DRY-DREDGING IN EASTERN CENTRAL NEW YORK 



By G. ARTHUR COOPER 



Assistant Curator, Division of Invertebrate Paleontology, 



U. S. National Museum 



New York State has long been classical ground for the study of 

 Paleozoic formations, particularly those of the Devonian system. 

 Many Devonian localities are now world famous and are visited every 

 year by geologists. It would not be expected, therefore, that much 

 of the new or unusual is still to be found. Nevertheless, several 

 regions in New York have been neglected or overlooked since the 

 earliest survey of the State in the years 1836- 1842. This is notably 

 true of the country lying between Chenango Valley and the Helder- 

 bergs in eastern New York. The writer has long been interested in 

 the Devonian rocks of this little-known region and most particularly 

 in the outcroppings in the vicinity of Hamilton, where the geologists 

 of New York's early survey chose the typical or reference region of 

 a series of rocks which they termed the Hamilton Group. When in 

 the employ of Colgate University some years ago, the writer mapped 

 the detailed stratigraphy of this critical area. It was his purpose this 

 year to make collections for the United States National Museum from 

 the more fossiliferous layers, few specimens of which had ever been 

 acquired by this institution. 



The region furnishing the bulk of the material collected is em- 

 braced by the Cazenovia, Morrisville, and Norwich quadrangles. 

 The Cazenovia and adjacent Morrisville quadrangles lie between the 

 meridians of Syracuse and Utica and some distance to the south. The 

 Norwich quadrangle adjoins the Morrisville on the south. Physio- 

 graphically the region is a portion of the maturely dissected Allegany 

 Plateau. The hills are gentle, having a relief of about 300-500 feet, 

 but rarely attaining 1,000 feet. Post-glacial gorges tributary to the 

 main streams afford adequate exposures and good collecting grounds. 

 Hamilton, a quiet little village, lies near the head of the Chenango 

 Valley. Natural exposures and quarries are abundant in and about 

 the village. 



The general geology of Hamilton and vicinity is rather simple. 

 The rocks are all Paleozoic in age, dipping gently to the southwest a 

 little less than one degree. Minor undulations cause local changes in 

 dip ; no faults complicate the sequence. The portion of the Paleozoic 

 column exposed is from the Upper Silurian (Vernon shale) to the 



19 



