Taxonomy term

geology

Travels in Geology: Cones and craters in Flagstaff, Arizona

Few places in the country exhibit as many types of volcanic features — including jagged lava flows, crumbly cinder cones and the remnants of a towering stratovolcano — in as small an area as northern Arizona’s San Francisco Volcanic Field.
04 Oct 2017

Minerals deformed by meteorites reveal age of impact

Researchers have discovered a new way to determine when a meteorite hit Earth, a technique that could not only help scientists date ancient meteorite strikes but also determine when planetary crusts first formed.

03 Oct 2017

Mineral Resource of the Month: Strontium

Two strontium-bearing minerals, celestite (strontium sulfate, SrSO4) and strontianite (strontium carbonate, SrCO3), contain strontium in sufficient quantities to make recovery practical. Celestite occurs much more frequently and is the primary source of the world’s supply of strontium. Celestite occurs as crystals and as massive or fibrous aggregates in sedimentary rocks. It often displays a delicate blue color owing to the presence of impurities. Celestite can occur in bedded evaporite deposits in conjunction with gypsum, anhydrite and halite. It can also occur in cavities within carbonate rocks where it is precipitated from strontium-bearing groundwaters or brines.

 
02 Oct 2017

New map of Arctic geology published

At first glance, it might seem there’s little more to the Arctic than frozen tundra, ice and seawater, but the top of the world is home to some unique geology and an impressive array of mineral resources. A new project led by the Geological Survey of Norway (GSN) has compiled all existing geologic data about the Circum-Arctic region into a book, database and interactive map.

28 Sep 2017

Geomedia: Radio: "Big Picture Science" aptly named

Titles can sometimes be a hard thing to live up to, but “Big Picture Science,” a weekly radio program broadcast on about 100 stations nationwide, delivers on its name. The show, which cleverly covers everything from a study of frogs in pants to efforts to create a compassionate computer, lives up to its mission of presenting a wide-angle view of science and technology.

27 Sep 2017

How the Arctic became salty

The Arctic Ocean hasn’t always been as salty as other oceans. In the Eocene, between 56 million and 34 million years ago, the water surrounding the North Pole — freshened by melt from sea ice and river runoff — was cut off from the Atlantic and Pacific oceans by land bridges. At some point, plate tectonic processes opened the North Atlantic, submerging the land bridges and allowing saltwater to pour into the Arctic, but the timing and details of these events are largely unknown. New research suggests a tipping point may have been reached as one particular land bridge submerged far enough below the ocean surface.

25 Sep 2017

Benchmarks: September 23, 1806: Lewis and Clark's Corps of Discovery returns from the West

It’s been called the greatest camping trip of all time. Statues, counties, waterways, mountains, military vessels, and even two colleges bear the names of the journey’s leaders. Their journals are among our greatest national treasures, and their adventures have inspired generations of explorers. Two hundred and eleven years ago this month, Captains Meriwether Lewis and William Clark and their 31-man Corps of Discovery returned to St. Louis, the frontier town where they had started their journey 28 months and nearly 13,000 kilometers of wilderness earlier on May 14, 1804.

23 Sep 2017

Volcanism triggered end-Triassic extinction

The end-Triassic mass extinction exterminated up to three-quarters of all species on land and in the oceans 201 million years ago. This die-off opened up ecological niches and allowed for, among other changes, dinosaurs to diversify and spread across terrestrial ecosystems during the rest of the Mesozoic. Volcanism has long been implicated in the extinction, but whether it had a major impact on the planet at the time has remained unclear. In new research, scientists observed elevated mercury concentrations in extinction-aged rocks from around the world. Because volcanism is the main nonanthropogenic source of mercury in the environment, the findings suggest that volcanic activity was likely the main extinction trigger at the end of the Triassic.

21 Sep 2017

Getting there and getting around Bolivia's Antiplano

Bolivia’s main gateway, El Alto International Airport (LPB), is located 13 kilometers southwest of the country’s capital, La Paz. It hosts regular, year-round flights to and from major destinations in South America, including Lima and Cuzco, Peru, Santiago, Chile, and Buenos Aires, Argentina, as well as connecting flights to Miami on American Airlines and Los Angeles, Washington, D.C. (Dulles) and Orlando, Fla., on Avianca. Several regional airlines, including Boliviana de Aviación (BoA) and Amaszonas, offer multiple flights daily from La Paz to Uyuni. The hour-long flight typically costs about $150 one way. We found the South American carriers to be extremely efficient; it’s important to arrive at the airport two hours in advance because the flights often depart early!

13 Sep 2017

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