Geology news

Giant fjords beneath Antarctica

Thiss story can be seen at www.sciencedaily.com/releases/2011/06/110601134253.htm and is based on a paper in Nature just out. It is also featured, with comments, at http://wattsupwiththat.com/2011/06/01/radar-mapping-reveals-ancient-anta... which indicates the manner of the research, radar mapping that is able to penetrate thick ice to look at what lies underneath. What they have been looking at is a subglacial basin buried under eastern Antarctica amd this basin, larger than Texas (and therefore larger than Yorkshire) is cut by fjords.

The biosphere ... beginnings

At www.sciencedaily.com/releases/2011/05/110518121227.htm 'Young Graphite in Old Rocks challenges the Earliest signs of Life' ... (the same story can be found at www.geology.com May 24th) and it seems that carbon found within ancient rocks has played a leading role in the development of a time-line for the emergence of biological life on earth. The rocks have been dated millions and even billions of years in the past - but now it has been found graphite (a carbon) dates somewhat younger, even very much younger, in what are some of the oldest rocks on earth in NE Canada.

Beringia

A little geological history of the Bering Straits or Land Bridge is available at ( http://archaeology.about.com/bcthroughbl/qt/beringia.html?nl=1 ). Whenever sea levels in the region dropped by 50 metres below the present position the land surfaced. The dates when this happened have been difficult to establish precisely simply because at the moment the region is submerged. In general terms it is thought Beringia was exposed between 60,000 to 25,000 years ago. During the Late Glacial Maximum, 25,000 to 18,000 years ago, it is thought Beringia was cut off both in the east and in the west.

Kerguelen, and drumlins

The idea of the geoid readjusting itself as a result of changes in the axis of rotation may not be acceptable to academic geology but it might explain a story in New Scientist 20th February 1999. An ancient land in the Southern Ocean is a geological fact of life. The Kerguelen Plateau, situated between Australia and the Antarctic, has on at least three occasions been dry land. Marine geologists discovered this piece of continental shelf system was formerly above sea level as sediments were found containing plant spores, seeds, pollen, fragments of wood and charcoal.

Can the Earth's crust move up and down?

This sounds like the sort of thing advocated by Steve Mitchell in the pages of SIS but the story is at www.physorg.com/print221727791.html and derives from a paper that claims the crust can move up and down like a yo-yo. However, it is nothing like the sort of thing suggested by Steve Mitchell as they are referring to plate boundaries - although the idea might possibly be extended to whole sections of plate, assuming plates are not neccessarily huge affairs.

Chesil Beach

At www.jurassiccoast.com/380/the-coast-uncovered-30/geo-highlights-226/ches... ... the Jurassic Coast was featured in BBC TVs Countrywise April 5th 2011 - and Chesil Beach was pictured and discussed. I had a quick look on the Net by search engine and came up with the above site. I can remember reading some years ago a tourist booklet that said the pebble and shingle beach was raised up in a storm.

The Grand Canyon ... again

Sparked by the same article as my post on March 31st, EM Smith at http://chiefio.wordpress.com/2011/04/01/where-did-the-grand-canyon-go/ asks an intriguing question. The aforesaid article says the Colorado River began cutting out the Grand Canyon 17 million years ago - other geologists have suggested 3 or 6 million years. It is 277 miles long, up to 18 miles wide and up to a mile deep - but where did all the material go that got washed away?

Grand Canyon

At http://geology.com/articles/age-of-the-grand-canyon.shtml is an article 'How Old is the Grand Canyon?' which describes some of the conventional thinking on how long it would take a river to cut through so many layers of rock - and millions of years are involved. However, a whole mountain range has apparently disappeared - over the course of the same period of time. The disappearance is equally as mysterious as the formation of the canyon - a great slash cut out of the crust of the earth. It is also clear that science does not really know how it was formed - but ideas abound.

More on those Arctic trees

At www.physorg.com/print219594362.html ... a buried forest was discovered after wood was found on the ground near a glacier. Earth scientist Joel Barker spotted some wood scattered on ground near a glacier and found the remains of trees that had once grown on Ellesmere Island in the High Arctic. Nowadays, the Hazen Plateau in Quttinirpaaq National Park is a tundra and glacier landscape, a pretty desolate kind of place where temperatures regularly fall below 50 degrees of freezing. It is thought the mummified tree remains lived millions of years ago - when the Arctic was warm.

Black Sea Floods

At www.sciencenews.org/view/generic/id/71291/title/Cave_formations_record_B... ... stalagmites in a cave in Turkey not far away from the Black Sea coastline contain a record of 19 flooding events - 0ver 650,000 years. It seems over the course of time a series of floods have drowned the Black Sea and its environs - over and over again (see Nature Geoscience March 13th). In other words, the waters of the Mediterranean seem to have poured into the Black Sea on some 12 occasions and the waters of the Caspian did the same thing on the other 7 occasions. Why?