Taxonomy term

february 2016

Mammoths may have suffered from bone disease

The demise of mammoths, which went extinct by the end of the Pleistocene about 12,000 years ago, is thought to have been brought about by a combination of climate change and overhunting by early humans. A new study indicates that another culprit might have contributed as well: Mammoth bones retrieved from Northern Eurasia — from sedimentary strata close to the animals’ last known appearance in the fossil record — appear to show evidence for bone diseases associated with nutrient deficiencies.
 
28 Feb 2016

Earliest Americans were wide-ranging wanderers

About 40 years ago, when the Monte Verde archaeological site in southern Chile was dated to 14,800 years ago, conventional ideas of American anthropology were turned on their heads. Until then, the “Clovis First” theory, which held that modern humans only began populating the Americas from Asia via the Bering land bridge roughly 13,500 years ago, was widely accepted. That people had lived thousands of kilometers farther south more than 1,000 years before the Clovis culture arose came as a shock initially, but the idea, and the Monte Verde site, has gradually become accepted over time.

27 Feb 2016

Volcanic aerosols not enough to cause mass extinctions?

Mass extinctions — when more than half of Earth’s species disappear in a geologic instant — offer some of the planet’s most perplexing unsolved mysteries. Prolonged periods of volcanic activity have long been prime suspects for these ancient whodunits, the most recent of which finished off the last nonavian dinosaurs at the close of the Cretaceous about 66 million years ago. But scientists debate how drastic the environmental effects of such volcanism might have been, and whether other factors — like asteroid impacts, as in the end-Cretaceous extinction — played a big role as well.

25 Feb 2016

A jaw all the wider to bite you with

Tyrannosaurus rex  is often depicted with its fearsome jaws wide open, but few studies have looked at how wide the Cretaceous predator’s gape could actually be.

23 Feb 2016

Urban geology: An emerging discipline in an increasingly urbanized world

Urban geology — the geology just outside, or perhaps under, our front doors — should be recognized as its own specialty. After all, its applications impact more than half of the global population.

21 Feb 2016

Urban type sections

It might surprise people to learn that some type sections can be found in cities. Type sites require conservation and protection

21 Feb 2016

Siwash Rock as an urban geoheritage icon

Siwash Rock in Stanley Park, Vancouver, British Columbia, is a prominent and photogenic sea stack — an erosional remnant of an Oligocene basalt dike that cuts through Cretaceous sandstones. The rock (properly named “Slahkayulsh,” meaning “he is standing up”) is a geoheritage locality in both aboriginal and nonaboriginal iconography. 
 
21 Feb 2016

Scarps and craters reveal moon's dynamic side

During their 1972 mission to the moon, Apollo 17 astronauts Eugene Cernan and Harrison Schmitt tried to ascend a steep rise in the lunar rover. The rover could not make it, so the pair drove up the incline in a zigzag pattern. The rise, it was later found, is the lobate scarp of a lunar thrust fault — one of many such features that, thanks to detailed images from NASA’s Lunar Reconnaissance Orbiter (LRO), are now known to occur across the moon’s surface. In a new study, researchers suggest these faults were formed by the same gravitational forces that cause the rise and fall of tides on Earth.

19 Feb 2016

Volcanic eruptions affect rivers around the world

Volcanic eruptions are some of the most powerful agents of climate change on the planet, with some very large events impacting global weather for up to a decade after an eruption. A new study highlights some of the indirect effects of large eruptions, such as how they impact rivers around the world.
 
17 Feb 2016

Uranium contamination in aquifers could be linked to nitrate

Nitrogen is an essential nutrient for plant life, but plants can only take up so much so fast. When excess nitrogen enters the environment by way of fertilizer and manure runoff, as well as in automobile and industrial emissions, it becomes a pollutant that can leach into waterways, carrying with it unintended — and often undesirable — consequences. In a new study, researchers have found evidence of one such consequence: elevated uranium levels in two major U.S. aquifers.

17 Feb 2016

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