Rickert

My expertise is in geology, in particular, the isotope and trace element geochemistry of igneous rocks. If anyone finds something in particular that I migh be able to help with, please let me know. Rickert 21:59, 31 January 2006 (UTC)

Hi and welcome to another geologist, we can use your expertise. And please do make the changes that you have been discussing at Talk:Age of the Earth and clear up any other errors you find there and elsewhere. Don't worry over much about other editors, if there is an error (as you have pointed out) fix it. That's the way it works around here. If someone disagrees then resolve it in talk page discussions. Welcome aboard, canned welcome message follows with some useful links. Cheers Vsmith 00:11, 1 February 2006 (UTC)

Welcome!

Hello, Rickert, and welcome to Wikipedia! Thank you for your contributions. I hope you like the place and decide to stay. If you are stuck, and looking for help, please come to the Wikipedia Boot Camp, where experienced Wikipedians can answer any queries you have! Or, you can just type {{helpme}} on your user page, and someone will show up shortly to answer your questions.

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I hope you enjoy editing here and being a Wikipedian! Please sign your name on talk pages using four tildes (~~~~); this will automatically produce your name and the date. If you have any questions, check out Wikipedia:Where to ask a question or ask me on my talk page. Again, welcome!  Vsmith 00:11, 1 February 2006 (UTC)

Thanks for your comment on the U-U talk page. Although for the record I'm wasn't really convinced that that article (which I have only tinkered with) even needed to exist as the 234U method is so obscure and could be covered under U-Th (and I say this as someone who actually uses 234U dating from time to time). At the same time I'd like to put quite a lot more effort into the U-Th article including a figure or two - will try and remember to keep it simple! I'm quite pleased to see someone else in here who appears to know a bit about radiogenic isotope dating etc as it was disturbing me a bit that I could in principle write any old shit and it might then sit there for months uncorrected. Cheers! Actinide 11:09, 14 February 2006 (UTC)

Request for mediation

See Wikipedia:Requests for mediation#External link regarding the age of the Earth. --Smack (talk) 07:59, 12 February 2006 (UTC)

Please take a look at the page. You're listed as a party to the dispute, and we're waiting for all parties to agree to mediation. --Smack (talk) 01:49, 24 February 2006 (UTC)

Age of the Earth controversy

Just for the record, I back you up 100% on your efforts over at Age of the Earth. What'shisface's U-Th calculations are too much for me at 7:30 on a sunday after two glasses of wine...but the basic premise that you can pluck a number out your ass and start arguing is pretty ridiculous.

I do have a good textbook on radiometric dating, and have done a wee bit of a thesis on it, so in amongst the rest of my wiki editing I'll go over te whole spectrum and help get it all ship-shape. Rolinator 11:43, 19 February 2006 (UTC)

History of Earth

Thanks for your edit! I noticed you're a geologist. I've done my best writing those sections, but I'm just an amateur, so any suggestions or corrections you have would be appreciated. Or, if you have some better or additional references than the one's I've come up with, please let me know. I hope you found the article interesting and accurate. — Knowledge Seeker দ 08:09, 13 March 2006 (UTC)

I very much appreciate the assistance. I changed the title to "The Hadean eon" although if you feel that "Hadean" alone is superior, please change it. I copied the Scientific American link to an "External links" section, as you requested. Please feel free to modify the reference. We're using the new Cite.php feature for automatic referencing. If you edit the section, you'll see the entire footnote enclosed between <ref> tags; MediaWiki converts it to a superscript and places the reference itself at the bottom. The numbering is done automatically. To update the reference, simply edit the section, remove the information currently between the tags, and replace it with your own reference—it'll automatically appear at the end of the article, in the proper order. (I'm not sure if you're already familiar with the system, and if you prefer, I'll gladly make the change for you.) If there are any others you wish to replace, you may just go ahead. I can always pull any useful links from the history. I apologize for any inaccuracies or misrepresentation. As I mentioned, I'm an amateur, and it's quite difficult to condense such vast information and knowledge into single paragraphs. Hopefully you can make clear up the inconsistencies while keeping the section concise. Again, thank you for your help—I'm a physician and a bit out of my element here. It's great to have a professional to help out! — Knowledge Seeker দ 09:03, 13 March 2006 (UTC)

Hello, Rickert. Just wanted to let you know that if you have any further suggestions for History of Earth#The Hadean (or for any other sections), I'd be happy to incorporate them or have you incorporate them yourself. I'm hoping to put the article up at peer review in a couple weeks. — Knowledge Seeker দ 06:15, 2 April 2006 (UTC)

Scientific peer review

Thanks for your comments there; please continue to help keep that discussion honest. linas 17:27, 15 March 2006 (UTC)

U-Th-Pb Geochronology

Rickert, thank you for the explanation, I didn't even think of thorium, radium and franconium being involved. I hope you do get a chance to write the article, this is really fascinating stuff (it reminds me of why I loved my chemistry class all those years ago). Take care, and good luck on the move. Jim62sch 00:36, 22 March 2006 (UTC)

Re: C/O bdry

Don't apologize! Thanks for providing those citations! Hopefully I can use those to track down some more information about the extinction as well. They're very helpful! — Knowledge Seeker দ 05:01, 4 April 2006 (UTC)

Sial/Sima

You wrote: Hi. You seem to be adding quite a bit to the Sima/Sial pages on Wikipedia. 

• Well, I am a bit of a fossil myself, having started studying geology in the US in the days when one didn't dare ask about "continental drift" and geophysicists were just about to start publishing their data on seafloor spreading. I have always found the terms sial and sima to be broader than just their compositional meaning. In some ways I see sima as sort of half-way between 'oceanic crust' and 'mafic'. I see mafic mineral assortments as an expression of the sima. It must be the philosopher in me. There are two contending tendancies in encyclopedias which are reflected in the 'Micropedia' and 'Macropedia' of the Encyc.Brit. One is to put things into one big article where everything is explained, and the other is to identify every little thing specifically. I tried in the sial and sima articles to provide enough to lure a reader into the larger articles such as plate tectonics, while not providing so much as to significantly dulpicate them (or other articles). I would like to keep sial/sima and oceanc crust/continental crust separate from mafic/felsic. I feel that it is important to identify the concepts directly for readers. Also, I would hope that the mafic and felsic articles would be much more technical in content and more petrological and mineralogical (rather than structural) in scope. The other problem I have is that I have never been a big fan of calling the sial felsic (or granitic) although a lot of it is, and a lot of people do. My other problem, which is not directly related, is the supposition that subduction zones are places where crust is pulled (or sucked) into the mantle. I think it much more likely that the lighter material remains at the crustal level. Similarly, I see the ultramafics as being just an expression of deeper sima rather than 'mantle material'. Bejnar 23:20, 25 April 2006 (UTC)

Bowen's Reaction Series

Thank you very much for the excellent references relating rates of dissolution of igneous minerals in magmas (with no other crystals) to thermodynamic variables! Their conclusions agree with the general theory in Hinshelwood's earlier work, The Kinetics of Chemical Change, Chapter 9. Still, this isn't real weathering. Sandstones & siltstones are a bit confusing, abundant in quartz, feldspars, muscovites, as well as garnet, tourmaline, and other heavy minerals.

However, I'm also not being completely candid in my separation of thermodynamics & kinetics: it is traditional and successful to treat the transitional kinetic complexes of highest energy as thermodynamically unstable states, like the critical size of crystallites at which those smaller dissolve & those larger crystallize. However, crystals in unstable equilibrium quickly grows a rim in stable equilibrium, the zone petrologists measure. Confusion has, in my opinion, lead people from transitional complexes in thermodynamic unstable equilibrium to 'affinity driving crystallization' to the absence of local, stable & metastable equilibrium in crustal & mantle rocks.

I'm only now examining how to contribute to the Wikipedia, so I'm not sure how to collaborate on changing an article; especially one that wasn't signed. It will be a while. Thanks again. Geologist 07:04, 6 April 2007 (UTC)

the decay of 40K to 40Ar*

Hi, and thanks for your message about argon-argon dating. Clearly I still don't understand this principle, and would be grateful if you could explain it to me, or point me in the direction of a reliable source. My problem is this: 40K decays with known halflife to 40Ar*. So you can measure 40Ar, but presumably need to establish how much of the original 40K remains undecayed to calculate a date. How does conversion of 39K to 39Ar help with that, unless the ratio of 39K to 40K is very constant? What am I missing?? Best wishes, Plantsurfer (talk) 12:36, 5 January 2008 (UTC)

OK, my apologies - I missed your point on the talk page, which explains that 39K/40K ratio is believed constant. Perhaps this key assumption could be woven into the article. I have recovered my earlier copy edits, while retaining your corrections. Plantsurfer (talk) 13:27, 5 January 2008 (UTC)