View allAll Photos Tagged SANDSTONE
Local boy at Vailima, come to admire the steam train.
One of a set of images taken by Geoff Cooke when he hosted the Geoff's Trains group at the Stars of Sandstone Festival in April 2019. Copyright Geoff Cooke. Please do not use without permission.
GEC_4067
I tried to warn them. I'm not exactly your classic, traditional family portrait guy. But, they were up for an adventure, so away we went.
Porous sandstone coaster absorbs the water from my sweating water glass, keeping the table dry. These slices of drill cores backed with cork, are far more useful as coasters than as landfill -- and far more effective coasters than the non-absorbent materials accumulating in my kitchen.
Our Daily Challenge: ROCKS, MINERALS, GEMSTONES
365 Days in Colour: July: "brown"
“Liesegang banded” sandstone in the Pennsylvanian of Kentucky, USA.
Irregular, reddish or brownish or orangish-brown iron banding is commonly seen in many porous rocks, particularly sandstones and pebbly sandstones. These have been almost universally referred to as “Liesegang banding”, representing precipitation lines of iron-rich minerals (e.g., hematite, limonite, goethite, etc.) at & along groundwater chemical interfaces. But, according to Neil Wells of Kent State University, the original concept of Liesegang banding (Liesegang, 1896) does not match up with what is seen in the rock record (see Wells et al., 2003).
True Liesegang banding refers to parallel bands of precipitate formed by diffusion along a single chemical gradient during one event. What's seen in the rock record often consists of sets of irregularly concentric iron bands, with different sets of bands quite frequently oriented in different directions, and showing cross-cutting and dissolution of older sets. Iron banding in the rock record is clearly the result of numerous precipitation events over long periods of time by moving groundwater (Wells et al., 2003). Iron mineralization along these bands appears to be induced by the presence of either a redox interface (change from reducing to oxidizing conditions in the groundwater) or a pH interface (change in acidity).
Because Neil Wells is the first (apparently) to point out that what geologists have been calling Liesegang banding really isn’t, a renaming seems to be in order. It was jokingly suggested in 2003 that the iron banding discussed above be called “Wells Banding”. I’m all for that.
Stratigraphy: Corbin Sandstone Member, Grundy Formation, Lower to Middle Pennsylvanian
Locality: outcrop along Laurel Creek Gorge, between the towns of Sandy Hook & Newfoundland, central Elliott County, northeastern Kentucky, USA
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References:
Liesegang, R.E. 1896. Ueber einige Eigenschaften von Gal-lerten [On some properties of gelatin]. Naturwissenschaftliche Wochenschrift 11: 353-362. (see also: Liesegang, R.E. 1945. Geologische Bänderungen durch Diffusion und Kapillarität [Geologic banding by diffusion and capillarity]. Chemie der Erde, Zeitschrift der Chemischen, Mineralogie, Petrographie, Geologie und Bodenkunde 15: 420-423.)
Wells, N.A., D.A. Waugh & A.M. Foos. 2003. Some notes and hypotheses concerning iron and iron remobilization features in the Sharon Formation (Summit County, Ohio). in Pennsylvanian Sharon Formation, past and present: sedimentology, hydrogeology, and historical and environmental significance, a field guide to Gorge Metro Park, Virginia Kendall Ledges in the Cuyahoga Valley National Park, and other sites in northeast Ohio. Ohio Division of Geological Survey Guidebook 18: 33-37.
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One of the pleasures of the Stars festival is the variety of heritage equipment that can be seen in action. Here, three stationary boilers are fired up by a team of international enthusiasts.
One of a set of images taken by Geoff Cooke when he hosted the Geoff's Trains group at the Stars of Sandstone Festival in April 2019. Copyright Geoff Cooke. Please do not use without permission.
We had the perfect shower stall at Calf Creek. All sandstone including a sandstone soap dish shelf, sandstone towel rack, and a sandstone drain in the sandstone floor. There was a built-in solar dryer to evaporate the solar-heated water, too.
There was one spot up on Route 12 where you could see right down in here but it was only the southbound direction, and then only the passenger could really see anything. And hey, if they looked, they got what they deserved :^)
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Two ex- Beira Railways Lawley 4-4-0's head out of Hoekfontein bound for Grootdraai on the Lesotho Border.
One of a set of images taken by Geoff Cooke when he hosted the Geoff's Trains group at the Stars of Sandstone Festival in April 2019. Copyright Geoff Cooke. Please do not use without permission.