Big Lake, Alaska and The Susitna Valley News, Weather, Events, And More

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Sunday, November 19 2017 @ 06:53 AM AKST

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New geochemical data released for the Tok and Denali Highway areas

Science(Fairbanks, AK) – The Alaska Division of Geological & Geophysical Surveys (DGGS) has published new geochemical data reports for rock samples collected in two areas of the eastern Alaska Range during summer 2015. These new datasets consist of new major- and trace-element analyses of rock samples collected to help DGGS and the public better understand the geology and mineral potential of this region of the state.

The first report includes geochemical analyses for 84 samples collected from the upper Tok River area between the Delta massive-sulfide district and the newly discovered Tetlin gold project. These data contain gold assays up to 14.5 ppm (0.423 oz/ton) with elevated As–Bi–Te content. These data will assist DGGS with its ongoing evaluation of the precious metals, lead, zinc, and copper potential of the area.

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Perplexing Pluto: New ‘Snakeskin’ Image and More from New Horizons

ScienceThe newest high-resolution images of Pluto from NASA’s New Horizons are both dazzling and mystifying, revealing a multitude of previously unseen topographic and compositional details.

One image, showing an area on Pluto’s best-mapped hemisphere near the line that separates day from night, captures a vast rippling landscape of strange, aligned linear ridges that has astonished New Horizons team members.

“It’s a unique and perplexing landscape stretching over hundreds of miles,” says William McKinnon, a New Horizons Geology, Geophysics and Imaging (GGI) team deputy lead from Washington University in St. Louis. “It looks more like tree bark or dragon scales than geology. This’ll really take time to figure out; maybe it’s some combination of internal tectonic forces and ice sublimation driven by Pluto’s faint sunlight.”

Snakeskin detail

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New maps indicate known and likely presence of naturally occurring asbestos

ScienceThe Division of Geological & Geophysical Surveys has released maps depicting the likelihood of naturally occurring asbestos in bedrock in Alaska. Areas of potential and known occurrences are shown on 21 maps that cover the state, with a color-coded scale that ranges from High-to-Known through Zero-to-Low potential. The maps were funded by the Alaska Department of Transportation & Public Facilities, which authorizes site-specific plans to provide immunity to landowners and contractors using gravel or aggregate material containing naturally occurring asbestos.

The new maps are meant to be a guide to places where bedrock might contain naturally occurring asbestos. However, determining the presence and amount of asbestos requires careful examination of the local geology and the collection and testing of samples. DOT&PF provides information on testing methodology and sampling protocol at http://www.dot.alaska.gov/stwddes/des.../noa.shtml

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New geologic mapping available for central Talkeetna Mountains area

ScienceThe Alaska Division of Geological & Geophysical Surveys (DGGS) today published the preliminary results of geologic mapping conducted in the Talkeetna Mountains during 2014. This map presents new, detailed information about bedrock geology, surficial deposits, and faults for a 450-square-mile area about 50 miles east of the town of Talkeetna. This map is a part of a multi-year DGGS assessment of the strategic and critical minerals of the western Wrangellia geologic province, an approximately 4,000-square-mile area stretching from Talkeetna to Paxson.

This map has implications for platinum, gold, and copper exploration in the region, and for the proposed Susitna–Watana hydropower project, which lies immediately north of the map area. It constitutes the most recent installment of an ongoing, long-term effort to develop an accurate understanding of the geology of Alaska to facilitate economic development and provide information for the management of the state’s natural resources. While detailed geologic maps are available for most of the Lower 48, many areas of Alaska, including the Talkeetna Mountains, have only reconnaissance-scale geologic mapping.

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Geophysical data released for Petersville, Fortymile and Livengood areas

ScienceThe Alaska Division of Geological & Geophysical Surveys (DGGS) has updated its 1996 Peters­ville, 1998 Fortymile, and 1998 Livengood electromagnetic and magnetic geophysical survey data products. The Petersville survey area is approximately 40 kilometers west of Talkeetna at the southwestern end of the Chulitna–Yentna mineral belt. The Fortymile survey is in the Fortymile mining district and the Livengood survey includes parts of the Rampart and Tolovana mining districts. These survey areas contain known gold and gold-associated deposits documented in the Alaska Resource Data Files (http://ardf.wr.usgs.gov/). International Tower Hill Mines, Ltd., discovered and delineated the 20.1-million-ounce Money Knob gold deposit at its Livengood Gold Project after the publication of the original Livengood geophysical survey data.

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NASA Unveils Celestial Fireworks as Official Image for Hubble 25th Anniversary

ScienceFrom NASA: The brilliant tapestry of young stars flaring to life resemble a glittering fireworks display in the 25th anniversary NASA Hubble Space Telescope image, released to commemorate a quarter century of exploring the solar system and beyond since its launch on April 24, 1990.

“Hubble has completely transformed our view of the universe, revealing the true beauty and richness of the cosmos” said John Grunsfeld, astronaut and associate administrator of NASA’s Science Mission Directorate. “This vista of starry fireworks and glowing gas is a fitting image for our celebration of 25 years of amazing Hubble science.”


Credits: NASA/ESA
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New Tok area geophysical survey data released

ScienceTo help catalyze new private-sector mineral exploration, discovery and, ultimately, development and production, the Division of Geological & Geophysical Surveys (DGGS) has issued a new report publishing data from the 2014 Tok electromagnetic and magnetic geophysical survey. The survey is centered roughly 56 kilometers west–southwest of Tok in the Nelchina mining district and covers approximately 2,500 square kilometers in the Mt. Hayes, Tanacross, Gulkana, and Nabesna quadrangles with high-quality, 400-meter-line-spacing data.

The west and northeast portions of the survey area contain numerous known copper, gold, and gold–silver–copper–lead–zinc prospects, some with drill-identified precious and base-metal resources documented in the Alaska Resource Data Files (http://ardf.wr.usgs.gov/). The absence of known mineral prospects in the remainder of the survey area is likely related to the lack of public data. By publishing the new data, this report will increase the geologic understanding of the area and provide a framework for further mineral exploration that could lead to new discoveries.

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NASA’s Hubble Observations Suggest Underground Ocean on Jupiter's Largest Moon

ScienceFrom NASA: "NASA’s Hubble Space Telescope has the best evidence yet for an underground saltwater ocean on Ganymede, Jupiter’s largest moon. The subterranean ocean is thought to have more water than all the water on Earth's surface."




Artist concept of Ganymede and Jupiter
In this artist’s concept, the moon Ganymede orbits the giant planet Jupiter. NASA’s Hubble Space Telescope observed aurorae on the moon generated by Ganymede’s magnetic fields. A saline ocean under the moon’s icy crust best explains shifting in the auroral belts measured by Hubble.
Image Credit:
NASA/ESA
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Geologic guidebook commemorates 50th anniversary of '64 Earthquake

Science(Fairbanks, AK) – The Division of Geological & Geophysical Surveys (DGGS) has released a new technical guidebook on the geology of coastal Southcentral Alaska that compiles the most recent developments in understanding the earthquake geology of the region. The guidebook is a reference tool intended for use by decision makers, planners, land managers, engineers, and scientists working in this seismically-active region.

The guidebook resulted from extensive collaboration by international scientists who came to Alaska in May 2014 to participate in a seven-day field conference focused on the geologic aspects of coastal change in Alaska. The conference, supported by the International Geoscience Programme and the Seismological Society of America, highlighted the 50th anniversary of the Great Alaska Earthquake of March 27, 1964, and included field visits to Southcentral Alaska sites impacted by the earthquake.

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The View from New Horizons: A Full Day on Pluto-Charon

ScienceFrom NASA: "This time-lapse “movie” of Pluto and its largest moon, Charon, was recently shot at record-setting distances with the Long-Range Reconnaissance Imager (LORRI) on NASA’s New Horizons spacecraft. The movie was made over about a week, from Jan. 25-31, 2015. It was taken as part of the mission’s second optical navigation (“OpNav”) campaign to better refine the locations of Pluto and Charon in preparation for the spacecraft’s close encounter with the small planet and its five moons on July 14, 2015.

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Updated geophysical data available for Iron Creek area

ScienceThe Division of Geological & Geophysical Surveys (DGGS) has issued a new report updating its 1997 Iron Creek electromagnetic and magnetic geophysical survey. The Iron Creek survey area covers approximately 1,766 square kilometers of the Talkeetna Mountains Quadrangle and the new report provides high-quality 400-meter-line-spacing data. The survey area is approximately 40 kilometers east of Talkeetna in parts of the Yentna–Cache Creek and Valdez Creek mining districts.

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Dawn Snaps Its Best-Yet Image of Dwarf Planet Ceres

ScienceThe Dawn spacecraft has delivered a glimpse of Ceres, the largest body in the main asteroid belt, in a new image taken 740,000 miles (1.2 million kilometers) from the dwarf planet. This is Dawn's best image yet of Ceres as the spacecraft makes its way toward this unexplored world.

"Now, finally, we have a spacecraft on the verge of unveiling this mysterious, alien world. Soon it will reveal myriad secrets Ceres has held since the dawn of the solar system," said Marc Rayman, of NASA's Jet Propulsion Laboratory in Pasadena, California, chief engineer and mission director of the Dawn mission.

(The Dawn spacecraft acquired this view as part of a calibration of its science camera. Ceres is the bright spot in the center of the image. A cropped, magnified view of Ceres appears in the inset image at lower left.
Image Credit:
NASA/JPL-Caltech/UCLA/MPS/DLR/IDA)

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Airborne geophysical data to be released for East Styx area

Science(Fairbanks, AK) – At 11:30 a.m. on Wednesday, Nov. 5, the Division of Geological & Geophysical Surveys will release airborne geophysical survey data and maps for the 1,060-square-mile East Styx survey area, which is centered about 100 miles northwest of Anchorage in the Yentna mining district, with small portions in the Redoubt and McGrath mining districts. The data will be useful for mineral exploration, planning, and land-use management.

Miners in the Yentna mining district have produced more than 200,000 troy ounces of gold since recordkeeping began in 1880. Much of the area is covered by surficial deposits and vegetation and has not been explored thoroughly. Airborne geophysics is a valuable tool for characterizing bedrock types, projecting geology between sparse outcrops, and for identifying vegetation-covered anomalous geologic signatures that might be associated with lode mineralization. The survey area hosts many prospects that are thought to represent several different deposit types including polymetallic veins, epithermal veins, and porphyry copper deposits. Many prospects are near plutonic rocks in the area.
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Dutch team is pioneering development of crops fed by sea water

ScienceThis article has implications for Alaska: "In a small army field-hut Dr Arjen de Vos shows off his irrigation machine with pride. Pipes lead out to several acres of muddy field, where only a few stragglers from the autumn harvest of potatoes, salads, carrots and onions are left. The tubes are lined with copper to stop corrosion because – in a move that defies everything we think we know about farming – de Vos is watering his plants with diluted sea water.

Last week the project beat 560 competitors from 90 countries to win the prestigious USAid grand challenge award for its salt-tolerant potato. “It’s a game changer,” said de Vos. “We don’t see salination as a problem, we see it as an opportunity.”

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US Topo Maps for Alaska

Science
From the U.S.G.S.:

US Topo Maps for Alaska

US Topo quadrangles are digital topographic maps produced by the National Geospatial Program of the U.S. Geological Survey (USGS). They are created in the familiar 7.5-minute quadrangle format similar to the legacy paper maps, with the addition of an aerial photo or satellite image as a visual base layer. Each map is delivered in PDF format with geospatial extensions (GeoPDF®) for free download and viewing on a computer or mobile device, including layers that can be controlled by the user and basic, on-screen geographic analysis.

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