Rau qhov kev piav qhia ntawm pob zeb, cov yam ntxwv sab nraud yog qhov tseem ceeb, uas qhia txog cov yam ntxwv ntawm lawv cov qauv. Cov paib zoo li no tau muab faib ua ob pawg: thawj zaug piav qhia txog cov qauv ntawm pob zeb, thiab qhov thib ob, uas peb yuav nyob hauv cov ntsiab lus ntxiv ntawm no, cuam tshuam rau kev ntxhib los mos.
Lub tswv yim ntawm cov qauv thiab kev ntxhib los mos ntawm pob zeb
Cov qauv qhia txog lub xeev ntawm cov pob zeb tsim cov ntxhia thiab cuam tshuam nrog cov txheej txheem ntawm crystallization thiab kev puas tsuaj ntawm cov ntxhia, uas yog, nrog rau kev hloov pauv ntawm cov khoom thaum lub sijhawm tsim cov pob zeb. Cov yam ntxwv muaj xws li cov yam ntxwv ntawm pob zeb raws li qib ntawm crystallinity, nrog rau qhov tseeb thiab qhov sib txheeb ntawm cov nplej uas ua rau pob zeb thiab lawv cov duab.
Kev ntxhib los mos ntawm lub pob zeb yog ib txheej ntawm cov yam ntxwv uas ua rau nws cov heterogeneity - nyob rau hauv lwm yam lus, yuav ua li cas cov txheej txheem sau qhov chaw nyob rau hauv lub pob zeb, yuav ua li cas lawv faib thiab taw qhia rau ib leeg.kwv tij phooj ywg. Cov tsos ntawm kev ntxhib los mos yog txuam nrog cov txheeb ze txav ntawm pob zeb Cheebtsam thaum nws tsim. Cov duab ntawm cov pob zeb tawg kuj tseem ceeb hauv kev piav qhia txog cov yam ntxwv ntawm nws cov khoom xyaw.
Kev faib cov ntaub ntawv thiab pob zeb genesis
Ntau hom pob zeb textures raug cais raws li cov hauv qab no:
- Kev sib koom ua ke ntawm pob zeb nplej. Muaj homogeneous (loj heev) thiab heterogeneous textures. Cov tom kawg, nyob rau hauv lem, muaj ntau yam: banded, gneiss, schlieren, fluidal, thiab lwm yam.
- Degree ntawm qhov chaw sau. Qhov kev ntxhib los mos tuaj yeem yog ntom lossis ntxeem tau ntawm ib qho lossis lwm qhov (slag, miarolitic, almond-pob zeb, spherical).
Qhov kev ntxhib los mos ntawm pob zeb, nrog rau lawv cov qauv, nyob ntawm keeb kwm. Raws li qhov kev ntsuas no, pob zeb tau muab faib ua igneous, sedimentary thiab metamorphic. Lawv txawv nyob rau hauv lawv cov tshuaj thiab mineralogical muaj pes tsawg leeg thiab tsim tej yam kev mob. Txhua tus ntawm lawv muaj nws tus kheej textures nta. Yog li ntawd, peb yuav xav txog cov hom kev ntxhib los mos hauv kev nthuav dav ntxiv rau txhua chav ntawm pob zeb sib cais.
Igneous rocks
Qhov tsim ntawm pob zeb ntawm hom no tshwm sim thaum lub sij hawm solidification ntawm magmatic melts. Nyob ntawm cov xwm txheej ntawm cov txheej txheem no, cov pob zeb uas tshwm sim tau muab faib ua ob hom. Cov qauv thiab textures ntawm cov pob zeb igneous uas yog lawv txawv nrog cov tshuaj zoo sib xws thiab ntxhia muaj pes tsawg leeg.
- Cov pob zeb tsis sib haum xeeb yog tsim los ntawmqeeb crystallization ntawm magma nyob rau hauv qhov tob ntawm lub ntiaj teb crust.
- pob zeb effusive yog tsim los ntawm qhov txias txias ntawm lava - magma tawg rau saum npoo, thiab lwm yam khoom hluav taws xob (ashes).
Hais txog ib nrab ntawm peb lub ntiaj teb lub pob zeb yog tsim los ntawm ob hom pob zeb tsis pom kev.
Yuav ua li cas cov pob zeb igneous yog li
Qhov kev ntxhib los mos ntawm magmatites yog qhov kev xav ntawm lub zog ntawm magma txav thiab kev siv ntawm nws lub cev thiab tshuaj lom neeg cuam tshuam nrog cov tswv tsev strata.
Yog tias cov pob zeb textures tau tsim ib txhij nrog lub zog ntawm cov magmatic yaj, lawv tau hais tias yog cov khoom sib txuas, suav nrog loj, kheej kheej, qhia, ntxeem tau. Kev ntxhib los mos yog tus cwj pwm los ntawm qhov pom ntawm kheej kheej lossis ellipsoidal formations hauv pob zeb; Cov lus qhia - los ntawm qhov pom ntawm subparallel oriented nplej ntawm flattened los yog elongated configuration.
Thaum muaj qhov hloov pauv hauv thawj hom, qhov tshwm sim zoo nkauj hu ua epigenetic. Piv txwv suav nrog amygdalic kev ntxhib los mos (tsim thaum npuas thiab qhov pores tau ntim nrog cov khoom siv hydrothermal) lossis breccia kev ntxhib los mos (tsim thaum tsis zoo li cov seem ntawm lwm cov magmatite sib sau hauv pob zeb).
Lub hauv paus chiv keeb ntawm textures tuaj yeem yog endogenous, cuam tshuam nrog cov txheej txheem ntawm pob zeb crystallization nws tus kheej, lossis exogenous, nyob ntawm qhov kev ua ntawm lwm yam.
Textural nta ntawm cov pob zeb intrusive
Cov yam ntxwv feem ntau cov yam ntxwv ntawm kev nkag mus yog:
- loj heev nrog kev faib khoom sib xws thiab random grain orientation (piv txwv li - dunites, syenites, diorites, qee zaum granite, gabbro);
- schlieren nrog lub xub ntiag nyob rau hauv lub pob zeb ntawm thaj chaw ntawm cov mineralogical sib txawv thiab cov qauv;
- banded (gneiss lossis cov lus qhia), tus cwj pwm los ntawm kev sib hloov cov hlua nrog cov qauv sib txawv lossis cov ntxhia hauv cov ntxhia (migmatites, qee zaum granite, gabbro);
- miarolic nrog cov kab noj hniav hauv cov pob zeb tsim los ntawm lub ntsej muag ntawm cov pob zeb crystalline.
Textures of igneous rocks of effusive origin
Volcanic pob zeb feem ntau muaj textures xws li:
Nyob zoo ib tsoom phooj ywg sawv daws. Lawv muaj ntau lossis tsawg dua voids uas tau tshwm sim los ntawm degassing ntawm magma thaum nws tawm hauv plab mus rau saum npoo. Yog li, hauv pumice (pumicite), qhov porosity tuaj yeem ncav cuag 80%.
Sedimentary pob zeb
Muaj peb qhov chaw ntawm pob zeb sedimentary:
- redeposition ntawm erosion khoom;
- nag los ntawm dej;
- kev ua haujlwm ntawm ntau yam kab mob nyob.
Raws li, nyob ntawm cov xwm txheej thiab cov txheej txheem ntawm kev tsim, pob zeb ntawm hom no tau muab faib ua clastic, chemogenic thiab organogenic. Tseem muaj cov yug me nyuam sib xyaw.
Lub hauv paus ntsiab lus ntawm cov pob zeb sedimentary suav nrog peb theem:
- Diagenesis yog txheej txheem ntawm hloov cov av xoob mus rau hauv pob zeb.
- Catagenesis yog theem uas lub pob zeb tau txais tshuaj lom neeg, mineralogical, lub cev thiab kev hloov pauv. Qhov tshwm sim ntawm catagenesis yog lub cev qhuav dej, compaction thiab ib nrab recrystallization ntawm pob zeb.
- Metagenesis yog theem hloov mus rau metamorphization. Muaj qhov siab tshaj plaws compaction ntawm pob zeb, kev hloov ntawm cov ntxhia muaj pes tsawg leeg thiab cov qauv nrog ntxiv recrystallization kom txog rau thaum cov seem ntawm cov kab mob nyob hauv cov pob zeb ploj mus.
Cov qauv thiab kev ntxhib los mos ntawm cov pob zeb sedimentary yog txiav txim los ntawm ob qho tib si thawj yam uas ua thaum lub sij hawm sedimentation (sedimentation) thiab lwm yam uas tau los rau hauv ib theem lossis lwm qhov ntawm cov pob zeb genesis.
Textural nta ntawm sedimentary pob zeb
hom pob zeb no yog tus yam ntxwv los ntawm kev sib xyaw ua ke, ua pawg raws li ob lub ntsiab lus: intralayer thiab txheej txheej txheej textures.
Kev sib koom ua ke ntawm cov pob zeb sedimentary nyob rau hauv cov txheej txheem xws li hom kev ntxhib los mos xws li:
- random (xws li, piv txwv li, ntawm coarse clastic conglomerates);
- layered ntawm ntau hom: oblique, wavy, flysch,kab rov tav (feem ntau);
- tubular lossis vacuolar, muaj cov voids tsim los ntawm cov nroj tsuag decomposed (pom nyob rau hauv cov dej tshiab limestones);
- pom kev ntxhib los mos ntawm ntau yam: streaky, zonal, flaky, scaly, thiab lwm yam;
- qauv, yam ntxwv ntawm av nplaum uas muaj cov ntxhia pob zeb loj;
- fluidal, lossis turbulence texture nrog cov kab ntawm kev cuam tshuam thawj qhov kev taw qhia ntawm cov qauv tsim.
Cov txheej txheem saum npoo ntawm txheej, uas tshwm sim los ntawm kev hloov pauv nyob rau lub sijhawm luv ntawm ib puag ncig ntawm sedimentation nrog kev faus neeg sai sai ntawm txheej, yog cov imprints sab laug los ntawm nag lossis daus, cov cim ripple tsim los ntawm cua, tam sim no lossis nthwv dej. ntws, ziab cov kab nrib pleb thiab lwm yam kab.
Feem ntau, cov pob zeb ntawm cov pob zeb ntawm sedimentary keeb kwm muaj ntau haiv neeg vim qhov kev hloov pauv siab ntawm cov xwm txheej hauv qab uas lawv tsim.
Metamorphic pob zeb
Lawv yog tsim nyob rau hauv lub thickness ntawm lub ntiaj teb crust los ntawm kev hloov igneous thiab sedimentary pob zeb nyob rau hauv lub zog ntawm lub cev (siab kub thiab kub) thiab tshuaj yam tseem ceeb. Cov txheej txheem ntawm kev hloov pob zeb yog hu ua metamorphism; Nyob rau hauv cov ntaub ntawv ntawm ib tug tseem ceeb kev hloov nyob rau hauv cov tshuaj muaj pes tsawg leeg, nws yog customary hais lus ntawm metasomatism.
Pob zeb ntawm chav kawm no tau muab faib ua pawg raws li hu ua metamorphic facies - aggregates nyob rau hauv uas lawv tuaj yeem muaj qhov sib txawv, tab sis tsim nyob rau hauv qee yam zoo sib xws. Cov qauv thiab kev ntxhib los mos ntawm metamorphicpob zeb qhia txog cov yam ntxwv ntawm cov txheej txheem ntawm recrystallization ntawm thawj sedimentary los yog igneous khoom.
Txoj kev sib ntxiv ntawm cov pob zeb metamorphic
Cov pob zeb metamorphosed yog cov hauv qab no:
- loj heev (pom, piv txwv li, hauv thaj chaw sib sib zog nqus ntawm metamorphism thiab hauv cov pob zeb metasomatic ntawm cov hauv paus chiv keeb uas tau khaws lawv cov kev ntxhib los mos);
- pom - qhov tshwm sim ntawm kev sib cuag-thermal metamorphism (spotted schists, hornfelses);
- almond pob zeb (tsis muaj zog metamorphosed pob zeb, qee zaum amphibolites);
- banded (gneiss) nrog cov ntxhia sib txawv ntawm cov kab sib txuas;
- slate yog qhov kev ntxhib los mos ntawm cov pob zeb metamorphic.
Slate kev ntxhib los mos tshwm sim nyob rau hauv kev cuam tshuam ntawm kev taw qhia siab. Nws muaj ntau yam xws li flaky - nyob rau hauv cov ntaub ntawv uas schistosity yog nyuaj los ntawm me me quav - thiab lenticular (los yog spectacled, nrog inclusions ntawm quartz los yog feldspar) textures.
Tsis tas li ntawd, cov pob zeb metamorphic feem ntau nthuav tawm ntau hom deformation textures, xws li boudinage.
Ntawm qhov sib txawv ntawm lub tswv yim
Nws yuav tsum raug sau tseg tias tsis muaj kev sib cais meej ntawm kev txhais cov ntsiab lus zoo sib xws li cov qauv thiab kev ntxhib los mos ntawm pob zeb. Hauv cov qauv ntawm cov pob zeb, muaj cov cim qhia uas tuaj yeem faib ua ob txoj hauv kev: piv txwv li, amygdalic muaj pes tsawg leeg ntawm pob zeb qee zaum hu ua cov yam ntxwv ntawm cov qauv. Lwm qhov piv txwv yog ooliticlimestones, uas nws yog ib qho nyuaj rau kev paub qhov txawv nta txuam nrog cov duab, qhov loj thiab cov qauv ntawm cov ntxhia nplej - oolites.
Lub ntsiab lus tsis meej meej ntawm cov ntsiab lus no kuj tshwm sim nyob rau hauv lub ntsiab lus ntawm kev siv cov ntsiab lus "structure" thiab "texture" hauv lus Askiv kab lis kev cai. Hauv kev tshaj tawm thoob ntiaj teb, raws li txoj cai, lub tswv yim dav dav ntawm "cov qauv thiab cov qauv siv" yog siv, tsis muaj kev sib cais ntawm cov qauv thiab cov pob zeb.
Txawm li cas los xij, qhov kev piav qhia tseeb ntawm kev ntxhib los mos ntawm pob zeb yog qhov tseem ceeb heev rau kev daws teeb meem ntau yam, piv txwv li, txiav txim siab lub cev los yog elucidating lub genesis ntawm pob zeb thiab cov dynamic tej yam kev mob rau lawv tsim.
