An association of Torlessia and late Middle—early Upper Triassic fossils at Pudding Hill Stream, central Canterbury

Abstract

Marine invertebrates of late Middle-early Upper Triassic age are associated in redeposited sediments with tubes of Torlessia at Pudding Hill Stream near Mount Hutt, central Canterbury. Bryozoans, taxodont bivalves, Plicatula, brachiopods including Mentzeliopsis, gastropods and crinoids are preserved in more or less fragmentary form in the coarse (granule-sized) bases of graded units, some of which contain Torlessia tubes in their finer-grained upper parts. The mode of occurrence suggests emplacement by subaqueous flow of both the tubes and the shelly remains. Contemporaneity of the tubes and the other fossils is certain and time equivalence of Pudding Hill Formation and Fingers Formation to the west is established. An east-facing palaeoslope seems likely for the Rangitata-Ashburton catchment area for at least part of Triassic time.