Ingta Formation

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

Ingta Formation
Stratigraphic range: Ediacaran–Lower Cambrian[1] (?) PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Thickness	up to 312 metres (1,020 ft)
Lithology
Primary	Interbedded Shale & Sandstone
Other	Subordinate limestone units
Location
Country	Canada

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]