Brachiopod and Bivalve taphonomy in subtropical siliciclastic settings of northern coast of São Paulo State: enviromental variation in taphonomic signatures, biostratinomic style and time-averaging

Resumo

The living-fossil B. rosea (Brachiopoda) and their shelly accumulations have been poorly researched. Thus, this project aims two major goals (Paleontological and Geological) to fill a critical gap in our taphonomic knowledge. We will investigate bioclastic concentrations in siliciclastic seafloors (~5~40 m. of depth) in the northern coast of São Paulo State, through taphonomic evaluation of death assemblages, sediment analysis and radiocarbon amino-acid dating of shelly material. The main project objectives are: 1- taphonomic analysis of the shelly concentrations of B. rosea; 2- study of the environmental variation in physical condition of the shelly material of death assemblages (Brachiopod versus Bivalve) across shallow, siliciclastic environments; 3- analysis of the effects of exirinsic (environmental) and intrinsic (Brachiopod and Bivalve life habits) factors in the origin of shell types (taphonomic signatures), and the biostratinomic style of the skeletal accumulations, and 4- study of the time-averaging among the accumulations in different embayments. (AU)