/1I9S2Kj Original paper, paywall access: http://bit.ly/1K8QiPP

On April 21st 2012, the Lyrid meteor shower peaked in the skies over Earth. While many photographers and astronomy enthusiasts were excitedly positioning their cameras and telescopes up towards the night sky, one man, from a different vantage point, was pointing his camera down...

Astronaut Dom Pettit, captured this beautiful image from the International Space Station. In the photo you can clearly see a distinctive meteor burning up in our planet’s atmosphere. Bill Cooke, a NASA astronomer, then mapped the meteor to the star field in this image and confirmed that the meteor originated from the Lyrid radiant.

The image is a six second exposure and has been rotated so that North is roughly at the top of the photo. The lights of Florida are clearly visible to the right of the meteor. Cuba, the Florida Keys and the eastern Gulf Coast shoreline are also visible. Some brilliant flashes of lightning are also prevalent in the image, as well as the beautiful glow of Earth. Wow.

-Jean

Image credit: NASA/JSC/D. Pettit

Pectolite While the usual hue of this mineral is a dull greenish grey or white, occasional localities contain some different colours, including the peachy mauve found in this 9.6 x 5.9 x 2.9 cm specimen from a vug in the basalt trapps of New Jersey. Its habit is usually fibrous, with radial crystal aggregates. It was first discovered in the Italian Alps in 1828, and named from the Greek words for well put together since it resists being powdered. Despite this it ias a fragile mineral and can flake off easily when roughly handled. It forms in a variety of ways, the main ones being in a kind of granitoid rock called a nepheline syenite, as hydrothermal alteration products in gas bubbles in basalt and in association with serpentine (metamorphosed mantle or volcanic rocks). While soft (4-5 on Mohs scale), it has been used in jewellery, particularly the lovely blue material from Hispaniola called Larimar that I will discuss in my next post. It is found in many places worldwide. Loz Image credit: Rob Lavinsky/iRocks.com http://www.galleries.com/Pectolite http://webmineral.com/data/Pectolite.shtml#.VLrGdi4mkkE http://www.minerals.net/mineral/pectolite.aspx http://www.mindat.org/min-3141.html http://www.gemselect.com/gem-info/pectolite/pectolite-info.php