Babban Matakala

Babban Matakala
	geological structure (en)
Bayanai
Ƙasa	Tarayyar Amurka

Babban bene babban jeri ne na yadudduka na dutsen da ke shimfidawa kudu daga Bryce Canyon National Park da Grand Staircase–Escalante National Monument, ta hanyar Sihiyona National Park, zuwa cikin Grand Canyon National Park .

Halaye

A cikin 1870s, masanin ilimin kasa Clarence Dutton ya fara tunanin wannan yanki a matsayin babbar matakalar da ke hawa daga kasan Grand Canyon zuwa arewa tare da dutsen gefen kowane Layer yana samar da manyan matakai. Dutton ya raba wannan kek na tarihin Duniya zuwa matakai biyar daga mafi ƙanƙanta (mafi girma) duwatsu:

Dutsen ruwan hoda
Grey Cliffs
Farin Dutsen Dutse
Vermilion Cliffs
Chocolate Cliffs

Tun daga wannan lokacin, masana kimiyyar ƙasa na zamani sun ƙara rarraba matakan Dutton zuwa nau'ikan dutse guda ɗaya.

Grand Canyon (A), Chocolate Cliffs (B), Vermilion Cliffs (C), White Cliffs (D), Canyon Canyon (E), Grey Cliffs (F), Pink Cliffs (G), Bryce Canyon (H)

Haɓaka a cikin Babban Matakan da aka fara da mafi ƙanƙanta (mafi girma) duwatsu: ^[1]

Tsarin Claron
Kaiparowits Formation
Samuwar Wahweap
Samuwar Dutsen Madaidaici
Tropic Shale
Dakota Sandstone
Samuwar Karmel
Haikali Cap Formation
Navajo Formation
Kayenta Formation
Samuwar Moenave
Samuwar Chinle
Samuwar Moenkopi
Kaibab Limestone
Samuwar Toroweap
Coconino Sandstone
Hermit Shale
Supai Group
Kafa Kanyon Mamaki
Redwall Limestone
Temple Butte Limestone
Muav Limestone
Bright Angel Shale
Tapeats Sandstone

Geology

Manyan sassan dutsen da aka fallasa a cikin Grand Canyon suna da shekaru 200 miliyan zuwa shekaru miliyan 600 kuma an ajiye su a cikin ramukan ruwa mara zurfi da kuma wuraren da ke kusa da gaɓa. Kusan ginshiƙan dutsen 40 da aka gano na Grand Canyon sun zama ɗaya daga cikin ginshiƙan ilimin ƙasa da aka fi yin nazari a duniya.

Mafi dadewa da aka fallasa a cikin Sihiyona National Park shine mafi ƙanƙanta da aka fallasa samuwar a cikin Grand Canyon - ~ 240-million mai shekaru Kaibab Limestone . Yankin Bryce Canyon zuwa arewa maso gabas ya ci gaba inda yankin Sihiyona ya tashi ta hanyar gabatar da duwatsun Cenozoic da suka tsufa shekaru miliyan 100. A gaskiya ma, mafi ƙarancin samuwar da aka gani a yankin Sihiyona shine mafi tsufa da aka fallasa a cikin Bryce Canyon - Dakota Sandstone . Akwai, duk da haka, raka'o'in dutsen da aka raba tsakanin duka ukun, suna ƙirƙirar babban jeri na gyare-gyare waɗanda masana ilimin ƙasa ke kira Grand Staircase. Samuwar Bryce Canyon sune mafi ƙanƙanta sanannun raka'a a cikin Grand Staircase. Ƙananan raka'o'in dutsen, idan sun kasance sun kasance, an cire su ta hanyar zazzagewa .

Wadannan yadudduka sun sami 5000 zuwa 10,000 ƙafa (1500 zuwa 3000 m) na haɓakawa, farawa kimanin shekaru miliyan 66 da suka wuce tare da Laramide orogeny, wanda ya kara yawan ikon kogin Colorado don yanke tasharsa don yin mutum ɗaya daga cikin yankin Plateaus na Colorado . Manyan kwalayen yankin ba su fara samuwa ba sai kimanin shekaru miliyan biyar zuwa shida da suka gabata, lokacin da mashigin tekun California ya bude kuma ta haka ya sauke matakin kogin (mafi ƙasƙanci).

Ilimin burbushin halittu

A cikin 1880s, an tono manyan kwarangwal din dinosaur da yawa daga kudancin Utah a yankuna arewacin babban bene. Bayan waɗannan binciken, babu sha'awar ƙarin bincike. A ƙarshen karni na 20 da farkon 21st, an sami sabbin abubuwan buƙatu a cikin madaidaicin babban bene, musamman tun da fallasa da tarin sabbin burbushin halittu a cikin ɓangarori waɗanda ba a tantance su ba yana da babban yuwuwar bayyana ragowar burbushin halittun da ba a iya gani har zuwa yanzu.

Fossilized skeleton (partial) of a young hadrosaur
displayed at the Grand Staircase–Escalante National Monument
Click image for display placard text

Kudancin Utah ya ci gaba da ba da lada ga masu bincike saboda yanayin yanayi "mafi dadi" don fallasa ragowar burbushin halittu don dubawa da tattarawa a saman. A wurare kudanci, a cikin Arizona, yanayin ya bushe sosai don haka zaizayar ƙasa tana da ɗan jinkiri. A arewa kuma, yanayin damina yana ƙarfafa haɓakar dazuzzuka, waɗanda ke lalata burbushin halittu ta hanyar tushen da ƙwayoyin cuta na ƙasa. A kudancin Utah, akwai isassun isassun guguwa mai ƙarfi da rigar da za su haifar da zazzaɓi cikin sauri da kuma sakamakon bullar burbushin halittu, amma tare da rashin isasshen ruwan sama na shekara-shekara don tallafawa rayuwa mai lalacewa, tushen shuka.

Gallery

(Kudu zuwa arewa, hawan matakala)

Vermilion Cliffs
Farin Dutsen Dutse
The Permian ta hanyar Jurassic bangaren matakala, kamar yadda aka gani a Glen Canyon NRA

Manazarta

↑ "Bryce Canyon National Park Geologic Resource Evaluation Report" (PDF). Mature.nps.gov. Archived from the original (PDF) on December 15, 2016. Retrieved 2016-07-16.

[1] "Bryce Canyon National Park Geologic Resource Evaluation Report" (PDF). Mature.nps.gov. Archived from the original (PDF) on December 15, 2016. Retrieved 2016-07-16.

[1]