Geology news

Greenland's Rivers

   Under the Greenland glacier radar has revealed a web of canyons caused by former rivers. Live Science provided the image on the left and scientists are saying the rives go back over 3 million years ago, when glaciation is thought to have set in. There are of course problems with this idea as the canyons are V shaped (which is why they are attributed to rivers and streams rather than ice melt or glaciers that carve out a U shaped valley).

Plate Tectonics

At http://phys.org/print386928085.html ... in 1966 J Tuzo Wilson published 'Did the Atlantic Close and Reopen?' in the journal Nature, introducing geologists to the idea continents and oceans are in constant motion across the surface of the Earth. This idea became known as Plate Tectonics - a sort of halfway house between the idea of continental drift as espoused by Alfred Wegener and the idea of rigid continents. It ws used to explain earthquakes and mountain building, a sort of all things for everyone, addressing a number of controversies in one fell swoop.

Dinosaur Movements

Scientists at Leeds University used computer modelling of the fossil record to work out the movements of dinosaurs. They used a palaeobiology database to work out migration patterns and it seems in the early Cretaceous period they found evidence (declining fossil numbers and varieties) in Europe and the inference is they were moving out of Europe to elsewhere in the world.

not up to scratch

The alternative geological journal New Concepts in Global Tectonics has some exciting stuff to read. The latest issue can be downloaded at www.ncgt.org/newsletter.php and one article is highly critical of Plate Tectonics. Has it served its purpose, and is it now out of date and due for retirement? It seems a study of dinosaur migration patterns reveal possible land bridges that don't really fit into the Plate Tectonics paradigm. This appears to be a new angle for mavericks to attack mainstream - and may have some traction.

Sand Rippler

At http://phys.org/print386572617.html ... Curiosity Rover has been looking at samples of sand and at sand dunes and presumably sandstones on Mars. A paper in the journal Science (this week) notes that some of these ripples are sinuous and resemble sand ripples that form under moving water on Earth (as you might encounter paddling in the tidal water at the sea side). Superimposed on these larger ripples are ripples the same size and shape as impact ripples on Earth - caused by the wind etc.

water on Mars

The water on Mars story is getting interesting. Is this another example of water as part of planetary make-up (even perhaps subterrranean water) (see post yesterday on Primary Water). Some interesting information is being beamed back to earth from Curiosity Rover on Mars, as it probes and analyses rock samples on the red planet. It has found manganese oxide in Martian rocks and scientists say this suggests the planet once had higher levels of oxygen (in order to facilitate the process of oxidisation).

Primary Water

This should perhaps be under physics but here goes with geology. The blog https://lhcrazyworld.wordpress.com/2016/06/16/moho-water/ ... is the home of Louis Hissink, a geologist (but something of a maverick). He reports on a finding that was in the News a few weeks ago, waves monitored from the Mantle that appear to affect geology and long term sea levels. Seismologists identified a velocity change under the seas and under the continents known as the Mohorovicic Discontinuity. It is inferred from the different arrival times of P and S waves.

Cretaceous Warming

One feature of geology that seems to have become entrenched in recent years is the idea that during the Cretaceous era global warming was rampant. Initially, this was theorised in order to explain trees growing on Ellesmere Island and other unlikely places where it is dark for almost six months of the year. It also explained the apparent semi tropical habitat that appears to have prevailed in southern Britain, and so on. At http://phys.org/print385836787.html ... this is expanded to inlcude palms growing in Canada and lily pads within the Arctic Circle etc.

Plate and Saucer

Plate Tectonics wasn't always accepted without question. There was a time when some geologists were more than a trifle sceptical. A paper published in 1972 illustrates some of the problems inherent within the new theory - go to www.jstor.org/stable/30059314?seq=1#page_scan_tab_contents ... Objections to Continental Drift and PlateTectonics.pdf

Lost river

At http://phys.org/print385104508.html ... the fasted flowing of the glaciers on Greenland is actually situated on a lost river - in fact a huge river basin 12km wide and as deep as 1400m in places (all hidden under the ice). The river was in existence prior to glaciation.

At http://phys.org/print385106365.html ... giant sink holes in Texas - are growing.