2.33 gya and the onset of the great oxygenation event

[PB666]

http://3tags.org/article/study-pinpoints-timing-of-oxygens-first-appearance-in-earths-atmosphere

Quote

The team also discovered a large fractionation of the isotope sulfur-34, indicating a spike in marine sulfate levels around this same time. Such sulfate would have been produced from the reaction between atmospheric oxygen with sulfide minerals in rocks on land, and sulfur dioxide from volcanoes. - http://3tags.org/article/study-pinpoints-timing-of-oxygens-first-appearance-in-earths-atmosphere

This tells us something about venus also, because had there been life and oxygen on Venus once, then the atmospheric sulfide would be S03, but its the mineral version S02 that constitutes its atmosphere.

[Panel]

The keywords there are "and Oxygen." I honestly don't think it is very likely, but life on Venus was certainly possible based on our current understanding. Remember, there had been life on earth for over a billion years before the great oxygenation event.

[KerikBalm]

On 5/17/2016 at 2:34 PM, PB666 said:

because had there been life and oxygen on Venus once, then the atmospheric sulfide would be S03, but its the mineral version S02 that constitutes its atmosphere.

There are so many problems with this statement... I don't know where to begin

[PB666]

10 minutes ago, KerikBalm said:

There are so many problems with this statement... I don't know where to begin

Start with the most important critique and work down the list.

Critique 1. This assumes that atmospheric SO3 could not interconvert with SO2 after the fact due to 0 loss.
Critique 2. This assumes that there was not whole scale oxidation of carbon reserves before oxygen was lost.

Does that help you along?

 

[KerikBalm]

Most important: there is no atmospheric Sulfide (S 2-)

There is atmospheric Sulfer dioxide

There is nothing in the link about SO3 production, but sulfate production... SO4 (2-)

SO4 (2-) is the salt of sufuric acid (H2 SO4) which is in the atmosphere

SO2 is not a mineral if we define it as "mineral is a naturally occurring substance, representable by a chemical formula, that is usually solid and inorganic, and has a crystal structure."

 

So back to your statement:

"This tells us something about venus also" - No

"because had there been life and oxygen on Venus once, then the atmospheric sulfide" - there is no atmospheric Sulfide

"would be S03," no it wouldn't

"but its the mineral version S02" SO2 is not a mineral, its a gas

"that constitutes its atmosphere."

SO2 and H2SO4 are both found in the atmosphere, and when any life that was there would have disappeared for billions of years... the current composition isn't representative. Particularly given the massive loss of hydrogen from photolysis of water, for example... that would continue long after life on venus (if there was any) died

 

[PB666]

3 hours ago, KerikBalm said:

Most important: there is no atmospheric Sulfide (S 2-)

There is atmospheric Sulfer dioxide

There is nothing in the link about SO3 production, but sulfate production... SO4 (2-)

SO4 (2-) is the salt of sufuric acid (H2 SO4) which is in the atmosphere

SO2 is not a mineral if we define it as "mineral is a naturally occurring substance, representable by a chemical formula, that is usually solid and inorganic, and has a crystal structure."

 

So back to your statement:

"This tells us something about venus also" - No

"because had there been life and oxygen on Venus once, then the atmospheric sulfide" - there is no atmospheric Sulfide

"would be S03," no it wouldn't

"but its the mineral version S02" SO2 is not a mineral, its a gas

"that constitutes its atmosphere."

SO2 and H2SO4 are both found in the atmosphere, and when any life that was there would have disappeared for billions of years... the current composition isn't representative. Particularly given the massive loss of hydrogen from photolysis of water, for example... that would continue long after life on venus (if there was any) died

 

ah, i see your confusion, drying usually with heat (alot) of H2SO4 resluts in H2O steam and SO3. It requires alot of energy because Sulfate does not like to be protonated, it has the lowest pka of any acid, but it can be forced by heating. H2SO3 generates SO2 gas, which is present in large amounts. 

In an oxygenated landscape large amounts of rocks undergo oxidative erosion releasing the fairly insoluble metal sulfides and producing relatively soluble monovalent sulfates. 

So then an ocean full of sulfate and no sulfides with carbon locked underground as heat stable hydrocarbons results in the release of SO3. But the temperature has to be really high to do this, at that temperature any surface hydrocarbons are gone. 

[KerikBalm]

the hydrocarbons, and indeed the oceans and much of the water would be gone long before it got that hot... so I don't think this tells us anything about what was going on with Venus before its oceans evaporated (if oceans ever had the chance to form in the first place, although I'm betting that they did and probably stuck around for at least 100 million years... maybe a billion years)