algae and the skeletal remains of coral, stromatoporoids, brachiopods, and other ancient marine fauna. The episodic eustatic rise and fall of sea level caused depositional environments to change or to shift laterally. As a result, the preserved faunal remains, and the character and composition of the sedimentary layers deposited in any particular location varied through time. The textural or compositional variations of the strata, as well as the changing fossil fauna preserved, are used to define the numerous sedimentary formations of Silurian through Devonian age preserved throughout the region. See also Ebenezer Emmons, the geologist who first described the Taconic system Queenston Delta, a clastic wedge of sediment deposited west of the Taconics at that time Notes References Ordovician orogenies Geology of New York (state) Geology of New Jersey Taconic Mountains