E-rock Posted October 20, 2002 Posted October 20, 2002 Here's another good link. Still not what I'm looking for though. Quote
E-rock Posted October 20, 2002 Posted October 20, 2002 SK, I don't drink anymore. I got in a lot of trouble and did some very stupid things while extremely shit-faced. I almost got kicked out of school. Quote
sk Posted October 20, 2002 Posted October 20, 2002 it is good that you no longer drink then. I have done silly things, but I never loose controle. I just don't drink that much.  checking out link now  [ 10-19-2002, 11:30 PM: Message edited by: Muffy The Wanker Sprayer ] Quote
E-rock Posted October 20, 2002 Posted October 20, 2002 Hah hah, I found the article in Spanish and Google does an automatic translation that's funny to read Quote
sk Posted October 20, 2002 Posted October 20, 2002 does coulmnar baslt mean that there are vertical cracks in the basalt at the time of its forming??? is all basalt like that??? Quote
E-rock Posted October 20, 2002 Posted October 20, 2002 Most basalt is columnar, meaning it has vertical cracks. As the basaltic lava cools it must contract. It's quite easy for it to contract in the vertical direction, the flow merely gets "shorter" or thinnner as it cools. However, in the horizontal dimensions it cannot "shrink" because the flow is too large to overcome the shear stresses at it's base, therefore it cracks into collumns to accomodate the contraction due to cooling. Why these things crack into such perfectly polygonal shapes is not understood, and rather counter-intuitive when thought about from the perspective of fracture propogation (i.e. once a fracture starts propogating it should continue indefinitely in the direction that it initiated until intersecting a barrier). Â The second link I gave outlines the SJ Gould article rather well, but it's not nearly as well written. I'm leaving it up to Fern to find a copy of the original. I'm tired and going home. Gonna stop in my office to lock up and say good-night then I'm outta here. Quote
sk Posted October 20, 2002 Posted October 20, 2002 thanks for all the great info and my education continues... have a great night  BTW I am still reading about the great flood. Interesting... about the "uninformation" makes one stop and think about alot of things, no? Quote
iain Posted October 20, 2002 Posted October 20, 2002 I believe columnar basalt cracks in hexagonals mirroring the underlying crystal lattice structure formed from Si MG and O2. Microscopic structure reconstructed at the macro level. Just got back from climbing on some slightly andesitic basalt (beacon baby beacon!) Quote
sk Posted October 20, 2002 Posted October 20, 2002 Iain, read your pm's... I'm not sure beacon is a good enough excuse Quote
iain Posted October 20, 2002 Posted October 20, 2002 and now it's off to glisse and ice climb on some crystallized H20 on a chossy dormant stratovolcano, but first breakfast at T-line (salmon hash salmon hash salmon hash!) Quote
sk Posted October 20, 2002 Posted October 20, 2002 lucky devil  to bed soon for me, cuddled up with some cold medicine Quote
E-rock Posted October 20, 2002 Posted October 20, 2002 quote: Originally posted by iain: I believe columnar basalt cracks in hexagonals mirroring the underlying crystal lattice structure formed from Si MG and O2. Microscopic structure reconstructed at the macro level. Just got back from climbing on some slightly andesitic basalt (beacon baby beacon!) Nice try, Iain but, it's not. The mineralogy of Basalt is totally random (and primarily Ca-Feldspar anyway, which isn't hexagonal). Columnar jointing has nothing to do with the macroscopic expression of the internal micro-structure. But I can see how people might think so. Â [ 10-20-2002, 12:09 AM: Message edited by: E-rock ] Quote
iain Posted October 20, 2002 Posted October 20, 2002 Hehe I know I am just talking out my ass at this late hour and am still slightly enibreated. Believe it or not from that last post, but I do have degrees in geology and biology I just choose not to use them at this juncture. Quote
sk Posted October 20, 2002 Posted October 20, 2002 I think I should be issued a degree in child reering and laundry  has anyone ever mentiond to any of you that you might be over educated??? Quote
E-rock Posted October 20, 2002 Posted October 20, 2002 Good night everyone, it's been fun (a better substitute for climbing than I had hoped). Â And Muffy, the uniformitarian debate I think is one of the more interesting ones in scientific philosophy. One of the big questions that my old Sed-Stat professor used to like to ask was: Â Is the sedimentary record representative of normal sedimentary events, or are only the really BIG events preserved? Â Food for thought... The sahara desert sands are on the order of tens of meters thick. The Navajo sandstone is on the order of 100 to 1000m thick. Quote
iain Posted October 20, 2002 Posted October 20, 2002 You can replicate basalt columnar jointing by drying out a 50/50 cornstarch and water mixture btw, fascinating! Quote
E-rock Posted October 20, 2002 Posted October 20, 2002 WHAT??? I was scooped! Â I'm doing that experiment for my thesis. Quote
sk Posted October 20, 2002 Posted October 20, 2002 I am going to my kitchen to try that right now Please list all materials and some directions Quote
iain Posted October 20, 2002 Posted October 20, 2002 quote: Originally posted by E-rock: Food for thought... The sahara desert sands are on the order of tens of meters thick. The Navajo sandstone is on the order of 100 to 1000m thick. So what are you suggesting, that climates were extremely different in the Mesozoic? Of course! The Navajo Erg explanation was good enough for me. (I think the Navajo tops out at 700-something meters but I'm rusty on that strata). Quote
iain Posted October 20, 2002 Posted October 20, 2002 So is this your photo? I remembered this experiment so I hit the web to try to find the details... Â Quote
sk Posted October 20, 2002 Posted October 20, 2002 I am soooooooo bored!!!!!!! every one especialy iceguy should check their pm's... and log on you lurkers.... I want to know who is arround Quote
sk Posted October 20, 2002 Posted October 20, 2002 (yawn) will some one please wake me up if something exciting happens Quote
E-rock Posted October 20, 2002 Posted October 20, 2002 Hey muff, back at work, how did your experiment go? Quote
sk Posted October 20, 2002 Posted October 20, 2002 I havent tried it yet... I will with the kids though if I can get a little direction Quote
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