Geology news

Fossils of the Soom Shale deposit

At www.geology.com/press-release/soom-shale/ ... a site near Table Mountain in South Africa has a rock layer a few metres thick that contains the petrified remains of bizarre early life-forms complete with eyes, guts, and muscles. It is a mystery how they were preserved in such a pristine condition but a paper in the December issue of Geology claims it was all down to the wind. A bitter wind blowing off an ice sheet.

Ice Age Sea Levels

At www.physorg.com/print210426748.html we learn that research at Southampton University is looking at the rate of sea level rise at the end of the Ice Age. Presumably computer simulation is being used which is programmed by the idea that sea levels rose as a result of a melting ice sheet rather than through a catastrophic redistribution of ocean waters.

Dead Sea sediment core

Israeli scientists are drilling into the sea bed of the Dead Sea in the hope of extracting a sediment core going back several hundred thousand years. This will provide geological and archaeological information that will take years to analyse piece by small piec as it should pigeon hole periods of drought and flood, and changing climate over time. Both Israeli and Palestinian scientists are said to be involved in the project and it is thought one thing that will show up quite clearly is a history of earthquake activity in the Jordan Valley as relevant layers will not line up.

Egyptian Wetlands

At www.sciencenews.org/view/generic/id/66507/title/Shuttle_images_reveal_Egypts_lost_giant_lake/ ... what is now a huge sand sheet to the west of the Nile was once a lake as large as Lake Erie before 80,000 years ago.

Cliff Fall in Dorset

Anyone holidaying in Dorset might be aware that you can walk the undercliff from Lyme Regis to Axmouth in what is now a quite pleasant wooded environment stretching some 10 miles or so that is maintained as a National Nature Reserve. It is in fact part of the South West Coastal Footpath, the section taking in the Jurassic Shore of Dorset and Devon. Most of the time there is no access to the beach because of the danger of falling rubble.

Dating Rocks

At www.physorg.com/print207997095.html ... we are told geologists have a general idea of when major events occurred in earth history but precise dates for the sequence and duration of geological events are not actually known for sure. As an example, how long did it take for mountain ranges to forme or the exact age of fossils. Geochronologists are thescientists who determine the age of rocks and minerals and to do this they measure radioactive elements.

The Atlantic current during the Ice Age - and melting ice sheets

At www.sciencedaily.com/releases/2010/11/101103141541.htm (see also http://news.yahoo/livescience/20101103/sc_livescience/atlantic ) there is a report on an article published this week in Nature which claims that during the Late Glacial Maximum the flow of deep waters in the Atlantic differed to what happens today.

Volcanoes

At www.physorg.com/print207817646.html we learn that some 22 volcanoes in Indonesia are displaying evidence of increased activity. Mount Merapi is periodically belching hot gas and debris and making people feel very nervous. Its slopes are covered in ash and many people have been evacuated - but other volcanoes are stiring from slumber.

Insects in Amber pose a few problems for geochronology

Again, at www.livescience.com/animals/Insects-in-Amber-Reveal-Ancient-Tropical-Forest ... 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.