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Posts treating: "surface"

Tuesday, 10 May 2016

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Scientists search the seas for soot 

AGU Meetings [2016-05-10 16:00:54]  recommend  recommend this post  (199 visits) info
Earth system scientists from the University of California, Irvine have taken water samples from the north Pacific, north and south Atlantic, and Arctic oceans in search of repositories of black carbon, soot from burning biomass and diesel engines, among other sources. They’ve found considerably less of the material than expected, and they’ve discovered that it exists in at least two varieties, a younger pool closer to the ocean’s surface that is absorbed into the environment in a roughly [...]

Nucelospira ventricosta from the Bois d'Arc formation of Oklahoma 

Views of the Mahantango [2016-04-01 09:01:00]  recommend  recommend this post  (132 visits) info

 Devonian; US
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This little, rounded shell appears to be a Nucleospira based on the shape.  I found it in the Bois d'Arc formation in Oklahoma. The brachial valve is slightly smaller and less convex than the pedicle valve but both are nearly perfectly circular. My fossil is smooth on the surface of the valve, at least in the areas where there is still shell, but it should be covered with lots of tiny, needle like spines. They likely either did not preserve well or were weathered away. There is a small [...]

Pictures From Peru's Sacred Valley 

Earthly Musings [2016-03-13 13:43:00]  recommend  recommend this post  (233 visits) info

 CA,PE,US,,TH
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I am traveling in Peru and Ecuador with Smithsonian Journey's and here are some photographs from the beginning of the trip in Peru's Sacred Valley - heart of the great Inca Empire.The Urubamba River flows through the heart of the valley and is a tributary of the great Amazon River system.This is a graphic that I showed in my first lecture depicting the extent of the Amazon drainage system when superimposed upon North America. Imagine a river going from San Diego to Montreal, with tributaries in [...]

Sphaerirhynchia lindenensis brachiopod from the Bois d'Arc formation of Oklahoma 

Views of the Mahantango [2016-03-10 09:01:00]  recommend  recommend this post  (143 visits) info

 Devonian; DE,US
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I found a number of these round, nut like brachiopods while searching the Bois d'Arc formation in Oklahoma. They are called Sphaerirhynchia lindenensis and seem to have a bit of variability in their features. Overall the shells are rounded to subpentagonal in outline and rectangular to square in cross section. Both valves are convex and have strong, rounded ribs decorating the surface. The margins of both valves are flat except along the anterior margin where the shell develops "teeth" that [...]

Atrypa oklahomensis brachiopod from the Bois d'Arc formation of Oklahoma 

Views of the Mahantango [2016-03-07 09:01:00]  recommend  recommend this post  (164 visits) info

 Devonian; US
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The brachiopod genera Atrypa makes an appearance in the Bois d'Arc formation, as one would expect. It's pretty much an index fossil for the Devonian period as far as I'm concerned. In this case we have Atrypa oklahomensis. The shell is rounded with a very convex brachial valve and a slightly convex to flat pedicle valve. The surface of both valves have regularly spaced ribs and fine concentric growth lines. There is a small fold and sulcus present to some degree on every specimen I have found [...]

Monday Geology Picture: Investigating Soil Horizons by Kayak 

Georneys [2016-02-29 19:57:03]  recommend  recommend this post  (194 visits) info

 ZA
A few weeks ago I participated in a kayak race on the Berg River a few hours north of Cape Town, South Africa. I went on a short warm-up paddle the evening before the race. While on this paddle, I couldn’t resist checking out some soil horizons that were visible along the river in several places. In the picture above, I am posing next to some soil horizons. You can see the horizons of surface

Stropheodonta gibbera brachiopod from the Boid d'Arc formation of Oklahoma 

Views of the Mahantango [2016-02-24 09:01:00]  recommend  recommend this post  (193 visits) info

 Devonian; DE,US
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The highly convex shape of the shell of this next specimen is indicative of the species Stropheodonta gibbera. I collected it from the Bois d'Arc formation in Oklahoma. The shell is subrectangular in shape with a rounded anterior margin and straight hing line. The pedicle valve is very convex while the brachial valve is very concave. This arrangement of valves is typical of the class Strophomenata. The surface of both valves have fine costellae that have low relief and fine concentric growth [...]

Orthostrophia strophomenoides brachiopod from the Bois d'Arc formation of Oklahoma 

Views of the Mahantango [2016-02-18 09:01:00]  recommend  recommend this post  (172 visits) info

 Devonian; US
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Orthostrophia strophomenoides is a species that I have not found anywhere else from the lower Devonian but is fairly prolific in the Bois d'Arc formation of Oklahoma. I have posted about specimens from the Haragan formation in the past but other than that I have not seen any specimens of the genus from elsewhere in the world. The shell of Orthostrophia strophomenoides is subrectangular in outline with both valves being slightly convex. The surface of the valves are decorated with coarse striae [...]

Update on Bárðarbunga volcano (Week 06/2016) 

Iceland Volcano and Earthquake blog [2016-02-11 22:14:22]  recommend  recommend this post  (186 visits) info
Short update on Bárðarbunga volcano. Bárðarbunga volcano continues to inflate at the depth of 15 – 10 km. Making it hard to observe it on the surface. Earthquake activity continues to increase, with regular earthquake swarms with magnitude … Continue reading

On the Surface, Feeling Further Away from the Ocean than Ever 

State of the Planet [2016-02-08 17:11:24]  recommend  recommend this post  (202 visits) info
My German colleague and I could conceptualize five kilometers horizontally—the same as her bike ride to work, the same as the first ever race I ran. Neither of us could quite grasp what flipping 5 kilometers 90 degrees might mean, as our pump continued on its 3-hour vertical journey to that

Eumetria costata brachiopod from the Chainman formation of Utah 

Views of the Mahantango [2016-01-16 09:01:00]  recommend  recommend this post  (597 visits) info

 Carboniferous; US
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While search for fossils at Conger Springs, Utah I found lots of examples of these little brachiopods called Eumetria costata. They are small shells that are longer than wide with the widest point about midway between the umbo and the anterior margins. Each valve is roughly equally convex and has around 20 radiating costae on the surface. The umbo extends beyond the brachial valve and curves slightly to the point where the circular formen opening is located.Specimen #1 - Brachial [...]

Questions to ask about soil 

Earth Learning Idea [2016-01-04 19:06:00]  recommend  recommend this post  (159 visits) info
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We continue this series with 'Questions for any rock face 3: soil; what questions about soil might be asked at any soil exposure?' Soil is the mixture of material at the Earth’s surface that can support the growth of plants. It has four key components: rock fragments (from the rock beneath or brought into the area), decaying plant material and other soil organisms, water and air. It often has

The Karst Topography...of California? A Look at California Caverns 

Geotripper [2015-11-17 08:20:00]  recommend  recommend this post  (236 visits) info

 US
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We took a field studies trip a few weeks ago, and it turned into a mini-series on the karst terrain of California, a landscape that forms over limestone and marble. The development of caverns leads to distinctive features on the surface above, including sinkholes and disappearing streams. I've covered the sights we saw on that trip, but there are plenty of other caverns across the

A day in the life of a Daspletosaurus bone 

RMDRC paleo lab [2015-11-12 23:03:00]  recommend  recommend this post  (187 visits) info
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Some people asked me not too long ago about what we do in order to get some of these bones ready for molding. In the case of Pete III, our Daspletosaurus from Montana, the condition of the bone gave us some additional problems. All specimens of course get excavated and painstakingly prepared by our expert staff, but in Pete III's case, even the prep necessitated the invention of new techniques which I published on a few years back. The entire specimen was pixelated, with some bones made up of [...]

Imaggeo on Mondays: Electron cloud gone wrong 

GeoLog-The official blog of the European Geosciences Union [2015-09-07 12:38:31]  recommend  recommend this post  (179 visits) info

 CN,ZA
Deciphering the past history of rocks and what they might reveal about the Earth’s future is a key part of geology, and tools such as Ion Probes can be used by Earth Scientists to extract valuable information about a rock’s past. Today’s Imaggeo on Monday’s image was acquired by Sarah Glynn, a researcher at the University of the Witwatersrand, in South Africa, who was analysing a potential calcite reference material (a mineral homogeneous enough to be considered a benchmark for future [...]

Florida Pool Pushed Out Of Ground After Heavy Rains 

GeoPrac.net [2015-08-31 08:24:33]  recommend  recommend this post  (188 visits) info

 US
The source website is calling this some kind of 'reverse sinkhole', which is definitely not the case. The article says there was a period of very heavy rain for about 11 days before this happened, with some areas seeing rainfall intensity up to 6.7 inches in 12 hours. It sounds like the water table rose to very close to the surface and buoyant forces pushed the pool out. The building inspector called it a 'popped pool'. [Source: Go see a video of this poor homeowners's pool at [...]

3-D maps illustrate formation of the Hangai Dome in central Mongolia 

AGU Meetings [2015-08-27 17:58:51]  recommend  recommend this post  (210 visits) info

 US,CA
Researchers at Rice University, the University of Toronto, and Princeton University generated 3-D maps of the Earth under the Hangai Dome in central Mongolia from seismic data. The 3-D image below shows the earth under the dome. Colored yellow, warm rock rises up from the deep mantle toward the Earth’s surface. The pressure on the rock drops as it rises. When the rock reaches 150 kilometers (93 miles) below the surface, it starts to melt and form magma, illustrated in red. Heat released by [...]

Rhytistrophia beckii brachiopod from the Kalkberg formation of New York 

Views of the Mahantango [2015-08-06 09:01:00]  recommend  recommend this post  (222 visits) info

 Devonian; DE,US
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Another tough fossil brachiopod for me to identify is the one shown below. At first it looked like a Leptanea sp. but the shell is not rectangular enough. Then I thought it might be a Strophomena sp. but I've not seen one that has the "corrugated" surface. Finally I settled on Rhytistrophia beckii after reading the description in Karl Wilson's book "Field Guide to the Devonian Fossils of New York" on page 79:Large, semielliptical or subquadrate shell; both valves nearly flat. Surface with [...]

Trilobites from the Kalkberg formation of New York 

Views of the Mahantango [2015-07-29 09:01:00]  recommend  recommend this post  (203 visits) info

 Devonian; DE,RU,US
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I have not found too many trilobite fossils in my limited searching of the Kalkberg formation but I did find pieces of two different species.The first are these free cheeks from Acidaspis tuberculatus. Note the knobby extensions that are spaced along the edge of the genal spine up to where the cheek attached to the rest of the cephalon.The other, major piece of trilobite that I found was this thorax-pygidium combo from what I believe was a Paciphacops logani.  I was very excited when I [...]

Ramping up for bigger, badder SUGAR Part 2 

SUGAR [2015-07-29 05:11:00]  recommend  recommend this post  (213 visits) info

 US,
We are in Georgia gearing up for the second phase of field work for the SUGAR project, which will involve collecting seismic refraction data along two profiles spanning eastern Georgia. In the coming weeks, we’ll deploy thousands of small seismometers along county and state roads across the region, which will record sound waves generated by a series of controlled blasts. We can use the sound waves to make pictures of geology beneath the surface. Geological structures beneath Georgia record [...]
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