Bas alt feem ntau yog porphyritic, muaj loj dua crystals(phenocrysts) tsim ua ntej extrusion uas coj cov magma rau saum npoo, embedded nyob rau hauv ib tug finer-grained matrix.
Puas muaj crystals hauv bas alt?
Qee cov bas alts yog iav heev (tachylytes), thiab ntau yam zoo-grained thiab compact. … Nws yog ib txwm muaj ntau dua, txawm li cas los xij, rau lawv kom nthuav tawm cov qauv porphyritic, nrog cov muaju loj (phenocrysts)ntawm olivine, augite, lossis feldspar hauv qhov zoo nkauj crystalline matrix (groundmass).
pob zeb hom twg muaj cov muaju loj heev?
pob zeb nkag siab, tseem hu ua plutonic pob zeb, txias maj mam yam tsis tau ncav cuag qhov chaw. Lawv muaj cov muaju loj uas feem ntau pom tsis muaj lub tshuab tsom. Qhov saum npoo no hu ua phaneritic kev ntxhib los mos. Tej zaum qhov zoo tshaj plaws-paub phaneritic pob zeb yog granite.
Puas bas alt muaj coarse crystals?
Cov no cov pob zeb ntxhib ntxhibua rau lub pob zeb zoo li qab zib li lub ntsej muag tiaj tus siv lead ua cuam tshuam lub teeb hauv ntau pua lub paj me me. … Yog hais tias muaj cov ntxhia pob zeb dub feem ntau thiab cov pob zeb yog cov nplej zoo, nws yog bas alt.
pob zeb bas alt zoo li cas?
Bas alt feem ntau yog dub grey rau xim dub, vim nws cov ntsiab lus siab ntawm augite lossis lwm yam xim tsaus nti pyroxene minerals, tab sis tuaj yeem pom ntau yam ntxoov ntxoo. Qee cov bas alts yog xim xim heev vim muaj cov ntsiab lus siab ntawm plagioclase, thiab qee zaum cov no tau piav qhia tias yog leucobas alts.
