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off so large a portion of the upper strata from the Kittatinny 

 Valley. Between Belvidere and Columbia, on the Delaware, the 

 tract of slate, which is here several miles in breadth, exhibits 

 numerous local changes of dip, the result probably of a series of 

 lesser anticlinal axes, which may traverse this end of the belt. 

 The oblique cleavage planes are so conspicuously displayed in this 

 part of its range, as to efface, very generally, all distinct traces 

 of the true stratification, rendering the determination of its axes a 

 work of extreme uncertainty. The simple synclinal structure of 

 this belt opposite Newton and Augusta may, however, be readily 

 established by a close attention to the true dip of the rocks. 



Only two other ranges of the lower Appalachian limestone, 

 besides those already referred to, occur within the State. These . 

 are, the belt traversing German Valley and its extension, and the 

 small patch in the valley of Mendham. Both of these have been 

 previously adverted to, as occurring in the form of narrow syn- 

 clinal basins, included between the adjacent ridges of the primary 

 rocks. The upheaving of these latter, by a series of axes of 

 elevation difficult to trace in detail, has manifestly given to the 

 limestone its synclinal posture in the intervening valleys, where 

 this rock obviously once spread itself over much wider tracts than 

 at present. 



Igneous Rocks connected with Formation 11. 



Of the changes induced upon the limestone hy igneous action. — 

 The blue limestone of the Kittatinny Valley exhibits, in certain 

 localities, some highly impressive and remarkable phenomena of 

 alteration of structure, induced by the heating agency of a series 

 of igneous injections. The altered bands of the rock may be cor- 

 rectly grouped into tv.'o distinct belts, ranging from northeast to 

 southwest, parallel to the general strike of all the strata in this 

 quarter of the State. The more northeastern of these belts oc- 

 cupies, at intervals, the valley which lies immediately at the foot 

 of the Hamburg or Wallkill Mountain, throughout nearly its 

 whole length, keeping usually towards its northwestern margin, 

 or near the base of the Pochuck Mountain, and the belt of hills 

 in its prolongation to the southwest, namely, the hills north of 



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