32 



conglomerate that marks the base of the St. John terrane. The space 

 between the granite and this conglomerate, measured by my assistant, 

 was two hundred feet. The indications are that the whole three 

 divisions of the Etcheminian are represented in this space as well as 

 the Coldbrook terrane, and it appears to be a case of scant deposition, 

 such as marks some of the valleys holding Cambrian deposits in 

 New Brunswick. 



The Etcheminian measures, which are out of sight in this section, 

 appear on the eastern branch of Gillis brook where they occupy the 

 bed of the stream with the breccia-conglomerate (of the St. John ter- 

 rane) on the south and the purplish-red sandstones and pink quartzites 

 to the north. The breccia-conglomerate here is full of fragments of 

 felsite, and of the red granite which appears in the hill to the north, 

 and there are a few fragments of black silicious slate, all of which are 

 found as rock masses, either in the Coldbrook terrane, or in the ad- 

 joining pre-Cambrian complex. 



Fossils at On the east branch of Gillis brook, where the beds of Division 3 are 



Indian brook, exposed beside the breccia-conglomerate, they contain various fossils, as 

 Acrothyra proaviacrassa, Acrothele proles, A. avia-puteis, Leptobolus 

 collicia, Leptobolus collis, Bradorona scrutator, a trilobite, Soleno- 

 pleura (?), &c. Between the ridge of breccia-conglomerate behind 

 Gillis house and the deep valley of Indian brook, the land descends 

 rapidly, and there are a few exposures of the gray flags and slates of 

 the Johannian division of the St. John terrane ; the space to Indian 

 brook is about 2000 feet. 



THICKNESS OF THE ETCHEMINIAN IN THE VALLEY OF THE MIBA RIVER. 



Basal In this valley I could not find the breccia-conglomerate, which on 



of St. John East bay so distinctly marks the upper limit of the Etcheminian ter- 

 F c jVP ajj? ent rane. The top of this group and the base of the St. John group in the 

 valley. Mira valley each consists of soft and fine sediments, and from the ero- 



sion of these beds the contact between the two terranesis seldom seen. 

 Their colour and relation to the overlying mass of flags and quartzites 

 of the Johannian division of the St. John group will often serve to 

 distinguish them. The slates of the Acadian division of the St. John 

 group in this valley are dark gray (often purplish-gray weathering) ; 

 those of the upper division of the Etcheminian are compact pale gray 

 (often greenish-gray weathering) ; there are also purplish-red slates in 

 this division, while only pure gray, or faintly purplish beds are known 

 in the St. John group. 



