REPORT OF THE DIRECTOR I9I3 37 



Of the several explanations offered for the existence of the 

 heavily carbonated waters of Saratoga, one has assumed that it is 

 along the fissure of the fault that the carbon dioxid has found its 

 way from great depths within the crust of the earth. 



Our present understanding of the geological origin of the mineral 

 springs waters, briefly stated, is this : The region eastward of the 

 fault is covered by a thick layer of impervious shale, which is very 

 much broken up in the vicinity of the Hudson river. Where these 

 shales are most disturbed and broken, the percolating meteoric 

 waters have penetrated and have traveled along the dip of the 

 underlying rock through the limestone beneath where as a result 

 of secondary changes there taking place in the limestone, they have 

 acquired carbon dioxid and when saturated with this gas have 

 gained an increased solvent power which has enabled them to take 

 up various soluble salts from the rocks through which they have 

 passed. Traveling easterly they reach the fault fissure which they 

 have been unable to traverse, and thus it happens that the springs 

 derived through natural crevices or artificial holes in this basin, 

 all lie on the east side of the fault line.^ Whatever the future of 

 the Saratoga mineral springs may be, and with the present and com- 

 ing development of the science of hydrotherapy the outlook is most 

 brilliant, Saratoga will always remain a place of high geological 

 interest from the very fact of the relations of these waters to the 

 rocks and to the fault line. It is therefore a matter of considerable 

 public interest that the State commission should have brought out 

 to its full effectiveness this fault cliff, even though the displacement 

 is of a lesser order of magnitude. To increase public apprecia- 

 tion it might be well worth while to attach to the accessible 

 face of the cliff, some placard or tablet which would explain the 

 cause of the fissure and its influence upon the mineral waters. 

 An eminent student of earthquake movements has suggested that 

 it would be well worth while to attach a tablet not only to the 

 face of the cliff but to the ground surface of the fault as well and 

 have a precise leveling between fixed points on these two tablets so 

 that it might be possible to determine any movement of the cliff 

 up or down, that is to say, any reappearance of seismic or earth- 

 quake movements along this ancient line of weakness. 



Stark's knob, Saratoga county. Stark's knob is a knoll of vol- 

 canic rock near the village of Schuylerville which, as its name 



^The Ainsworth spring lying on the west of the fault, traversed it and 

 derived its water from the east side. 



