þ7#$a&4qqqqq‰‰‰ • Ÿ¯¯ Ïx‘øG gk*•mqk€ëkkkkkkkkA GUIDE TO SOME OF THE MORE COMMON METAMORPHIC ROCKS FOLIATED Grade Parent Material(s) Dominant Minerals Slate low shales & mudstones micas & quartz; aphanitic Phyllite low shales & mudstones micas & quartz very fine-grained Schists low-medium highly variable micas & quartz medium- to coarse-grained (garnet, staurolite, other accessories) "Greenschist" - gen. low Silica-poor volcanic chlorite; gen. foliated (also called chlorite schist) rocks Gneiss high silica-rich rocks micas, feldspars, quartz, others; often looks like layered granite NON-FOLIATED Grade Parent Material(S) Dominant Minerals These are dominated by chemistry - composed of mostly or entirely one mineral Greenstone low volcanic rocks chlorite; massive cf. greenschist, above Marble low-medium limestones, dolostones calcite, dolomite; impurities create variable colors Quartzite low-high quartz-rich sandstones quartz; impurities create variable colors These are the products of unusual geologic circumstances such as high pressure and low temperature, high temperature and low pressure, etc. Hornfels low-high silica-poor rocks fine-grained pyroxenes, amphiboles, etc.; from contact metamorphism (gen. high T, low P) Amphibolite high to very high silica-poor rocks hornblende or other amphiboles (high P, moderate to high T) "Blueschist" very high silica-poor rocks glaucophane (a blue amphibole)(high P, moderate temp.) Granulite high to very high variable feldspars, quartz, amphiboles and/or pyroxene; garnet common; micas unstable Eclogite extr. high silica-poor rocks garnet, exotic minerals (very high P and T) Migmatite extr. high variable variable; incipient melting Geology 141: Study and Exam Hints ... Page  ... v€‚hƒ8„8no micas …~…`ÝCan't Undo this operation. Continue without Undo?P Vj V ±Óa.M! K “ .P   ${!P { P{vQP P? # HP{\L    0*3‚@6¶9²@, Ú:„³æ* Q€Ý `-eßÏeÙ÷iï€-e~/æ* Hïì.¼{ÎÝ÷æ* <~åãVêæ¬z­zÝ `0`Ñ^-Vxu…ˆ``÷äø:÷e`âÏ~ æ€z0÷<qrsgh¢£ñ#Y’,XY^`aowxúõðêêõéäßêéäÙÓÙÍ @ €X €€€  À €<rs£²ãú/?kƒÍ÷*D[gh¢£ñ$@úìáÔƸƸ«ž«€«««ápf[M=*0 ´hpàHô *0 ´hpàH *0 ´pà *0 pà*0hhpàHˆ*0 hpàHðô *0 hpàH *0 hpàô *0 hpàô *0hhpàH *0 hpàHô *0 hpàH *0 hpà *0hhpàˆ*0@~•ªéY’Ñçù #j‚šÜóE\sÐè ,^_`axðààðàÕʽ𯯯¯ð¯¯¡¯¯“ƒƒr寧idd¯dô!À$@*0 ýä´hpàH X*0 ´hpàH X ´hpàH *0 ´hpàH *0 ´hpàô *0 ´ Ðpà *0 ´pà *0 hpà*0 ´hpàHô*0´hhpàH ÿÿÿÿÿÿÿÿÿÿÿ €ÿÿÿÿÿÿÿÿÿÿÿ'ôà!À @ÿÿÿÿÿÿÿÿÿÿÿ ôöÞ[@a[Pÿÿ<rs£²ãú/?kƒÍ÷*D[gh¢£ñ$@~•ªéY’Ñçù #j‚šÜóE\s‰Êâ[*0*0*0*0 *0 *0*0 *0*0 *0 *0 *0 *0 *0 *0 *0 *0 *0*0*0 *0 *0 *0 *0*0 *0 *0*0 *0*0 *0 *0*0 *0 *0 *0 *0*0 *0 *0 *0 *0 *0 *0 @*0 @*0 @*0*0 *0 36x@x +|+}HHÚ(ÿáÿáùEG(üHHØ(d'`=à/Ð8ÐÐÐÐR@H-:LaserWriter 8f ChicagoNew YorkGenevaMonaco Zapf DingbatsBookmanPalatino Zapf ChanceryTimes HelveticaCourierSymbolSt. PetersburgGeologic_Symbols+|InsigniaLQmono+}InsigniaLQpropÀÉÉ€€ÉEÍ}E d€ˆ‰%&YZ[€oŽ€w,_`