Английская Википедия:Ingta Formation

Материал из Онлайн справочника
Перейти к навигацииПерейти к поиску

Шаблон:Infobox rockunit

The Ingta Formation is a geological unit containing green sandstones and shales; it crops out in the Canadian Mackenzie Mountains.[1] Its age is poorly constrained, though it straddles the Precambrian/Cambrian boundary.[2] Below the boundary its ichnofauna comprises subhorizontal Planolites burrows; above it, Phycodes burrows immediately appear, with Nemakit-Daldyn SSFs appearing soon after.[2]

Stratigraphy

The formation is overlain by either the Backbone Ranges Formation and the Vampire Formation, depending on the locality. These two formations have a common base with the Ingta formation, and both continue onwards until the base of the Sekwi Formation. [3]

Depositional environment

The rocks are submarine, and were deposited in a nearshore to offshore location on the continental shelf, with no freshwater influence evident—although overlying units bear evidence of deltaic and braided river deposits.[4]

Palaeontology

The formation has yielded a range of SSFs including eggs and embryos, anabaritids, Protohertzina, Zhejiangorhabdion, and phosphatized tubes, spines and plates.[5]

References

Шаблон:Reflist


Шаблон:Geologic-formation-stub

  1. Шаблон:Cite journal
  2. 2,0 2,1 Ошибка цитирования Неверный тег <ref>; для сносок auto не указан текст
  3. Шаблон:Cite book
  4. Шаблон:Cite journal
  5. Шаблон:Cite journal