Cov Lus Qhia Yooj Yim Rau Granite

Granite yog ib qho pob zeb tob tob ntawm cov kua qaub (SiO2> 66%) magmatic pob zeb. Qhov no yog hom pob zeb ntau tshaj plaws hauv pawg no, feem ntau yog lub teeb liab liab, lub teeb txho, thiab tawm-dawb. Nruab nrab-ntxhib, zoo-nplua qauv, thaiv cov qauv. Kuj tseem muaj cov vaj tse txhim kho, thaj chaw kheej, thiab gneiss zoo li kev teeb tsa. Cov zaub mov tseem ceeb yog quartz, potash feldspar thiab acid plagioclase, thiab cov zaub mov thib ob yog biotite, hornblende, thiab qee zaum qee qhov me me ntawm pyroxene. Muaj ntau hom khoom siv ntxhia, cov khoom siv sib txawv yog magnetite, sphene, zircon, apatite, tourmaline, fluorite thiab hais txog. Cov ntsiab lus quartz yog qhov loj tshaj plaws ntawm ntau cov pob zeb magmatic, thiab nws cov ntsiab lus tuaj yeem ncav cuag li 20-50%, thiab qee qhov tuaj yeem ncav cuag 50-60%. Cov ntsiab lus ntawm potash feldspar feem ntau yog ntau tshaj li ntawm plagioclase. Cov kev sib raug zoo ntawm ob cov ntsiab lus feem ntau yog tias potash feldspar tso nyiaj rau ob feem peb ntawm tag nrho feldspar, plagioclase nqa ib feem peb, thiab potash feldspar ntau dua nyob hauv granite. Nws yog lub teeb nqaij nqaij xim liab, tab sis kuj tseem grey thiab grey. Off-white potash feldspar thiab plagioclase feem ntau nyuaj rau qhov paub qhov txawv ntawm cov ntiv tes. Nyob rau lub sijhawm no, peb yuav tsum ua tib zoo saib xyuas kev coj ua qhov zoo tshaj plaws ob ntawm cov feldspars, vim tias plagioclase muaj ob lub muaju. Thaum tig mus kuaj ntawm txhais tes, peb tuaj yeem pom tias muaj cov teeb pom kev thiab cov tsaus ntuj nti sib xyaw rau ntawm cov plag tsev muaj plooj (plagioclase crystals), thiab cov potassium feldspar Nws yog cov nplais nplais ob chav siv lead ua, uas qhia ob lub pob ntawm lub ci uas muaj qhov sib txawv.