Geology news

No One Has Ever Been Here - where?

http://cosmictusk.com August 13th ... George Howard has a couple of pictures of craters on the Gilf Kahir plateau in the Egyptian Sahara, near the border with Libya. Norbert Brugge, a German geologist, said 'no one has ever been here!' What he means is that no geologist or anyone with a camera has visited the site, and George laughs, it 'only reinforces my belief that people (scientists as well as the general public) overestimate what we know and vastly discount what we do not'.

An Indonesian glacier

At www.physorg.com/print200656127.html we have an interesting story about a shrinking glacier on a 16,000 feet high Indonesian mountain ridge that is disappearing - rapidly. The glacier is another victim of AGW according to the bumph (supported by a National Science grant). Three cores have been drilled out of the glacier and it is hoped evidence of past climate change will emerge that might throw some light on the ebb and flow of El Ninos, for example, as well as past cooling and warming episodes.

Mountains on Titan

At www.jpl.nasa.gov/news August 12th .... Titan, a moon of Saturn, ripples with mountains - but how did they form? On earth mountains form at plate boundaries as a result of subduction, it is thought, but it is being suggested that on Titan mountains form as a result of Titan shrinking, wrinkling the surface. Apparently, a similar kind of thing might have happened on earth where the lithosphere crumpled to create the Zagros mountain chain in the Middle East.

Gondwanaland - massive shift at the beginning of the Cambrian!

At www.sciencedaily.com/releases/2010/08/100810163456.htm a study published in Geology 2010: 38 (8), and a press release from Yale University, says the Gondwanaland supercontinent underwent a 60 degree rotation across the surface of the earth during the early Cambrian period.

Himalayan Odds

At www.physorg.com/print200237328. html there is a report on a geological study into the formation of the Himalayas, the movement of the Indian plate into the Asian plate. The Indian plate was subducted and this in turn led to the creation of the mountain chain as it just kept pushing against the other. The Indian plate also included oceanic crust which was pushed down into the mantle. Now, researchers on the high mountains have discovered eclogites and the samples have been found to contain garnet.

Elevation in the Andes

Along the coastline of South America there are a series of well known stranded beaches which indicate changes in sea level - or seismic shifts. The idea that mountain building in the Andes was recent was popular at one stage because Lake Titicaca, for example, was formerly located at a much lower altitude, it was thought, as it had been a coastal lagoon.

Chile EQ aftermath

Another link to www.physorg.com/print199692636.html comments on geology in South America investigating the February 2010 earthquake in Chile. It ruptured a very long fault that follows the coastline of Chile but its effects on land varies. In the south it tended to cause an elevation of land while in the north the land tended to sink.

A New Greenland Ice Core in the offing

At www.physorg.com/print199550264.html we learn that a drilling team has reached bedrock in Greenland after 5 years of boring through 2.5km of solid ice. What they want are sample from the core dating between 130,000 and 115,000 years ago during what is known as the Eemian warming (the last inter-glacial period). It is thought temperatures were a few degrees warmer than they are now so they want to know to what extent the Greenland ice cap shrank.

Indonesian Geology

At www.sciencedaily.com/releases/2010/07/100726144011.htm there is a new intepretation of the Banda Arc, a giant 1000km long 180 degree curve in eastern Indonesia which has never been adequately explained. In fact, there has been considerable controversy about how to explain the feature - its origin and evolution. A paper in Nature Geoscience sets out to do just that, using a computer simulation or model.

A tectonic computer model

at www.physorg.com/print198495599.html July 16th ... a group of earth scientists has developed a new way to explain the global movements of tectonic plates on the surface of the earth. For example, the Basin and Range Province in Nevada was created by a plate sliding beneath the North American continent - just 30 million years ago.. This is fairly recent as far as geological time is concerned, and the paper, in Science July 16th, suggests plates in the modern world move at the rate of around a few centimetres per year.