Sedimentology and Neoichnology of a Wave-Dominated, Tidally-Influenced, Fully Marine Bay, Oregon, USA

Abstract

In the field of ichnology it is understood that modern process ichnological observations of biogenically generated structures, in response to various physicochemical parameters, have substantial applicability to deciphering trace fossil assemblages observed in the rock record. Previous research has described various animal-sediment distributions within a fully marine realm. However, limited modern studies have directly assessed trace genesis in high energy, constantly shifting sandy substrates or the paleoecology of firmgrounds in a fully marine bay. In this thesis the effects of hydraulic energy, sediment erosion, sediment deposition, substrate firmness, and overall paleoecological aspects of various substrate types on macrofaunal burrowing behaviour and resultant trace distributions were assessed. This was achieved through detailed sedimentological and neoichnological observations conducted along transect locations within Netarts Bay, Oregon. The knowledge gained through this study strengthens ichnofacies models and offers new insight into trace distributions within shallow, fully marine environments.