DETAILS OF THE SECTIONS 4/ i 



section, I wish to limit myself to the more salient features, especially in 

 the case of the conglomerates, since this formation has been studied in 

 great detail by Mr. Paul Billingsley, a graduate student in Columbia. 

 University, whose work is to be published elsewhere. 75 Careful perusal 

 of his studies and the conclusions drawn therefrom is recommended. 



The Green Pond conglomerate and Longwood shale of the Paleozoic 

 fault-block of New Jersey and eastern New York.— A long outlier of 

 Paleozoic strata, the eastern extension of the beds found in the Front 

 Eange of the northern Appalachians, occurs in northern New Jersey and 

 southeastern New York. The ridge forms Green Pond Mountain at the 

 south and Skunnemunk Mountain on the north. Intense folding and 

 faulting have complicated the original synclinal structure and rendered 

 measurement of sections difficult. The mass is separated on the west by 

 a fault throughout its entire extent, and there can be no question but 

 that it was originally connected with the strata of similar age in the 

 Front Eidge of the northern Appalachians farther west. In this outlier 

 the eastern extension of the clastic micl-Siluric beds are found in the 

 Green Pond conglomerate and the Longwood shale. 



The name "Green Pond conglomerate" was originally applied to two 

 distinct formation's, but was restricted by Darton in 1894 to the basal 

 Siluric conglomerate, exposed in the vicinity of Green Pond Mountain, 

 New Jersey, and representing the age equivalent of the New York 

 Shawangunk. 76 Its thickness was estimated by Kriiminel and Weller 77 to 

 be approximately 1,200 and possibly 1,500 feet in the center of the area, 

 from which point it decreases northward and southward. At Skunne- 

 munk Mountain, New York, Hartnagel measured 250 feet, but some 

 portion of the formation is concealed. At the railroad section near Corn- 

 wall station only about 25 feet are shown. Southward it likewise thins 

 away, though measurements are not available. 



The rock consists throughout of coarse, red conglomerates in its lower 

 part and buff and reddish quart/dies in the upper, these characters re- 

 maining uniform throughout. The pebbles are largely quartz, from one- 

 half to 3 inches in diameter, with a dull red sandy matrix. Pebbles arc 

 usually aumerous, but decrease iii nuinher locally. They are generally 

 well rounded, hid may also he angular. In one place large masses of the 

 underlying limestone are included. \l Cornwall, where the conglom- 

 erate rests unconformably oh the Hudson series, the pebbles range in 

 size up to 2 inches. As compared with its next western exposure, the 



' Manuscrlpl <l<>|H>sil< ; <l in <\>hnnl>i:i I ! ni\ (>i-sil \ 



"Bull. Geol. Soc. Am., vol. 5, 1894, p. 888. 

 WQeol, Ni'w Jersey, Ann. Report, 1901, i». 18. 



