GEOLOGY OF THE VICINITY OF LITTLE FALLS 59 



Character and slope of the pre-Cambrian floor 



The pre-Cambrian rock exposures of the Little Falls outlier 

 extend for 2 miles in an east and west direction, with a general 

 breadth of a half mile. While the contact with the overlying 

 Beekmantown formation is actually shown in but two places, it is 

 but scantily covered elsewhere, being within a few feet of showing 

 continuously on both sides of the river. The surface on which the 

 Beekmantown rests is surprisingly smooth and even. There are not 

 even minor irregularities in it. For the first mile (between the 

 two faults) it is nearly horizontal, though with slight westward 

 inclination. Beyond the westerly fault it drops to the westward 

 at the rate of 200 feet to the mile up to the point of disappear- 

 ance beneath the river level. In this western portion the Beekman- 

 town rocks slightly overlap on it, their fall to the west being 

 slightly less rapid. The same may be true of the remainder 

 though it is not certain. 



The outlier at Middleville is not sufficiently extensive to afford 

 much evidence in this connection. The creek has here cut down 

 on the summit of a low fold. There is no evidence here of irregu- 

 larity of original surface, but there is slight opportunity for such 

 evidence. 



The small outlier at the " Gulf ", 2J miles northeast of Little 

 Falls, seems to represent the summit of a small knob of the old 

 surface projecting up into the overlying Beekmantown. But it 

 can not be much of a hill at best. The pre-Cambrian surface, at 

 the fault line east of Little Falls, has an altitude of 700 feet; 4 

 miles to the northward, where it reappears from underneath the 

 Beekmantown rocks to the west of the fault line, its altitude is 

 1000 feet; the little outlier is midway between the two and is at 

 860 feet elevation. 



Along the main line of contact between the Beekmantown and 

 pre-Cambrian the same evidence of comparative evenness of the 

 rock surface on which Beekmantown deposition took place, is 

 presented. Exposures are not all that could be asked, and at 

 Diamond hill there is evidence of a low hill rising some 100 feet 

 above the general level, that being the greatest irregularity of sur- 



