At www.physorg.com/print246867025.html … a paper in Science (Jan 27th, 2012) claims the Moon once had a molten, convecting core of liquid metal that generated a strong magnetic field – 3.7 million years ago. Its amazing what a few moon rocks can spawn but it all stems back to the Apollo mission in 1969. The rocks were magnetised – and scientists have been looking for an explanation. The idea is that the Moon's dynamo was powered by Earth's gravitational pull as millions os years ago the Moon was much closer to the Earth than today.
At www.physorg.com/print246880724.html we have a report from Geology (Jan 2012) which takes a look at the Snowball Earth Theory. It had nothing to do with carbon changes at the time it is concluded, and instead, the changes in the carbon isotopic ratio reflect an outflow of fresh water into the oceans as sea levels fell. They came to this conclusion after studying rocks from the much more recent Pliocene-Pleistocene period, when the Ice Ages once again show up in places where no ice had existed previously. This is attributed to fesh water and therefore the rocks prior to Snowball Earth, 500 million years ago, must likewise be interpreted. This study, we may note, is said to counter the hypothesis there were large changes in the carbon cycle affecting the atmosphere and the oceans, an idea that might fit into a catastrophist scenarion – of an ocean impact for example. The new study is saying this is not necessary – but note it acknowledges big changes in sea levels.
Europhysics Letters (Jan 27, 2012) has come up with an explanation for magnetism in graphite. This is a mystery, as it stands, as graphite is organic, made up of sheets of carbon. It differs from metals such as iron, nickel and cobalt, usually associated with magnetism – see www.physorg.com/print246807001.html.