An kiyasta cewa duniya tana da kimanin shekaru biliyan 4.54 (miliyan 4,540), kuma ana iya raba tarihinta zuwa lokutan yanayi daban-daban bisa la’akari da muhimman abubuwan da suka faru kamar rugujewar jama’a, samuwar nahiyoyin duniya, da sauyin yanayi. An san wannan rarrabuwa da ma'aunin lokacin yanayin ƙasa, wanda ke ba da tsarin fahimtar duniyar da ta gabata da kuma tsinkayar makomarta.
A. Eonothems ko eons
Mafi girman rabo na ma'aunin lokacin geological shine Eonothem, wanda aka ƙara raba shi zuwa eons huɗu: 1) The Hadean, 2) Archean, 3) Proterozoic, da 4) Phanerozoic. Sa'an nan kowane eon ya rabu zuwa zamani (erathem).
1. Hadean Eon
Hadean eon, wanda ya dade tun daga samuwar Duniya zuwa kimanin shekaru biliyan 4.6 da suka gabata, ana daukarsa a matsayin “zamanin duhu” saboda rashin kwararan hujjojin kasa daga wannan lokacin. An yi imani da cewa a cikin Hadean eon, Duniya ta kasance tana fuskantar karo akai-akai tare da sauran sassan sararin samaniya, wanda ya haifar da mummunan aiki na volcanic da samuwar wata.
2. Archean Eon
Archean eon ya bi Hadean kuma ya kasance daga kimanin biliyan 4 zuwa biliyan 2.5 da suka wuce. A wannan lokacin, duniya tana aiki ne a fannin ilimin geological, tare da matsanancin fashewar volcanic, samuwar nahiyoyin farko, da bullowar sifofin rayuwa na farko. Duwatsun da aka fi sani da su, tun shekaru biliyan 3.8 da suka gabata, ana samun su a Yammacin Greenland kuma sun bayyana kasancewar ƙananan ƙwayoyin cuta da ake kira stromatolites, waɗanda su ne shaidar farko ta rayuwa a duniya.
Archean Eon ya kasu kashi hudu:
2.1. Eoarchean Era: Daga shekaru biliyan 4 zuwa 3.6 da suka gabata
A wannan lokacin, duniya har yanzu tana cikin matakan farko na samuwarta kuma ana gudanar da muhimman abubuwan da suka shafi ƙasa da na halitta. Eoarchean yana da alaƙa da samuwar tsaffin duwatsun da aka sani a Duniya, gami da Acasta Gneiss a Kanada da Isua Greenstone Belt a Greenland. Waɗannan duwatsun suna ba da mahimman bayanai game da matakai na farko waɗanda suka tsara ɓawon ƙasa. Har ila yau Eoarchean ya ga fitowar sifofin rayuwa na farko, ko da yake sun kasance masu sauƙi da ƙananan ƙwayoyin cuta a cikin yanayi. Gabaɗaya, Eoarchean yana nuna wani muhimmin lokaci a cikin tarihin Duniya yayin da yake saita mataki don haɓaka rayuwa da samun ƙarin sifofin yanayin ƙasa.
2.2. Zamanin Paleoarchean: Daga shekaru biliyan 3.6 zuwa 3.2 da suka gabata.
A wannan lokacin, sararin duniya har yanzu yana cikin matakan farko na samuwa, kuma yanayin ba shi da iskar oxygen. Rayuwa a Duniya galibi ta ƙunshi ƙwayoyin cuta da ƙananan ƙwayoyin cuta. Paleoarchean yana da alaƙa da samuwar wasu tsoffin duwatsu da ma'adanai a Duniya, gami da Barberton Greenstone Belt a Afirka ta Kudu. Wannan zamanin yana ba da haske mai mahimmanci game da farkon ci gaba da juyin halitta na duniyarmu.
2.3. Mesoarchean Era: Daga 3.2 zuwa 2.8 shekaru biliyan da suka wuce
A wannan lokacin, ɓawon duniya yana ci gaba da yin aiki mai mahimmanci na tectonic. Nahiyoyi na farko sun fara fitowa, kuma tsarin rayuwa na farko, irin su kwayoyin cuta da archaea, sun bayyana a cikin teku. Yana da yanayin zafi da sanyi, da kuma kasancewar ayyukan volcanic da samuwar wasu tsoffin duwatsu a doron ƙasa.
2.4. Zaman Neoarchean: Daga 2.8 zuwa 2.5 shekaru biliyan da suka wuce
A wannan lokacin, nahiyoyi sun fara daidaitawa, suna samar da manyan filayen ƙasa. Har ila yau Neoarchean ya ga juyin halittar mafi hadaddun sifofin rayuwa, gami da fitowar kwayoyin halitta masu yawa. Bugu da ƙari, yanayin ya fara ƙunshe da iskar oxygen mai yawa, wanda ya ba da hanya ga ci gaban kwayoyin halitta. Gabaɗaya, Neoarchean yana nuna wani muhimmin lokaci a tarihin Duniya, yana kafa matakin ci gaba na gaba a cikin ilimin geology na duniya da ilmin halitta.
3. Proterozoic Eon
Proterozoic eon, wanda ya dade daga biliyan 2.5 zuwa shekaru miliyan 541 da suka gabata, yana da alaƙa da ci gaba da juyin halittar sifofin rayuwa, gami da fitowar wasu ƙwayoyin cuta masu rikitarwa kamar algae da farkon ƙwayoyin hannu masu yawa. Wannan lokacin kuma ya shaida samuwar manyan nahiyoyin duniya, irin su Rodinia, da bayyanar iskar oxygen a sararin samaniya saboda ayyukan kwayoyin photosythetic masu samar da iskar oxygen.
Proterozoic Eon ya kasu kashi uku:
3.1. Paleoproterozoic Era: Daga 2.5 zuwa 1.6 shekaru biliyan da suka wuce
A wannan lokacin, Duniya ta sami sauye-sauyen yanayin ƙasa da na halitta. Babban nahiyar Columbia ya fara watsewa, wanda ya kai ga samuwar sabbin nahiyoyi da tekuna. Hakanan yanayin ya sami manyan sauye-sauye, tare da haɓaka yanayi mai wadatar iskar oxygen wanda ke tallafawa tsarin rayuwa masu rikitarwa. Rubutun burbushin halittu daga wannan lokacin yana ba da mahimman bayanai game da farkon juyin halitta na rayuwa, gami da fitowar kwayoyin halitta na photoynthetic da na farko kwayoyin halitta masu yawa. Gabaɗaya, Paleoproterozoic lokaci ne mai mahimmanci a cikin tarihin duniya, wanda ya kafa mataki don bambance-bambancen rayuwa na gaba a cikin wannan zamani masu zuwa.
3.2. Mesoproterozoic Era: Daga 1.6 zuwa 1 biliyan shekaru da suka wuce
Wannan zamanin yana da manyan abubuwan da suka faru na ilimin ƙasa da na halitta, gami da samuwar manyan nahiyoyin duniya kamar Columbia, glaciations mai yawa, da bambance-bambancen ƙwayoyin eukaryotic na farko. Ana ɗaukar wannan zamanin a matsayin lokaci mai mahimmanci a tarihin duniya yayin da yake saita matakan haɓaka sifofin rayuwa masu rikitarwa a cikin waɗannan zaɓaɓɓun.
3.3. Neoproterozoic Era: Daga biliyan 1 zuwa 538.8 shekaru miliyan da suka wuce
Wannan abin lura ne cewa Hadean, Archean da Proterozoic, waɗannan eons uku ana kiran su tare da Precambrian Era. Wannan shi ne zamani na farko kuma mafi tsayi, tun daga samuwar Duniya kimanin shekaru biliyan 4.6 da suka gabata har zuwa farkon zamanin Paleozoic (wato, har zuwa farkon Phanerozoic eon).
4. Phanerozoic Eon
Phanerozoic Eon ya fara kimanin shekaru miliyan 541 da suka wuce kuma ya ci gaba har zuwa yau. An raba shi zuwa zamani uku: Paleozoic, Mesozoic, da Cenozoic.
4.1. Zamanin Paleozoic
The Paleozoic Era, wanda ya dade daga 541 zuwa 252 shekaru miliyan da suka wuce, an san shi da saurin sauye-sauyen nau'o'in rayuwa, ciki har da haɓakar dabbobin ruwa, mulkin mallaka na ƙasa da tsire-tsire, da bayyanar kwari da farkon dabbobi masu rarrafe. Hakanan ya haɗa da sanannen taron ɓarnawar jama'a na Permian-Triassic, wanda ya shafe kusan kashi 90% na dukkan nau'in ruwa da kashi 70% na nau'in kashin baya na ƙasa.
4.2. Mesozoic zamanin
Mesozoic Era, wanda aka fi sani da "Age of Dinosaurs," ya kasance daga 252 zuwa 66 shekaru miliyan da suka wuce. Wannan zamanin ya shaida yadda dinosaur suka mamaye kasa, da kuma bullowar sauran rukunonin halittu da dama da suka hada da dabbobi masu shayarwa, tsuntsaye, da shuke-shuken furanni. Mesozoic kuma ya haɗa da wani babban abin da ya faru na ɓarna, Ƙarfafawar Cretaceous-Paleogene, wanda ya haifar da mutuwar dinosaur da ba na avian ba da kuma tasowar dabbobi masu shayarwa a matsayin manyan vertebrates na duniya.
4.3. Zaman Cenozoic
Zamanin Cenozoic ya fara kimanin shekaru miliyan 66 da suka gabata kuma yana ci gaba har zuwa yau. An yi masa alama da bambance-bambance da rinjaye na dabbobi masu shayarwa, gami da fitowar manyan dabbobi masu shayarwa irin su giwaye da whale. Har ila yau, juyin halittar ɗan adam yana cikin wannan zamanin, tare da bayyanar da haɓakar Homo sapiens wanda ya faru kusan shekaru 300,000 da suka wuce.
B. Zamani, zamani da shekaru
Don ƙara rarraba ma'auni na lokacin yanayin ƙasa, kowane zamanin Phanerozoic ana raba shi zuwa lokuta (tsari), waɗanda aka ƙara zuwa zamanin (jeri), sannan zuwa shekaru (mataki).
Lokaci a cikin Paleozoic Era
The Paleozoic Era, wanda ya fara kusan shekaru miliyan 541 da suka gabata kuma yana dawwama har zuwa shekaru miliyan 252 da suka gabata, ana kiransa da “Age of Invertebrates” kuma ya ƙunshi lokuta masu zuwa:
- Zaman Cambrian: An san shi da "Fashewar Cambrian," wanda ya ga saurin sauye-sauyen nau'ikan rayuwa, gami da bayyanar farko na yawancin phyla na dabba.
- Lokacin Ordovician: Alama ta yaɗuwar marine invertebrates da kuma farkon mulkin mallaka na ƙasa da tsire-tsire.
- Lokacin Silurian: A wannan lokacin, rayuwa ta ci gaba da haɓakawa, tare da fitowar kifin jawed na farko.
- Lokacin Devonian: Sau da yawa ana kiransa "Age of Fishes," wannan lokacin yana shaida bambance-bambancen kifin da bayyanar tetrapods na farko.
- Lokacin Carboniferous: Sanannen ga bunƙasa sararin fadama da kuma samuwar kwal adibas na gaba.
- Lokacin Permian: Wannan lokacin ya ƙare Paleozoic Era kuma ana nuna shi ta hanyar bayyanar dabbobi masu rarrafe da farkon bayyanar dabbobi masu shayarwa.
Lokaci na Mesozoic Era
Mesozoic Era, wanda ya tashi daga shekaru miliyan 252 da suka gabata zuwa shekaru miliyan 66 da suka gabata kuma ana kiransa da “Zamanin Rarraba,” ya ƙunshi lokuta masu zuwa:
- Lokacin Triassic: Rayuwa a hankali ta murmure daga halakar taro a ƙarshen Permian, tare da juyin halittar dinosaur na farko da dabbobi masu rarrafe.
- Lokacin Jurassic: Wannan lokacin ya shahara ga mamayar dinosaur, gami da mafi girman dabbobin ƙasa da suka taɓa rayuwa.
- Zaman Halitta: Lokaci na ƙarshe da na ƙarshe na Mesozoic Era yana da alamar bayyanar tsire-tsire masu fure, da bambance-bambancen dinosaur, da kuma abin da ya faru na ƙarewa wanda ya shafe dinosaur ba na ruwa ba.
Lokaci na Cenozoic Era
Kamar yadda aka fada a baya, wannan shine zamanin na yanzu, wanda ya kama daga shekaru miliyan 66 da suka gabata zuwa yau, wanda galibi ana kiransa da “Zamanin Dabbobi.” An raba shi zuwa lokuta masu zuwa:
- Lokacin Paleogene: Wannan lokacin ya haɗa da zamanin Paleocene, Eocene, da Oligocene, lokacin da dabbobi masu shayarwa suka bambanta kuma suka samo asali zuwa nau'i daban-daban.
- Zaman Neogene: Wannan lokacin ya haɗa da zamanin Miocene da Pliocene kuma an yi masa alama ta haɓakar dabbobi masu shayarwa na zamani da bullowar hominids na farko.
- Zaman Kwata-kwata: Zamani na yanzu, wanda ya ƙunshi zamanin Pleistocene, wanda ke da shekarun ƙanƙara da bayyanar Homo sapiens, da kuma zamanin Holocene mai gudana, lokacin da wayewar ɗan adam ta haɓaka.
Kowane lokaci a ƙarƙashin zamanin da ke cikin Phanerozoic Eon yana ƙara rushewa zuwa ƙananan raka'o'in lokaci da ake kira zamanin. Alal misali, a cikin Cenozoic Era, zamanin da sun haɗa da Paleocene, Eocene, Oligocene, Miocene, Pliocene, Pleistocene, Da kuma Holocene. Saboda haka, lokacin Quaternary, wanda ke na Cenozoic Era (da Phanerozoic Eon), an yi shi ne ta zamani biyu: Pleistocene da Holocene.
Pleistocene da Holocene Epochs
Pleistocene Epoch da Holocene Epoch lokuta biyu ne a jere a tarihin Duniya.
Pleistocene Epoch ya kasance daga kimanin shekaru miliyan 2.6 da suka wuce zuwa kusan shekaru 11,700 da suka wuce. Yana da alamar glaciations mai maimaitawa, inda manyan wuraren ƙasa ke rufe da zanen kankara da glaciers. Wadannan glaciations sun sa matakan teku sun ragu sosai kuma sun haifar da canje-canje a yanayin yanayi, wanda ya haifar da bacewar nau'o'in nau'in nau'i da yawa da kuma juyin halitta na sababbin. Sanannen megafauna, irin su mammoths da kuliyoyi masu haƙora saber, sun yi yawo a duniya a wannan lokacin. Pleistocene Epoch kuma ana kiranta da zamanin Ice, kamar yadda aka yi masa alama da matsakaicin yanayin sanyi na duniya idan aka kwatanta da na yau.
The Holocene Epoch ya fara ne bayan lokacin dusar ƙanƙara na ƙarshe, wanda ke nuna sauyi zuwa yanayi mai dumi, kwanciyar hankali. Ya fara kusan shekaru 11,700 da suka shige kuma ya ci gaba har zuwa yau. Holocene yana da alaƙa da ja da baya na glaciers, hawan matakan teku, da kafa yanayin yanayin zamani. Wannan lokacin ya ƙunshi haɓakar wayewar ɗan adam, gami da haɓaka aikin noma da zuwan rubutaccen tarihi.
Gabaɗaya, Pleistocene Epoch lokaci ne na gagarumin canje-canjen muhalli da kuma fitowar nau'ikan nau'ikan nau'ikan halittu daban-daban, yayin da Holocene Epoch ke wakiltar lokacin kwanciyar hankali tare da rinjayen Homo sapiens da canje-canjen da ɗan adam ya haifar ga muhalli.
An ƙara raba Pleistocene Epoch zuwa Gelasia, Calabrian, Chibanian da kuma Tarantian / Late Pleistocene Shekaru Yayin da Holocene Epoch ya kasu kashi Greenlandian, Northgrippian da kuma Meghalayan (zamanin yanzu) Shekaru.
Ya kamata a ambaci cewa Phanerozoic Eon shine mafi mahimmancin ɓangaren lokaci na tarihin duniya a kimiyya, yana mai da Paleozoic, Mesozoic da Cenozoic mafi mahimmancin zamanin duka.
Karshe kalmomi
Ana sabunta sikelin lokacin yanayin ƙasa koyaushe ana sabunta shi yayin da aka gano da kuma nazarin sabbin shaida. Ci gaban fasaha da ikon tantance duwatsu da kasusuwa daidai lokacin sun taimaka wajen fahimtar tarihin duniya. Ta hanyar nazarin ma'aunin lokacin yanayin ƙasa, masana kimiyya za su iya samun ilimi mai yawa game da matakai da al'amuran da suka tsara duniyarmu da yin tsinkaya game da makomarta.
Lura: Don kiyaye labarin mai sauƙi, taƙaitacce da fahimta ba mu rubuta game da kowane ɓangaren sikelin lokacin yanayin ƙasa ba. Idan kuna son ƙarin koyo game da jadawalin yanayin ƙasa, karanta wannan Shafin Wikipedia.
