Abstract: Freshwater Ichnocoenoses from Triassic Red Beds of East Greenland
R. G. Bromley, U. Asgaard
On the west shore of Carlsberg Fjord, Jameson Land, the Orsted Dal and Malmros Klint Members of the Fleming Fjord Formation (Upper Triassic) are developed as a series of red-bed mudstones and siltstones with sandstone intercalations. A rich series of ichnocoenoses is present in these beds, chiefly as hypichnial demireliefs in the sandstones. The assemblages are more diverse and better preserved than is normal for red beds and include new forms. At any one horizon the diversity is low, but the members as a whole contain the following trace fossils: Cruziana sp., interpreted as ploughing traces of notostracans; Rusophycus sp., resting traces of same; Isopodichnus problematicus, distinct from Cruziana in size and ornament, and probably ascribable to arthropods or gastropods; Diplichnites sp., also probably attributable to notostracans; Lockeia (Pelecypodichnus) sp., possibly the resting traces of conchostracans; Scoyenia gracilis, with filling material in places containing distinct coprolites; narrow vertical burrows with rounded terminations and longitudinally scratched walls, perhaps the work of insects; narrow horizontal burrow systems dichotomously branched and transversely scratched, with loosely packed fill; wide, oblique, loosely stuffed burrows; and ?Rhizocorallium sp., a very short-legged form with a loosely organized spreite. The ?Rhizocorallium sp. are chiefly at a well-defined horizon and possibly represent a marine influence in the otherwise freshwater environment.
AAPG Search and Discovery Article #90968©1977 AAPG-SEPM Annual Convention and Exhibition, Washington, DC