Observations on the geology of southern New Brunswick, made principally during the summer of 1864.

Before proceeding to give an explanation of the districts which have been examined during the past season, it will be necessary first to briefly review what has already been published on this subject.The lower portion of JS T ew Brunswick, especially including the Counties of Charlotte, King's, Saint John, and Albert, has been long known to be composed of rocks chiefly of a metamorphic character, extending, somewhat irregularly, from the western boundary of the Province eastward as far as Shepody Mountain, in the County of Albert, where they were known to gra- dually disappear under deposits of carboniferous age.These metamorphic rocks, though extensively altered, were early recognized as being in large part sedimentary, being composed, as usual, of sandstones, conglomerates, shales, and limestones ; but these were found to be so intricate in structure, and so much confused by the occurrence of beds of volcanic origin, that little if any attempt was made to separate them into groups, or to determine their relative age and distribution.By Dr. Gesner, who first undertook a systematic survey of the Province, but at a time when the ideas entertained of geological phenomena were much more vague than at present, the general character of the district to be described was recognized, and a division made into several groups.To the westward of the Saint John River, and in the County of Charlotte, the exist- ence of a broad belt of granitic rocks, extending from the neighbourhood of Saint Stephen to the Saint John River, was pointed out, as was also the occurrence of another district southward of the above, and consisting prin- cipally of syenite and trap.The latter band of rocks was stated to be con- tinuous across the Peninsula of Kingston, and to constitute the broken tract of country eastward of the Saint John, in the neighbourhood of Loch Lo- mond, and thence to Shepody Mountain.South of the above, and stretching across the entrance of the Saint John, another group of rocks, classed as Silurian, and consisting of syenite, slate, and trap, with large beds of altered limestone, was pointed out, and stated to extend eastwardly into the County of Albert.The syenite was described as forming an anticlinal, against the slopes of which reposed the rocks of sedimentary origin.The limestones of the group, though well developed at the outlet of the Saint John, were found to be comparativel} 7 local, not extending to the eastward beyond the Hammond River.To the west, how- ever, limestones, referred to the same group, were found at several points in the County of Charlotte.The slates and "greywacke" of this system, on the eastern side of the Saint John, which were described as containing the remains of plants and mollusks, were stated to be of wider distribution, running parallel to, and leaning upon the "primary" rocks through their whole extent.Yet another group of altered rocks, consisting of micaceous, chloritic and talcose slates, with sandstones, conglomerates-and trap beds, and largely developed in the neighbourhood of Mispeck and Black River, was pointed out, and from the evidence of apparent unconformability and the absence of The age of the limestone was rightly referred to the base of the Carbon- iferous system.The sandstones, surrounding the coal measures, and along its northern and southwestern sides consisting of but a narrow belt, were found to widen greatly to the southeast, occupying an extended area in King's and Westmorland, stretching indeed from the Ivennebeccasis and the Belleisle, east- ward beyond Moncton.Southward of the latter place and along a space of considerable width, extending through the central portion of Albert into the Parish of Sussex, other sandstones were pointed out and referred to the true Coal Measures.Below the latter, however, red sandstones, similar to those of the Sussex Valley, were again found between Salisbury Cove and Hills- borough, as also at Porchester and Sackville.These reddish sandstones, which were found to be characterized throughout by the presence of salt and gypsum, were at first referred by Dr. Gesner to the New Red Sandstone or Saliferous System of Europe, but subsequently, from their resemblance to similar beds in Nova Scotia, to the Carboniferous System.Besides the sandstones above alluded to, others of variable character, and in isolated deposits, were found at several points along the northern shore of the Bay of Fundy, especially at Saint Andrews, Saint George, Lepreau, and Quaco.These were variously referred to the Carboniferous and New Red Sandstone Groups.*Note.-In the use of geological terms throughout this Report, it has been taken for granted that readers either have, or pOflMM the means of obtain injr, a general knowledge of llicir meaning or appli- cation.Any other course would greatly increase tlic difficulty of explanation, and at the same tune, enlarge the Report to undue limit*.I do not by these criticisms desire in any way to disparage the labours of Dr. llobb.His work was faithfully and zealously performed, and to no one were the imperfections of the map more thoroughly known than to himself At that period no better ma}) could have been readily constructed, and the method adopted of representing mineralogical rather than geological formations, answered the purpose for which it was employed, while it left all doubtful points to be determined by subsequent exploration.While presenting this map, however, Dr. liobb made two very important observations ; first, that most cf the red coloured sandstones, with and without gypsum, were of an age below the productive coal measures, being either of the age of the mountain limestone, or perhaps Devonian, instead of New Ked Sand- stone, as supposed by Dr. Gesner; secondly, that the district described by Dr. Gesner as trappean in the Counties of Saint John, Charlotte, King's and Queen's, is a slate country, although much disturbed by igneous action.Jt will be hereafter seen that both of these observations of Dr. Pobb have been confirmed.The want of a purely geological map, which should distinguish with accu- racy the position and distribution of these different groups, has continued to be felt.Principal Dawson, in a map accompanying his Acadian Geology, corrected some of the errors of the earlier map, and suggested the probable Devonian age of many of the altered sediments ot the Southern Counties.This map, however, as far as related to New Brunswick, was still imperfect, and much remained to be done in working out the doubtful groups.In the meantime, deposits, somewhat similar to those occurring in New Btuijs- 1XTK0DUCTI02C.wick, were pointed out in Nova Scotia, Canada and Maine, and from the study of their fossils were pronounced to be of Devonian age.Among those especially active in endeavouring to throw light upon the structure of this section, was an association of young geologists in the City of Saint John, who, under the guidance of Messrs. Hartt and Matthew, explored the different formations in the neighbourhood of the City, and succeeded in discovering facts which have made the geology of this district second in interest to no portion of.North America.Rocks before supposed to contain no determinable fossils, were ascertained to be rich in organic relics, and a band of slates, stretching across the Harbour of Saint John, was discovered, rich in an abundant and beautiful fossil vegetation.By the study of these remains, Principal Dawson was enabled to ascertain the true age of the deposits in which they occur, pronouncing them to be the equi- valents of the Chemung and Portage Groups, sub-divisions of fhe Upper Tabular View of Rock Formations in New Brunswick, §*c.-Continued.Aires and Periods.

Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.