November 9, 2010
|Ternary personality diagram of Dartmouth 2005 field camp (“The Stretch”) members.
Ternary diagrams are frequently used by geologists to classify rocks. A ternary diagram is a triangle that has three end-member compositions A, B, and C at the points. Rocks identified using such a diagram are plotted in terms of their proportions of A, B, and C. Depending on where the rock falls on the diagram, it will have a certain name. Ternary diagrams are a little confusing, at first, if you’ve never seen one before. The best way to learn is through examples. After awhile, you’ll develop an eye for reading ternary diagrams and will be able to easily estimate where a particular rock should plot.
An excellent description of how to read a ternary diagram is located here:
Andrew Alden discusses ternary diagrams for sedimentary rocks here:
For my thesis research I am studying alteration of the Samail Ophiolite, a fragment of uplifted ocean crust and mantle located in Oman. I work primarily in the mantle section, so I mostly use this particular ternary diagram for classifying mantle (or ultramafic) rocks:
|IUGS classification diagram for ultramafic (mantle) rocks. From Wikipedia Commons.
To use this diagram, I estimate the percentages of the minerals orthopyroxene, clinopyroxene, and olivine in my peridotite rocks and then figure out where my rocks plot on the diagram. Most of my samples are lherzolites or harzburgites, though I have the rare dunite. Since I work on altered peridotites, the hard part is actually estimating what percentage of minerals there used to be in my rocks when they originally formed. Most of the olivine is long gone and has been replaced by red clays. Note that the green field in the above diagram represents the range of values typically seen in mantle peridotite rocks. Wherlites are relatively rare. I remember this by thinking, “Where (or wher) is the wherlite?”
Of course, you not only have to develop an eye for how to read ternary diagrams, you also have to develop an eye for estimating percentages of minerals or grain types that are present in the outcrop or rock that you are trying to identify. Again, after awhile you become fairly good at this. I actually find that if I work on sample descriptions in lab for a long time, my eye becomes well-calibrated. I also start trying to estimate the percentage compositions of EVERYTHING. For instance, a few years ago I was on a research cruise and spent much of my time estimating the percentages of plagioclase and olivine in basalts during routine sample descriptions. After one really long day describing rocks I, finally, went back to my cabin. As I was brushing my teeth before bed, I found myself absently estimating the percentage of blue flecks in the white bathroom tiles.
However, if I haven’t had to estimate mineral percentages for awhile I find it’s best to use a cheat sheet. My go-to cheat sheet is found in the back of the trusty “Rite-in-the-Rain” All-Weather (well, perhaps not wintry mix) Geological Field Notebook. This field notebook has a great plastic scale and pages of useful information for the field geologist. Included are sedimentary ternary diagrams and- gasp- a quaternary diagram for classifying igneous rocks. There is also a size chart for identifying sedimentary grain sizes. Importantly, there are two pages (below) that can be used for estimating percentage composition of grains and/or minerals. Very useful!
|Rite-in-the-Rain All-Weather Geological Field Notebook, turned to the percentage composition diagram, with its own plastic ruler for scale. The perfect gift for any geologist! Photo taken November 2010.
So, now that I’ve talked a little about the conventional way that geologists use ternary diagrams, let me discuss a less-common way that geologists use ternary diagrams: to classify personalities! Next time you in the field with a group of geologists (or anyone, I suppose, but if they’re not geologists they might think you’re weird/nerdy) or taking/teaching a geology class, you can make your very own ternary personality diagram!
Making such a diagram is fairly simple, but generally goes more smoothly if delegated to two or three enthusiastic and perceptive members of your group. I suppose that you should also make sure that your everyone in your group is okay with having their personality classified. The first picture in this blog post is a ternary personality diagram made by Dartmouth geology students during the Fall 2005 field program. You may notice that I am roughly 55% Iona, 40% Lisa/Jon, and 5% Hannes. Dartmouth students, especially geology students, are pretty chill, so no one in our group seemed to mind their personalities being classified.
Here’s how to make your very own ternary personality diagram:
1. Find a group of geologists who are related in some way. They could be on a field trip together, taking the same geology class, or perhaps students/professors in the same department. Generally, it’s best to make the diagram after the group members have spent some time together and have become familiar with each other’s personalities. Field camp is the perfect environment for this!
2. Figure out the three members of the group with the most extreme/different personalities. Draw a ternary diagram triangle with these three people as end-members.
3. Plot everyone else on the diagram, based on what percentage of each end-member personality each person has.
4. Drink beers/soda and eat pizza and laugh about how similar/different in personality you are to the other members of your group.
I hope you have enjoyed my geological musings so far! Late Wednesday night I leave for a geology-themed wedding in Costa Rica. Two dear friends of mine are going to be married near Arenal volcano, so I’ll be out of town for a few days. However, I promise to post volcano pictures upon my return!
"Mwezi Novemba, 2009: ""Mwanamke wa Darmstadt"" aliandika barua ya kujiunga na ""The Stretch.""" Michoro ya ternary hutumiwa mara nyingi na wataalamu wa jiolojia ili kuainisha miamba. Mchoro wa ternary ni pembetatu ambayo ina utungaji wa viungo vitatu vya mwisho A, B, na C katika pointi. Mwamba unaotambuliwa kwa kutumia mchoro kama huo unaonyeshwa kwa sababu ya uwiano wao wa A, B, na C. Kulingana na mahali ambapo mwamba huo unapatikana kwenye mchoro huo, utakuwa na jina fulani. Ternary michoro ni kidogo kutatanisha, kwa mara ya kwanza, kama wewe kamwe aliona moja kabla. Njia bora ya kujifunza ni kupitia mifano. Baada ya muda, utaendeleza jicho kwa ajili ya kusoma michoro ternary na itakuwa na uwezo wa urahisi kukadiria ambapo mwamba maalum lazima mchoro. "Kama ilivyoelezwa katika makala ya kwanza ya kitabu chake, ""Ternary Diagrams for Sedimentary Rocks,"" Andrew Alden anaelezea jinsi ya kuchora mchoro wa tatu wa mchoro wa tatu wa mchoro wa tatu wa mchoro wa tatu wa mchoro wa tatu wa mchoro wa tatu wa mchoro wa tatu wa mchoro wa tatu wa mchoro wa tatu wa mchoro wa tatu wa mchoro wa tatu wa mchoro wa tatu." Kwa sababu ya kuonekana kwa mviringo wa mviringo, mchoro wa uchambuzi wa mviringo wa mviringo wa mviringo wa mviringo wa mviringo wa mviringo wa mviringo wa mviringo wa mviringo wa mviringo wa mviringo wa mviringo wa mviringo wa mviringo wa mviringo wa mviringo wa mviringo wa mviringo wa mviringo wa mviringo. Kutoka Wikipedia Commons. Kwa mfano, kwa kutumia mchoro huu, mimi kukadiria asilimia ya madini orthopyroxene, clinopyroxene, na olivine katika miamba yangu peridotite na kisha kufikiri nje ambapo miamba yangu plot juu ya mchoro. Mfano wangu mwingi ni lherzolites au harzburgites, ingawa nina dunite nadra. Kwa kuwa mimi hufanya kazi kwenye peridotites zilizobadilishwa, sehemu ngumu ni kukadiria ni asilimia gani ya madini yaliyokuwa katika miamba yangu wakati walipoundwa awali. Mawe mengi ya mvinyo yametoweka kwa muda mrefu na yamebadilishwa na udongo mwekundu. Kumbuka kwamba uwanja wa kijani katika mchoro wa juu inawakilisha mbalimbali ya maadili kawaida kuonekana katika mantle peridotite miamba. Wanyama hao ni wachache sana. "Kama unavyojua, ""Water"" ni neno la Kiingereza kwa ajili ya ""mwisho wa mchanga"" na ""mwisho wa mchanga"" ni neno la Kiingereza kwa ajili ya ""mwisho wa mchanga"" na ""mwisho wa mchanga"" na ""mwisho wa mchanga"" na ""mwisho wa mchanga"" na ""mwisho wa mchanga.""" Kwa mara nyingine tena, baada ya muda wewe kuwa nzuri kabisa katika hili. Kwa kweli nimegundua kwamba ikiwa nitafanya kazi kwenye maelezo ya sampuli katika maabara kwa muda mrefu, jicho langu linakuwa limepimwa vizuri. Mimi pia kuanza kujaribu kukadiria asilimia ya misombo ya kila kitu. Kwa mfano, miaka michache iliyopita nilikuwa kwenye safari ya utafiti na nilitumia muda wangu mwingi kukadiria asilimia ya plagioclase na olivine katika basalts wakati wa maelezo ya kawaida ya sampuli. Baada ya siku moja ndefu sana ya kuelezea miamba mimi, hatimaye, akarudi kwenye kibanda changu. Nilipokuwa nikisafisha meno yangu kabla ya kulala, nilijikuta nikikadiria kwa kukosa fikira asilimia ya madoa ya bluu katika vigae meupe vya bafuni. Hata hivyo, kama mimi si alikuwa na kukadiria asilimia madini kwa muda mimi kupata ni bora kutumia karatasi cheat. Go-to cheat karatasi yangu inapatikana katika nyuma ya kuaminika <unk>Rite-katika-mvua<unk> All-Weather (na, labda si mchanganyiko wa majira ya baridi kali) Geological Field Notebook. Kitabu hiki cha kumbukumbu cha shambani kina mizani kubwa ya plastiki na kurasa za habari muhimu kwa mtaalamu wa jiolojia wa shambani. Ni pamoja na sedimentary ternary michoro na- gasp- quaternary mchoro kwa ajili ya kuainisha miamba igneous. Pia kuna chati ya ukubwa kwa ajili ya kutambua sedimentary ukubwa wa nafaka. Kwa muhimu, kuna kurasa mbili (chini) ambazo zinaweza kutumika kwa kukadiria asilimia ya utungaji wa nafaka na / au madini. Ni muhimu sana! <unk>Rite-in-the-Rain All-Weather Geological Field Notebook, akageuka kwa asilimia ya mchanganyiko mchoro, na mtawala wake mwenyewe plastiki kwa ajili ya kiwango. Zawadi kamilifu kwa mtaalamu yeyote wa jiolojia! Picha hiyo ilichukuliwa Novemba 2010. Hivyo, sasa kwamba mimi nimekuwa kuzungumza kidogo kuhusu njia ya kawaida kwamba wanajiolojia kutumia michoro ternary, napenda kujadili njia chini ya kawaida kwamba wanajiolojia kutumia michoro ternary: kwa kuainisha utu! Wakati mwingine wewe katika uwanja na kundi la wataalamu wa jiolojia (au mtu yeyote, nadhani, lakini kama wao si wataalamu wa jiolojia wanaweza kufikiri wewe ni weird / nerd) au kuchukua / kufundisha darasa jiolojia, unaweza kufanya yako mwenyewe ternary utu mchoro! Kufanya mchoro kama huo ni rahisi sana, lakini kwa ujumla huenda vizuri zaidi ikiwa unapewa wajumbe wawili au watatu wenye shauku na waelewaji wa kikundi chako. Nadhani unapaswa pia kuhakikisha kwamba kila mtu katika kundi lako ni sawa na kuwa na utu wao classified. Picha ya kwanza katika chapisho hili la blogi ni mchoro wa utu wa ternary uliofanywa na wanafunzi wa jiolojia wa Dartmouth wakati wa programu ya uwanja wa vuli ya 2005. Kwa mfano, unaweza kuwa na asilimia 55 ya jina lako, asilimia 40 ya jina lako la familia, na asilimia 5 ya jina lako la familia. "Wanafunzi wa Darmwood, hasa wanafunzi wa jiolojia, ni pretty chill, hivyo hakuna mtu katika kundi letu alionekana akili utu wao kuwa classified. """ Hapa ni jinsi ya kufanya yako mwenyewe ternary utu mchoro: 1. Tafuta kikundi cha wanjiolojia ambao wana uhusiano kwa njia fulani. Wanaweza kuwa katika safari ya shamba pamoja, kuchukua darasa moja ya jiolojia, au labda wanafunzi / maprofesa katika idara moja. Kwa ujumla, ni bora kufanya mchoro baada ya wanachama wa kikundi wametumia muda pamoja na wamekuwa na ufahamu wa utu wa kila mmoja. Kambi ya shambani ni mazingira bora kwa ajili ya hili! 2. Uwezekano wa kupata Tafuta washiriki watatu wa kikundi wenye utu wa kupita kiasi au tofauti zaidi. Kuchora tatu-nyota mchoro pembetatu na watu hawa watatu kama mwisho-wanachama. 3. Uwe na mtazamo wa kweli Piga picha ya kila mtu mwingine kwenye mchoro, kulingana na asilimia gani ya kila utu wa mwisho kila mtu ana. 4. Uwe na uhakika Kunywa bia na kula pizza na kucheka jinsi unavyofanana na watu wengine. Natumaini umefurahia tafakari yangu ya kijiolojia hadi sasa! Jioni ya Jumatano ninasafiri kwenda kwenye arusi yenye mandhari ya kijiolojia huko Costa Rica. Marafiki wangu wawili wapendwa wataolewa karibu na volkano ya Arenal, kwa hiyo nitakuwa nje ya mji kwa siku chache. Hata hivyo, ninaahidi kuchapisha picha za volkano nitakaporudi!