A Marine Incursion In the Lower Pennsylvanian Tynemouth Creek Formation, Canada: Implications For Paleogeography, Stratigraphy and Paleoecology

Abstract

We document the occurrence of a marine bed, and its associated biota, in the Lower Pennsylvanian (Langsettian) Tynemouth Creek Formation of New Brunswick, and discuss its implications for paleogeography, stratigraphy and paleoecology. This is only the second marine interval found in the entire Pennsylvanian fill of the Maritimes Basin of Canada, the other being recently found in the broadly same-age Joggins Formation of Nova Scotia. Evidence for the new marine transgression comprises an echinoderm-rich limestone that infills irregularities on a vertic paleosol surface within the distal facies of a syntectonic fluvial megafan formed under a seasonally dry tropical climate. Gray, platy ostracod-rich shales and wave-rippled sandstone beds that directly overlie the marine limestone contain trace fossils characteristic of the Mermia Ichnofacies, upright woody trees, and adpressed megafloras. This association represents bay-fills fringed by freshwater coastal forests dominated by pteridosperms, cordaites, and other enigmatic plants traditionally attributed to dryland/upland habitats. The fossil site demonstrates that marine transgressions extended farther into the interior of Pangea than has previously been documented, and may allow correlation of the Tynemouth Creek and Joggins Formations with broadly coeval European successions near the level of the Gastrioceras subcrenatum and G. listeri marine bands. It also helps explain the close similarity of faunas between the Maritimes Basin and other paleotropical basins, if transgressions facilitated migration of marine taxa into the continental interior.

Fish and tetrapod communities across a marine to brackish salinity gradient in the Pennsylvanian (early Moscovian) Minto Formation of New Brunswick, Canada, and their palaeoecological and palaeogeographical implications

“…), whose salinity slowly decreased in a landward direction over many hundreds of kilometres (Falcon‐Lang ; Falcon‐Lang et al . ), similar to the present‐day Baltic Sea (Andersson et al . , ).…”

“…) and Tynemouth Creek (Falcon‐Lang et al . ) formations, and the new marine band (reported here) from the early to mid‐Bolsovian part of the Minto Formation. Colour online.…”

“…; Falcon‐Lang et al . ) and early Moscovian stages (Minto Formation; this paper). However, brackish incursions were far more common, spanning the entire Carboniferous interval (Archer et al .…”

Mid-Carboniferous diversification of continental ecosystems inferred from trace fossil suites in the Tynemouth Creek Formation of New Brunswick, Canada

“…What is less certain is whether the burrows represent activity within freshwater tracts of the fluvial channels, or whether they are expressions of marine influence in the distal part of channel systems. The Tynemouth Creek Formation consists overwhelmingly of terrestrial red bed deposits, although a marine bed recently has been identified in the distal megafan (Falcon-Lang et al, 2016). Although Diplocraterion is characteristic of marine-influenced shoreface settings, the trace fossil also has been reported from freshwater fluvial channel tracts (Trewin and McNamara, 1994;Kim and Paik, 1997;Buatois and Mángano, 2004;Smith et al, 2012).…”

“…The Lower Pennsylvanian (Bashkirian; Langsettian) Tynemouth Creek Formation conformably overlies the Boss Point Formation near Giffin Pond (Fig. 1C), and may be correlated (at least in part) with one or more of the Little River (Calder et al, 2005), Joggins (Davies et al, 2005) and Springhill Mines (Rygel et al, 2014) formations in the eastern part of the Cumberland Basin, and with the Lancaster Formation in the far western part of the basin (Falcon-Lang and Miller, 2007) based on biostratigraphy (Falcon-Lang et al, 2006Utting et al, 2011;Bashforth et al, 2014) and marine-based lithostratigraphy (Falcon-Lang et al, 2016) (Fig. 2).…”