Geology news

Antarctica - when was it glaciated?

At ... one of the forums at Thunderbolts this week is on the release of Peter Jupp's new video - the subject is Antarctica. Peter Jupp is a member of SIS and attended the EU Presentation during the summer. We hope to have several of his videos available for sale to interested parties in the near future.

Tortoises and Alligators in the Arctic - where it is night for six months of the year

At ... being Ellesmere Island in the high Arctic, north of Greenland. Millions of years ago tortoises and alligators thrived on the island - and endured darkness for six months of the year. I did notice this article elsewhere but passed it over - but it seems geologists appear to take it seriously. The key of course is temperature - in this instance, during the Eocene era.

An Iron Meteorite

At ... in 1920 a farmer's plough struck a lump of metal in a field near Grootfontein in Namibia. It was an iron meteorite estimated to be 66 tons in weight - and is still where it was found. It was once much larger on the basis of the abundance of iron oxide in the surrounding soil which is thought to imply the object has suffered oxidation since it fell out of the sky some 80,000 years ago.

End of Ice Age - New Zealand

At a new paper in Nature seems to indicate that New Zealand was not affected by the Younger Dryas cooling event. Antarctic ice cores are reputed not to record a cold phase of around 1000+ years that is extremely prominent in the northern hemisphere.

A coral reef is evidence of an extremely rapid change in sea levels during the Holocene

At there is a story on a relic coral reef 600km off SE Australia - 20 times bigger than the modern coral reef nearby. It thrived between 9000-7000 years ago - or that is when it was submerged and now lies 20+m below the sea surface.

Water and Ocean Currents

At there is another ESA report - this time on the role of the Amazon and the Orinoco in the Ocean Circulation system in the South Atlantic. Fresh water from the Amazon tends to create a flow or current of low salinity surface water. It seems to circle back on itself as a result of a much stronger ocean current off the coast of northern Brazil which is the southern equivalent of the North Atlantic's Gulf Stream - and well recorded in ocean circulation research.

The Antarctic of the Past

At is a strange title as it gives the impression a paper with a lead author from the British Antarctic Survey was referring to the continent of Antarctica dissected by a waterway - when in fact they were saying no such thing.

San Andreas Fault ... tremblors going back 700 years

At earthquakes have been a regular feature along the San Andreas fault system for a long time and a series of tremblors have been charted over the last 700 years. The September issue of Geology says that large ruptures have occurred on a stretch of the fault 100 miles NW of Los Angeles (where the research took place), at a rate of between 45 and 144 years apart. The last really big quake was in 1857, over 150 years ago.

K/T boundary event - a compromise?

BBC News August 30th ... the K/T boundary event, it seems, involved more than one meteorite, or asteroid strike, according to a new study in the journal Geology by Professor David Jolley at Aberdeen University. The Boltysh Crater in the Ukraine was first reported (in the west) in 2002 and scientists have now examined pollen and spores of fossil plants in the layers of mud that have infilled the crater. They found that immediately after the impact ferns quickly colonised the davastated landscape.

The Layer Cake

If this is cake it ain't got a lot of fruit. At ... research has found the North American continent is a layer cake (see Nature August 26th). Exploration of seismic factors at the interior of the earth illuminate how the continents formed. The continental land masses have been broken into pieces, joined back together, and then broken up again - but some old pieces of the lithosphere have existed over very long periods of time.