Geoarchaeology

geoarchaeology

Speartips point at south-to-north Clovis dispersal

During the last ice age, long before people first entered North America, much of the Canadian and American Rockies were buried under massive ice sheets. As the ice age waned about 13,000 years ago, an ice-free corridor 1,500-kilometers long and several hundred kilometers wide opened east of the Rocky Mountains.

02 Aug 2018

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.

23 Jan 2018

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

On the trail of Hannibal's army - and elephants - in the Alps

In the third century B.C., during the Second Punic War between the Romans and Carthaginians, Carthaginian general Hannibal led a massive army over the Alps to invade Italy from the supposedly impenetrable north. It is one of the most famously brazen moves in military history, but the exact route that Hannibal’s army — which included tens of thousands of foot soldiers and cavalrymen, thousands of horses and nearly 40 elephants — took through the mountains has long been a mystery. Now, a team has found microbial evidence that a large number of horses crossed the Alps from France into Italy over the 3,000-meter Col de la Traversette pass around 218 B.C. But not everybody is convinced that the Traversette pass route matches detailed historical accounts of Hannibal’s journey.

24 Jul 2016

Ancient African villages shed light on Earth's magnetic field

Throughout Earth’s history, the planet’s magnetic field has changed polarity hundreds of times, with the magnetic north and south poles swapping positions. These reversals sometimes occur every few thousand years, or after hundreds of thousands of years. The last known magnetic reversal took place nearly 800,000 years ago, leaving many to wonder if we’re overdue for a reversal. Now, research from southern Africa, an understudied region, analyzing magnetized minerals preserved in the charred floors of 1,000-year-old torched huts has shed light on geomagnetic patterns that may indicate — or perhaps even trigger — such a switch. 
 
15 Dec 2015

Earliest stone tools pre-date Homo

Tool making is thought to be one of the defining characteristics of the transition from apes to early man. Now, the discovery of a set of stone tools dating to 3.3 million years ago is pushing back this critical stage of early human development by more than half a million years, and, according to one researcher involved, disproving “the long-standing assumption that Homo habilis was the first tool maker.”

05 Sep 2015

From boom to bust in Neolithic Europe

As agricultural practices spread from the Fertile Crescent across Europe, gradually expanding west and north starting about 8,500 years ago, they brought increased and localized food production to a continent where nomadic hunter-gatherers had long made their living subject to the whims of climate and the environment. With agriculture, long-term settlements developed, fertility rates rose and, thus, populations grew steadily. Or at least that’s been the conventional wisdom.

20 Mar 2014

Hydrological models locate ancient human migration routes

Archaeologists and geologists have long hypothesized that major river systems flowed north through the Sahara Desert about 100,000 years ago. These rivers would have provided a sort of network of “green corridors” across the Sahara that early humans could have traversed as they migrated out of Africa. Ancient lake records, fossil river systems, and radioisotope data have offered evidence for the existence of flowing water in the region.

01 Nov 2013

Hominin skull discovery fuels debate about early human evolution

Hailed as a find for the ages, a rare skull of a 1.8-million-year-old human relative could provide answers to longstanding questions about the lineage of our species. It also fuels debate over what differentiates one hominin species from another, and could mean that Homo habilis, Homo rudolfensis and other early bipedal hominins may all be members of Homo erectus, rather than distinct species.

17 Oct 2013

Sinking sediment in deltas is as important as swelling seas

Sea-level rise due to melting ice is a common worry in coastal areas. But the sea-level story is much more complicated: What lies below the surface — sediment, and the rate at which it compacts — is also an important consideration, especially in deltas.

In a new study, researchers exploring the role of subsurface sediment compaction in coastal subsidence along Egypt’s Nile Delta, most of which lies just a meter above sea level, found subsidence rates there are four times greater than the rate of sea-level rise.

26 Sep 2013

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