8 



NEW YORK STATE MUSEUM 



Pamelia (Stones river) formation in the region. It was found 

 to extend across the Clayton quadrangle with increasing thickness 

 and into Canada in much greater force than could have been in- 

 ferred. About Kingston it has much the same thickness as in the 

 Clayton region and it probably runs from there westward all the 

 way across Ontario as the basal member of the Paleozoic series 

 of that district. It also extends up the Black river valley in 

 greater thickness than could have been anticipated from any pub- 

 lished descriptions of the region. Detailed field work has definitely 

 determined an unconformity between it and the overlying Low- 

 ville limestone. 



The Paleozoic rocks of the district display a series of low folds 

 In two directions, one trending northeast and another of later date 

 and minor amount trending northwest and folding the earlier folds, 

 producing domes at intersections of the arches of the two sets 

 and shallow basins at trough intersections. 



It is specially noticeable in the southern half of the Clayton area 

 that the dip of the rocks and the direction of the drainage coin- 

 cide. Wherever the gradient of the streams becomes steeper than 

 the dip, there has resulted a local downcutting which brings to 

 light the lower strata in patches entirely inclosed by the higher; il- 

 lustrated particularly by the exposure of irregular patches along 

 active or abandoned stream channels, of the Lowville limestone 

 in the midst of a blanket of the Black River limestone. Dr Ruede- 

 mann who has studied and plotted these areas, regards them as of 

 identical character with the Fenster " of the German geologists, 

 windows out of which look the lower formations. As an English 

 term of equivalence he proposes the expression erosion inliers as 

 distinguished from the more usual depositional inliers which are 

 of tectonic origin. Besides these erosion inliers the same area also 

 exhibits patches of the Lowville beds exposed in the mantle of over- 

 lying Black River limestone by solution of the latter along joint 

 planes making solution inliers. Though these are usually of small 

 area yet some are large enough to record on the topographic base. 

 Another crosional phenomenon of interest better exhibited on the 

 Clayton sheet than elsewhere in the State is expressed by long 

 tongues of Black River beds capping narrow ridges that project 

 northward in groups from the Black River zone. The ridges in 

 each group are of subequal width and parallel to each other. They 

 arc believed by Dr Ruedcmann to have originated from the pluck- 

 ing action of the glacial ice along joint planes and their main di- 

 rection is consequently parallel to the direction of the principal 

 joints in each locality and to the movement of the ice. 



