332 
GEOLOGY OF THE FIRST DISTRICT. 
3). A high mural precipice, originating in a fault, passes along the east shore, while two long 
promontories with arched strata stretch far into the lake from its extremities (Vide PL 26, fig. 
2). The same continues to the other pond, and the continuation of this fault and anticlinal 
axis is easily traced thence by the eye over the whole line of hills, to the summit of the Sha- 
wangunk mountain, ranging south fifteen to twenty degrees west. This line of fault continues 
south-southwest by Flint’s quarries, between which and Bridgeport it forms the high mural 
scarp of mountain on its west side; thence across the country from Bridgeport, with mural 
escarpments, to a high cliff on the Shawangunk (Vide PI. 7, fig. 1). 
Other lines of fault are seen at Lawrenceville, and which may be traced to cliffs on the 
Shawangunk. Near Lawrenceville, the limestone beds may be seen downheaved, and abutting 
against the Shawangunk grit (which underlies) by successive faults (Vide PI. 7, fig. 4). 
A disruption, or double line of fault, wdth an included anticlinal axis, may be seen between 
the upper end of Lawrenceville and the bridge across the Rondout, on the road to Highfalls 
(Vide PI. 26, figs. 4, 5, 6). It extends south twenty degrees west, to the gap on the Shawan¬ 
gunk mountain, where the same appearance presents itself, and which can be seen on the 
opposite side of the mountain from many parts of Orange county (Vide PI. 26, fig. 6). 
Various sections and diagrams will illustrate these and numerous similar facts in Plate 26,. 
in fig. 8 of PI. 27, and on PI. 8. 
The limestones of the Helderberg division, in the Mamakating valley, from Carpenter’s 
point on the Delaware, to Kingston, are all upturned, and frequently at a pretty high angle. 
In the township of Deerpark, Orange county, they “ form a narrow range of hills or low 
mountains,” sometimes sinking almost to the level of the Neversink valley, and at others 
rising to one-third or half the elevation of the Shawangunk. They are always narrow, and 
generally close to the base of the last named mountain. The rising and subsiding, of the tops 
of this ridge afford one of the most prominent features of this part of the valley, and add 
greatly to its picturesque beauty.”* These limestones dip in a west-northwest direction,, 
lying upon the subjacent Shawangunk rocks conformably; but some of the strata are rather 
enigmatical, and appear to dip to the east-southeast in consequence of the cleavage or shiver¬ 
ing of the strata since their deposition. In some of the strata, the real dip is evident, but in 
others it is not,t and it was only after minute examination that the real direction was with 
certainty determined. 
In Sullivan county, the Helderberg limestone rarely shows itself above the level of the 
quaternary deposits of the Mamakating valley, to which it is confined; but where it is visible,, 
it dips to the west-northwest, at a high angle. From Redbridge, on the canal, on the line 
between Sullivan and Ulster-counties, these rocks show*themselves more frequently, emerg¬ 
ing from the quaternary deposits of the valley, from the place mentioned down the valley by 
Ellenville, Napernock andWawarsing (Vide PI. 15, at Ellenville; PI. 6, fig. 7, at Redbridge;. 
PI. 39, figs. 1,2, at Redbridge. 
♦ Dr. Horton’s Report on the Geology of Orange county, N. Y. Geol. Rep. of 1839, pp. 150, 151. 
t Vide (d) PI. 39, fig. 3, c, d, e, in this section form the Helderberg division. 
