Video: Hom fossil yog ib qho ammonite?
2024 Tus sau: Miles Stephen | [email protected]. Kawg hloov kho: 2023-12-15 23:36
Ammonites yog kab tias cov pob txha paub ntau tshaj plaws, muaj cov kab uas feem ntau ribbed kauv-daim plhaub raws li daim duab saum toj no. Cov tsiaj no nyob hauv hiav txwv ntawm 240 - 65 lab xyoo dhau los, thaum lawv tau ploj mus nrog rau dinosaurs.
Dhau li ntawm no, puas yog ammonite fossils tsawg?
Anaptychi kuj yog tsis tshua muaj raws li pob txha . Lawv pom sawv cev ammonites los ntawm lub sij hawm Devonian mus rau lub sij hawm Cretaceous. Calcified aptychi tsuas yog tshwm sim hauv ammonites los ntawm Mesozoic era. Lawv yuav luag ib txwm pom cais tawm ntawm lub plhaub, thiab tsuas yog heev tsis tshua muaj khaws cia rau hauv qhov chaw.
Ib sab saum toj, dab tsi yog ammonite plhaub ua los ntawm? Tsuas yog rau sab hauv-feem ntau whorl, lub plhaub yog ua nce ntawm peb txheej. Cov innermost thiab outermost txheej yog nyias muaj li ntawm prisms ntawm aragonite (ib daim ntawv ntawm calcium carbonate). Lub thicker nruab nrab txheej yog nacreous (niam-ntawm-pearl), tsim ntawm me me tabular crystals ntawm aragonite.
Ib sab saum toj no, ua li cas ammonite fossils tsim?
Lawv yog feem ntau pom li pob txha , tsim thaum cov seem los yog kab ntawm cov tsiaj tau faus rau hauv cov av xuab zeb uas tom qab ntawd solidified rau hauv pob zeb. Ammonites yog cov tsiaj hauv hiav txwv thiab muaj lub plhaub sab nraud zoo ib yam li niaj hnub pearly nautilus.
Muaj pes tsawg ammonite fossils?
Fossil Cov ntaub ntawv Ammonites yog cov yug me nyuam loj hlob, nyob hauv tsev kawm ntawv, thiab muaj ntau tshaj plaws pob txha pom hnub no. Lawv tau ploj mus nrog cov dinosaurs 65 lab xyoo dhau los. Cov kws tshawb fawb siv ntau yam duab thiab qhov ntau thiab tsawg ammonite shells uas tshwm sim thiab ploj mus dhau lub hnub nyoog mus rau lwm yam pob txha.
Pom zoo:
Qhov twg yog ib qho piv txwv ntawm ib qho kev xeeb tub?
Hauv tib neeg, qhov muag xim yog ib qho piv txwv ntawm tus cwj pwm qub qub: ib tus neeg yuav tau txais 'xim av-qhov muag zoo' los ntawm ib tus niam txiv. Cov txiaj ntsig tau txais txiaj ntsig yog tswj hwm los ntawm cov noob thiab cov txheej txheem tag nrho ntawm cov noob hauv ib lub cev lub genome yog hu ua nws cov genotype
Dab tsi yog qhov txawv ntawm ib qho ultramafic ib qho mafic nruab nrab thiab felsic pob zeb?
Hauv cov txheej txheem kev faib tawm silica-cov ntsiab lus dav dav, pob zeb nrog ntau dua 65 feem pua silica hu ua felsic; cov uas muaj li ntawm 55 thiab 65 feem pua silica yog nruab nrab; cov uas muaj li ntawm 45 thiab 55 feem pua silica yog mafic; thiab cov uas tsawg dua 45 feem pua yog ultramafic
Ib qho piv txwv ntawm ib qho alloy yog dab tsi?
Ib qho piv txwv ntawm cov hlau yog sib xyaw ntawm cov hlau thiab hlau. Ib qho piv txwv ntawm cov hlau yog cov tin hauv qhov sib xyaw ntawm tooj liab thiab tin uas ua rau tooj liab. Lub alloy yog ib qho fusion ntawm ob lossis ntau dua hlau lossis cov hlau uas tsis yog hlau. Ib qho piv txwv ntawm cov hlau yog tooj dag, uas yog tsim los ntawm tooj liab thiab zinc
Dab tsi yog ib qho kev qhia uas muaj tsawg kawg yog ib qho kev sib txawv?
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Dab tsi yog qhov index fossil Dab tsi yog ob qhov yuav tsum tau ua ib qho index fossil?
Cov pob txha muaj txiaj ntsig zoo yuav tsum yog qhov sib txawv lossis pom tau yooj yim, muaj ntau, thiab muaj qhov dav ntawm thaj chaw faib khoom thiab muaj ntau yam luv luv los ntawm lub sijhawm. Index fossils yog lub hauv paus rau kev txhais cov ciam teb nyob rau hauv lub sij hawm geology thiab rau kev sib raug zoo ntawm strata