A marine incursion in the Lower Pennsylvanian Tynemouth Creek Formation, Canada: implications for paleogeography, stratigraphy and paleoecology

TY - JOUR

T1 - A marine incursion in the Lower Pennsylvanian Tynemouth Creek Formation, Canada

T2 - implications for paleogeography, stratigraphy and paleoecology

AU - Falcon-Lang, Howard

AU - Pufahl, Peir

AU - Bashforth, Arden

AU - Gibling, Martin

AU - Miller, Randall

AU - Minter, Nicholas John

PY - 2015/11/9

Y1 - 2015/11/9

N2 - 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.

AB - 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.

KW - Pennsylvanian

KW - Maritimes Basin

KW - marine transgression

KW - fluvial megafan

KW - mangroves

KW - ichnology

KW - RCUK

KW - NERC

KW - NE/F014120/2

U2 - 10.2110/palo.2015.031

DO - 10.2110/palo.2015.031

M3 - Article

VL - 30

SP - 779

EP - 791

JO - Palaios

JF - Palaios

SN - 0883-1351

IS - 11

ER -