October 2014
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Atlanta Geological Society Newsletter Next meeting of the Atlanta Geological Society is October 28, 2014 Fernbank Museum of Natural History (Clifton Road) Social begins at 6:30 pm – Meeting begins at 7:00 pm October 2014 ODDS AND ENDS The clear, dry days of fall are upon us. I maybe OCTOBER MEETING getting used to finding all sorts of new geology ideas and images in the web but it is Join us Tuesday, October 28, 2014 at still suprising to se what’s out there, literally. the Fernbank Museum of Natural This month, a satellite of the Eurpoean Space History, 760 Clifton Road NE, Agency is getting closer to Comet 67P (a.k.a Atlanta GA. The meeting social Chury) and plans to send a pod to land on it November 11! As a friend of mine says, ‘That’s starts at 6:30 pm. This month the crazy talk!’ The newsletter has a series of speaker is Dr. Grant S. Boardman, images each taken nearer to the comet and the currently a Visiting Assistant details are amazing. Professor of Geology at Berry And there’s a bucket list of sorts from the College. His presentation will be : Geological Society of London; The 100 Great “Straight from the Eocene Horse's Geosites in the UK and Ireland. (Link below) I’ve been to a few of these on my one vacation Mouth: Using Enamel Stable there. I’ll have to work in Siccar Point when I Isotopes to Uncouple Regional go to Scotland, someday. Geomorphic Change from Global Also in the fall, the Geologic Society begins the Climate Fluctuation” annual election process. This month, Our sponsor for this evening ans nominations for officers will be received by well as next month’s meeting is Ken Simonton andalso during this month’s meeting. The elections will be held during the Premier Drilling of Loganville, GA. November meeting. Please consider stepping Please read their information in the up and becoming more involved in the following pages. running of our/your Atlanta Geological Society – Like Burton Dixon! He has recently Please come and enjoy the social become the membership chairman. Many time, pay your dues if necessary, thanks to Burton. talk with our generous sponsor and Ben Bentkowski, Newsletter Editor learn from an interesting http://apps.esriuk.com/app/GreatGeosites/3/wmt/view/5e0d44 presentation. 970b3a4b4dafb7da0404b2d8ed/index.html Page 2 AGS OCTO BER 2014 SPEAKER ’S BIO: Bio: Dr. Grant S. Boardman is a vertebrate paleontologist and stable isotope geochemist who earned his Ph.D. from the University of Nebraska - Lincoln in 2013. Dr. Boardman is currently a Visiting Assistant Professor of Geology at Berry College. Dr. Boardman's research focuses on the use of light stable isotopes in paleoecological interpretation. _______________________________________________________________________ Enigmatic fossils could be oldest known animals Thursday, 25 September 2014Stuart Gary ABC http://www.abc.net.au/science/articles/2014/09/25/4093899.htm Scientists have discovered some of the oldest multicellular organisms - and possibly the world's first animals - in 600 million year old Ediacaran fossils from China. A detailed examination of the unusual, small, spheroidal fossilised organisms concludes that they could be the ancient precursors to animals, or a type of multicellular algae. Reported in the journal Nature, the research is offering scientists fresh insights into the early evolution of complex multicellular organisms. "Our work shows evidence that this organism developed multiple kinds of cells 600 million years ago," says one of the study's authors, Professor Shuhai Xiao from Virginia Tech. "This is an important discovery for cell differentiation, and a critical step towards multicellular life." The fossils provide evidence that multicellularity appeared nearly 60 million years before the Cambrian Explosion, when most major animal phyla suddenly appeared in the fossil record. AGS OCTOBER 2014 Page 3 Page 4 AGS OCTOBER 2014 AGS OCTOBER 2014 Page 5 Lots o' Water! 117 Million Lakes Dot Earth, Most Accurate Survey Finds By Becky Oskin, Senior Writer | September 29, 2014 05:09pm ET This natural- color satellite image shows small blue and green lakes in northern Siberia, near the Gulf of Ob. Credit: NASA Earth Observatory http://www.livescience.com/48061-how-many-lakes-on-earth.html Until now, no one knew for sure how many lakes exist on Earth. Blame geography — most of the world's lakes are in places where humans don't live, said David Seekell, an environmental scientist at Umea University in Sweden. "This is something one would have assumed had been done long ago, and was in a textbook somewhere," Seekell said. Lake size was a liability, too. Millions of lakes are too small for mapmakers to bother charting. Instead of counting lake by lake, earlier estimates were statistical guesses, based on the number of lakes in a parcel of land or on average lake size. One widely cited study from 2006 estimated the lake total at 304 million. A new study published Sept. 16 in the journal Geophysical Research Letters sidesteps these problems. With high-resolution satellite data and supercomputers to check every cloudless pixel, researchers now have the best count yet of lakes on Earth. The result? There are 117 million lakes in the world. Yet the bodies of water cover more land (3.7 percent of Earth's surface) than previous studies had predicted. This is because quite a few medium- to large-size lakes were missing from older databases. How many lakes there are in the world and how much surface area do they cover? About 90 million of the lakes fall in the smallest size category, measuring 0.5 to 2.5 acres (0.2 to 1 hectare), the study reports. That's equal to a country house lot, a large farm pond or 1.9 American football fields. "Most lakes are in the far North, and there's actually quite a few of them," said Seekell, a co- author of the new study. "Even if they're small and no one sees them, they are potentially important for global-scale environmental issues like the carbon budget," he told Live Science. Page 6 AGS OCTOBER 2014 VIDEO OF EXFOLIATION OF RECENTLY EXPOSED GRANITE There is an ongoing geological drama going on the Sierra Nevada that may be unique (to the extent of my knowledge, which is admittedly limited in this area). Exfoliation, a process long recognized as the shaper of granitic domes and monoliths, is presently busting up the surface of a small dome at Twain Harte Lake a few miles east of the Mother Lode town of Sonora. The process has been captured on video, and is presently being monitored, due to the effects it is having on a reservoir abutment. The event burst into the news in August when a possible dam failure warning was issued following a loud popping sound and the leakage of water from the edge of the reservoir. Once the site was investigated, a decision was reached to drain the lake until the full extent of the damage was clear. There have been at least three 'events', the last on August 3. Recent exfoliation. Paste the link to find the video of the exfoliation releasing the stress. The money shot is at about 40 seconds. Look for the dust in the background, on the other side of the slab releasing. Ed. http://geotripper.blogspot.com/2014/09/ongoing-exfoliation-event-at-twain.html AGS OCTOBER 2014 Page 7 49 Open Challenges in Earth Science - The Known Unknowns http://retosterricolas.blogspot.com/2014/02/49 -open-challenges-in-earth-science.html What keeps Earth scientists busy? These 4 of the 49 open scientific questions aim at providing an updated, fully-referenced account of the main current scientific questions, disputes, and challenges in Geoscience. 1. Was there ever a collision of the Earth with another planet Theia, giving birth to our satellite? [Canup, 2013,Science] There is compelling evidence, such as measures of a shorter duration of the Earth's rotation and lunar month in the past, pointing to a Moon much closer to Earth during the early stages of the Solar System. [Williams, CSPG Spec. Pubs., 1991] 2. What is the relative importance of the forces driving plate tectonics: slab pull, slab suction, mantle drag, and ridge push? [e.g., Conrad & Lithgow-Bertelloni, 2004; Negredo et al., GRL, 2004 , vs. van Benthem & Govers, JGR, 2010]. What is the force balance and the geochemical cycle in subduction zones? [Emry et al., 2014, JGR] How much water (and how deep) penetrates into the mantle? [Ranero et al., 2003, Nature]How much subcontinental erosion takes place under subduction areas? [Ranero et al., 2000, Nature] 3. Do we need a new geological epoch called Anthropocene? When do the Homo Sapiens start to have a significant impact on the Earth System? 8000 BP?[Ruddiman, 2003, Climatic Change]; 2000 BP? [Scalenghe, 2011, The Holocene]; 1850 AD? [Crutzen & Steffen, 2003] 4. What were the causes and what shaped the recovery from mass extinctions as those at the K-T boundary, the Permian-Triassic or the Late Triassic? Massive volcanism? Meteorites? Microbes? [recent papers: ex.8, ex.9, ex.10, Rothman et al., 2014, PNAS] http://geolog.egu.eu/2014/10/17/the-known-unknowns-the-outstanding-49-questions-in-earth-sciences- part-iv/ ___________________________________________________________________________________ http://hint.fm/wind/ An invisible, ancient source of energy surrounds us—energy that powered the first explorations of the world, and that may be a key to the future. This map shows you the delicate tracery of wind flowing over the US. Page 8 AGS OCTOBER 2014 BENEFITS OF AN AGS MEMBERSHIP Location – AGS meets at the Fernbank Museum of Natural History, which is a truly awesome facility central to most of our membership.