THE DISTRIBUTION OF ANCIENT VOLCANIC ROCKS. 1 9 



retarding effect on the deciphering of New Brunswick geology. 

 Numerous occurrences of felsite, porphyries and amygdaloids 

 were described between Musquosh Harbor and Loch Lomond, 

 near the city of St. Johns, and along the line between Kings 

 and Queens counties (Coldbrook and Bloomsbury groups). 

 Similar rocks were traced from L'Etang Harbor, near Passama- 

 quoddy Bay, along the edge of the Bay of Fundy to Shepody, 

 in Albert County (Coastal group) ; and finally, a belt of ana- 

 logous composition was described between the Long Reach of 

 the St. Johns river and Mace's bay (Kingston group). These 

 rocks were at this time, however, on account of Hunt's influ- 

 ence, united with their associated sediments, and nothing is said 

 about their volcanic character. These authors were forced to 

 regard similar rocks on the shores of Passamaquoddy bay as 

 Silurian, because of associated fossils, in spite of their litholog- 

 ical identity with the "Huronian." These they called the Mas- 

 carene series.^ 



Four years later the same authors united the Kingston and 

 Mascarene groups and regarded both as upper Silurian.^ In a 

 report of the pre-Silurian rocks of Albert, eastern Kings, and 

 St. Johns counties. Ells gives some clear statements relative to 

 the volcanic rocks of southern New Brunswick. He says : 



" In their lithological aspect, the rocks forming the southern metamorphic 

 belt present great diversity. Their general character is of two kinds — altered 

 sedimentary and volcanic. * * * In the latter we include the great mass 

 of petrosiliceous rocks, so called, with breccias and other ash rocks, which 

 in places show bedding, but this is often so obscurely marked as to be exceed- 

 ingly doubtful. * * * Near the contact of the volcanic and sedimentary 

 rocks we find an extraordinarj^ development of generally coarsely crystalline 

 diorites and syenites, which would seem to form the basal portion of the vol- 

 canic part of the series. "^ 



A report on the same rocks was published at the same time 

 by Bailey, who divides them into a feldspathic, syenetic and 

 gneissic group, including limestones, serpentines, and dolomites 



^Ib., pp. 144-158. 



= lb., 1874-75, pp. 85-89. 



3 lb., 1877-78, D. p. 3. 



