484 H. M. AMI THE GEOLOGY OF QUEBEC. 



In this district the Trenton is again seen to occur at the foot of the falls 

 up the brook and ravine at the north end of the gorge, where the limestones 

 are made to abut at a high angle against the Archean escarpment by a down- 

 throw fault. The limestones are light-gray colored, impure and bituminous. 

 There are only a few feet of apparently upper Trenton beds seen at this point 

 between the cliff and the disturbed Utica beds alongside of and overlying 

 them."^ The following is a list of the species of fossils obtained from the 

 limestones up the ravine and along the brook : 



Hyalostelia, sp. und. ; Orthis testudinaria ; 



Glyptocrimis, or Glyptocystites, Primitia, sp. und. ; 



sp. und. ; Illcenus, sp. und. ; 



LejjtcEna sericea; Calymene senarla. 

 Strophomena, sp. und. ; 



On the right bank of the river and close to the falls on Mr. Hall's prop- 

 erty (near his residence) the following Trenton species were obtained: 



Crinoidal fragments ; Zygospira modesta ; 



Dictyophyton (?), sp. und. ; Strophomena aliernata; ^ 



L'uigula, s]). und.; Conularia, sp. nov. ; 



Orthis probably testudinaria; Trinacleus concentricus. 



Pointe-aux-Trembles. — Among the remaining localities where the Trenton 

 terrane has been met we have Pointe-aux-Trembles, near the mouth of the 

 Jacques Cartier river, where the Utica shales also occur, overlying the lime- 

 stones. From these the following species of characteristic Trenton fossils 

 were obtained : 



Heterocrinus canadensis; Leptcena sericea; 



Monticidipora, sp. und. ; Dahnanites callicephalus ; 



Strophomena alter nata; Calymene senarla ; 



" deltoldea; Asaphus platycephalus ; 



Orthis testudinaria ; Ceraurus pleurexanthemns. 

 Anastrophla hemlpllcata ; 



The above lists of species from Lorette, Charlesbourg, Beauport, Mont- 

 morency and Pointe-aux-Trembles are sufficiently characteristic to leave no 

 question whatever as to the age of the rocks from Avhich they were obtained. 



The Utica: Distribution. — The Utica shales are observed at several places 

 about Quebec city, and are readily recognized by the fauna which they con- 

 tain. For the most part the shales consist of brown or buff weathering and 

 black bituminous calcareo-argillaceous materials in a finely divided state and 

 very brittle or friable. At Montmorency falls, Beauport and Charlesbourg 



♦The quRrtzose limestone or calcareous sandstones of Trenton age, underlying the Trenton and 

 overlying the gneiss at Montmorency, are also of Trenton age, no Potsdam, Galciferous, or Chazy 

 being present. 



