Sedimentology and depositional environment of the Lower Devonian Wapske Formation, Perth-Andover/Mount Carleton region, northwestern New Brunswick

Abstract

The Low er Devonian Wapske Formation o f the Tobique Group in the Perth-Andover/M ount Carleton region, northw estern N ew Brunsw ick, forms part o f the tectonostratigraphic Tobique Zone. In this area, the formation, 4000 to 9000 m thick, is interpreted to com prise seven regionally recognizable sedimentary facies. These are: conglomerate facies (Facies 1), massive and parallel-laminated sandstone facies (Facies 2), thin-to thick-bedded sandstone w ith minor mudstone interbeds and/or mud-capped facies (Facies 3), thin-bedded sandstone and mud stone facies (Facies 4), thin-bedded, graded, fine-grained sandstone facies (Facies 5), very thin-bedded, fine grained sandstone and silty m udstone facies (Facies 6), and thin-and m edium -bedded siltstone and m udstone facies (Facies 7).The absence o f unequivocal shallow-water sedimentary structures, depositional cycles and in situ body fos sils in these lithofacies and, instead, the presence o f Boum a depositional sequences and deep-water trace-fossil associations, is supportive o f a deep-m arine origin (below storm -w ave base) for the Wapske Form ation in the study area. Accordingly, the facies are grouped into five facies associations interpreted to reflect a deep-marine fan system comprising distributary channels, depositional lobes, lobe or fan fringes, and interchannel areas asso ciated with a basin plain.Regional considerations suggest that the Wapske Formation records a transition from shallow-water marine, locally terrestrial, deposition to the east and southeast o f the study area, to deep-w ater deposits, as described herein, to the w est and northw est in the Perth-Andover/M ount Carleton region.La formation du Devonien inferieur Wapske du groupe de Tobique dans la region de Perth-Andover / du mont Carleton, dans le nord-ouest du Nouveau-Brunswick, fait partie de la zone tectonostratigraphique de Tobique. On interprete la formation de 4 000 a 9 000 m d'epaisseur de ce secteur comme un ensemble de sept facies sedimentaires regionalem ent reconnaissables, notam m ent : un facies de conglom erats (facies 1); un facies de gres m assif en feuilles paralleles (facies 2); un facies de gres mince a epais avec petite quantite de mudstones interstratifies ou couronne de boue (facies 3); un facies de gres et de mudstones finem ent stratifies (facies 4); un facies de gres a grain fin grano-classe et tres finement stratifie (facies 5); un facies de mudstones vaseux et de gres a grain fin tres finem ent stratifies (facies 6); ainsi qu'un facies de mudstones et de microgres finem ent a moyennement stratifies (facies 7). L'absence de structures sedimentaires univoques en eau peu profonde, de cycles sedimentaires et de fossiles massifs sur place a l 'interieur de ces lithofacies et la presence, plutot, des sequences sedimentaires de Boum a et d iss o c ia tio n s d 'em preintes fossiles en eau profonde appuient l'hypothese d 'une origine marine profonde (sous l'onde de tem pete) dans le cas de la formation Wapske, dans le secteur etudie. En consequence, les facies sont re...

The Lower Devonian Compton Formation in southern Quebec: from delta front to pro-delta sedimentation

“…The Wapske Formation is a time and correlative unit of the deep-marine Témiscouata Formation and Fortin Group in adjacent northernmost New Brunswick (Carroll 2003) and southwestern Gaspé and Témiscouata regions (Bourque et al 1995;Hesse and Dalton 1995). The reconstruction proposed by Han and Pickerill (1995), which suggests shallower conditions to the east and southeast, agrees well with the paleogeographic reconstruction of Bourque et al (1995Bourque et al ( , 2000 that locates deep-marine conditions for northern New Brunswick and Témiscouata in LochkovianPragian time.…”

“…This interpretation has been proposed for the Lochkovian Indian Point Formation of the Gaspé Peninsula (Bourque et al 1995(Bourque et al , 2002 and for the Siegenian Matagamon Sandstone and Tarratine Formation of northern Maine (Pollock et al 1988). It is noteworthy that in Lochkovian, deeper marine sediments (Fortin Group, Témiscouata, and Wapske formations) are known in western Gaspé -northern New Brunswick (Hesse and Dalton 1995;Han and Pickerill 1995;Carroll 2003). Time and facies correlations are proposed between the Lochkovian Milan member and Indian Point Formation.…”

“…1), detailed sedimentologic analysis for the Lower Devonian strata is available only for the Lochkovian-Pragian Wapske Formation (Han and Pickerill 1995). The study suggested, based on detailed litho-and ichnofacies studies that the Wapske Formation recorded deepmarine fan sedimentation.…”

“…This paleogeographic scenario occurred in the early phases of the second major deepening phase (T2) that affects the post-Taconian basin. This event culminated in latest Lochkovian-Pragian (Siegenian) in the sedimentation of deep-marine limestones (Upper Gaspé Limestones;Lavoie 1992aLavoie , 1992b and of the below wave base clastics of the Fortin Group -Témiscouata Formation in eastern Quebec (Hesse and Dalton 1995) and the Wapske Formation in northern New Brunswick (Han and Pickerill 1995).…”

“…Some sedimentologic studies are available in the adjacent Devonian succession of northern New Brunswick (Han and Pickerill 1995). This paper presents the first sedimentological study of coeval successions in southern Quebec.…”