518 PKOCEEDINGS OF THE ROCHESTER MEETING 



Archean rocks which crosses the Saint Lawrence river between the city of Kingston 

 and Brockville and connects with the great Adirondack massif to the south. 



The Frontenac axis divides the Ordovician strata, to the east as well as to the 

 west, into two series, which, though not very distant, geographically speaking, 

 are nevertheless marked by important features and differences. 



On the east and west sides of the axis the following order of succession in the 

 geological formations obtains : 



Ordovician East of the Frontenac Axis 



Formations Character of Strata 



VII. Lorraine Buff weathering and dark silicious shales and mudstones. 



VI. Utica Dark brown and black bituminous shales and limestones at 



the base. 



V. Trenton Dark gray, impure, and semicrystalline fossiliferous lime- 



, stone. 



IV. Black River Heavy bedded and hard compact fine-grained impure lime- 

 stones, etcetera. 



III. Chazy Limestones, shales, sandstones, and grits. Shallow water 



deposit at the base. 

 II. Beekmantown (Calciferous) Dark gray, impure magnesian limestone or dolomites, cav- 

 ernous and fossiliferous. 

 I. Potsdam Light yellow and rusty colored sandstones and conglomer- 

 ates, shore deposits resting on the Archean crystal lines. 



Ordovician West of the Frontenac Axis 



V. Lorraine Arenaceous shales and mudstones, at times very fine grained 



argil lites. 



IV. Utica Dark brown and black fossiliferous shales, &c. 



III. Trenton Gray impure fossiliferous limestones. 



II. Birdseye and Black River Heavy bedded impure fossiliferous limestones and fine- 

 grained compact lithographic beds at the base. 



1. Rideau Mostly red and yellow (at times green) colored sandstones ; 



shallow water deposit, false bedding prevalent, a basal 

 series resting unconformably upon the subjacent Archean 

 crystallines. 



An attempt is made to solve the problem arising from the discussion of these 

 differences in the sedimentaries on each side of the axis, and in the remains of life 

 entombed in them. 



Remarks were made on the subject of the paper by Bailey Willis, W. M. 

 Davis, and the President. An abstract is printed in Science, volume xv, 

 January 17, 1902, page 82. 



The following paper was read by Mr Shinier : 



HAMILTON GROUP OF THEDFORD, ONTARIO 

 BY H. W. SHIMER AND A. W. GRABAU 



The paper was discussed by J. M. Clarke, H. S. Williams, and H. M. 

 Ami. It is printed as pages 149-186 of this volume. 



