A lacustrine shoreface succession in the Albert Formation, Moncton Basin, New Brunswick

Abstract

The Albert Formation (Horton Group) of the Moncton Basin, New Brunswick, is host to the only onshore petroleum system in the Maritime Provinces from which oil and natural gas are commercially produced. Production from the McCully gas field is from tight reservoir sandstone in the upper part of the Albert Formation. An outcrop analogue is herein identified on the basis of a comparison of subsurface and surface gamma ray logs. The analogue is exposed in four roadcuts 15 km to the west of the field, between Sussex and Norton. The succession in the roadcuts is about 60 m thick and can be divided into three, roughly 20 m thick units: a lower interbedded grey mudstone and sandstone interval, a medial organic rich grey mudstone interval, and an upper interbedded grey sandstone and mudstone interval. The lower interval is interpreted as having been deposited in a lacustrine offshore transition and lower shoreface setting. The overlying medial interval is interpreted as offshore, with the upper interval assigned to a lacustrine shoreface and shoreline (with some fluvial, possibly deltaic influence). The lower and upper interbedded sandstone intervals are viewed as progradational sediment packages deposited during times of stable lake level whereas the intervening mudstone-dominated medial interval represents a period of renewed lake deepening. On a larger scale, the entire succession is considered part of the final progradation of an axial fluvio-deltaic system into the Albert lake. RÉSUMÉLa formation Albert (Groupe Horton) du bassin de Moncton, Nouveau Brunswick, abrite le seul système pétrolier terrestre dans les Provinces Maritimes à partir duquel le pétrole et le gaz naturel sont exploités commercialement. La production de gaz naturel du champ de McCully provient d'un réservoir de grès peu perméable, situé dans la partie supérieure de la formation Albert. L'affleurement analogique ci-inclus est identifié sur la base d'une comparaison de diagraphies de rayons gamma souterrains et en surface. L'analogue est exposé dans quatre affleurements sur le bord de la route à 15 km à l'Ouest du champ, entre Sussex et Norton. Dans ces affleurements, la succession indique une épaisseur d'environ 60 m, et peut être divisée en trois unités d'une épaisseur approximative de 20 m: un intervalle inférieur intercalé de mudstone gris et de grès, un intervalle médian de mudstone gris riche en matières organiques, et un intervalle supérieur intercalé de grès et de mudstone gris. L'intervalle inférieur est interprété comme ayant été déposé au cours d'une transition de dépôt lacustre hauturier et d'une sédimentation inférieure d'avant-côtes. L'intervalle médian sus-jacent est interprété comme étant hauturier, avec l'intervalle supérieur affecté à un dépôt lacustre d'avant-côtes et littoral (avec quelques influences fluviales, possiblement deltaïques). Les intervalles intercalés de grès inférieurs et supérieurs sont considérés comme étant des sédiments compacts progradants, déposés durant les époques de niveaux stables du lac, alors que l'appari...

Sedimentology and chemostratigraphy of Carboniferous red beds in the western Moncton Basin, Sussex area, New Brunswick, Canada: possible evidence for a middle Mabou Group unconformity

“…Other possibilities exist but are less likely. For example, animals and plants are known to have colonized the local landscape by Mississippian times (e.g., Keighley andPickerill 1994, 2003;Falcon-Lang 2004). Thus, massively bedded siltstones might indicate complete bioturbation of the substrate (Rhoads 1967), but there is no instance of partly bioturbated beds with distinct burrows or roots to suggest soil-forming activity, which would be an odd dichotomy.…”

“…Red beds are common in Upper Devonian to Pennsylvanian strata of southeastern New Brunswick, where they form part of the fill in a system of basins (Cocagne Graben, Moncton, Sackville, and Cumberland basins) that are components of the regional Maritimes Basin Complex ( Fig. 1; Keighley 2008). Three tectono-sedimentary megacycles ("allocycles" of St.…”

Geological setting and resource potential of conventional petroleum plays in Paleozoic basins in eastern Canada

“…The Horton Group generally consists of a basal section of coarse-grained alluvial redbeds and an upper section of black shale and lacustrine sandstones (Albert Formation in New Brunswick). 17) were deposited in grabens and half-grabens, with significant lateral thickness and facies variations (Knight, 1983;Keighley, 2008;St. 17).…”

Evolution of an organic‐rich lake basin – stratigraphy, climate and tectonics: Piceance Creek basin, Eocene Green River Formation

“…Medium to coarse‐grained sandstones with gravel beds and layers of carbonate and organic clasts indicate deposition in a high‐energy environment (Renaut & Gierlowski‐Kordesch, 2010). Occurrence of graded bedding, amalgamation of up to coarse‐grained sandstones, and hummocky and swaley cross‐stratification suggests storm wave activity and deposition in the lake shore area (Renaut & Owen, 1991; Bray & Carter, 1992; Keighley, 2008). These deposits are interpreted as being formed due to longshore transport in a shoreline setting (Fig.…”