Geology news

Insects in Amber pose a few problems for geochronology

Again, at ... in this instance, amber found in India. The cache of insects is said to indicate India was not isolated for millions of years out of reach of the rest of the world.

Dating the Ice Ages

New Scientist 22nd May 2010 had a story on the Hulu cave system near Nanjing in China which contains some very useful stalagmites that have been used to date the Ice Ages - or at least the last four. James Croll, a Scottish self taught physicist, proposed that periodic change in the earth's orbit caused the amount of sunshine reaching the surface of the earth to vary over time. Low sunshine in winter led to snow accumulating. As ice sheets grew the earth reflected more heat back into space amplifying the effects of orbital changes.

Oscillating Sea Levels

At is a report going back to March 2000 on the study of fossil tube worm holes that have been C14 dated (in Australia) and they show that, for example, around 2000BC, sea levels were some 2m higher than modern ones. Indeed, sea levels appear to have risen and fallen on a number of occasions in the last 6000 years. Similar evidence to support the research came from South Africa, Brazil, South Carolina, and New Caledonia.

Volcanoes and Neanderthals - update

At there is more on the October Current Anthropology paper by Golovanova and Doronichov. They think the Neanderthal demise was abrupt - a catastrophe. This involved powerful volcanic activity in western Eurasia around 40,000 years ago. It created mass depopulation - a die-off Neanderthals and many other species. Large numbers were involved.

Climate and Early Humans

At we have news of some remarkable research at Olduvai Gorge on the edge of the Serengeti Plain. It famous for its hominid remains. Geologists are now investigating the chemical composition of carbonate rocks that lie below the surface where early human fossils have been uncovered - in order to understand environmental changes.

Deep sea corals in the Mediterranean

At  an underwater coral reef just 40km off the coast from Tel Aviv and some 700m belong the surface has been found. At there is a four page piece on Neanderthals - and how close to modern humans in ability and strategies they seem to have been.

Plinian eruptions, and Babylonian poems

At we have a new post that outlines the nature of Plinian volcanic eruptions and their relationship to ignimbrites. Once again the comments are interesting - the idea of melting rock requires first the melting and then the flow - but how can this happen as a result of blast and heat? It won't flow if it has not first melted, a scenario with obvious parallels to volcanism, and lava - and see the response by Dennis Cox.

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.