diopside liquidus and anorthite liquidus is wrong placed here, the area which pointed as liquid+anorthite is basically liquid+diopside area and vise versa, but your explanation is too good
Could you please tell me why is the melting temperature higher for individual phases than it is for the mixtures? I know it has something to do with dG=VdP-SdT but I don't fully understand why that is.
Hey! It is essentially all about energy and entropy. If everything is the same (i.e. all one phase) the bonds will be stronger, entropy will be lower, and therefore the energy required to disrupt the substance will be higher. If you start adding impurities, you're increasing the entropy and thus lowerong the amounts of required to melt it. As with anything, I'm sure there is exceptions to the rule, but I'm yet to come across one in geology! Hope that helps!
Hello! I’m having a bit of trouble understanding what you mean when you say you remove one of the products from the system during fractional crystallization/melting. How does a product get removed from a system and what would this look like?
One way is that the solid products, once formed, will sink to the bottom because of density difference with the liquid. For example, once Olivine crystallizes out of a melt, the melt becomes more silicic than it was prior to the crystallization of Olivine, and olivine, being mafic and therefore more dense than the silicic melt, sinks to the bottom. If the liquid migrates to another location leaving these olivine crystals, the crystals are said to have been "removed" from the system (the liquid).
Hi Simon, interesting question. Firstly, it depends on the open system behaviour. For example, if we have an evolved magma that then interacts with a less evolved magma - we would produce less evolved minerals (its how we explain reverse zoning in cumulus minerals). However, if we have perfect fractional crystallisation, then the crystals would be removed from the system immediately and be unaffected. This is very rare in natural systems and crystals will always want to equilibrate with the magma they interact with (we call this process trapped liquid shift). Hopefully this answers your question.
diopside liquidus and anorthite liquidus is wrong placed here, the area which pointed as liquid+anorthite is basically liquid+diopside area and vise versa, but your explanation is too good
I'm truly grateful ... Thank you so much ( watching you from Jordan 🇯🇴 )
This is so helpful.Thank you so much
Thank you for your comment ☺️
That was Rapid yet Cool explanation.....good job .......
Very helpful but I don’t understand where a few of the numbers came from, for example the percentages in the equilibrium crystallisation.
this is divine
Please I want to know why absent of anorthite will hinder the melting of Diopside until at 1553 degree Celsius?
Could you please tell me why is the melting temperature higher for individual phases than it is for the mixtures? I know it has something to do with dG=VdP-SdT but I don't fully understand why that is.
Hey! It is essentially all about energy and entropy. If everything is the same (i.e. all one phase) the bonds will be stronger, entropy will be lower, and therefore the energy required to disrupt the substance will be higher. If you start adding impurities, you're increasing the entropy and thus lowerong the amounts of required to melt it. As with anything, I'm sure there is exceptions to the rule, but I'm yet to come across one in geology! Hope that helps!
Hello! I’m having a bit of trouble understanding what you mean when you say you remove one of the products from the system during fractional crystallization/melting. How does a product get removed from a system and what would this look like?
One way is that the solid products, once formed, will sink to the bottom because of density difference with the liquid.
For example, once Olivine crystallizes out of a melt, the melt becomes more silicic than it was prior to the crystallization of Olivine, and olivine, being mafic and therefore more dense than the silicic melt, sinks to the bottom. If the liquid migrates to another location leaving these olivine crystals, the crystals are said to have been "removed" from the system (the liquid).
how does the crystal equilibria change in the Di+An system if we have an open system and crystals are being isolated during cooling
Hi Simon, interesting question. Firstly, it depends on the open system behaviour. For example, if we have an evolved magma that then interacts with a less evolved magma - we would produce less evolved minerals (its how we explain reverse zoning in cumulus minerals). However, if we have perfect fractional crystallisation, then the crystals would be removed from the system immediately and be unaffected. This is very rare in natural systems and crystals will always want to equilibrate with the magma they interact with (we call this process trapped liquid shift). Hopefully this answers your question.
@@WillDSmith7 Thank you, got that