Taxonomy term

dating

No river meant no floods for ancient Indus settlements

Large Middle Eastern rivers like the Nile, Tigris, Euphrates and Tiber were critical for the development of early urban societies in Egypt, Mesopotamia and Ancient Rome. And researchers have long thought that the rise, and eventual decline, of cities in the ancient Indus Civilization, which spread across about 1 million square kilometers of what’s now northwestern India and Pakistan from roughly 4,600 to 3,900 years ago, also depended on major rivers, namely those emerging from the Himalayas. But a new study looking at river sediments from the time of the civilization and earlier suggests that wasn’t the case for every ancient Indus city; some may have benefited from being farther away from large rivers and their periodic floods.

01 Apr 2018

Humans arrived Down Under earlier than thought

Analysis of sediments surrounding a trove of artifacts discovered in northern Australia suggests the first humans arrived on the continent about 10,000 years earlier than previously thought, a finding that has implications for the hypothesized role of humans in the extinctions of Australian megafauna.

07 Nov 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

Jerusalem tower facelift reveals it's 1,000 years younger

Jerusalem is one of the oldest cities in the world, dating back to at least 2400 B.C. Downhill from the heart of the city is Gihon Spring, a year-round natural fount that was likely the primary water source for the ancient city. Defensive fortifications built around the spring, known as the Spring Tower, were originally dated to the Middle Bronze Age, around 1700 B.C., but a new study reveals the tower could be as much as 1,000 years younger.

19 Sep 2017

Magnetic method dates glacial floods in Iceland

In Iceland, volcanoes buried under glaciers occasionally melt huge quantities of ice, setting off massive glacial floods called jökulhlaups. Dating past jökulhlaups helps geologists better understand the eruptive history of Iceland’s many active volcanoes, which, in turn, sheds light on future volcanic hazards. But such dating is no easy task. A new study of magnetic minerals preserved in large boulders moved by floodwaters might provide a new tool in the effort.

07 Jul 2017

Timing of famed "Millennium Eruption" pinpointed

Changbaishan Volcano in northeastern China, on the border with North Korea (where it’s known as Mount Paektu), is steeped in superstition, having produced devastating eruptions several times in recorded history. Legends that a massive eruption in the 10th century led to the downfall of a regional empire have now been refuted, however, thanks to a new analysis of a fossilized tree killed by the eruption that dates the eruption to after the kingdom fell.

25 May 2017

Meteorites did not spark Ordovician biodiversification

During the Ordovician Period, roughly 470 million years ago, an asteroid the size of a small moon collided with another rocky object in the belt between Mars and Jupiter, shattering the asteroid into billions of pieces. Fragments from the epic collision still occasionally fall to Earth today, making up a large share of the meteorites recovered. But in the immediate wake of the Ordovician event, many pieces rained down on the planet, settling on the surface and in layers of rock forming at the time. In a new study, researchers studying some of these meteorite-rich layers have refined the timescale for the collision. The results bring into question a proposed link between the meteorite bombardment and an evolutionary uptick known as the Great Ordovician Biodiversification Event (GOBE).

23 May 2017

Move over Homo habilis: Early human evolution remapped

Mapping out how one species of early hominin branches to another has always been complicated by the rarity of complete specimens and lack of precise dating methods for fossils more than 50,000 years old. Now researchers studying the braincase, pelvis, hands and feet of a primitive hominin — which lived about the same time early Homo species were evolving — are taking full advantage of a rare, nearly complete assemblage of fossils and a new highly accurate dating method to once again redraw humankind’s ancient lineage.

07 Sep 2011