PETROLEUM AND NATURAL GAS IN NEW YORK 401 



contained in such strata, is in most instances saline. With re- 

 spect to water found at a depth of 500 feet or more, the presump- 

 tion in many parts of the world is that it is saline. Compounds 

 of soda and potash are widely diffused in the crust and many of 

 them are very soluble and are gathered, accordingly, in under- 

 ground water. Where the arrangement of the rocks is such that 

 outflow occurs, the soluble compounds will, in the course of time, 

 have all been carried out, and the outflowing water may at last 

 have a high degree of purity. But, in multitudes of instances, 

 the porous strata are so folded that the water of large portions 

 has no access to the surface. When the drill reaches such 

 areas, concentrated brines are often found. Saline water is al- 

 ways heavier than fresh water. It is not uncommon to find these 



deep waters increased in gravity by one tenth beyond the propor- 



» 

 tions of pure water. It goes without saying, therefore, that the 



synclines of the porous rocks, would be occupied by these heavy 

 waters, and it is equally obvious that all the oil will rise to 

 the sides and summits of the arches unless gas accompanies the 

 oil, in which case, the highest level will necessarily be occupied 

 by the latter. 



The great development of anticlines and synclines is to be 

 found in mountain regions, and here they are shown in their most 

 striking forms. Parts of the great Appalachian system afford 

 the most complete exhibition of these types of structure that is 

 known in the world, though the Jura mountains of western 

 Europe also furnish admirable examples of folded rock series. 

 It is not in mountain regions, however, where he that runs can 

 read the arches, the elements that constitute them, their dips and 

 their directions, that accumulations of petroleum are to be looked 

 for. W T hen the rocks are folded into great arches that constitute 

 the principal scenic features of the regions which they occupy, 

 they have not escaped fracture at their summits. Faulting has 

 also taken place in numerous instances along their axes, and 

 by these two agencies, namely, fractures and faults, great accu- 

 mulations of oil and gas have been made impossible. Such frac- 

 tures give rise to a slow escape of oil, gas or mineral water, the 

 latter often being characterized by temperatures above the nor- 



