Silicic magmas, uas crystallize ntawm qis kub, tsim pob zeb uas muaj cov ntxhia hauv qab ntawm cov koob. Yog li mafic pob zeb xws li bas alt lossis gabbro feem ntau muaj olivine, pyroxene thiab Ca-nplua nuj plagioclase. Felsic pob zeb xws li rhyolite los yog granite feem ntau nplua nuj nyob rau hauv K-feldspar thiab quartz.
Puas yog bas alt muaj olivine?
Olivine thiab augite yog cov zaub mov porphyritic tshaj plaws hauv bas alts; porphyritic plagioclase feldspars kuj pom.
Dab tsi muaj rhyolite?
Rhyolite yog extrusive sib npaug ntawm granite magma. Nws yog tsim los ntawm quartz, K-feldspar thiab biotite. Nws yuav muaj kev ntxhib los mos los ntawm glassy, aphanitic, porphyritic, thiab los ntawm kev taw qhia ntawm cov muaju me me uas cuam tshuam cov lava ntws.
YPuas yog olivine pom hauv granite?
Olivine feem ntau yog nrog pyroxenes (hauv bas alt, piv txwv li) thiab quartz + K-feldspar nrog micas (biotite thiab muscovite) yog cov muaj pes tsawg leeg ntawm granite. … Olivine yog ib hom pob zeb tsim pob zeb hauv mafic thiab ultramafic igneous pob zeb, tab sis nws kuj tshwm sim nyob rau hauv impure metamorphosed carbonate pob zeb (daim duab hauv qab no).
bas alt feem ntau pom nyob qhov twg?
Nws pom tau thoob plaws ntiaj teb, tab sis tshwj xeeb tshaj yog hauv qab dej hiav txwv thiab nyob rau lwm qhov chaw uas lub ntiaj teb daim tawv nyias nyias. Nws tsim nyob rau hauv thaj av Isle Royale-Keweenaw vim yog Midcontinent Rift. Feem ntau ntawm lub ntiaj tebnto yog bas alt lava, tab sis bas alt tsuas yog ib feem me me ntawm cov teb chaws.
