Ingta Formation
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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: | |
| 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]
