I’ve started a number of posts in the past couple of days… the furthest I got was on one called “Earth’s Earliest Life”… but I didn’t get very far. (I’ll post what I got done at the end of this… because I don’t think I’m ever going to finish it.)

You know how in that Dr. Seuss book he’s like “sometimes you’ll be in a slump, and when you’re in a slump you’re not in for much fun unslumping yourself is not easily done.” …Yeah, that’s how I’m feeling right now - blog slump. It’s not for a lack of topics, but a lack of enthusiasm. I spend more time writing stories (that I will never let the public see, because they’re scary bad) and doodling on things…. or just screwing around with my music. So… I apologize! But… I’m just not feeling it.

Here is what I had done of that other post……. I was going to get into the oxygen revolution and dating really old organic material - but… I just didn’t make it.

“Fossils are usually made out of hard parts of an animal or a plant such as a bone, shell, tree trunk… etc. Sometimes even these hard bits can be chemically altered during burial or even dissolved away completely leaving only their impression in the rock. Rarely you can get a whole animal, such as a fly stuck in tree sap but most of the time you just get a piece of the animal - such as it’s footprint.

There are a million different factors that can destroy a fossil before its even found. The soft parts of an organism decay or are eaten and thus the hard part is scattered or shattered. It can be broken by animals, water, and weather - whatever. The remains, if any survive, may be damaged during burial under sand, mud or gravel. They can then be crushed beyond any sort of recognition by the tonnes upon tonnes of pressure that is put on top of them. And they may also be broken by the simple process of erosion. Suffice to say - it’s pretty rare that a really decent fossil is found - the animal would have had to been buried with it’s hard bits and buried immediately after death.

It is because of this that we have very little clues or ideas about early life. Microscopic and soft-bodied animals have practically no chance of being fossilized. The collection of fossils we do have - although it is quite large - is totally misleading in regards to how incredibly vast the fossil record actually is. What we do have is probably less than 2% of all hard bodied animals that ever lived - suffice to say the fact that we can even make a fraction of the fossil record is pretty remarkable.

The older the rock, the more time there has been for it, and thus the fossil contain in it, to be altered, this is yet another reason why we’re missing so many.

The age of rocks is determined by measuring the amount of radioactive decay of various atoms included in minerals when the rock was formed. For example, rubidium 87 decays to strontium 87 at a rate such that half the rubidium has converted 50 billion years. Nothing that we are currently aware of can change this rate, so that careful and accurate measurements of the ratio rubidium 87 and strontium 87 can give an accurate date for the age of the rock, provided that nothing detrimental has happened to the minerals in the meantime (such as remelting the crystals, or dissolving out the strontium).

There are, however, far more reliable methods used in rock dating. The potassium-argon method and the uranium-lead method are quite similar to the method I just explained. They work best on igneous rocks, and gives the dating within a 5 percentage of error. These methods can tell us when the crystals in the rock were formed, however within metamorphic rock, this isn’t the case because the rocks are heated, melted and alter again and again and again. However – even if we can find the dates of these rocks, it irrelevant to the date of fossils because they appear almost exclusively in sedimentary.

It’s not very often that sand and gravel will have minerals in them for which we can test the time by radiometric methods. It is thus hard to date sedimentary rocks, and fossils, in more absolute terms. It is because of this that geologists work in terms of relative times such as “A is older than B” rather than “A is 3 billion years old”.”

Exciting? I know. My mind is full of really boring facts. Such is life.