112 NEW YORK STATIC MUSEUM 



a breccia toil appearance. TIk* Canadian <jeolo<?ists report the 

 presence of conglomerate bands in the s.vnchronous graptolite 

 <hale of Quebec; and Mr Kinnniel and Dr WeUer have discovered 

 a congh)nierate bed at the base of the Trenton in New Jersey. 

 I( is. howcvci*. nioiH' Hum doubtful that tlict^e ocrurreuccs havt* 

 luy ri'latiun to ihe bt'd in Kenssehu'r county, sjHH'ially as the 

 New Jersey conglomerate is considered a basal conglomerate, and 

 that of Rysedorph hill is evidently intraforraational, containing 

 pebbles of the same*ejK)ch and intercalated in shales of the same 

 epoch. It has, however, been demonstrated that a continuous 

 stratum of conglomerate, over which, on a .^inking c<)«st, younger 

 deposits creep, may belong to many successive horizons. This 

 has been most clearly pointed out by De la Beche in the south- 

 west of England^ The New Jersey conglomerate may therefore 

 be only apparently basal and actually synchronous with the more 

 northern one., 



As the study of the conglomerate beds of various formations 

 and the investigation of the conditions along coasts where such 

 beds are formed, has furnished ample evidence that conglomer- 

 ates are the most inconsistent of all sedimentary formations, 

 usually sinking or swelling up suddenly, thinning out and reap- 

 l>earing, it is also to be assumed o priori that the bed extending 

 from Rysedorph hill to Schodack I>an5ing is not of such a wide 

 extent as to allow its connection with the beds of Quebec or New 

 Jersey. 



However that may be, the Rysedorph hill conglomerate con- 

 tinues to be remarkable as an intraformational conglomerate. 

 A conglomerate, according to the experience of geologists, gen- 

 erally indicates a break in the continuity of the sedimentation, an 

 erosion of a preexisting formation and, therewith,- an important 

 change^ in the physical conditions of the region. The writer feels 

 however th'at the presence of true intraformational conglomer- 

 ates in the Cambric and lowest lower Biluric of the Api)alachian 

 region has been so distinctly and vividly set forth by Wal- 

 cott ^ that no reasonable doubt of the existence of this phe- 



■ rietkJ**. TpxtlKK>k of Keolof^-. 1893. p. 516. 

 • 0©ol. ■•"' ^'^ '■"' '*''•* '■ 1''*'. 



