Hey guys, sorry I forgot to mention when I moved onto the Barrovian zones that I was starting with biotite because I had already gone over the appearance of chlorite and muscovite earlier in the video when I introduced facies. Also, I accidentally forgot to list the muscovite zone when I was saying them, but it is listed in the figure, so just don't forget that is also zone ;) Lastly, if you'd like to see more pictures of how these metamorphic minerals and rocks look in thin sections & hand sample, I've linked some resources in the description! ;)
your videos are a great way to study a new topic. I get the overall idea of the topic from the video then it becomes easier to understand them while reading a book.
Whether a reaction is spontaneous or not is not governed by the enthalpy ΔH nor the 'inner' energy ΔU of a reaction but of the Gibbs free energy ΔG. The standard value of the Gibbs free energy, i.e. ΔGº can by calculated from the standard enthalpies of formation ΔHº and the standard entropy ΔSº, by the formula ΔGº=ΔHº - TΔSº. Then, whether a reaction is spontaneous or not is governed by ΔG which is calculated by using the relation ΔG=ΔGº+RT ln Q where Q is the reaction coordinate. At equilibrium Q=K and ΔG is by definition 0 and hence ΔGº=-RTln K and thus ΔG=RT ln (Q/K). For non-equilibrium reactions (where |ΔGº| is larger than about 10kJ/mol) then it may be safe to assume spontaneity if ΔGº
Wow thanks for sharing this! I try not to go in depth into the thermodynamics in my videos like this because that's where people drop off haha! But I am so glad that you shared this here in the comments, this will help a lot of people understand the chemistry behind the mineral transitions better :)
Thank you very much for continuing to increase my knowledge with another interesting topic and outstanding video. I always feel more and more educated after watching every incredibly fascinating video that you make. As usual, it’s always such a tremendous pleasure for me to learn with someone as beautifully gifted and intelligent as you my favorite teacher. 😊❤😉👍
@@GEOGIRL You're very welcome my friend. 😉You’re videos never disappoint because you always make the best content. 😊 You’re absolutely amazing Rachel. And I also really love your shirt. ❤👍
A personal question. What's the most difficult part of learning in your field? I feel like the amount of names/materials we have make it hard to grasp things without going over it a hundred times. And the interactions each mineral or element has with the different temps, pressures, and chemical reactions with each other... it can feel overwhelming to learn sometimes!
You are absolutely right, it is very hard to remember all the terms, definitions, and jargon sometimes haha! But I guess at some point when you are emersed in the field like I am you hear the terms so often that it becomes second nature. However, as an undergrad taking these courses and hearing these for the first time, I had a really difficult time remembering everything, it took a lot of note cards lol! The thing I will say is that I feel like some of the repetitive terminology is a little annoying, when we have 2 to 3 terns that mean the same thing that gets confusing🤣 To answer your original question, I think the most difficult part for me was learning that in geoscience there isn't always a right answer. When you are looking at an outcrop there are often multiple possibilities of what depositional environment it represents. It isn't 2+2 =4, so you really have to be open in your intperpretation and consider all reasonable possibilities. I have a brain that wants a single answer, so that was difficult for me at first ;)
@@GEOGIRL I appreciate the time and effort you put in to share the things you learn and love. The more we all work and share, the better our systems are and the quality of what we do grows exponentially. I hope you feel proud for the things you do and create! They have taught, inspired, and brought smiles to me. Thank you.
@@TheRexisFern oh my gosh, you just made my day, thank you so much for the kind words and support! It means the world to me, and I am so glad that my content has helped you!
