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