kinks, bends, fractures, fillings.. oh my.. (by Ale*)
Many of the iron-rich layers in this outcrop show extremely fine lamination. In this example there are four couples of pink and brown bands at the base, followed by a few whitish bands and then an overall lighter pattern before ending up in the black cherts. If one looks to the right, it is possible to see a discontinuity, a microfault, that breaks the bands. Across the fault, the bands have different thicknesses, but they are consistent in number and order. It looks like that when the bands were folded, they expanded towards the outside the bend. The cracks have been filled likely with calcite, but they stop at the edge of the iron layer: you can not follow the cracks into the chert, indicating that the iron was already a solid rock when the chert, above and below, was plastic enough to flow following the deformation.
Banded Iron Formations
Fuente: Flickr / greenriver
Unfortunately stone has an undeserved reputation for being uncommunicative. The expressions ‘stone deaf’, ‘stone cold;, ‘stony silence’ and, simply, ‘stoned’ reveal much about the relationship most people have to the rocks beneath their feet. But to a geologist, stones are richly illustrated texts, telling gothic tales of scorching heat, violent tempests, endurance, cataclysm, and reincarnation. Over more than 4 billion years, in beach sand, volcanic ash, granites and garnet schists, the planet has unintentionally kept a rich and idiosyncratic journal of its past.
3D animation - Mediterranean isolation and desiccation during the Messinian Salinity Crisis (by daniggcc)
Geography of the Gibraltar Arc during the early stages of the Messinian Salinity Crisis (the period of restricted connection between the Mediterranean and the Altlantic). The interpretation by Garcia-Castellanos & Villaseñor (2011, Nature) proposes that, at a depth of about 100 km, a piece of dense lithosphere detached from Iberia and sunk in the Earth’s mantle. As a result, southern Iberia uplifted and the seaways that connected both seas emerged, This uplift had to compete with the erosion produced by the inflow of Atlantic water into the Med, allowing a long-lived inflow that explains the enormous amount of salt precipitated in the bottom of the Mediterranean. The lack of oceanic water supply and the arid climate of the Mediterranean sea both lead to a drawdown of its level. This video visualizes the interpretation of a research published in Nature in Dec. 2011, but not all of its contents is part yet of a consensus among specialists. More outreach info in this blog post.
Observing the Moon (by Science Museum London)
Diapositive of photograph taken with the Kew Photoheliograph, 1860–62. This photograph of the Moon was taken by Warren De La Rue using the Kew photoheliograph, the first astronomical instrument with built-in photography. At Kew Observatory, the instrument was used to track changes in the appearance of the Sun and Moon.
Fuente: Flickr / sciencemuseum
In 1859, Richard Carrington observed a large group of sunspots, and two solar flares. The flares’ path is marked A-C and B-D. This was one of the first observations of solar flares, which Carrington suspected were the cause of the disruption on Earth. Credit: Science Museum. (via Stories from the stores)
Sphere of the heavens (by Science Museum London)
Clock-driven Chinese celestial globe, 1830. This celestial globe has an internal clockwork drive so that it turns to represent the motion of the stars. On the surface you can see the stars grouped according to Chinese constellations. The Milky Way is shown by a band of dots, and five patches represent star clusters.
Fuente: Flickr / sciencemuseum
Fig. 5 in A. Baucon, Studi Trent. Sci. Nat., Acta Geol., 83, 15 (2008): Selection of body fossils from the Musaeum Metallicum. a. Aldrovandi describes this specimen as a “Rock pregnant with a shell”. b. Aldrovandi describes such fossils as “Astroitis”, referring to the star-like morphology of certain echinoderms and corals. (via Storia della Geologia)
Earthquakes - Shock Waves (by USGS)
Source: http://gallery.usgs.gov/videos/438. This short excerpt is from a USGS/Bay Area Earthquake Alliance produced television program “Shock Waves: 100 Years After the 1906 Earthquake”. This specific segment describes some of the history behind our modern understanding of the earthquake process. The program received numerous industry awards and was nominated for a regional Emmy Award in the Bay area. It aired twice on KPIX CBS5 and its affiliate station around the time of the April 18, 2006, 100 year anniversary of the Great San Francisco Earthquake. The full program is streamed at the link:http://earthquake.usgs.gov/regional/nca/1906/shockwaves/
US First Lady Lou Hoover (1874-1944)
- Desegregated White House functions
- Only First Lady (so far) to speak an Asian language. Sometimes Herbert and Lou would speak Chinese to foil eavesdroppers.
- Along with her husband, she translated Agricola’s De Re Metallica from Latin. It is still the standard English translation today.
- Decorated by King Albert I for her work with Belgian refugees during WWI.
- First women to receive a geology degree from Stanford University
- Advocate for Girl Scouting