CONDITIONS OV SI';I)IMI:N TATION 103 



Mr Van rno:en also rej)orts oiitc'ro[)s of the conglomerate on the .lay- 

 cox farm, just north of \Vappin«!;er's falls. He says: 



"Atrjiiniat this olifT (of dolomitic limestone) the Trenton was deposited. The 

 line of eontact is quite plainly seen and is rather inej^ular, witli nndercnt projec- 

 tions. . . . The limestone here is partly a conglomerate of the dolomite peh- 

 bles and partly clear of these. . . . The i>ecnliar feature of this locality is that 

 the pebbles are not restricted to the lower layers, but occur at two or more levels, 

 the intervening layers being either non-fossiliferous, dark, impure limestone or 

 filled with the >^olenopora. The true base of the limestone cannot be seen here, 

 so that I was unable to determine whether it is conglomeratic or not. The peb- 

 bles are often large — five inches." 



Dwight^also mentions a locality in the Wappinger valle}^, 2 miles 

 southeast of Pleasant valley and 15 miles north of the ahove-mentioned 

 locality, where the rock is " filled with limestone ])ehbles of various 

 sizes and lighter in color than the mass." He states that many of these 

 may have been organic, although no organic structure was visible. His 

 words, however, describe exacth^ an exposure of the Trenton conglom- 

 erate. The occurrence of the conglomerate in Orange and Dutchess 

 counties, New York, seems certain. 



Although the conglomerate occurs beyond the limits of New Jersey 

 to the northeast, it is, so fiir as our own brief observations and the writ- 

 ings of others go, absent to the southwest. In Pennsylvania and southward 

 the Trenton beds follow those containing Calciferous and Chaz}'' fossils 

 with apparently no break in sedimentation. The region chiefly affected 

 by the uplift, so far as data in hand show, was small as compared to 

 the great extent of the Kittatinny limestone, and the movement gave 

 rise, perhaps, to only a series of low, rocky islands and reefs, against 

 which the waves beat and about which the conglomerate was formed ; 

 but the profound life change at this horizon, wherever the rocks of this 

 age are exposed, even though the conglomerate and accompanying 

 unconformity be not found, indicates something more than a local dis- 

 turbance. The break in the record was long enough for the incursion 

 of an abundant fauna of ver}^ different facies from that })reviously occu- 

 pying the sea. 



The passage from the Trenton limestone into the overlying shale and 

 slate was due to changes prevailing along the entire Appalachian valley — 

 changes which Mr Weller's faunal studies show were inaugurated in New 

 Jersey earlier than in the typical Trenton area in New York. 



Date of Folding and Faulting 

 So far as observed, there are in New Jersey no data showing absolutely 



*Am. Jour. Sci., 3d series, vol. xvii, p. 390. 

 XXIV— Hum.. Geoi,. Soc. Am.. Vor.. 12, 1900 



