From yalegeotravels (emphasis mine):
The first stop in Vredefort was of a basement granite exposure that contained thin veins of pseudotacylite stretching through it like spider webs. This black silicate infill was presumably once glass, which as a amorphous solid degrades readily over geologic time. At this outcrop, the veins were meters thick and contained large pieces of the host granite within them. This site was a decommissioned granite quarry where huge blocks of granite had been cut and harvested before it became uneconomical to do so.
The rounded edges of those granite chunks within the pseudotacylite matrix, many larger than a human head, showed the immediate heat that grasped them and the sheer fury of the upheaval from an asteroid impact. It takes a lot to liquify granite and feldspar, push the molten mixture through fractures in the host rock, and create enough pressure to propagate the veins throughout the host rock.
On that day some 2.02 billion years ago, you didn’t want to be at Vredefort.
It would have been a very bad day.
Stromatolites (by mrfuller)
These are the oldest lifeforms on Earth, existing for over 3.5 billion years. This is a UNESCO heritage site and one of the only places in the world to find living stromatolites. And they don’t mind the heat: It was 47˚C when I took this.
Fuente: Flickr / mrfuller
Table Topography: Wood Furniture Embedded with Glass Rivers and Lakes by Greg Klassen
Banded Iron Formations (by Ale*)
The Banded Iron Formations (BIFs) are a series of stratigraphic rock units deposited at different times in different environments. They contain higher-than-usual amounts of iron (Fe). These deposits are all Precambrian in age, and the ones in the image in particular are Archean (older than 2.5 billion years ago, that is 2,500,000,000 years). The current explanation for the abundance of Fe in these layers, albeit not totally accepted by the scientific community, is that Fe existed in solution in Archean ocean waters in its reduced form. Sudden increase in the amount of available oxygen, caused by the beginning of photosynthetic life in the form of stromatolite-building cyanobacteria, would have caused the reduced Fe to oxidize to hematite (and possibly magnetite). There is evidence in the fossil and rock records of an increase in atmospheric oxygen right after the last deposited BIFs. BIFs were never to form again. At the very beginning, before any BIFs were ever deposited, the most common form of Fe on Earth’s surface was pyrite. Pyrite today would not stand a chance of preservation in subaerial environment because of the abundance of oxygen in the atmosphere.
Fuente: Flickr / greenriver
YURI PATTISON, chelyabinsk eBay extrusions <three>, 2013
.925 silver, 316L stainless steel, titanium, .STL files
When the Chelyabinsk meteor entered Russia in 2013, Yuri Pattison watched as meteorite fragments were instantly commodified on eBay. Fascinated by the market, the perceived spirituality or superstitious quality of the fragments, looming questions of authenticity, and how meticulously the fragments were photographed, Pattison saved hundreds of images onto his computer. He started to think about how he could materialize and heighten the question of supply and demand, seeing as how reports on the size of the meteorite varied greatly and the actual supply of fragments was unknown.
"The interesting thing about working digitally, especially with 3D printing," he wrote, "is that the information that’s contained and conveyed through the work is of primary importance. The value isn’t necessarily based on whether the piece is a copy or an original." Ultimately, Pattison reverse engineered the images back into physical form as 3D printed objects in silver, stainless steel, and titanium, returning the meteorite fragments, layered with new meaning, to the realm from which they emerged. (Text by Paddles ON! curator Lindsay Howard)
South America’s second largest river, the Paraná River (and its tributaries) is seen here in this astronaut photo acquired on April 9, 2011, revealing an 18-mile-across (29 kilometers) expanse of the river downstream from Goya, Argentina. - NASA Earth Observatory [x]
The Magnificent Neptunian System
Astrophotographer Rolf Wahl Olsen made this composite image from data acquired during NASA’s Voyager 2 closest approach to Neptune on August 25, 1989. The dim outer planet, largest moon Triton, and faint system of rings can all be seen. From just beyond Neptune’s orbit, the interplanetary perspective looks back toward the Sun, capturing the planet and Triton as thin sunlit crescents.