Lub ntiaj teb kev nyab xeeb ib ntus dhau los ua qhov hloov pauv loj cuam tshuam nrog kev hloov pauv huab cua txias, nrog rau kev tsim cov nplooj khov nab kuab ruaj khov nyob rau sab av loj, thiab ua kom sov. Lub hnub nyoog dej khov kawg, uas xaus li ntawm 11-10 txhiab xyoo dhau los, rau thaj chaw ntawm East European Plain hu ua Valdai glaciation.
Systematics thiab terminology ntawm lub caij txias snaps
Cov theem ntev tshaj plaws ntawm kev txias txias hauv keeb kwm ntawm peb lub ntiaj teb kev nyab xeeb yog hu ua cryo-eras, lossis cov hnub nyoog dej khov ntev mus txog ntau pua lab xyoo. Tam sim no, Cenozoic cryoera tau mus txog li 65 lab xyoo hauv ntiaj teb thiab, pom meej, yuav txuas ntxiv mus ntev heev (kev txiav txim los ntawm cov theem zoo sib xws).
Thaum lub sijhawm, cov kws tshawb fawb txheeb xyuas cov hnub nyoog dej khov, sib cuam tshuam nrog cov theem ntawm cov txheeb ze sov. Lub caij nyoog tuaj yeem kav ntau lab thiab kaum lab xyoo. Niaj hnub nimno glaciallub sij hawm - Quaternary (lub npe yog muab raws li lub sij hawm geological) los yog, raws li lawv tej zaum yuav hais, Pleistocene (raws li ib tug me me geochronological chav tsev - lub sij hawm). Nws pib txog 3 lab xyoo dhau los thiab, pom tau tias, tseem nyob deb dhau lawm.
Thiab, cov hnub nyoog dej khov yog tsim los ntawm lub sijhawm luv - ntau txhiab txhiab xyoo - glacial epochs, lossis glaciations (qee zaum lo lus "glacial" yog siv). Lub sijhawm sov sov ntawm lawv yog hu ua interglacials, lossis interglacials. Peb tam sim no nyob raws nraim li lub sijhawm interglacial, uas hloov lub Valdai glaciation ntawm Lavxias teb sab Plain. Glaciations, nyob rau hauv lub xub ntiag ntawm undoubted common nta, yog yus muaj los ntawm lub regional nta, yog li ntawd lawv muaj npe nyob rau hauv ib cheeb tsam.
Nyob rau hauv lub sijhawm, theem (stadials) thiab interstadials yog qhov txawv, thaum lub sijhawm huab cua muaj qhov hloov pauv luv tshaj plaws - pessimums (txias) thiab qhov zoo tshaj plaws. Lub sijhawm tam sim no yog tus cwj pwm los ntawm kev nyab xeeb zoo ntawm subatlantic interstadial.
Lub hnub nyoog ntawm Valdai glaciation thiab nws theem
Raws li lub sijhawm ua haujlwm thiab cov xwm txheej ntawm kev faib mus rau theem, lub glacier no txawv me ntsis ntawm Wurm (Alps), Vistula (Central Europe), Wisconsin (North America) thiab lwm yam dej khov sib xws. Nyob rau sab hnub tuaj European Plain, qhov pib ntawm lub sijhawm uas hloov Mikulin interglacial yog kwv yees li 80 txhiab xyoo dhau los. Nws yuav tsum tau muab sau tseg tias tsim kom meej meej lub sij hawm txwv yognyuaj nyuaj - raws li txoj cai, lawv yog qhov muag plooj - yog li cov xwm txheej ntawm cov theem hloov pauv ntau.
Cov kws tshawb fawb feem ntau paub qhov txawv ntawm ob theem ntawm Valdai glaciation: Kalinin nrog dej khov siab tshaj plaws txog 70 txhiab xyoo dhau los thiab Ostashkovskaya (kwv yees li 20 txhiab xyoo dhau los). Lawv tau sib cais los ntawm Bryansk interstadial, qhov sov sov uas kav li ntawm 45-35 txog 32-24 txhiab xyoo dhau los. Qee cov kws tshawb fawb, txawm li cas los xij, muaj kev faib feem ntau ntawm lub sijhawm - txog rau xya theem. Raws li kev khiav tawm ntawm lub qhov dej khov, nws tshwm sim dhau lub sijhawm 12.5 txog 10 txhiab xyoo dhau los.
Geography ntawm cov dej khov thiab cov xwm txheej huab cua
Qhov nruab nrab ntawm qhov kawg glaciation hauv Tebchaws Europe yog Fennoscandia (xws li thaj chaw ntawm Scandinavia, Gulf of Bothnia, Finland thiab Karelia nrog Kola Peninsula). Los ntawm no, lub glacier ib ntus loj hlob mus rau sab qab teb, suav nrog rau Russia Plain. Nws yog tsawg dua nyob rau hauv qhov ntau dua li yav dhau los Moscow glaciation. Lub ciam teb ntawm daim ntawv dej khov Valdai khiav nyob rau sab qaum teb sab hnub tuaj thiab qhov siab tshaj plaws tsis ncav cuag Smolensk, Moscow, thiab Kostroma. Tom qab ntawd, nyob rau thaj tsam ntawm Arkhangelsk cheeb tsam, ciam teb tig mus rau sab qaum teb mus rau Dawb thiab Barents Seas.
Nyob rau hauv nruab nrab ntawm glaciation, lub thickness ntawm Scandinavian daim ntawv ices mus txog 3 km, uas yog piv rau thickness ntawm dej khov nyob rau hauv Antarctica. Lub glacier ntawm East European Plain muaj ib tug tuab ntawm 1-2 km. Nws yog qhov nthuav tias Valdai glaciation tau tshwm sim los ntawm huab cua hnyav nrog lub npog dej khov tsawg dua. Qhov nruab nrab txhua xyoo kub thaum lub sij hawm kawg glacial siab tshaj plaws - Ostashkovsky - tsuas yog me ntsis tshaj qhov kub ntawm lub era ntawm lub zog Moscow glaciation (-6 ° C) thiab yog 6-7 ° C qis dua hnub no.
Qhov tshwm sim ntawm glaciation
Txoj kab uas nyob ib puag ncig ntawm Valdai glaciation ntawm Lavxias teb sab Plain ua tim khawv rau lub zog uas nws muaj nyob rau toj roob hauv pes. Lub glacier tshem tawm ntau qhov tsis sib xws uas tau tso tseg los ntawm Moscow glaciation thiab tsim thaum lub sijhawm nws tawm, thaum cov xuab zeb, khib nyiab thiab lwm yam kev suav nrog tau yaj tawm ntawm cov dej khov loj, tso tawm mus txog 100 meters tuab.
Cov dej khov tau txav mus tsis nyob rau hauv qhov nruam, tab sis nyob rau hauv qhov sib txawv ntws, ntawm ob sab ntawm cov khoom siv detrital tsim - marginal moraines. Cov no yog, tshwj xeeb, qee qhov ridges hauv Valdai Upland tam sim no. Feem ntau, tag nrho lub tiaj yog tus cwj pwm los ntawm qhov chaw toj-morainic, piv txwv li, ntau tus drumlins - qis elongated toj.
pom tseeb ib qho ntawm cov dej khov yog cov pas dej ua rau hauv qhov khoob ploughed los ntawm glacier (Ladoga, Onega, Ilmen, Chudskoye thiab lwm yam). Cov dej ntws hauv cheeb tsam kuj tau txais kev pom zoo niaj hnub no vim qhov cuam tshuam ntawm daim ntawv dej khov.
Valdai glaciation hloov tsis tau tsuas yog toj roob hauv pes, tab sis kuj muaj pes tsawg leeg ntawm cov nroj tsuag thiab fauna ntawm Lavxias teb sab Plain, cuam tshuam rau thaj tsam ntawm kev daws teeb meem ntawm cov txiv neej thaum ub - hauv ib lo lus, nws muaj qhov tseem ceeb thiabkev cuam tshuam ntau yam.
