173 Paleontology (Posters) III: Biogeography, Biostratigraphy, and Taphonomy
Tuesday, 11 October 2011
9:00 AM - 6:00 PM
Hall C
THE TAPHONOMIC MODES IN THE FLUVIAL SYSTEM OF THE UPPER TRIASSIC ISCHIGUALASTO FORMATION, NW ARGENTINA
Paper number: 173-8
Program: Technical Sessions
Time: 9:00 AM – 6:00 PM
Authors
Abstract
Detailed taphonomic studies in the vertebrate and floristic assemblages have identified the taphonomic modes that characterized each of the sub-environments. These are: A) low sinuosity channels, characterized by silicified roots of woody plants, uncommon silicified allochthonous tree trunks, and rare paleovertebrates, mostly highly altered isolated remains mineralized by calcite; B) high sinuosity channels; typified by more abundant allochthonous silicified tree trunks together with troughs having concentrated parautochthonous leaf cuticles, and similar taphonomic patterns in respect to the palevertebrates; C) levees, typified by abundant herbaceous carbonized roots and root halos and the most significant collection of paleovertebrates from fresh, articulated skeletons to isolated highly weathered remains, mineralized by calcite and/or hematite; D) distal well-drained floodplains with calcisols, with abundant root halos and similar taphonomic features of paleovertebrates, although with a dominance of isolated hematite mineralized remains; E) distal well-drained floodplains with argillisols, distinguished by an additional abundance of carbonized herbaceous roots and isolated paleovertebrate remains mineralized by hematite in the highest weathering stage; F) crevasses, characterized by carbonized herbaceous and silicified woody roots and an entire range of paleovertebrate types of preservation, dominated by semi-articulated mineralized with calcite remains; G) abandoned channels; with the particular preservation of authochtonous leaf cuticles, palynomorphs, some carbonized herbaceous roots, very rare burned remains of paleovertebrates and molds of cochostracons; finally the mode H) burrows, is characterized by a completely articulated fresh skeleton, sometimes associated to more than one.