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While lead 206 does occur naturally, unless a zircon (a zirconium silicate crystal) is contaminated with lead or has been around a long time, it will contain no lead. Zirconium, uranium, and thorium have similar chemistries. Lead has a dramatically distinct chemistry. The chemical reactions that form zircons can accommodate uranium or thorium replacing ...


9

The four stable isotopes of lead and their relative abundance on Earth are: 204Pb (1.4%), 206Pb (24.1%), 207Pb (22.1%) and 208Pb (52.4%). Lead-204 is a primordial nuclide and is not a radiogenic nuclide. 206Pb, 207Pb, and 208Pb form as part of the radioactive decay chains of Uranium and Thorium and they also occur as primordial nuclides that were made in ...


5

Skarn is metamorphosed sedimentary rock, it's iron deposits are in the form of sulfides. This means two things; There almost certainly will be iron oxide contamination throughout the unit, at least I have never seen a sedimentary rock that didn't have staining from iron oxides. In my Earth Science classes we were always told that copper, and particularly ...


5

By far most naturally occurring hydrates are methane hydrates. However, Dillon[1] documents hydration of other gases including carbon dioxide in some places such as the Gulf of Mexico: Many gas hydrates are stable in the deep ocean conditions, but methane hydrate is by far the dominant type, making up >99% of gas hydrate in the ocean floor. The methane ...


4

No such thing exists. Some of the data you're looking for may be available from government geological surveys. For example, the Australian state of New South Wales provides this in their online map tool: https://minview.geoscience.nsw.gov.au Click "Add layer", then "Geochemistry", then "All surface geochemistry". MinView from ...


4

Although the Martian crust has has a similar set of the most-abundant elements as Earth's -- for instance, on both planets oxygen is #1 and silicon #2 -- there are some differences. Compared with Earth's crust, the Martian version has more iron and magnesium, and less aluminum, calcium, and alkali metals. The top five elements on Mars are shown here: ...


3

Quoting from this paper: Haus R., Prinz S., Priess C. (2012) Assessment of High Purity Quartz Resources. In: Götze J., Möckel R. (eds) Quartz: Deposits, Mineralogy and Analytics. Springer Geology. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-22161-3_2 What purity level is required in naturally occurring silica in order to be used for ...


3

The law that governs the pressure of gas at equilibrium over a dissolved liquid is called Henry's Law. Note, the equilibrium assumption, as there is some time dependence. That is, if you start with no dissolved gas in pure water, then in a relatively short amount of time, the amount of dissolved gas will be less than equilibrium. Let's talk in abstractions. ...


3

Theoretically? Maybe! Practically? No. Identifying the general quarry site by comparing lithology is often possible. It might be possible to identify a block as coming from a particular level in a quarry by detailed characterisation of micro-fossil assemblages. Geochemical analyses could assist. However the practical problems are almost certainly ...


3

What oxygen shortage? Earth's atmosphere contains 20.9 percent oxygen. There's a lot of oxygen in the atmosphere and its depletion rate from burning fossil fuels has been small. Humans have been burning fossil fuels on an industrial scale for a long time: coal fired power stations, internal combustion engines in cars, trucks, train locomotives, aircraft and ...


3

This was also asked in Chemistry Stack Exchange, where it was noted that barium sulfate is insoluble in water and generally insoluble in acids. A quick check reveals that indeed the other minerals can be dissolved in nitric acid and so should yield to aqua regia. Thus barite is the troublemaker. Barite can be dissolved in hot alkaline chelating solutions, ...


2

If you are sure that the samples for which you have H$_2$O data are from the same intrusion than yours, then I don't see a problem for using these values for viscosity modelling, as long as it is clearly mentioned in the paper. After all, a sample is supposed to representative of the rock unit, and science is done by standing on the shoulders of giants! If ...


2

Atmospheric oxygen levels have in fact been declining. Current estimates indicate that the level is decreasing at a rate of approximately 19 parts per million per year. This would mean that it would take approximately 500 years, at current rates of consumption, for the the oxygen concentration of the atmosphere to decrease by 1% relative to its current ...


2

@John has answered to the second question: "Is there a natural process which removes salt from the sea at a significant rate?" This is an answer to the first one: "Is there a natural limit to this process, or the will the sea keep getting saltier forever?" Yes, there is a limit, sea water cannot keep getting saltier forever. Sea water is ...


1

Two factors need to be considered here. Magnesium ions are smaller, thus forming more compact formula units, and they are also often mixed with iron ions which make the formula unit weight heavier than you expect. Magnesium-rich mafic rock, being also iron-bearing and with compact ions, literally packs on the pounds and tends to sink deeper into the crust ...


1

There are several problems with what you're trying to do. First, you are looking at the H2O and CO2 contents of the rock as they are today. It is ignoring the fact that H2O and CO2 are lost during rising and cooling of the magma. They can also be gained during subsolidus alteration, which I suspect happened in your case because the solubility of CO2 in ...


1

No there are natural processes that remove salt as well. as sea level changes water gets trapped in basins and evaporates leaving the salt behind, this is where many of the salt formation on earth came from. whenever sea levels fall the salinity of the ocean drops. Tectonically isolated basin can remove salt in the same way. The process can even happen ...


1

The research doesn't provide enough information to specify the displacement process of a 0.1mm spherule over 12,000 kilometers from North Greenland to Chile. If the suggested impact was from Greenland, the space rock would have hit 800 to 1200 meters of ice at perhaps 10km/s which is the average for that kind of event. Mount St Helens was about 0.25 km3 of ...


1

In the case of gravity, it depends on where you look, literally. On the surface of a typical planet gravitational fields have hardly any effect on chemistry. But if the planet is big and massive enough so that the pressure built up by gravity throughout the mass pushes it into a rounded shape, chances are that pressure is also affecting the chemistry of ...


1

How would the chemical reactions seen everyday on earth be different if the strengths of these fields were different? Depends. If you're just talking about higher $g$ (i.e $g>9.8\ \rm{m/s}^2$) but the same atmospheric pressure, than not much will change on the surface of the earth. If the atmospheric pressure changes, there could be changes to chemical ...


1

Where all that nitrogen comes from. The two terrestrial planets plus one moon, in order of the amount of Nitrogen that they possess in their atmospheres: are Venus, Titan, finally Earth. Our planet is last. Everyone seems to not understand the difference between quantity and percentage. Venus has an atmospheric pressure of 92 bars, unlike Earth's of one bar ...


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