Lub tswv yim ntawm geochemical barrier yog txuam nrog tib neeg tsim cov pa phem ntawm ib puag ncig los ntawm kev tsiv teb tsaws ntawm cov tshuaj nrog rau nag lossis daus, hauv av lossis dej ntws. Qhov concentration ntawm cov teeb meem sib txuas tuaj yeem ncav cuag qhov txaus ntshai hauv chav kawm 1, thiab lawv qhov siab tshaj plaws tso cai tuaj yeem dhau ntau zaus, uas ua rau muaj qhov tshwm sim ntawm geochemical anomalies nyob rau hauv av thiab reservoirs txawm nyob rau hauv loj deb ntawm qhov chaw ntawm cov pa phem. Kev tshawb fawb ntawm geochemical teeb meem tau muab cov ntaub ntawv tshiab hais txog qhov muaj peev xwm txo qis kev txav mus los ntawm cov tshuaj lom.
Definition
Lo lus "geochemical barrier" yog thawj zaug qhia los ntawm Lavxias tus kws tshawb fawb AI Perelman. Nws cov ntsiab lus nyob rau hauv lub npe ntawm thaj chaw ntawm lub ntiaj teb crust, qhov twg muaj ib tug ntse txo nyob rau hauv lub zog ntawm kev tsiv teb tsaws thiab cov concentration ntawm cov tshuaj. Yog li ntawd, lawv dhau los ntawm lub xeev ntawm technogenic dispersion mus rau cov koom haum ntxhia ruaj khov. Cov kev txwv no yog siv los uativ thaiv ib puag ncig los ntawm kev ua qias tuaj.
Txoj kev xav no yog siv dav hauv ecology, geology, geochemistry ntawm toj roob hauv pes, dej hiav txwv thiab hiav txwv. Ib qho piv txwv yooj yim ntawm kev thaiv yog kev tsiv teb tsaws ntawm cov dej hauv av saturated nrog hlau ions. Hauv av, cov khoom no yuav luag tag nrho yaj hauv cov kua. Thaum ncav cuag qhov chaw, hlau yog oxidized nyob rau hauv lub zog ntawm oxygen, thiab cov hlau precipitates nyob rau hauv daim ntawv ntawm ib tug ntsev, uas yog, nws kis mus rau hauv cov ntxhia theem. Tib qhov tshwm sim yog pom thaum cov hlau tov yog thauj los ntawm cov kav dej. Hauv qhov no, lawv hais txog kev thaiv tus txiv neej.
Geochemical teeb meem thiab lawv cov kev faib tawm
Txheej txheem yog qhov txawv ntawm ntau yam:
- Los ntawm keeb kwm (kev faib cov caj ces): ntuj; technogenic (tsim nyob rau hauv tus txheej txheem ntawm tib neeg kev ua ub no); natural-technogenic.
- Los ntawm qhov loj me: macrogeochemical teeb meem, uas txo qis hauv kev tsiv teb tsaws tshwm sim ntawm qhov kev txiav txim ntawm ntau txhiab meters; mesobarriers (los ntawm ob peb meters mus rau 1 km); microbarriers (los ntawm ob peb millimeters mus rau ob peb meters).
- Los ntawm qhov xwm txheej ntawm kev txav ntawm cov khoom: ob sab - kev tsiv teb tsaws ntawm cov dej ntws los ntawm ntau sab, ntau hom kev sib koom ua ke tuaj yeem tso rau hauv qhov thaiv (pom hauv daim duab hauv qab no); lateral (subhorizontal); txawb; radial (sub-verttical).
- Raws li cov tshuaj nkag mus: diffusion; infiltration.
Natural and man-made types
Ntawm cov saum toj no hom geochemical teeb meem, cov chav kawm hauv qab no yog qhov txawv:
- Mechanical. Thaum lub sij hawm tsiv teb tsaws ntawm cov khoom, lawv theem tsis hloov, tab sis lawv txav mus (feem ntau nyob rau hauv lub biosphere). Ib qho piv txwv yog dov ntawm cov khib nyiab raws cov toj roob hauv pes.
- Physico-chemical. Cov teeb meem tshwm sim los ntawm kev hloov pauv hauv ib puag ncig physicochemical. Tam sim no, chav kawm ntawm qhov tshwm sim no yog qhov kev kawm tshaj plaws thiab ua haujlwm tau zoo (nws piav qhia hauv qab no).
YBiogeochemical (phytobarriers thiab zoobarriers). Lawv yog tus cwj pwm los ntawm kev hloov pauv ntawm lub xeev thiab ib txoj hauv kev me me ntawm kev tsiv teb tsaws chaw. Feem ntau, xws li ib qho teeb meem yog txuam nrog rau tsub zuj zuj ntawm cov tshuaj raws li ib tug tshwm sim ntawm lub tseem ceeb kev ua si ntawm tsiaj thiab nroj tsuag. Cov chav kawm no suav nrog ob qho tib si ntuj thiab tib neeg tsim geochemical teeb meem (khoom tsiv teb tsaws ntawm thaj av ua liaj ua teb thiab pastures).
Complex barriers
Thaum ob peb chav kawm ntawm cov phenomena no superimposed nyob rau hauv qhov chaw, ib tug complex geochemical barrier tshwm sim, uas yog cais mus rau hauv ib tug nyias muaj nyias ib pawg. Cov kws tshawb fawb ntseeg hais tias nyob rau hauv tej yam ntuj tso tej yam kev mob xws li barrier nyob ib tug ntawm cov thawj qhov chaw. Ib qho piv txwv yog kev sib xyaw ntawm cov pa oxygen thiab sorption barriers nyob rau hauv roob roob:
- caij nplooj ntoos hlav nce mus rau saum npoo ntawm lub ntiaj teb nyob rau hauv gley qab ntug yog saturated nrog yaj ferric hydroxides, uas yog oxidized nyob rau hauv lub cua ntawm atmospheric huab cua (oxygen barrier);
- precipitating colloids yog sorbents zoo rau lwm tustshuaj lom neeg;
- vim qhov tshwm sim, qhov thib ob sorption barrier yog tsim.
Lub luag haujlwm loj ntawm cov teeb meem nyuaj kuj tau ua pov thawj los ntawm qhov tseeb tias ntau cov pob zeb hauv av tau tsim los ntawm lawv.
Ntau yam ntawm lub cev thiab tshuaj tiv thaiv
Cov nram qab no ntawm lub cev thiab tshuaj tiv thaiv yog qhov txawv:
- Oxygen. Oxidation tshwm sim nyob rau hauv lub xub ntiag ntawm ib tug loj npaum li cas ntawm cov dawb oxygen nyob rau hauv cov dej mus txog rau lub barrier.
- Sulfide (hydrogen sulfide). Cov dej nag los ntawm cov tshuaj tiv thaiv nrog H2S.
- Gley. Qhov teeb meem no yog tus yam ntxwv los ntawm kev txo cov tshuaj tiv thaiv (tsis muaj oxygen dawb thiab hydrogen sulfide).
- Alkaline. Raws li qhov tshwm sim ntawm qhov txo qis hauv acidity, tsim cov hydroxides thiab carbonates, uas precipitate rau hauv insoluble precipitate.
- Acid. Nrog rau qhov txo qis hauv pH, kev tsim cov ntsev me ntsis soluble yog pom.
- Evaporative. Qhov concentration ntawm cov tshuaj migratory nce vim dej evaporation thiab ntsev crystallization.
- Sorption. Muaj kev rho tawm ntawm qee yam tshuaj vim yog ntuj sorbents (av nplaum, humus thiab lwm yam).
- Thermodynamic. Ua kom cov concentration thiab nag lossis daus ntawm cov khoom nrog ib tug ntse hloov nyob rau hauv siab thiab kub. Cov txheej txheem no tau tshaj tawm hauv cov dej uas muaj carbonic acid.
Subclasses
Ntawm cov pab pawg ntawm lub cev thiab tshuaj tiv thaiv, kuj tseem muaj kev gradation los ntawm subclasses. Tag nrhomuaj 69 ntawm lawv. Lawv txawv ntawm cov kua qaub-puag rau txhua hom kev thaiv.
Ntawm cov kev teeb meem ntawm kev siv tshuab, muaj cov subclasses nyob ntawm lub xeev ntawm kev sib sau ua ke thiab lwm yam ntxwv ntawm cov khoom hauv kev tsiv teb tsaws:
- minerals thiab isomorphic impurities;
- dissolved gases (steam);
- colloidal systems;
- cov khoom siv hluavtaws;
- tsiaj thiab tsob nroj kab mob.
Examples
Cov piv txwv yooj yooj yim ntawm geochemical teeb meem ntawm chav kawm physicochemical yog raws li hauv qab no:
- Nyob rau hauv huab cua ntub hauv hav zoov, muaj zog litter ntawm nplooj poob. Ib qho tshwj xeeb ntawm cov dej hauv av nyob rau hauv cov xwm txheej zoo li no yog tias nws tsis muaj oxygen. Yog li ntawd, cov ntsiab lus tshuaj yog leached los ntawm cov av, nrog rau manganese thiab hlau. Thaum lawv ncav cuag qhov chaw, lawv oxidation pib nrog kev tsim ntawm insoluble hydroxides (oxygen barrier). Cov txheej txheem no ua rau kev tsim cov tshuaj sulfur hauv ib txwm muaj.
- Yog tias muaj cov pob zeb hauv av uas muaj sulfides ntawm cov hlau thiab lwm yam hlau ntawm thaj av siab, ces lawv ntxuav tawm los ntawm ntuj nag los pab tsim cov dej hauv av nrog cov kua qaub ntawm ib puag ncig. Nyob rau hauv cov lowlands, nyob rau hauv high humidity thiab anaerobic (tsis muaj oxygen), sulfates raug txo kom sulfides (sulfide barrier). Deposits ntawm tooj liab, selenium thiab uranium feem ntau yog nyob rau hauv xws li ib tug mechanism.
- Yog cov av muaj limestonepob zeb, ces nyob rau hauv ib qho kev nyab xeeb huab cua, nyob rau hauv lub cuam tshuam ntawm decaying organic residues, hlau, npib tsib xee, tooj liab, cob alt thiab lwm yam yog leached. Limestones tsim ib qho alkaline geochemical barrier uas pab neutralize acidic av hauv av thiab tsim insoluble hydroxides.
kev nyuaj siab
Nyob rau hauv niaj hnub geochemistry, ib tug tshiab subclass kuj txawv - social geochemical teeb meem. Lawv qhov txawv feature yog tias lawv tsis tau tshwm sim yav tas los nyob rau hauv tej yam ntuj tso rau cov tebchaw uas yog concentrated rau lawv. Cov teeb meem ntawm cov subclass no tsuas yog txiav txim siab hauv cov ntsiab lus ntawm tib neeg tsim lossis nyuaj geochemical teeb meem.
Ntawm lawv muaj 4 subclasses:
- tsev neeg (kev pov tseg ntawm cov khoom khib nyiab lossis kua hauv tsev);
- construction;
- kev lag luam;
- kev sib xyaw ua ke (kev pov tseg rau kev tsim kho, kev lag luam thiab kev pov tseg hauv tsev).
