Taxonomy term

geology

Thirsty mantle: Subduction zones swallow more water than thought

For all the water stored in oceans, ice and other reservoirs at Earth’s surface, there’s likely even more in the planet’s interior, where it plays important roles in many geological processes, including the formation of magma and the lubrication of earthquake-producing fault zones. Uncovering just how much water is inside Earth — and the extent to which it moves back and forth between the surface and subsurface — has long been a challenge for scientists interested in understanding the planet’s water cycle. A new study peering beneath the Mariana Trench in the Western Pacific has revealed that some subduction zones might pull significantly more water into Earth’s interior than previously thought.

30 Jan 2019

Mineral Resource of the Month: Boron

Boron does not occur in nature in an elemental state. It is always found in oxidized states as borate salts. Four mineral forms account for the majority of the economically viable borate deposits throughout the world: two sodium borates, tincal and kernite; a calcium borate, colemanite; and a sodium-calcium borate, ulexite. Borate deposits are formed in areas that are tectonically active with arid climates. Large deposits are found in the Mojave Desert of the United States near Boron, Calif., the Tethyan belt in western Asia and the Andean belt of South America. Most borates are extracted in California and Turkey.

30 Jan 2019

Melting glaciers shift Earth's axis

A perfectly round desk globe spins evenly on a fixed axis, but that’s not the case with Earth, which wobbles as the position of its spin axis — the imaginary line running between the North and South poles — slowly drifts over time. In a new study in Earth and Planetary Science Letters, scientists suggest that there are three main reasons for the movement of Earth’s spin axis, called polar motion.

28 Jan 2019

Oman ophiolite suggests subduction started with a shove

Plate tectonics is a fundamental control on how Earth operates and is important for the planet’s habitability, but how this crustal recycling process got started has long been a mystery. A new study examining some uniquely coupled metamorphic and volcanic rocks in Oman is adding some needed clarity about the initiation of subduction zones, a critical component in plate tectonics.

23 Jan 2019

Ocean circulation change suffocating Gulf of St. Lawrence

Estuaries are among the most nutrient-rich and biologically productive areas of the ocean, and the Gulf of St. Lawrence, where freshwater from the Great Lakes and the St. Lawrence River meets the salty Atlantic Ocean in eastern Canada, is the largest estuary in the world. But the biodiversity and long-thriving fisheries of the Gulf of St. Lawrence could be threatened by declines in oxygen levels over the last half century. 

18 Jan 2019

Geologic Column: Muinntir a' ghlinne so

The author examines the idea of lament — for humanity, Earth and the universe — through the lens of the “pibroch,” a Gaelic word meaning a Scottish bagpiper’s variations on a musical theme, and the title of a Ted Hughes poem.

18 Jan 2019

Getting there and getting around Tibet

Tibet is a long way from most everywhere. There are no direct flights from North America, so it’s usually cheapest and most convenient to fly into a major Chinese city such as Beijing and then catch the next flight to Lhasa Gonggar Airport (LXA). Air China, Tibet Airlines, Sichuan Airlines and China Southern are among the carriers offering direct and connecting flights to Lhasa from most major Chinese cities. Sichuan Airlines and Air China also provide nonstop service from Kathmandu, Nepal. The Lhasa airport is located 65 kilometers south of the city center and takes about an hour to reach.

17 Jan 2019

Travels in Geology: Lhasa, Tibet: Journey to the roof of the world

On a trip to the Tibetan capital of Lhasa, one of the world’s highest cities, you can cross the Eurasian- Indian collision suture zone, admire the sparkling turquoise waters of sacred Yamdrok Lake, tour hidden monasteries belonging to different Buddhist sects, and marvel at Mount Everest, the world’s tallest mountain.
17 Jan 2019

The geology of kidney stones revealed

Kidney stones are an excruciatingly painful problem for 10 percent of the world’s population. In a new study applying geobiological methods to the study of human kidney stones, researchers have shed light on how the stones form, and revealed that they partially and repeatedly dissolve inside the kidney — which could help in developing new protocols to treat the pervasive affliction.

15 Jan 2019

Rising carbon dioxide may raise risk of nutrient deficiencies in humans

Plants absorb carbon dioxide to fuel their growth. As humans increase the amount of the greenhouse gas in the atmosphere, more will be available to vegetation around the world. But according to a new study, too much carbon dioxide might eventually lead to plants that are deficient in key nutrients for humans, which could be especially detrimental in the developing world.

11 Jan 2019

Pages