As materials, comprising the clastic wedge, become coarser in close proximity to the Taconic source rocks, siltstone and sandstone layers are predominant in New York.

[2] The formation is wedge-shaped, thick (up to 300 metres (980 ft) below Lake Erie), and laterally extensive, outcropping from Western New York to Cabot Head.

Colouration is connected to post-depositional processes: red portions are the result of oxidation of iron-bearing minerals and green comes from reduction, possibly by acidic groundwater.

[6] The formation is devoid of fossils in the uppermost shaly layers and is poorly fossiliferous throughout other parts, particularly, the bioclastic beds, where brachiopods, bryozoans, ostracodes, pelecypods, gastropods, tabulate corals and trilobites (Acernaspis) are found.

Most of the sediments was deposited in the near-coastal semiarid setting with shallow, wide, muddy, prograding shore, affected by tides, frequent storms and fluctuating sea level of tectonic or, possibly, eustatic origin (Andean-Saharan glaciation).

Facies association A, composed mostly of dark grey shales, was deposited on a shelf, shallow enough to be affected by storms, that resulted in sandstone and bioclastic limestone layers.