Paleocene-Eocene Mafi Girma

Matsakaicin zafi na Eocene"Paleocene-Eocene (PETM), a madadin "Eocene thermal matsakaicin 1 (ETM1) " kuma wanda aka fi sani da "Eocene na farko " ko "Matsayin zafi na Paleicene na ƙarshe", wani ɗan gajeren Lokaci ne na geologically wanda ke nuna 5-8 ° C (9-14 ° F) matsakaicin zafin jiki na duniya da kuma shigar da carbon mai yawa cikin teku da yanayi. An fara taron ne, yanzu an tsara shi a hukumance, a daidai lokacin iyaka tsakanin zamanin Paleocene da Eocene. Takamaiman shekarun da tsawon lokacin PETM ya kasance ba a tabbatar da shi ba, amma ya faru a kusa da shekaru miliyan 55.8 da suka gabata (Ma) kuma ya kasance kusan shekaru dubu 200 (Ka). 

PETM a takaice yana wakiltar mafi kyawun analog ɗin mu na baya wanda don fahimtar yadda ɗumamar duniya da zagayowar carbon ke aiki a cikin duniyar greenhouse. McInerney FA, Wing SL (30 May 2011). "The Paleocene-Eocene Thermal Maximum: A Perturbation of Carbon Cycle, Climate, and Biosphere with Implications for the Future". Annual Review of Earth and Planetary Sciences. 39 (1): 489–516. Bibcode:2011AREPS..39..489M. doi:10.1146/annurev-earth-040610-133431.   Ana nuna tazarar lokaci ta hanyar tafiye-tafiye mara kyau a cikin isotope na barga na carbon ( δ 13 C ) daga ko'ina cikin duniya; musamman, an sami babban raguwa a cikin 13 C / <sup id="mwPQ">12</sup> C rabo na ruwa da carbonates na ruwa da carbon Organic kuma an haɗa su a cikin ɗaruruwan wurare.    Girma da lokaci na PETM ( δ 13 C ) balaguron balaguron balaguro, wanda ke tabbatar da yawan sakin carbon da ya gabata zuwa tekunmu da yanayinmu, kuma tushen wannan carbon ya kasance batutuwan babban bincike na geoscience na yanzu.

Abin da ya bayyana a cikin 'yan shekarun da suka gabata shi ne cewa sassan Stratigraphic a fadin PETM suna nuna canje-canje da yawa fiye da dumama da fitar da carbon.McInerney FA, Wing SL (30 May 2011). "The Paleocene-Eocene Thermal Maximum: A Perturbation of Carbon Cycle, Climate, and Biosphere with Implications for the Future". Annual Review of Earth and Planetary Sciences. 39 (1): 489–516. Bibcode:2011AREPS..39..489M. doi:10.1146/annurev-earth-040610-133431. Daidai da iyakar Epoch, bayanan burbushin halittu da yawa suna nuna manyan juyin juya hali. A cikin yankin ruwa, babban lalacewar foraminifera na benthic, fadada duniya na dinoflagellate na subtropical, da kuma bayyanar taxa na balaguro, gami da cikin foraminifera da Nannofossils na calcareous, duk sun faru ne a farkon matakan PETM. A ƙasa, yawancin umarnin dabbobi masu shayarwa na zamani (ciki har da primates) ba zato ba tsammani sun bayyana a Turai da Arewacin Amurka.

 Saitawa 
Tsarin tekuna da nahiyoyi ya ɗan bambanta a farkon Paleogene dangane da yau. Isthmus na Panama bai riga ya haɗa Arewacin Amurka da Kudancin Amurka ba, kuma wannan ya ba da izinin yaduwar kai tsaye tsakanin Tekun Pacific da Tekun Atlantika. An rufe Hanyar Drake, wanda yanzu ya raba  da Antarctica, kuma wannan watakila ya hana keɓewar zafi na Antarctica. Har ila yau, Arctic ya fi ƙuntata. Kodayake wakilai daban-daban don yawan CO na yanayi da ya gabata a duk faɗin Cenozoic ba su yarda da cikakkun kalmomi ba, duk suna nuna cewa matakan a farkon Paleogene kafin da bayan PETM sun fi girma fiye da na yanzu. A kowane hali, manyan kankara na ƙasa da kankara na teku ba su wanzu a ƙarshen Paleocene ta farkon Eocene ba.

 Rashin jituwa na sake zagayowar carbon 
Tabbatacciyar shaida don ƙaƙƙarfan ƙari na 13 C-depleted carbon a farkon PETM ya fito ne daga abubuwan lura guda biyu. Na farko, babban balaguron balaguron balaguron balaguro a cikin abun da ke tattare da isotope na carbon ( δ   ) na matakan ɗaukar carbon yana nuna PETM a wurare da yawa (> 130) yaɗuwa daga wurare daban-daban.   Na biyu, rushewar carbonate yana nuna alamar PETM a cikin sassan daga zurfin teku. 

 Manazarta