Taphonomic signature as a function of environmental process: Shells and shell beds in a hurricane-influenced inlet on the Texas coast

摘要: Abstract Criteria for taphonomic processes, including dissolution, breakage, abrasion, size sorting and shell orientation, were statistically correlated against environmental parameters representing source, depositional environment depth of burial, using samples obtained from San Luis Pass, a microtidal inlet on the Texas coast. Core intervals differentiated by cluster analysis into shell-poor sands, slightly shelly shell-rich sands gravels based their percent carbonate gravel content. Boundaries between these sedimentary classes represent thresholds in physical processes forming deposits. We propose that this classification scheme sediments may be useful field descriptions variety tectonic settings. The death assemblages predominantly composed whole fragmental molluscan shells. Most shells show effects such as edge rounding, surface abrasion sorting. A significant minority evidence minor chemical alteration (dissolution). Patterns rounding differed significantly mixed-faunal assemblage derived different habitats (bay, inlet/beach, inner shelf unrestricted). Thus, habitat where species lived, rather than its final environment, controlled most aspects taphonomy. Only orientation size-frequency distribution affected deposition. hypothesis discrete high energy (hurricane) “event” can imprint unique signature is, consequently, false. Although hurricanes physically winnow material, single merely concentrates with preexisting characteristics without further alteration. Depth burial was poorly biostratinomic effects, dissolution. Significant dissolution must occur only near sediment-water interface. Accordingly, quantified might identifying original deposited mixed accumulations; “taphofacies” reflect not process, but also origin.