Fossil forest
Check out this article from BBC.com about some spectacularly preserved plant fossils discovered in an underground coal mine in Illinois.
“The fossil forest was rooted on top of the coal seam, so where the coal had been mined away the fossilized forest was visible in the ceiling of the mine. We walked for miles and miles along pitch-black passages with the fossil forest just above our heads. We were able to make a map of the forest by the light of our miners’ lamps.”, said Dr. Falcon-Lang from the University of Bristol.
Look for the paper in the journal Geology.
Review of ‘Thin Ice’ by Mark Bowen
A couple months ago, Thermochronic over at Apparent Dip started a list of popular science books and will be reviewing them as he reads/re-reads them (here’s the first).
He asked fellow geobloggers to suggest books for this effort.
I recently finished Thin Ice by Mark Bowen…i’m going to provide a short review here (hopefully not stealing Thermochronic’s thunder!).
The subtitle of this book, Unlocking the secrets of climate in the world’s highest mountains, succinctly sums up what this book is about. Bowen successfully weaves together adventure and science. For any of you out there who have done a lot of field work, you will like it. There are many anecdotes about working and surviving in the field, ranging from humorous to tragic. I tend to like stories about adventurers who are also scientists (rather than people going through hardships just to do it).
Lonnie Thompson, a climate scientist at Ohio State University, and an assortment of others from his research team are the main ‘characters’ in this story. For decades, Lonnie and his team have been drilling and studying cores from high alpine ice sheets, including Peru (Quelccaya), Bolivia (Sajama), Tanzania (Kiliminjaro), and Qinghai-Tibetan Plateau (Dunde). An interesting aspect of this story is how in the 1970s and 80s the paleoclimate community more-or-less regarded alpine cores, especially from low latitudes, as useless to climate reconstruction. Everyone believed all the answers were in the big continental ice caps near the poles (Greenland and Antarctica). The results from Thompson’s work showed that these ice caps have records going back maybe not has far as the continental ice sheets but much farther than had been postulated (100,000 years). Furthermore, the climatic fluctuations that are recorded in these lower-latitude archives have important implications for weather patterns that the polar records just cannot address. Bowen also includes great sections on the history of climate and paleoclimate science interspersed with the narrative of the ice coring work of Thompson’s team.
I found this book to be at a great level for a scientist (who’s not a paleoclimate expert) or a layperson who is motivated. That is, you need some background to stay engaged but you don’t need to be an expert in atmospheric dynamics.
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Underground musicians
Literally…in this case.
This is a video of flute player Greg Pattillo and cello player Eric Stephenson at Union Square subway in NYC (via Hidden Track and on YouTube, where you can find other videos of Pattillo).
It’s a couple minutes long….give it a listen.
Friday Field Foto #13: Permian rocks of the Delaware Mts
This is from west Texas (my old master’s degree stompin’ grounds). The Permian Brushy Canyon Formation is the sandstone and siltstone making up the foreground cliffs. In the background, along the skyline, is the Guadalupe Mountains, which is the highest point in Texas.
The geology of this area is very unique in that these mountains expose a shelf, shelf-margin, and basin transition across ~100 km nearly continuously. One of these days, I’ll post some more info about that.
This photo taken by and courtesy of my friend Marieke
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Yes! More sea-floor laboratories! I posted just last week about a somewhat similar plan for Monterey submarine canyon. This one is in the northeastern Pacific Ocean, offshore of BC, Washington, and Oregon.
Here are the highlights from this article in ScienceDaily:
- NEPTUNE (North-East Pacific Time-Series Undersea Networked Experiments) is a joint U.S.-Canada venture led by the University of Victoria in Canada and the University of Washington in the United States.
- Located in the northeast Pacific on the active Juan de Fuca tectonic plate.
- NEPTUNE will allow scientists to monitor biological, oceanographic and geological processes over a period that could stretch to more than two decades.
- Six unmanned sea floor nodes, each roughly the size of a sport utility vehicle and each hosting an array of instruments, equipment and video cameras will be installed on the ocean floor in Canadian waters.
- The first stage of NEPTUNE is scheduled to start in summer 2008.
Let’s hope their equipment doesn’t get destroyed by a turbidity current…..on the other hand….we could use the data :)
Where on (Google)Earth? #8
I’m not gonna give any clues….not until there’s at least a few guesses.
Video of landslide in Japan
UPDATE: As of Aug ’07, this video was removed from YouTube…sorry
I finally took 5 minutes and figured out how to embed YouTube videos on this blog. From time to time, I’m gonna post geo-related footage. This one is of a landslide that occurred in Japan.
Back to regular life…
I’m nearly done with this latest stint on the SHRIMP…I need to blast about 5 more zircons. What a way to spend a Friday night.
I was gonna work on finishing up a paper that needs to get off my desk, my upcoming spring review progress report, reading a bunch of papers that i’ve been meaning to get to, and various other research-related activities while running this machine the last 3 days.
Instead, I played around on the internet.
Surfing the web is such a spasmodic and nonlinear activity — it actually goes perfect with running this machine, which has a sequence of mindless tasks every 7 minutes.
I’ve been checking out some music-related sites/blogs…I started a list on the sidebar. I haven’t posted too much about live music on this blog, because I just haven’t seen much lately. The whole finishing-up-the-dang-PhD thing has gotten in the way. I’m hoping to change that this summer.
…okay, 4 zircons to go…
Friday Field Foto #12: Combined-flow ripples
I realized today that I haven’t done a Friday Field Foto since early February…go here to see all the previous FFF posts.
Today, I decided to show a close-up instead of the usual landscape-scale views that I usually post. This is from the Cretaceous of central Utah (associated w/ these rocks) and shows some very nice ripple cross-laminated sandstone. In this case you can very nicely see some slightly climbing ripple-laminated sandstone toward the bottom overlain by some ripples heading the other way (apparently), and then some wavy laminae and smaller-scale ripples on top. Above and below this bed are abundant hummocky cross-stratified sandstones indicating that these ripple-laminated deposits are likely the product of combined flow (oscillatory + unidirectional) associated with storm waves (i.e., between storm- and fair weather-wave base).
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Inverted depositional features on Mars
FYI – this post is not about brand new discoveries — you can find information about these features on Mars Global Surveyor website and also check out a Science paper from 2003 by Malin et al. that goes over this stuff in more detail…I just felt like posting about it.
I was living in Colorado some years back when I went on a trip to look at the local geology of the Front Range and had one of those great field moments when the trip leader pointed out some inverted topography. In this case, a relatively small volcanic eruption produced lava flows that were isolated in a mountain valley. Since that time, the surrounding much softer sediments and sedimentary rocks have eroded away leaving lava-capped mesas that are now segmented by the modern river. The image below is of Golden showing the modern Clear Creek cutting the lava-capped mesa in two (yes, that complex of structures right in the valley is Coors brewery). Image courtesey of www.tablemountains.org.
These modern positive topographic features are representing an ancient valley! Very cool.
So, while wasting time on the internet – in 7-minute increments – I came across some old bookmarks about some inverted topographic features on Mars. The group of features, discovered in November 2003 by Mars Global Surveyor (MGS), have been dubbed the Eberswalde Delta.
The image above is Fig. 2 straight from Malin et al. (2003) showing the exhumed fluvial distributary fan (click on all images for larger view). The conspicuous curvilinear features at closer examination are actually positive topography. Inset of box A below clearly shows the deposits of a migrating meandering stream standing as a plateau above the surrounding area.
This is a striking example of inverted topography. In this case, the channel deposits contain coarser material (likely sand/gravel) and therefore are more resistant than the out-of-channel material (likely mud/silt). No data from the planet surface exists for this location but these are reasonable guesses. The cross-cutting relationships of this feature also nicely reveal that the wide meander swing was abandonded for a shorter, more direct route at some point.
The image below (inset box B) shows more cross-cutting ridges representing channel-fill deposits. I would sure like to walk up the edges of those ridges and plateaus to check out the cross-section of that fill. Another thing to notice is the apparent spreading out of coarser-grained material from left to right. Malin et al. interpret this as the lobe deposits at the end of these channel features….which seems pretty reasonable to me.
The implications of all this, of course, are further evidence of flowing water on Mars. The big problem we are faced with at this point is not so much if water flowed on Mars, but when. The next generation of rovers are gonna half to brush up on their geochronology.
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Clastic Detritus 