Modern ma'aunan kasa zamanin. Mene ne yanzu zamanin

Don gane da abin da yake a yanzu da zamanin, shi wajibi ne don duba a yanke shawara II zaman na kasa da kasa Sashen Congress, da aka gudanar a 1881. Sa'an nan da masana kimiyya jayayya game da ma'aunan kasa tarihi na duniya tamu. Akwai da dama wuraren view, wanda ya gabatar da rikice a cikin kimiyya. Janar zaben na kwararru, an yanke shawarar cewa yanzu ma'aunan kasa zamanin - Cenozoic. Yana fara 66 da miliyan shekaru da suka wuce, kuma ya ci gaba da wannan rana.

Features na Cenozoic

Hakika, na zamani ma'aunan kasa zamanin - wannan ba wani abu monolithic kuma monotonous. An kasu kashi uku lokaci: da Paleogene, Neogene da Quaternary. A wannan lokaci, da duniya ta canja da cika fuska. A farkon matakai na Cenozoic da Earth duba quite ba daidai ba, kamar yadda yake a yau, ciki har da cikin sharuddan Flora da fauna. Duk da haka, shi ne to da yawa abubuwa faru a sakamakon wanda duniya ya zama abin da muka sani shi.

Yana fara gyara da duniya tsarin na juna teku igiyoyin. Yana da aka sa ta unprecedented nahiyar gantali. Its sakamako mai wahala zafi musayar tsakanin Equatorial da iyakacin duniya tasa.

nahiyar gantali

A Paleogene raba supercontinent Gondwana. An muhimmin taron da cewa alama zamani ma'aunan kasa zamanin, ya mai karo na Indiya da kuma Asia. Afirka daga kudu maso yammacin "makale" a Eurasia. Kamar haka nan kuma ya bayyana a kudancin duwãtsu na Old World kuma Iran. Sashen lokaci tafi sannu a hankali amma inexorably taswirar Duniya zama kamar yau.

A zamanin d Tethys Ocean, raba arewacin da kuma kudancin Gondwana Laurasia ƙarshe bace. Yau, kawai teku zauna na shi (Rum, Black kuma Caspian). A kudancin yammancin duniya ma halarta muhimmanci events. Antarctica m kashe daga kasar Australia, ya tafi zuwa ga gefen cikin iyakacin duniya, zama a glacial jeji. Isthmus of Panama fito da nasaba Arewa da Kudancin nahiyar Amirka, a karshe raba da Pacific da kuma Atlantic tekuna.

paleogene

A farkon lokaci, wanda ya buɗe zamani ma'aunan kasa zamanin - da Paleogene (66-23 shekaru miliyan da suka wuce). Wani sabon mataki na ci gaba da gudanar da duniya. Mesozoic da Cenozoic iyaka da aka alama ta wata babbar lamba na taro nau'i nau'i na jinsi. Mafi yawan mutane san wannan masifa ta nau'i nau'i na dinosaur.

A wurin wani sabon Shellfish zo Mesozoic mazaunan duniya, fitar kasusuwan jikinsu kifi da angiosperm ciyayi. A baya ma'aunan kasa lokuta a kan ƙasar mamaye dabbobi masu rarrafe. Yanzu sun ba hanya zuwa manyan matsayi dabbobi masu shayarwa. Na dabbobi masu rarrafe tsira kawai crocodiles, kunkuru, macizai, kadangaru da kuma wasu sauran jinsunan. Kafa wani zamani look halittar dabba mai kafafuwa. A cikin iska, shi ya kafa dominance tsuntsaye.

Neogene

A al'ada jerin ma'aunan kasa dazamani ya furta cewa, na biyu lokaci ya zama Cainozoe Neogen, biye da kuma gabanin Paleogenic Quaternary. Yana fara 23 da miliyan shekaru da suka wuce da kuma kare 1,65 shekaru miliyan da suka wuce.

A ƙarshen Neogene kwayoyin duniya karshe soma zamani fasali. A teku ya zama dadaddun diskotsikliny, assiliny da nummulites. Ƙwarai canja abun da ke ciki na Organic duniya a kan ƙasar. Dabbobi masu shayarwa sun saba da rayuwa a filayen, m gandun daji, da kuma Semi polustepyah haka colonizing manyan yankunan. Yana bayyana a cikin Neogene proboscidians, ungulates da kuma sauran wakilan fauna kowa a yau (hyenas, beyar, martens, badgers, da karnuka, dorina, da na tumaki, da shanu, da sauransu. D.). Mannyan birai suka fito daga cikin kurmi suka lugar bude sarari. 5 shekaru miliyan da suka wuce, na farko magabatan na zamani mutum na iyali na hominids. A arewacin latitudes fara bace samar da thermophilic Flora (ci-zaƙin, Laurel, itatuwan dabino).

Da samuwar na zamani duwãtsu, kuma tekuna

A Neogene ci gaba da aiwatar da dutsen gini, wanda aka ayyana da zamani wuri mai faɗi da na duniya. A Amirka, ya kafa Cordillera da Appalachian Mountains a Afirka - Atlas. Duwatsu bayyana a cikin gabashin Australia da kuma a cikin India. wani m teku a yammacin Pacific (Japan da kuma Okhotsk). The aiki na daban-daban volcanoes, da ruwa ya tashi da volcanic baka.

Ga wasu lokaci duniya teku matakin sama na yanzu, duk da haka, ya sake fadi zuwa karshen na Neogene. Glaciation cover ba kawai Antarctic, amma kuma Arctic. Climate zama mafi m da bambanci, wanda ya gaskiya musamman ga na gaba Quaternary.

fauna hijirarsa

A Neogene lokaci, karkarar da Arewa Hemisphere karshe sõyayya a cikakke sarari. Akwai wani Rum hanya tsakanin Afirka da kuma Turai. A cikin West Siberian Bayyana bace turgai teku. Yana raba Turai daga yankin Asia. Bayan shi ta kafe Facilitated hijirarsa tsakanin sassa daban daban na duniya. Daga America zo herbivorous doki, da kuma daga Asia - irin gada da kuma bijimai. Proboscidians yada waje na Afirka. Cats da suke da farko saber-toothed kuma zauna a Amirka, cike Eurasia.

4 shekaru miliyan da suka wuce, da Isthmus of Panama tashi. Akwai wani ƙasar alaka tsakanin biyu nahiyar Amirka, wanda ya jagoranci wani mini ne unprecedented dabba hijirarsa. Kudu fauna a ko'ina cikin Cenozoic ya a Jihar kadaici, a zahiri zaune a kan babbar tsibirin. Yanzu, baki da juna jinsunan zo a cikin lamba. Fauna Mix. A arewa, ya nuna har armadillos, sloths da marsupials. Horses, tapirs, hamsters, aladu, barewa, camelids (llamas) sun karkashin mulkin mallakar Kudancin Amirka. Arewa fauna wadãtar. Amma akwai wani real hadarin a kudancin Amirka. Saboda sabon fafatawa a gasa, a fuskar ungulates da yara ya zama dadaddun yawa hakori da marsupials. Wadannan bambamcin events zama da aka sani da Great American musayar.

quaternary

Sai da na ɗauki dama shekaru biliyan zuwa yawa ma'aunan kasa dazamani da lokutan nasara juna, kuma a karshe ya zo da wata ma'ana inda wani rabin miliyan da suka wuce, ya fara Quaternary lokaci na Cenozoic. Ya ci gaba da wannan rana, don haka shi za a iya daukan zamani.

Duk lokaci da kuma yanayi dazamani na geologic tarihi ne daban-daban daga juna musamman fasali. Quaternary ma kira anthropogenic, kamar yadda yake a wannan lokaci ya ga ci gaba da kuma samuwar mutum. Da farko magabatan bayyana a Gabashin Afrika. Sa'an nan suka zauna a Eurasia, kuma daga zamani Chukotka zo Amirka. Mutane sun tafi a hanyar da dama matakai na raya kasa. Last (m mutum) ya faru 40 shekara dubu da suka wuce.

A daidai wannan lokaci na musamman a cikin Quaternary yanayin kona. A karshe shekaru miliyan ya na da lokacin da za a je ta hanyar da dama kankara shekaru daban-daban, suna jin wutar ni a. Climate woes sun kai ga nau'i nau'i na thermophilic Flora da fauna. Bace da dabbobi sun saba da rayuwa a cikin Ice Age (mammoths, woolly rhinoceroses, saber-toothed damisa).

Holocene

A amsar wannan tambaya, abin da yake a yanzu da zamanin, an riga an samu (Cenozoic). A lokaci guda, shi ci gaba a yau a karkashin Quaternary lokaci. Haka kuma an rarraba su zuwa sassa. Modern sashen Quaternary lokaci - da Holocene epoch. Yana fara 12,000 da suka wuce. Masana kimiyya kira shi da interglacial. Wannan shi ne wani lokaci bayan gwaji Warming.

A daidai wannan lokaci da zamani bil'adama ta gudanar ya kama 'yan kananan kankara shekaru daban-daban. Canjin yanayi ne halayyar da Quaternary lokaci, a karshe 12 shekara dubu hawan keke da aka maimaita sau da yawa. A lokaci guda sikelin da ya rage kankanin kuma ba haka ba ban mamaki. Climatologists ce da Little Ice Age, wadda ta zo a cikin 1450-1850 biennium. Hunturu yanayin zafi a Turai ya ragu, wanda ya kai ga m amfanin gona kasawa da kuma kona a cikin m tattalin arziki. Little Ice Age aka gabãta ta Atlantic ganiya (900-1300 gg.). A wannan lokacin, da sauyin yanayi da yawa milder, da kuma glaciers rage muhimmanci. Ya kamata mu tuna cewa Vikings wanda ya gano Greenland a tsakiyar zamanai, aka kira "da kore kasar", ko da yake a yau shi ne ba "kore".