『Abstract
Studies of fine-grained sediment dispersal in the marine environment
have documented diversity in the behavior of depositional systems
on continental margins with different oceanographic conditions
and morphologies. Based on the pattern and nature of sediment
accumulation for twenty-three case studies, we propose there are
five basic types of dispersal systems, and these are related to
river, wave, tide and margin characteristics. Data suggest that
the type of dispersal system on any margin can be predicted with
knowledge of sediment load, mean significant wave height, tidal
range and continental-shelf width at a river mouth, and from these,
a hierarchical decision tree is developed. Analysis of the dispersal-system
type of more than 100 river mouths reveals that proximal-accumulation-dominated
(PAD) and marine-dispersal- dominated (MDD) systems are most abundant.
But, estuarine-accumulation-dominated (EAD) systems also are anticipated
to be numerous globally. Research quantifying marine sediment
dynamics in these system types is needed. Although less common,
the size and nature of subaqueous-delta-clinoform (SDC) and canyon-captured
(CC) systems also warrant future attention to their study. Strong
correlations between physical characteristics (i.e., significant
wave height and tidal range) and the depth and distance to the
nearest maximum shelf depocenter provide evidence that in reality
a continuum exists between the system types. The process-related
partitioning of sediment in the five different types of marine
dispersal systems has important implications for understanding
the stratigraphic record and the cycling of carbon.
Keywords: deltas; rivers; continental margins; sedimentation』
1. Introduction
2. Background
3. Methods
4. Results
5. Discussion
5.1. Sediment partitioning and fluvial dispersal systems
5.1.1. Estuarine-accumulation-dominated (EAD) systems
5.1.2. Proximal-accumulation-dominated (PAD) systems
5.1.3. Canyon-captured (CC) systems
5.1.4. Marine-dispersal-dominated (MDD) systems
5.1.5. Subaqueous-delta-clinoform (SDC) systems
5.2. A prediction tool
5.3. A continuum of systems
5.4. System types through geologic time
5.5. Implications
6. Conclusions
Acknowledgements
References