12 NEW YORK STATE MUSEUM 



GENERAL FEATURES OF THE GEOLOGY OF NEW YORK 

 AND THE DISTRIBUTION OF THE MINERAL 



RESOURCES 



Geology supplies the basis for the study of mineral deposits 

 in their broader relations. The first essential in the investigation 

 of the mineral occurrences of a particular region is to become 

 acquainted with the geological conditions — the nature and deriva- 

 tion of the constituent rock materials, their mutual relationships, 

 structural characters, sequence, and the marks of physical and 

 chemical changes that have taken place since their accumulation. 

 Some of this required information may be conveyed by a geological 

 map; an adequate map of the kind serves as a ground plan for the 

 systematic description of the mineral resources of any state or 

 country.^ 



New York covers an area of 49,204 square miles, inclusive of its 

 waters which have a surface of 1550 square miles. It has a range 

 of altitude of a little more than i mile — from sea level to 5344 

 feet, the high point of the Adirondacks represented by Mt Marcy. 



Few states of comparable area contain so long a sequence of 

 geological formations and at the same time illustrative of such a 

 variety of characters. Among the formations are representatives 

 of almost every class of the deep-seated igneous rocks and of nearly 

 all the important sedimentary groups from the early Cambrian to 

 the present day. In the Adirondacks the State includes a part of 

 the Laurentian highland, the foundation of the North American 

 continent, made up entirely of Precambrian igneous and metamorphic 

 materials. In the southeastern Highlands, which belong to the 

 Appalachian mountain system, Precambrian strata are also exposed, 

 both igneous and sedimentary, with later sediments lying on the 

 northern flank. The Taconic uplift, with its upturned and meta- 

 morphosed Cambrian and Ordovician strata, occupies the area east 

 of the Hudson and north of the Highlands. West of that river 

 and stretching across the State to the western boundaries is the 

 plateau province of Devonian sandstones and shales, giving way 

 on the north to the Lake Ontario plain which is floored mainly by 

 Silurian strata. South of the Highlands, the Hudson Palisades 

 represent an intrusion of basic igneous rock (diabase) in Triassic 

 sandstones and shales. The Atlantic coastal plane of Cretaceous 



^ The inclusion of a. geological map with the present report has not been feasible 

 on account of the time required for its preparation, which would have neces- 

 sitated a long delay in the publication of the volume. Separate maps of the State 

 and in some instances of particular districts may be obtained from the State 

 Geologist on special request. The latest map that covers the whole State is the 

 edition of 1901, on the scale of 5 miles to i inch. 



