Assessing palaeobathymetry and sedimentation rates using palynomaceral analysis: a study of modern sediments from the Gulf of Papua, offshore Papua New Guinea

© 2015 © 2015 AASP - The Palynological Society. Palynologists interested in better understanding the sedimentation and energy of depositional environments have often included studies of palynomaceral fragments, particularly when performing palynofacies analyses. Due to the difficult nature of classifying these fragments, researchers have developed numerous, often overlapping, classification schemes. These different schemes make it difficult to compare and contrast between research projects. Determining the appropriate scheme to apply when counting these fragments can be confusing, and application of these schemes can yield inconclusive results, especially when sedimentation and energy are in constant flux. A scheme of five categories, including brown wood (palynomaceral 1-2), leaf cuticle (palynomaceral 3), black debris (palynomaceral 4), structureless organic matter (SOM) and resin, is utilised here. It is applied to the analysis of 64 modern samples from the top 0-4 cm of sediment collected throughout the Gulf of Papua, Papua New Guinea. These samples span a suite of common marine depositional environments: river mouths and deltas, the proximal portion of the continental shelf dominated by a large clinoform, and turbidite and hemipelagic/pelagic deposits on the slope and in the deep ocean basin. Principal component analysis (PCA) confirms this simplified classification scheme provides an indirect means of assessing distance from shore and shelf-slope break, overall water depth and sediment accumulation rate, but other factors, such as processing technique, marine productivity, sediment source, time in transport and residence and bioturbation, are taken into account to fully explain distribution