Search

Southern New Brunswick consists of a collage of fault-bounded belts of Late Neoproterozoic igneous and metamorphic rocks, early Paleozoic sedimentary, metamorphic and igneous units, and overlying Carboniferous and locally Triassic sedimentary rocks. The area also contains the boundary between Avalonia and Ganderia as interpreted in the northern Appalachian orogen. New detrital zircon ages reported here provide improved understanding of depositional ages and provenance of diverse Neoproterozoic to Carboniferous rocks in this complex area. Detrital zircon data from samples with Neoproterozoic maximum depositional ages indicate a dominantly Gondwanan provenance with strong influence from the Amazonian craton. However, quartzite from The Thoroughfare Formation on Grand Manan Island contains dominanly 2 Ga zircon grains, consistent with derivation from the West African craton. The age spectrum is similar to that of the Hutchins Island Quartzite in the Isleboro block in Penobscot Bay, Maine, strengthening the possibility of correlation between the two areas. Cambrian samples also show prominent peri-Gondwanan provenance with strong influence from F.diacaran to early Cambrian arc magmatism. The maximum depositional ages of these samples are consistent with previous interpretations of Cambrian ages based on fossil correlations and field data. A Carboniferous sample from Avalonia shows a significant contribution from Devonian magmatism as the youngest detrital component, although its depositional age based on field relationships is Carboniferous. The results exemplify the need to integrate multiple datasets in making interpretations from detrital zircon data. Le sud du Nouveau-Brunswick est constitue d'un collage de ceintures delimitees par des failles de roches ignees et metamorphiques du Neoproterozoique tardif, d'unites sedimentaires, metamorphiques et ignees du Paleozoique precoce, ainsi que de roches sedimentaires sus-jacentes du Carbonifere et, par endroits, du Trias. Le secteur comprend egalement la frontiere etablie entre Avalonia et Ganderia selon son interpretation a l'interieur de la partie septentrionale de l'orogene des Appalaches. De nouvelles datations de zircon detritique rapportees ici permettent une meilleure comprehension des ages sedimentaires et de la provenance des diverses roches neoproterozoiques a carboniferes dans ce secteur complexe. Les donnees relatives au zircon detritique obtenues des echantillons faisant etat d'ages sedimentaires remontant au maximum au Neoproterozoique signalent une provenance en predominance gondwanienne avec une forte influence du craton amazonien. Le quartzite de la Formation The Thoroughfare sur l'ile Grand Manan renferme toutefois predominament des grains de zircon de 2 Ga, ce qui correspond a une derivation du craton de l'Afrique occidentale. Le spectre de l'age est similaire a celui du quartzite de l'ile Hutchins a l'interieur du bloc Isleboro dans la baie Penobscot, au Maine, ce qui renforce la possibilite d'une correlation entre les deux secteurs. Les echantillons du Cambrien font eux aussi etat d'une provenance perigondwanienne prononcee, marquee d'une forte influence d'un magmatisme d'arc de l'Ediacarien au Cambrien precoce. Les ages sedimentaires maximaux de ces echantillons correspondent aux interpretations anterieures des datations du Cambrien basees sur des correlations de fossiles et des donnees d'echantillonnage sur le terrain. Un echantillon du Carbonifere provenant d'Avalonia revele une contribution prononcee du magmatisme devonien a titre d'element detritique le plus recent, mais son age sedimentaire le situe au Carbonifere d'apres les relations etablies sur le terrain. Les resultats illustrent la necessite d'une integration de plusieurs ensembles de donnees pour effectuer des interpretations a partir de donnees provenant de zircon detritique. [Traduit par la redaction], INTRODUCTION AND GEOLOGICAL SETTING Southern New Brunswick consists of a complex assemblage of three fault-bounded belts of mainly Neoproterozoic rocks with minor Paleozoic rocks termed (from southeast to northwest) Caledonia, [...]

The Norumbega Fault system is traced from southern New England to Prince Edward Island, and its major strike-slip history is pre-Carboniferous. Carboniferous and later movements are less well constrained. Along the Fredericton Fault in western New Brunswick, offsets affect outcrops of Carboniferous strata in several ways. Revision of Carboniferous stratigraphy in this area using new miospore data and mapping of new exposures augmented by LiDAR imagery permits refinement of some of the post-Devonian movement history. The oldest post-Silurian unit recognized, the Longs Creek Formation, is fault-dissected and tightly folded, with faults and folds overlapped by the unconformity at the base of the upper Visean Shin Formation. The age of the Longs Creek Formation is uncertain and may be late Devonian to early Visean. Faults affecting the Shin Formation and Royal Road basalts are truncated by the unconformity at the base of the Bolsovian Minto Formation. Beneath this unconformity the presence of fault-bounded panels of vertical Langsettian strata (Boss Point and Deerwood formations) along the Fredericton Fault demonstrate late Visean to Serpukhovian, and post-Langsettian, pre-Bolsovian (Duckmantian) movements. At least three phases of movement can be seen affecting the Minto Formation. All the movement phases along the Fredericton Fault appear to be right-lateral strike-slip, except for one phase of post-Bolsovian left-lateral displacement. Le systeme de failles de Norumbega s'etend du sud de la Nouvelle-Angleterre jusqu'a I'Ile-du-Prince-Edouard, et son decrochement le plus important date du pre-Carbonifere. Les mouvements survenus durant le Carbonifere et ulterieurement ne sont pas aussi contraints. Le long de la faille de Fredericton dans l'ouest du Nouveau-Brunswick, des decalages influent sur les affleurements des strates du Carbonifere de plusieurs facons. La revision de la stratigraphic carbonifere dans cette region a l'aide de nouvelles donnees sur les miospores et la cartographie de nouvelles expositions, augmentees par l'imagerie par LiDAR, permet de mieux suivre l'histoire des mouvements post-devoniens. La plus ancienne unite post-silurienne reconnue, la formation de Long Creek, est dissequee en failles et arbore des plissements serres, avec des failles et des plis chevauches par une discordance a la base de la formation de Shin, du Viseen superieur. L'age de la formation de Long Creek est incertain - celle-ci pourrait dater de la fin du Devonien au debut du Viseen. Les failles influant sur la formation de Shin et les basaltes de Royal Road sont tronquees par une discordance a la base de la formation de Minto, datant du Bolsovien. Sous cette discordance, la presence de panneaux failles d'une strate verticale remontant au Langsettien (formations de Boss Point et de Deerwood) le long de la faille de Fredericton temoigne de mouvements du Viseen tardif au Serpoukhovien ainsi que de mouvements post-langettiens de la periode pre-bolsovienne (duckmantienne). Au moins trois phases de mouvements influant sur la formation de Minto peuvent etre degagees. Toutes les phases de mouvements le long de la faille de Fredericton semblent associees a des decrochements lateraux du cote droit, a l'exception d'une phase de deplacement lateral vers la gauche durant la periode post-bolsovienne. [Traduit par la redaction], INTRODUCTION The Fredericton Fault in southwestern New Brunswick is part of the Norumbega Fault system mapped from New England to the Gulf of St. Lawrence (Ludman and West 1999). It [...]

This paper presents a taxonomic revision of filicopsid taxa from the lower to middle Westphalian strata of Nova Scotia and New Brunswick, Maritime Provinces of Canada. Most of the material represents sporadic historical collecting by Geological Survey of Canada (GSC) personnel, and specimens are in the GSC collections in Ottawa. Additional specimens are in the New Brunswick Museum at Saint John, the Fundy Geological Museum at Parrsboro, and the Joggins Fossil Institute at Joggins. Two specimens from outside Canada clarify specific characteristics. The revision involved the detailed examination of 20 adpression (mainly impression) taxa, of which one, Germera brousmkheae, is new. Detailed synonymy lists, with particular focus on records from Canada and the USA, facilitate a refinement of the stratigraphic and geographic distribution of these species. Most of the taxa from the Maritimes are the same as those from other parts of the paleoequatorial belt of Pennsylvanian times. The Maritimes record of filicopsid taxa closely resembles the filicopsid floras of western Europe, most notably the British Isles. Cet article presente une revision taxonomique des taxons de Filicopsida provenant de la strate westphalienne moyenne a inferieure de la Nouvelle-Ecosse et du Nouveau-Brunswick, des provinces maritimes du Canada. La plupart des documents decrivent la collecte de donnees historiques sporadiques effectuee par les membres du personnel de la Commission geologique du Canada (CGC), et des specimens se trouvent dans les collections de la CGC a Ottawa. D'autres specimens sont exposes au Musee du Nouveau-Brunswick de Saint John, au Fundy Geological Museum de Parrsboro, et au Joggins Fossil Institute de Joggins. Deux specimens preleves a l'exterieur du Canada apportent des precisions sur des caracteristiques particulieres. La revision a necessite l'examen de 20 taxons en adpression (principalement en impression), parmi lesquels un taxon, Germera brousmkheae, est nouveau. Des listes detaillees de synonymes, mettant un accent particulier sur les registres provenant du Canada et des Etats-Unis, facilitent le raffinement de la repartition geographique et stratigraphique de ces especes. La plupart des taxons des Maritimes sont les memes que ceux des autres parties de la ceinture paleoequatoriale du Pennsylvanien. Les registres de taxons de Filicopsida provenant des Maritimes ressemblent fortement aux flores de la classe des Filicopsida de l'Europe de l'Ouest, plus particulierement des iles Britanniques. [Traduit par la redaction], INTRODUCTION This study is the eighth part of a taxonomic revision of the upper Namurian to middle Westphalian floras of the Maritime Provinces of Canada. The revision was embarked upon [...]

The Late Devonian Eagle Lake Granite is an elongate 1.2 km-long hypabyssal stock located in southwestern New Brunswick just south of the Belleisle Fault. Copper, Mo, and Au mineralization is [...]

The Atlantic Geoscience Society (AGS) undertakes a wide range of communication and educational activities and projects, one of which is the publication of geological highway maps. One of the newest [...]

The Belleisle Fault (Lubec Fault in southeast Maine) is one of several large strike-slip faults in the Appalachians of Maritime Canada. For much of its length, the Belleisle Fault is [...]

The Miramichi inlier is the largest Ganderian Cambrian--Ordovician belt in New Brunswick, extending 250 km from Chaleur Bay to the Maine border. It is also the northwesternmost Ganderian belt in [...]

A palynological (plant spores) biostratigraphic study of the Tournaisian (Early Carboniferous) aged sites between the townships of Bloomfield and Norton, New Brunswick is being conducted. Newly collected and historical samples [...]

The Coldbrook Group is a unique suite of Late Ediacaran volcanic and epiclastic rocks that together with related plutons was emplaced in the Avalonian Caledonia terrane of southern New Brunswick. [...]

An assessment of the surface and subsurface geology in New Brunswick has identified several regions, close to Large Final Emitters (industrial sites releasing carbon dioxide, C[O.sub.2], into the atmosphere), underlain by large volumes of various sedimentary rocks that could act as either the reservoir or seal in a carbon storage operation. There is a lack of subsurface data with which to make an assessment for the New Brunswick Platform, the Gulf of St. Lawrence, and Northumberland Strait. In the Moncton Basin, the McCully Gas Field is hosted in tight gas sands where it would be difficult to pump down C[O.sub.2] at an economical rate. The Stoney Creek Oil and Gas Field south of Moncton is not at sufficient depth for C[O.sub.2] to be in a supercritical state, necessary for compressed storage. Saline reservoirs could underlie suitably large areas around these fields, but again there is limited information on the quality of the potential reservoir rock. In the Bay of Fundy, south of Saint John, one borehole indicates a prospective location that includes a saline reservoir with suitable thickness and wireline-calculated porosity and permeability, a seal with suitable thickness, and limited faulting to potentially compartmentalize the reservoir or, conversely, compromise the continuity of the seal. The major uncertainty is trap volume, which is particularly difficult to assess based on the borehole being the only data point within a 50 km radius. This is also an environmentally sensitive offshore area. Until data deficiencies are addressed, no locations can be recommended for carbon storage. Une evaluation de la geologie de surface et de subsurface au Nouveau-Brunswick a permis le reperage de plusieurs regions proches de grands emetteurs finals (sites industriels rejetant du dioxyde de carbone--C[O.sub.2]--dans l'atmosphere) reposant sur des volumes importants de diverses roches sedimentaires qui pourraient agir comme reservoirs ou materiau de scellement pour le stockage de carbone. On dispose de donnees de subsurface insuffisantes pour effectuer une evaluation dans le cas de la plate-forme du Nouveau-Brunswick, du golfe du Saint-Laurent et du detroit de Northumberland. Dans le bassin de Moncton, le champ gazier McCully est inclus dans des sables a gaz compacts ou il serait difficile de stocker du C[O.sub.2] par pompage a un cout economique. Le champ petrolier et gazier de Stoney Creek au sud de Moncton n'a pas une profondeur suffisante pour que le C[O.sub.2] atteigne letat supercritique essentiel au stockage sous compression. Des reservoirs salins pourraient reposer sous des secteurs suffisamment vastes pres de ces champs, mais encore une fois, on dispose de renseignements limites sur la qualite des roches-reservoirs eventuelles. Dans la baie de Fundy, au sud de Saint John, un trou de forage signale un emplacement possible comprenant un reservoir salin d'une epaisseur et d'une porosite et permeabilite, calculees au moyen d'un essai au cable, qui conviennent, un materiau de scellement d'une epaisseur adequate et une deformation par des failles limitee pour une eventuelle compartimentalisation du reservoir ou, a loppose, une absence de continuite du materiau de scellement. Le principal aspect incertain est le volume de la zone de piegeage, qui est particulierement difficile a evaluer du fait que le trou de forage constitue la seule source de donnees dans un rayon de 50 kilometres. Il s'agit en outre d'un secteur extracotier ecosensible. Aucun emplacement ne pourra etre recommande pour le stockage de carbone jusqua ce quon obtienne les donnees qui manquent. [Traduit par la redaction], INTRODUCTION Increasing amounts of carbon dioxide (C[O.sub.2]) in the global atmosphere were first identified by Keeling (1960), and in the subsequent years annual peak concentrations have steadily risen from ~315 [...]

A 67 m near-continuous stratigraphic core was recovered from drilling at Grand Lake Meadows, located near the junction of Grand Lake and the Saint John River, approximately 40 km south of Fredericton, New Brunswick. From analyses of recovered samples and finite radiocarbon dating, four phases of development of the study site and surrounding environs were identified to have occurred following the Late Wisconsinan glacial maximum. Phase I, related to the formation of the DeGeer Sea, commenced more than 15 000 calyBP from deglaciation accompanied by marine transgression. Phase II began ~14 000 calyBP and continued until approximately ~8000 calyBP during which time there was major isostatic readjustment in the region and formation of a stratified, mostly brackish, ancestral Grand Lake and transformation into a mostly freshwater, Lake Acadia. Phase III began shortly after 8000 calyBP and continued until after 3000 calyBP accompanied by return of the Saint John River to a fluvial -dominated system after down-cutting an outlet at the Reversing Falls gorge, and draining much of Lake Acadia. During phase IV, ~3000 calyBP to present, estuarine conditions were initiated as marine water advanced up-stream over the Reversing Falls, leading to the development of the modern river system and Grand Lake Meadows. On a obtenu une carotte stratigraphique quasi continue de 67 m d'un forage dans la region des pres du Grand Lac, pres de la jonction du Grand Lac et de la riviere Saint John, a environ 40 km au sud de Fredericton, Nouveau-Brunswick. L'analyse des echantillons recuperes et la determination au radiocarbone de l'age fini ont permis de preciser que quatre phases de developpement se seraient produites sur le site detude et les terrains avoisinants apres le maximum glaciaire du Wisconsinien tardif. La phase I, liee a la formation de la mer DeGeer, a debute plus de 15 000 ans cal BP, a la suite d'une deglaciation accompagnee d'une transgression marine. La phase II a commence environ 14 000 ans cal BP et a dure jusqua plus ou moins 8 000 ans cal BP. A ce moment-la, il y eut, dans la region, un reajustement isostatique majeur et la formation du Grand Lac ancestral stratifie, principalement saumatre, ainsi que la transformation du lac Acadia en un lac principalement compose deau douce. La phase III a commence peu de temps apres, il y a 8 000 ans cal BP, et sest poursuivie jusqu'a il y a 3 000 ans cal BP. Cette periode a vu la riviere Saint John redevenir un systeme principalement fluvial apres avoir reduit le debit de la gorge des chutes reversibles et draine la majeure partie du lac Acadia. Durant la phase IV, qui setend depuis environ 3 000 ans cal BP jusqua ce jour, des conditions estuariennes se sont manifestees alors que leau de mer sest introduite en amont des chutes reversibles, conduisant au developpement du systeme fluvial actuel et des pres du Grand Lac. [Traduitpar la redaction], INTRODUCTION Discovering and understanding the geomorphological processes operating on the physical environment is a current focus in geological, environmental, ecological, and archaeological research. The mechanisms driving these physical processes are [...]

The Lumsden Zn-Cu-Pb deposit, situated in the eastern Caledonia Highlands of the Avalon Zone in southeastern New Brunswick, is hosted by the highly deformed Crooked Creek Formation of the Neoproterozoic [...]

The Williams Brook South occurrence is situated approximately 90 km west of Bathurst in north-central New Brunswick. The occurrence consists of a series of gold bearing quartz veins cutting rhyolite [...]

The Cape Spencer area is located 15 km southeast of Saint John in southern New Brunswick, Canada. Gold mineralization has been identified in illitized (illite-carbonate [+ or -] quartz [+ [...]

The Elmtree deposit is situated approximately 5 km west of Petit Rocher and hosts a resource of over 300 000 ounces of gold and subordinate polymetallic (Ag, Zn, Pb, Sb) [...]

Soil property measurements to determine carbon (C) stocks are traditionally collected using physical samples or excavation practices which rely on small scale interpretations for sitewide averages. Such methods are limited [...]

The Early Devonian (400 Ma) Blue Mountain Granodiorite Suite (BMGS) underlies an area of approximately 80 [km.sup.2] in the Benjamin River South area of northeastern New Brunswick. Porphyry-related copper and [...]

Grand Lake Meadows is Atlantic Canada's largest freshwater wetland, providing flood storage for the lower Saint John River basin. Each spring, the spring freshet submerges the 5000ha floodplain with high [...]

The Wildcat Brook Mo-W deposit is located approximately 9 km east of the former Mt. Pleasant Sn-W-Mo mine in Charlotte County, New Brunswick. It is hosted by a leucocratic, quartz-feldspar [...]

The renowned Brunswick belt (BB) that hosts the Brunswick Horizon (BH), the stratigraphic sequence constituting the upper contacts of the Nepisiguit Falls Formation (NFF) with the overlying Flat Landing Brook [...]

Recent integration of seismic profiles, palynology, industry reports, boreholes, and field interpretation has confirmed the existence of the Millstream Subbasin, an approximately 80 k[m.sup.(2) pull-apart basin within the Midland area [...]

The Key Anacon Titan deposit is a Bathurst-type volcanogenic massive sulfide (VMS) hosted in the same stratigraphic horizon as the well-known Brunswick No. 12 mine. The current mineral resource reported [...]

ABSTRACT A till composition study was carried out around the Sisson W-Mo deposit, New Brunswick, Canada, one of the largest W deposits in the world, to test modern analytical methods [...]

ABSTRACT The Late Silurian Landry Brook and Dickie Brook plutons and Charlo plutonic suite underlie a combined area of approximately 80 [km.sup.2] in the northeastern part of the Ganderian Tobique-Chaleur [...]

The Early Devonian Campbellton Formation in northern New Brunswick, Canada, yielded its first eurypterid fossils in 1881. Based on recent taxonomic work, all known specimens have been assigned to Pterygotus [...]

Vertebrates preserved in calcareous concretions collected from Silurian marginal-marine deposits near Nerepis, southern New Brunswick include agnathan thelodonts, a heterostracan, and possibly an anaspid, as well as spines and scales from an acanthodian (the only jawed fish remains). Several incomplete specimens of acanthodians, all determined as the same taxon Nerepisacanthus denisoni nov. gen. et sp., are described based on material identified in several museum collections. The fish-bearing nodules are from the Silurian Cunningham Creek Formation, which has been dated from ?late Llandovery (Telychian) - Ludlow (Ludlovian). The new species is only the second undisputed pre-Devonian acanthodian taxon known from articulated, although incomplete, specimens. N. denisoni has robust flank scales with a smooth crown bearing short subparallel ridges along the anterior edge, plus flatter scales with a crown formed of elongate, curved, areal-growth ridges, anterior to the pectoral region. The anterior dorsal fin spine is long, slightly curved and bears up to seven smooth longitudinal ridges of varying width on each side. The perichondrally ossified scapula is thin-walled and probably has a U-shaped cross section. 'Dentition' cones and small denticles are preserved in the branchial or pharyngeal region. Although elements indisputably identifiable as dentigerous jaw bones were not found in the specimens, N. denisoni appears most closely related to the Early Devonian ischnacanthiform Acritolepis and is tentatively assigned to the family Acritolepidae Valiukevicius and Burrow. Des fossiles de vertebres conserves dans des concretions calcaires provenant de depots marins marginaux siluriens a proximite de Nerepis, dans le sud du Nouveau-Brunswick, comprennent des thelodontes agnathes, un heterostracan et possiblement un anaspide, ainsi que des epines et ecailles d'un acanthodien (les seuls restes de poisson a machoire). Plusieurs specimens incomplets d'acanthodiens, tous affectes au meme taxon, Nerepisacanthus denisoni nov. gen. et sp., sont decrits a la lumiere de materiel provenant de plusieurs collections museales. Les nodules proviennent de la Formation silurienne de Cunningham Creek, datant du Llandovery (Telychien) ?tardif - Ludlow (Ludlovien). La nouvelle espece n'est que le deuxieme taxon d' acanthodiens pre-devoniens non conteste identifie sur la base de specimens articules, bien qu' incomplets. N. denisoni presente des ecailles laterales robustes dotees d'une couronne lisse portant de courtes cretes subparalleles le long de leur bordure anterieure, en plus d' ecailles plus plates dotees d' une couronne formee de cretes de croissance areale allongees et recourbees anterieures a la region pectorale. L' epine de la nageoire dorsale anterieure est longue et legerement recourbee et presente de part et d'autre jusqu'a sept cretes longitudinales lisses de largeur variable. La scapula ossifiee perichondralement a des parois minces et, vraisemblablement, un profil en U en coupe transversale. Des cones de ' dentition ' et de petits denticules sont preserves dans la region branchiale ou pharyngienne. Bien que des elements constituant incontestablement des os maxillaires dentigeres n' aient pas ete trouves dans les specimens disponibles, N. denisoni semble se rapprocher le plus de l' ischnacanthiforme Acritolepis du Devonien precoce et est provisoirement affecte a la famille des Acritolepides Valiukevicius et Burrow. [Traduit par la Redaction], Introduction Vertebrate fossils from Silurian deposits in the Nerepis area near Cunningham Creek (Fig. 1), southern New Brunswick, eastern Canada were first found well over a century ago. Matthew (e.g., [...]

ABSTRACT Red-bed strata generally considered to be of Triassic age are present in outcrop at Point Lepreau and St. Martins, New Brunswick. These successions preserve assemblages of invertebrate trace fossils [...]

ABSTRACT The Utopia Granite is part of the Saint George Plutonic Suite, a gabbroic to granitic assemblage of plutons of Late Silurian--Late Devonian age in southwestern New Brunswick. New U-Pb [...]

Patterns of softwood (SW) - hardwood (HW) change from 1946 to 2006 in 32 unharvested mixedwood (MW) stands in northern New Brunswick were analyzed using aerial photographs (1946, 1966, 1982, and 2006), sampled, and related to disturbance and stand conditions. Five stand development patterns were identified based on 1946 SW content (70%- 80%, termed SW versus 30%-60%, termed MW) and change in SW content from 1946 to 2006 (SW-stable, SW-de-clining, MW-fluctuating, MW- stable, or MW-declining). Species composition was surprisingly changeable over this 60-year period, with change in SW content varying from +18% to -62%. High canopy cover reduction from 1946 to 1966 resulted from balsam fir (Abies balsamea (L.) Mill.) mortality due to old age and a 1950s spruce budworm (Choristoneura fumiferana Clem.) outbreak plus birch (Betula sp.) dieback. SW-stable stands that maintained SW composition from 1946 to 2006 (+7%) had more red spruce (Picea rubens Sarg.) than all other classes in which SW declined by 15%-47%. SW-declining stands were located on southerly aspects (1898) and had higher mean elevations (423 m) than other classes. Results suggest that balsam fir - tolerant HW MW stands may be naturally transitional due to disturbance, species, and stand conditions, which has significant implications for forest management designed to maintain static proportions of MW and SW stands. Resume: Les patrons de changement de la composition en essences resineuses et feuillues pendant la periode 1946-2006 ont ete etudies dans 32 peuplements mixtes non coupes du nord du Nouveau-Brunswick a l'aide de photographies aerien-nes (1946, 1966, 1982 et 2006) pour ensuite etre echantillonnes et relies aux conditions de perturbation et de peuplement. Cinq patrons de developpement de peuplement ont ete identifies en se basant sur le contenu en resineux observe en 1946 (peuplement resineux: de 70% a 80%; peuplement mixte: de 30% a 60%) et sur les changements du contenu en resineux de 1946 a 2006 (resineux stable, resineux declinant, mixte fluctuant, mixte stable et mixte declinant). De facon sur-prenante, la composition en especes a beaucoup fluctue pendant cette periode de 60 ans avec des changements du contenu en resineux de +18 % a -62%. De fortes reductions du couvert de la canopee ont ete produites de 1946 a 1966 par le de-perissement du bouleau (Betula sp.) et par la mortalite du sapin baumier (Abies balsamea (L.) Mill.) causee par son age avance et par l'e pidemie de tordeuse des bourgeons de l'e pinette (Choristoneura fumiferana Clem.) des annees 1950. Les peuplements a resineux stable qui ont maintenu leur composition en resineux de 1946 a 2006 (+7 %) contenaient plus d'epinette rouge (Picea rubens Sarg.) que toutes les autres classes de peuplement dans lesquelles le contenu en resineux a diminue de 15 % a 47 %. Les peuplements a resineux declinant etaient sur des versants sud (1898) et etaient situes a une altitude moyenne (423 m) plus elevee que celle des autres classes de peuplement. Les resultats indiquent que les peuplements mixtes a sapin baumier et a feuillus tolerants peuvent naturellement etre en etat de transition a cause de perturbations, des especes en presence et des conditions du peuplement. Ces dernieres ont donc des implications importantes pour l'amenagement forestier visant a maintenir des proportions statiques de peuplements mixtes et resineux. [Traduit par la Redaction], Introduction Managing stand types native to a region, often as a percentage of the landscape, is an important component of forest management planning. Concern about reduction in the number and [...]

Three Appalachian tectonostratigraphic terranes converge in the Beaver Harbour area of southern New Brunswick, overlain by two upper Paleozoic sedimentary sequences. The Ediacaran to Cambrian New River and Brookville terranes [...]

The Middle Ordovician Poplar Mountain Volcanic Complex, southwestern New Brunswick, consists of three main volcanic phases: porphyritic rhyodacite, rhyodacitic volcaniclastic rocks, and basaltic volcanic rocks; previous U-Pb zircon dating indicates [...]

The Clarence Stream deposit in southwestern New Brunswick consists of several antimony-bearing gold mineralized zones hosted within large-scale structures in metasedimentary and metavolcanic sequences of the Cookson and Mascarene groups, [...]

Early Silurian volcanic and subvolcanic rocks are preserved in the lower part of the Chaleurs Group at two locations in northern New Brunswick. At Quinn Point, mafic to intermediate rocks are hosted by sedimentary rocks of the Weir Formation, and at Pointe Rochette, a bed of felsic tuff occurs near the base of the Weir. These rocks are interpreted as the first evidence in New Brunswick of magmatism associated with Late Ordovician - Early Silurian subduction of Tetagouche-Exploits back-arc oceanic crust. At Quinn Point, mafic rocks include a thick basaltic flow or sill and intermediate to mafic cobbles in overlying conglomerate beds. The in situ mafic rocks and the conglomerate clasts are chemically alike and display subduction-related affinities on tectonic discrimination diagrams. At Pointe Rochette, fine-grained felsic tuff contains elevated Th and U and depleted high-field-strength elements, consistent with a subduction-influenced setting, although rare-earth element (REE) abundances are low and the REE profile is relatively flat. A U-Pb (zircon) age of 429.2 ± 0.5 Ma was obtained from the tuff, consistent with the late Llandovery to early Wenlock age of the overlying La Vieille Formation and coinciding with the latter stages of development of the Brunswick subduction complex. Volcanic rocks were emplaced in the arc to arc-trench gap region, probably reflecting local step-back of the magmatic axis due to accretion of continental back-arc ribbons. The low volume of Early Silurian subduction-influenced rocks is probably related to the relatively narrow width of the back-arc basin and the young, 'warm' character of back-arc crust. Des roches volcaniques et hypabyssales sont preservees dans la partie inferieure du Groupe de Chaleurs a deux endroits dans le nord du Nouveau-Brunswick. A Quinn Point, des roches mafiques a intermediaires sont encaissees par les roches sedimentaires de la Formation de Weir et, a Pointe Rochette, un lit de tuf felsique se trouve a la base de la Formation de Weir. Ces roches sont interpretees en tant que les premieres evidences, au Nouveau-Brunswick, de magmatisme associe a la subduction de la croute oceanique d'arriere-arc Tetagouche--Exploits, a l'Ordovicien tardif--Silurien precoce. A Quinn Point, des roches mafiques comprennent un epais ecoulement basaltique ou un filon-couche et des galets intermediaires a mafiques dans les lits de conglomerats sus-jacents. Les roches mafiques in situ et les clastes dans les conglomerats sont chimiquement semblables et elles presentent des affinites reliees a la subduction sur des diagrammes de discrimination tectonique. A Pointe Rochette, un tuf felsique a grains fins contient de hautes teneurs en Th et en U et presente un appauvrissement en elements a forte electronegativite, ce qui concorde avec un environnement influence par une subduction, bien qu'il y ait peu d'elements des terres rares et que le profil des elements des terres rares soit relativement plat. Un age U--Pb (zircon) de 429,2 ± 0,5 Ma a ete obtenu du tuf, ce qui concorde avec un age Llandovery tardif a Wenlock precoce de la Formation de La Vieille sus-jacente et qui coincide avec les etapes finales du developpement du complexe de subduction Brunswick. Les roches volcaniques ont ete mises en place dans la region entre l'arc et l'ouverture arc-fosse, ce qui est probablement le reflet du rebroussement de l'axe magmatique en raison de l'accretion de << rubans >> de l'arriere-arc continental. Le faible volume de roches influencees par la subduction datant du Silurien precoce est probablement relie a l'etroitesse relative du bassin d'arriere-arc et au caractere jeune et << chaud >> de la croute d'arriere-arc. [Traduit par la Redaction], Introduction The northern Appalachian Orogen experienced a protracted and complex tectonic evolution that led to a collage of accreted tectonic elements (van Staal et al. 1998). In simple terms, the [...]

ABSTRACT A major ductile high-strain zone up to 5 km in width can be traced for at least 70 km diagonally across the Avalonian Caledonia terrane of southern New Brunswick. [...]

ABSTRACT The Mechanic Settlement Pluton, southern New Brunswick, is a high-level mafic-ultramafic pluton of Late Neoproterozoic age (ca. 557 Ma). Based on surface-outcrop and drill-core samples, the pluton includes six [...]

The Pennsylvanian Lancaster Formation ('Fern Ledges') of Saint John, New Brunswick, Canada contains a world-famous fossil biota. Largely unstudied since the works of Hartt, Dawson, Matthew, and Stopes in the mid-nineteenth to early twentieth century, we present new data concerning biostratigraphy, taxonomy, palaeoenvironments, and palaeoecology. Megafloral assemblages suggest a mid- to late Langsettian age for the succession, making it approximately coeval with the classic Joggins Formation of nearby Nova Scotia. Facies analysis suggests deposition on a tectonically influenced coastal plain whose braided channels drained into a shallow brackish gulf. Most of the historical fossil collections are derived from flooding surfaces formed by abrupt subsidence events along the coastline. Three communities are recognized. Phoronids, crustaceans, and xiphosurans lived in brackish coastal waters. A lowland community of gastropods, insects, arachnids, and myriapods inhabited coastal forests. Coastal vegetation was dominated by shrubby cordaitaleans and pteridospenns whereas ferns, sphenopsids, and lycopsids were rare. An upland or dryland community, discernible from allochthonous assemblages, comprised forests of giant cordaitaleans, archaic pteridosperms, and plants of uncertain affinity.

Abstract: The most northwesterly outcrop of Lower Cretaceous Chaswood Formation is in a pit at Vinegar Hill, south of Sussex, New Brunswick. New mapping and boreholes show thick, fluvial, loosely [...]

ABSTRACT The Devonian fauna from the Campbellton Formation of northern New Brunswick was discovered in 1881 at the classic locality in Campbellton. About a decade later A.S. Woodward at the [...]

ABSTRACT The islands known as The Wolves are located in the Bay of Fundy, approximately 10 km offshore from mainland southwestern New Brunswick. They are underlain by monzodiorite, gradational to [...]

ABSTRACT The coastal cliffs along the eastern shore of Chignecto Bay, Nova Scotia contain one of the finest Carboniferous sections in the world. In 1843, Sir William Logan measured the [...]

ABSTRACT U-Pb (zircon) ages for eight samples from southern New Brunswick were determined during the early 1990's as part of a regional mapping and correlation program. Although most of the [...]

Arenig strata in the Napadogan area of the Miramichi Highlands of west-central New Brunswick are similar to those of the Lunksoos anticlinorial area of eastern Maine. Strata from both areas were deposited in a volcanic back-arc setting upon Cambrian-Tremadoc, deep-water, turbiditic quartzose strata on the northwest-facing Gander margin of Gondwana. Tremadoc southeastward obduction of the Penobscot Arc, formed in the Iapetus Ocean to the northwest of the margin, was followed by local uplift, rift faulting, erosion, and finally by local deposition of late Arenig gravel within the early stages of a subsiding back-arc basin that was related to a younger, northwest-facing, early Arenig-Llanvirn Popelogan Arc lying to the northwest. These strata became overlain by late Arenig marine felsic tuff, sandy and silty tuff and mudstone, coarse textured and many hundreds of metres thick in the Lunksoos area but much finer and only a few metres thick farther from the volcanic centres, in the Napadogan area. During Llanvirn, the strata became covered with deep-water, commonly manganiferous, ferruginous shalechert in a basin shielded from currents carrying coarse detritus. Arenig strata of the Napadogan area probably developed to the southeast of the main rift-volcanism zone that perhaps extended between the Lunksoos and northeastern Miramichi Highlands during the Arenig. Brachiopods of the Celtic paleogeographic assemblage colonized newly formed shelves flanking islands along the zone. Shell beds developed upon fresh layers of ash in a nutrient-rich environment between episodes of volcanism. These Celtic brachiopods developed in cool waters of high southern latitudes off Gondwana, different from those on the Laurentian margin in warm waters of low southern latitudes., RESUME Les strates de l'Arenig dans le secteur de Napadogan du massif de Miramichi, dans le centre-ouest du Nouveau-Brunswick, sont semblables a celles du secteur anticlinorial de Lunksoos dans l'Est [...]

Silurian-Devonian bimodal volcanism--a common feature of the northern Appalachians of the northeastern United States and eastern Canada forms--major belts of igneous rocks including the Coastal volcanic belt of New England and New Brunswick. The Coastal volcanic belt is one of the largest bimodal volcanic provinces in the world. Controversy remains regarding the tectonic setting of this volcanism; suggestions range from volcanic arc, to extensional continental rift, transpressional basin, backarc, or plume-modified subduction zone. The mapped Passamaquoddy Bay volcanic sequence of the Coastal volcanic belt of southwestern New Brunswick has a minimum thickness of 4 km and comprises 63 lithologic units that are divided into four distinct cycles of mafic-felsic volcanism. A preliminary U-Pb zircon date indicates an age of 423 Ma, similar to the age of the Cranberry Island bimodal volcanic series of the Coastal volcanic belt in Maine. Our analysis of 115 volcanic rocks for major and trace element concentrations indicates that the sequence is subalkalic and bimodal (basalt-rhyolite) with within-plate tectonic affinities. Most mafic rocks range in composition from basalt to basaltic andesite. The Mg# [defined as 100 x MgO/(MgO + FeO), where FeO = Fe[O.sub.T] X 0.9] of the basalts ranges from 30 to 70, and there is a trend toward more primitive compositions upward in the section. The light rare earth element abundances of the basalts are enriched to levels of 30-130 times chondritic values. The flows are enriched in incompatible elements with respect to primitive mantle and show distinct Nb, Hf, and Sr anomalies. We interpret the basalts to be mantle melts modified by crustal contamination and mantle metasomatism from a previous subduction event. Most of the chemical variation can be explained by replenishment and fractionation of small magma chambers. The rhyolitic rocks are crustal melts, modified by crystal fractionation. Within each of the rhyolitic cycles there is an upward trend toward more evolved compositions as a result of an evolving magma chamber and magma-chamber zonation. We suggest that the rocks were erupted in an extensional environment and that there was a significant zone of continental extension during the Late Silurian in the northern Appalachians. However, controversy remains regarding the precise nature of the tectonic setting and the duration and extent of this volcanism. Keywords: bimodal volcanism, Coastal volcanic belt, continental extension, northern Appalachian volcanism, petrogenesis.

ABSTRACT Latest Neoproterozoic and Cambrian plutons in the Brookville terrane of southern New Brunswick are termed the Golden Grove Plutonic Suite. Four groups are recognized on the basis of composition: [...]

ABSTRACT Felsic tuffs from the Letete and Waweig formations of the Mascarene Group in southwestern New Brunswick have essentially identical U-Pb ages of 437 ± 7 and 438 ± 4 [...]

The Pocologan River and Long Reach areas are situated in the New River belt, which comprises the westernmost exposures of Neoproterozoic rocks in southern New Brunswick. Previous mapping in the [...]

Early Paleozoic turbiditic sedimentary rocks and submarine volcanic-arc rocks in the Eel River area have been designated, respectively, as the Woodstock and Meductic groups and divided into six formations. The [...]

Palaeophycus bolbitermilus, a new ichnospecies of Palaeophycus Hall, is described from turbiditic strata of the Lower Silurian Upsalquitch Formation of northern New Brunswick, eastern Canada. The ichnospecies is unbranched, thinly [...]

Stratigraphic, petrographic and geochemical evidence indicate that the volcano-sedimentary rocks of the Late Devonian Piskahegan Group, located in the northern Appalachians of southwestern New Brunswick, represent the eroded remnants of a large epicontinental caldera complex. This complex - the Mount Pleasant Caldera - is one of few recognizable pre-Cenozoic calderas and is divisible into Exocaldera, Intracaldera and Late Caldera-Fill sequences. The Intracaldera Sequence comprises four formations that crop out in a triangular-shaped area and includes: thick ash flow tuffs, thick sedimentary breccias that dip inward, and stocks of intermediate to felsic composition that intrude the volcanic pile or are localized along caldera-margin faults. The Exocaldera Sequence contains ash flow tuffs, mafic lavas, alluvial redbeds and porphyritic felsic lavas that comprise five formations. The Late Caldera-Fill Sequence contains rocks that are similar to those of the outflow facies and comprises two formations and two minor intrusive units. Geochemical and mineralogical data support the stratigraphic subdivision and indicate that the basaltic rocks are mantle-derived and have intraplate chemical affinities. The andesites were probably derived from basaltic magma by fractional crystallization and assimilation of crustal material. The various felsic units are related by episodes of fractional crystallization in a high-level, zoned magma chamber. Fractionation was repeatedly interrupted by eruption of material from the roof zone such that seven stages of caldera development have been identified. The genesis of the caldera is related to a period of lithospheric thinning that followed the Acadian Orogeny in the northern Appalachians.

Mafic rocks in the Ordovician volcanic rock in northern Maine are divided geographically into three groups, all the groups dominated by tholeiite. Two groups are similar in composition but are separated by eruption inside a plate setting. The third group of rocks is characterized by the lifted island arc magma.