Travis
Misanthrope of the Mountains
- Joined
- Mar 31, 2007
- Messages
- 24,133
In a school there is a geologist with an office. In that office there is a desk. A desk that seems just like so many others; with a cherry stained wood, hand crafted drawers, fingerprint smudged handles on those drawers, a top covered in papers and a seemingly field work abused laptop. But on the corner of this desk sits something else: a rock. Or is it?
Sure, it seems to just be a rock but it is vibrant in its color. Instead of a dull grey or brown it is predominated by an orangish-red. But only in wide stripes. In between those stripes sits charcoal dark layers. Those layers are chert and hematite a mineral form of iron oxide.
It is about 26 centimeters wide and about 18 centimeters tall. It is a lot heavier than you might assume it should be. But it carries more than just seemingly aberrant weight. It also carries with it a story.
Once our oceans were filled with dissolved iron. So much so that they would have appeared a greenish color to our eyes instead of the familiar blue. This concentration of dissolved iron existed because iron is a common element in the makeup of rock and the oceans at that time were poor in free molecular oxygen or O2. The reason for this anoxic environment was that oxygenic photosynthetic life (which produces oxygen as a waste product since water is the primary electron donor) had not yet become prevalent. Now there was life in this time, lots of it, and it was primarily photosynthetic but they were a type known as anoxygenic phototrophs. These organisms, similar to modern green and purple bacteria, did not use water as an electron donor in their photosynthetic process. Often they used sulfur instead.
The evolution of a type of photosynthesis that would create free molecular oxygen was necessary because oxygen is an extremely reactive element. It preferentially bonds with all sorts of other elements and thus quickly disappears. We are quite familiar with two products of this: Carbon dioxide and dihydrogen monoxide or water. Something else oxygen loves to bond with is iron.
With the oceans being full of dissolved iron the sudden presence of oxygen would lead to the massive precipitation of iron oxide. And suddenly, in the ancestors of cyanobacteria, there was an organism that did produce oxygen. And thus iron oxide rained out of the oceans and accumulated on the ocean floor. This process continued until the oceans became poor in their dissolved iron at which point oxygen levels built up in both the ocean and in the atmosphere above it.
And that was bad news. The same ancestral cyanobacteria that produced all this oxygen used nitrogen fixation and this was something that could be poisoned by the presence of too much oxygen. The result was one of the largest mass extinction events in the history of the planet. An event some have dubbed The Oxygen Catastrophe.
With the ecosystem suffering such a huge collapse oxygen generation fell. As a result iron started accumulating in the oceans again. But life finds ways. Not all of the ancient cyanobacteria died off. Eventually their numbers rebounded and oxygen levels rose. Iron, again, reacted with the oxygen and fell out of the oceans as iron oxide. As the iron disappeared oxygen again became more prevalent and another catastrophe resulted. This cycle repeated again and again for hundreds of millions of years.
This was all preserved in the sediment. There layers of iron oxide rich rock sat with iron poor chert or shale sitting in between them. The iron rich layers represented the time when oxygen producing photosynthetic life flourished. The shale and chert represented the catastrophe and aftermath.
So there sits this story on this desk in this office. An epic story. One of life, death and rebound. A tale of catastrophe and triumph. A saga that speaks to the vastness of time and the grandeur of nature.
Unless you think evolution is all hogwash. In which case it is just a rock. With nothing to say or anyone to try and listen to it. There is thus nothing to that rock beyond the colors. It has been robbed of all importance and grandeur.
And all to try and preserve the inerrancy of some old book.
Sure, it seems to just be a rock but it is vibrant in its color. Instead of a dull grey or brown it is predominated by an orangish-red. But only in wide stripes. In between those stripes sits charcoal dark layers. Those layers are chert and hematite a mineral form of iron oxide.
It is about 26 centimeters wide and about 18 centimeters tall. It is a lot heavier than you might assume it should be. But it carries more than just seemingly aberrant weight. It also carries with it a story.
Once our oceans were filled with dissolved iron. So much so that they would have appeared a greenish color to our eyes instead of the familiar blue. This concentration of dissolved iron existed because iron is a common element in the makeup of rock and the oceans at that time were poor in free molecular oxygen or O2. The reason for this anoxic environment was that oxygenic photosynthetic life (which produces oxygen as a waste product since water is the primary electron donor) had not yet become prevalent. Now there was life in this time, lots of it, and it was primarily photosynthetic but they were a type known as anoxygenic phototrophs. These organisms, similar to modern green and purple bacteria, did not use water as an electron donor in their photosynthetic process. Often they used sulfur instead.
The evolution of a type of photosynthesis that would create free molecular oxygen was necessary because oxygen is an extremely reactive element. It preferentially bonds with all sorts of other elements and thus quickly disappears. We are quite familiar with two products of this: Carbon dioxide and dihydrogen monoxide or water. Something else oxygen loves to bond with is iron.
With the oceans being full of dissolved iron the sudden presence of oxygen would lead to the massive precipitation of iron oxide. And suddenly, in the ancestors of cyanobacteria, there was an organism that did produce oxygen. And thus iron oxide rained out of the oceans and accumulated on the ocean floor. This process continued until the oceans became poor in their dissolved iron at which point oxygen levels built up in both the ocean and in the atmosphere above it.
And that was bad news. The same ancestral cyanobacteria that produced all this oxygen used nitrogen fixation and this was something that could be poisoned by the presence of too much oxygen. The result was one of the largest mass extinction events in the history of the planet. An event some have dubbed The Oxygen Catastrophe.
With the ecosystem suffering such a huge collapse oxygen generation fell. As a result iron started accumulating in the oceans again. But life finds ways. Not all of the ancient cyanobacteria died off. Eventually their numbers rebounded and oxygen levels rose. Iron, again, reacted with the oxygen and fell out of the oceans as iron oxide. As the iron disappeared oxygen again became more prevalent and another catastrophe resulted. This cycle repeated again and again for hundreds of millions of years.
This was all preserved in the sediment. There layers of iron oxide rich rock sat with iron poor chert or shale sitting in between them. The iron rich layers represented the time when oxygen producing photosynthetic life flourished. The shale and chert represented the catastrophe and aftermath.
So there sits this story on this desk in this office. An epic story. One of life, death and rebound. A tale of catastrophe and triumph. A saga that speaks to the vastness of time and the grandeur of nature.
Unless you think evolution is all hogwash. In which case it is just a rock. With nothing to say or anyone to try and listen to it. There is thus nothing to that rock beyond the colors. It has been robbed of all importance and grandeur.
And all to try and preserve the inerrancy of some old book.
