ABRAHAM GESNER REVIEW OF HIS SCIENTIFIC WORK. 33' 



Dr. Gesner's older Graywacke group also contained strata of 

 various ages. To him, the distinctive features of this group, 

 were its incipient metamorphism as shown by the innumerable 

 quartz veins mixed with talc and chlorite, that traverse the 

 rocks, and the absence of organic remains. Of the three masses 

 of strata associated by Dr. Gesner in this lower Graywacke 

 group, the lowest consists of the schists of the Coastal (Huron- 

 ian) group, the middle of the southern basin of Dadoxylon sand- 

 stones of the Little River group and the upper part of the con- 

 glomerate beds to the north of them. The unusual hardejuing 

 of the Pal?eozoic and older rocks at Mispec give to this " older 

 Graywacke " group of Dr. Gesner an appearance of greater 

 antiquity than that possessed by the strata further north. 



Four years after closing his engagement with the government 

 of New Brunswick, Dr. Gesner published a general work on that 

 province, describing its topography, resources, etc., and giving 

 an outline of its geology. In this there is a later expression of 

 Dr. Gesner's views respecting the age of the schistose rocks of 

 the southern coast. Here he classes the Lower Graywacke 

 group with gneiss and the clastic schists under the head of 

 Metamorphic Backs* and states that these rocks skirt the shores 

 of the Bay of Fundy from Salisbury Cove to Chamcook Bay. 

 He says that no fossils have been discovered in these rocks, and 

 evidently they are his Lower Graywacke group. 



As regards the Upper Graywacke group, it would appear 

 that Dr. Gesner at this time was disposed to assign a part of 

 them to a higher horizon than he had previously. In one of his 

 geological reports he had remarked that several of these vegetable 

 relics were discovered in slate and Graywacke, which agree in 

 their general characters with the sandstones and shales of the 

 upper coal series.! The thought here foreshadowed seems to 

 have governed Dr. Gesner in his final remarks upon the plant- 

 bearing and shell-bearing beds at St. John, for he says that the 

 sandstones containing the fossilized remains of coniferous trees- 



* New Brunswick, p. 343. + Second Report, p. 12, 



