282 OBSERVATIONS ON THE GEOLOGY OF THE WESTERN PENINSULA 



Canadian shore, we encounter the rock just described, in another series of 

 quarries lying about two miles east of the river. Extensive openings, said to 

 occupy an area of nearly forty acres, expose the strata to a moderate depth. 

 The layers vary considerably in texture and aspect, some, when weathered, 

 being of a yellowish tint, and arenaceous, while others are compact and com- 

 paratively pure, resembling exactly the purer variety met with at Truago. In 

 these quarries it was difficult to establish any decided dip. If a general incli- 

 nation of the beds does prevail, it is westward. 



Neither at the Maiden nor Truago quarries did we meet with any trace 

 of the pitted rock, nor with any bed containing the hopper-shaped cavities 

 seen in the limestone below the pitted rock on the Maitland. From these 

 facts we are convinced that the Maiden and Truago beds overlie the vesicu- 

 lar rock of Gros' Isle. They are therefore identical in position, as they ob- 

 viously are in lithological character, and organic remains, with the limestones 

 of the Maitland. These beds are highly fossiliferous, abounding in Stropho- 

 mena lineata, S. rugosa, Delthyris, Atrypa, Leptsena, Cyathophillum ceratites, 

 Favosites, Encrini, Orthoceratites, Trilobites, and several other fossils not yet 

 specifically determined. 



Rocks of the Maumee River, and of Sandusky Bay. — Near Maumee city, on 

 the Maumee River in Ohio, we again meet with the well-marked pitted lime- 

 stone, identical in all respects with that already described as occurring at Gros' 

 Isle and Goderich. Its exposure in this position on a line drawn through 

 Goderich and Gros' Isle, is a fact of the higliest interest; for it goes to establish 

 unequivocally, both the existence and direction of the extensive anticlinal axis 

 which we had conjectured to pass from Upper Canada into western Ohio. 

 The position of this important axis, is probably some distance east of the 

 Maumee, for the rocks on that river have a visible western dip. It crosses 

 Lake Erie most probably nearly midway between the western head of the 

 Lake, and the chain of Islands which stretch from Point Sandusky to Point 

 Au Playe. 



Comparing the rock laid open in the quarries at Marblehead, near Sandusky 

 Bay, with that seen at the head of the Lake, we cannot hesitate to refer them 

 to the same formation, the opposite direction of their dips resulting from the 

 axis above mentioned. An examination of the fossils most prevalent in the 

 Sandusky limestone establishes, beyond a question, the identity of this forma- 



