Tagasi otsingusse
Pickerill & Forbes, 1979

Ichnology of the Trenton Group in the Quebec City area

Pickerill, R. K., Forbes, W. H.
DOI
DOI10.1139/e79-188
Aasta1979
AjakiriCanadian Journal of Earth Sciences
Köide16
Number10
Leheküljed2022-2039
Tüüpartikkel ajakirjas
Keelinglise
Id6843

Abstrakt

Marine limestones of the Middle Ordovician (Caradocian) Trenton Group in the Quebec City area are extensively burrowed. Traces referable to Anconichnus horizontalis, cf. Biformites, Bifungites cf. halli, Chondrites, Cruziana cf. pudica, Cruziana, Isopodichnus, Palaeophycus, Planolites, ? Rhizocorallium cf. R. irregulare, Rusophycus, Teichichnus cf. rectus, Tomaculum and Trichichnus are described in detail. Miscellaneous traces, those not morphologically distinct and (or) sufficiently abundant to warrant formal taxonomic treatment, are briefly described. The trace fossil assemblage can be broadly equated with the Cruziana ichnofacies. Southwest of Quebec City the Trenton Group was deposited in a gradually deepening offshore bar to shallow inner shelf situation, whereas to the northeast deposition occurred in a shallow inner shelf to deeper outer shelf – upper slope environment. The spatial and temporal distribution and abundance of the trace fossils are examined in relation to these broad environmental changes. The observed patterns are perhaps best related to variation in energy conditions, substrate stability, and food availability, parameters all broadly related to water depth. The trace fossil density and diversity patterns are analogous to those exhibited by modem and ancient shelly macrobenthos, where in shallow subtidal regimes they are low, then peak in slightly deeper subtidal situations, and gradually decrease seawards with increasing depth and distance from shore.

Viimati muudetud: 20.6.2023
KIKNATARCSARVTÜ Loodusmuuseumi geokogudEesti Loodusmuuseumi geoloogia osakond
Leheküljel leiduvad materjalid on enamasti kasutamiseks CC BY-SA litsensi alusel, kui pole teisiti määratud.
Portaal on osaks teadustaristust ning infosüsteemist SARV, majutab TalTech.
Open Book ikooni autor Icons8.