174 



Highlands. It is seen well developed about one mile north of 

 the head of Green Pond, where it forms the point of the Green 

 Pond Mountain, near the notch or dislocation which traverses it 

 two miles south of the Pequannock. Both in this vicinity and 

 in other parts of the range, this stratum is divided by a system 

 of oblique cleavage joints, which cross the general plane of the 

 dip nearly at right angles, having an inclination of about 45° to- 

 wards the southeast. These joints impart to much of this rock 

 a slaty structure, calculated readily to mislead the observer 

 respecting the true direction in which these strata have been ele- 

 vated. The conglomerate is in like manner jointed by planes of 

 cleavage, but at far wider intervals ; being divided into large 

 massive cuboidal blocks. These joints observe the same direc- 

 tion and dip as those in the overlying fine-grained red sandstone 

 and shale. 



The total thickness of the formation, including the conglomerate 

 and the red sandstone, probably exceeds six hundred feet; but 

 from the appearance of great faults or dislocations in these strata, 

 the determination of their precise depth is attended with much 

 uncertainty. 



Of the probable Origin of the Formation. — From the wholly in- 

 sulated position of these unconformable strata, encompassed on 

 all sides by rocks of older date, and from the nonappearance 

 hitherto of any organic remains of a distinctive kind, by which to 

 infer their age and mode of origin, we are prevented from arriving 

 at any very satisfactory views regarding the particular circum- 

 stances under which they were produced. The striking analogy 

 which they bear, however, to the strata of the middle secondary 

 series both in composition and appearance, and their lying in the 

 same unconformable manner upon the previously uplifted rocks 

 of the Appalachian group, induce us to consider them as deposits 

 from the same mass of waters. This suggestion acquires addi- 

 tional weight, when we reflect that the long and narrow valley 

 embracing this belt of conglomerate and sandstone, opens imme- 

 diately into the great basin of the middle secondary series. From 

 the denuded condition of the southwestern portion of the Green 

 Pond range, and from the apparently natural outlet which German 

 Valley would afll^rd for the waters in their passage across this 

 mountainous district, it seems not improbable that these rocks 



