460 ANNALS NEW YORK ACADEMY OF SCIENCES 



Announcement was made of the issue of a circular letter inviting the 

 geologists and mineralogists of New England, New York, New Jersey and 

 eastern Pennsylvania to participate in a joint meeting April 6. 



The following program was then offered: 



E. 0. Hovey, The Annual Meeting of the Geological Society 



or xAvierica, Albuquerque, New Mexico, Decem- 

 ber 30-31, 1907. 



Charles P. Berkey, A Revised Cross-section of Rondout Valley along 



THE Line of the Catskill Aqueduct. 



James F. Kemp, Present Trend of Investigations on Underground 



Waters. 



Summary of Papers. 



Dr. Julien's paper presented at the last meeting of the section was dis- 

 cussed briefly by the author who showed two newly prepared charts of 

 minerals not shown at the former meeting. Remarks were made by Pro- 

 fessor J. F. Kemp. 



Dr. Hovey gave an account of the chief points of interest in connection 

 with the meeting at Albuquerque and a brief summary of the papers. 



Dr. Berkey said in abstract: The explorations of the Board of Water 

 Supply of New York City have now been made so complete across the 

 Rondout Valley, a distance of five miles, that it is possible to construct by 

 the aid of this data probably the most accurate cross-section of the rock 

 structure yet known in New York State. There are twelve distinct forma- 

 tions of stratified rock involved, all of which will be cut by the projected 

 pressure tunnel. One marked unconformity in the series separates the 

 Ordovician Hudson River slates from the overlying conglomerates, shales, 

 sandstones and limestones of Silurian and Devonian age. There are three 

 faults of considerable displacement, together with smaller ones and minor 

 foldings. In the eflfort to determine the variations of these formations as to 

 thickness, depth from surface, displacements, physical conditions, water 

 content and capacity, the presence of caves and relative solubility, and the 

 position and depth of the buried channels beneath the drift cover, the 

 available figures are so abundant that the section may be considered accurate 

 within a few feet for a considerable proportion of the whole width of the 

 valley and to a depth of 300 to 400 feet. 



Several drawings illustrating these features in detail, originally prepared 

 for the Chief Engineer of the Board of Water Supply, were shown by per- 



