GeoLog

Geochemistry, Mineralogy, Petrology & Volcanology

Volcanic darkness marked the dawn of the Dark Ages

June 15, 2016
Volcanic darkness marked the dawn of the Dark Ages
Volcanic ash can spread far and wide. Credit: Taro Taylor via Flickr.

The dawn of the Dark Ages coincided with a volcanic double event – two large eruptions in quick succession. Combined, they had a stronger impact on the Earth’s climate than any other volcanic event – or sequence of events – in the last 1200 years. Historical reports reveal that a mysterious dust cloud dimmed the sun’s rays between in 536 and 537 CE, a time followed by global societal decline. Now, ...[Read More]

Great walls of fire – Vitrification and thermal engineering in the British Iron Age

May 25, 2016

It’s long been recognised the peoples of European prehistory occasionally, and quite deliberately, melted the rocks from which their hilltop enclosures were made. But why did they do it? In today’s blog post Fabian Wadsworth and Rebecca Hearne explore this question. Burning questions Throughout the European Bronze and Iron Ages (spanning 2600 years from 3200 BC to 600 BC), people constructed stone ...[Read More]

Imaggeo on Mondays: Moving images – Photo Contest 2016

May 23, 2016

Since 2010, the European Geosciences Union (EGU) has been holding an annual photo competition and exhibit in association with its General Assembly and with Imaggeo – the EGU’s open access image repository. In addition to the still photographs, imaggeo also accepts moving images – short videos – which are also a part of the annual photo contest. However, 20 or more images have to be submitted ...[Read More]

Imaggeo on Mondays: Half dome at sunset

May 16, 2016
Imaggeo on Mondays: Half dome at sunset
Half dome at sunset . Credit: Alessandro Demarchi (distributed via imaggeo.egu.eu)

Yosemite’s Half Dome stands, majestic, over a granite dominated terrain in the Yosemite Valley area;  one of the most beautiful landscapes in northern America, and arguably, the world – it is also an Earth scientist’ playground. Stamped into the west slope of the Sierra Nevada range, the Yosemite Valley is a collection of lush forests, deep valleys, meandering rivers and streams, all punctua ...[Read More]