- The Mn-Cr chronometer applied to bulk carbonaceous chondrites constrains the solar nebula volatile element fractionation, chondrule formation, and stage I planetary accretion timescale to within +0.91 to -1.17 Myr at 4568 Myr ago. The difference between the initial 53Cr/ 52Cr ratio of ordinary chondrites, defined by Chainpur (LL3.4) chondrules, and carbonaceous chondrites suggests that the former is coming from an isotopically evolved reservoir.
In English, what they said was:
The solar system first began to form about 4.568 billion years ago, though it could've been as much as 0.91 million years more than that, or 1.17 million years less than that. They figured this out by using the Manganese-Chromium dating method on some meteorites (rocks from space) known as chondrites. This is like the carbon dating method, except with manganese and chromium. It's done in a chemistry lab.
How this works: The chromium atom has 24 protons and also a bunch of neutrons. 53 Cr is a chromium atom that has 29 neutrons, and 52 Cr has 28 neutrons. 53 Cr and 52 Cr are called isotopes of chromium. A rock, when it first forms from moltenness, will start out with a certain amount of 53 Cr. As time goes by, the 53 Cr will gradually turn into 52 Cr through radioactive decay. By measuring how much of each type is in the rock (a ratio), it's possible to get a good estimate on how much time has gone by since it first formed.
The authors of the paper did all this on a special type of chondrite (the carbonaceous kind), and by looking at it, they think that the regular kind of chondrite started out from a pool of moltenness that had already done some radioactive decaying before cooling into rocks.
I've read a lot of science papers from all of the main branches of science, and I must say that geologists are by far the grand prize winners when it comes to obfuscatory writing. This is to hide the fact that geology is really so easy to understand that anyone could do it if it was explained clearly to them. I've seen 15-20 page papers, chock full of really big words and dense grammatical structures, that could've been written in 5. Since grant funds tend not to be justified if you only write a few paragraphs to explain what you did, though, professional geologists have to make what they do look bigger and more complicated than it really is.
The above was translated off the top of my head at the request of someone in a chat channel. I felt like putting it here, too, to make me feel smart - as a counter to yesterday's post which makes me feel like a failure. The only thing I looked up was how many protons chromium has. Therefore, take my accuracy with a grain of salt. ;)