As both represent aspects of their environment, sediment and organisms can be closely related. In deltaic systems, numerous studies have examined the range of delta types and subenvironments and characterized facies and icnology. Yet, these relations are less well characterized in outer shelf deltas, a niche that Dasgupta and co-authors fill. This paper characterizes and ranks ecologic stress factors on the interactions between animals and substrates in a shelf-edge delta environment of the Plio-Pleistocene Gelasian Mayaro Formation of Trinidad Island, Trinidad. The field observations of the equatorial paleo-Orinoco system reveal a diverse suite of sedimentologic and ichnologic attributes, interpreted to reflect an extremely variable and dynamic marine environment. These data lead to an exposition of a comprehensive ichno-sedimentological conceptual model for large-river, low-latitude, accommodation-driven, shelf-edge deltas.
Living on the edge: evaluating the impact of stress factors on animal-sediment interactions within subenvironments of a shelf-margin delta, the Mayaro Formation, Trinidad Sudipta Dasgupta, Luis A. Buatois, and M. Gabriela Mángano