One of the most important and distinguished geologists in the history of the earth sciences was Ebenezer Emmons Sr., father of the Taconic System. The overthrust which places Lower Cambrian rocks in contact with Middle Ordovician rocks, known as Emmons' Line, formerly Logan's Line, is a segment that extends from Canada through New York, and as far south as Alabama. Emmons, a graduate of Rensselaer in the first class of 1826, was inspired by Amos Eaton. Emmons became junior professor at Rensselaer in 1830, a position he held for ten years, and while serving there, was appointed State (Chief) Geologist of the northern Geological District of the New York State Geological Survey in 1836. He named the Adirondack Mountains (1838), and the Taconic Mountains (1844, 1846) and acquainted the public with these regions. Emmons had noted the presence of a group of rocks between the Potsdam Sandstone, the oldest of the then recognized sedimentary formations in New York, and what was called then the Primitive Rocks of Central Vermont. Emmons inferred that the deformed rocks in Washington County, New York, north of Troy, New York, were older than any fossiliferous rocks then known. For these oldest fossil-bearing rocks he coined the name Taconic System. Emmons later became state geologist of North Carolina, spreading the influence of Rensselaer, and promoted his ideas of the Taconic System.Emmons' student at Rensselaer, James Hall became the chief American paleontologist of his era and one of the greatest American scientists of the 19th century. Emmons and Hall ‘dueled’ over the age of the Taconic rocks, a disagreement that became known as the Taconic controversy. Hall said they were younger, whereas Emmons claimed them to be older. This division led to suit and counter suit, and ultimately Emmons was forced to leave New York as a result of a court decision favoring Hall. Emmons and Hall are buried next to each other at the Albany Rural Cemetery in Albany, New York. The argument over the Taconic fossils raged for many years, and ultimately Emmons was vindicated, for Joachim Barrande, the chief student of European Paleozoic faunas, agreed with Emmons. The Taconic rocks of Troy, New York, are comparable in age and lithology to the rocks of the district near Prague which have been named Barrandian after Barrande. The American Museum of Natural History in New York honors "Scientists Who Have Served the State of New York and the Nation"; this list includes four geologists, three of whom are from Rensselaer. The first listed is Eaton, founder of Rensselaer, and last is Ebenezer Emmons.
