Physical property characterization of quaternary sediments in the vicinity of the paleo-Seomjin River of the continental shelf of the South Sea, Korea

Abstract

Thirty-two core samples were collected from the continental shelf area of the South Sea, Korea. They have been used to characterize physical properties in relation to sedimentary units (interpreted from seismic and core data) and to interpret physical property variation as a function of burial depth. The physical property data were readily classified into sedimentary units: Units S1, S2, S3, S4, and S5, in descending order. The variations in physical properties reflect well the relative characteristics of sedimentary units (equivalent to seismic units). Moreover, the relationships between physical properties are well grouped by each sedimentary unit. In addition, the distributions of physical properties match well with the grain size distribution and bathymetry of the study area. In particular, the lithology (e.g., grain size) plays an important role in the variation of physical properties. These results suggest that the physical properties of these sediments are mainly controlled by depositional processes in the vicinity of the paleo-Seomjin River, and that sea-level change specifically was a dominant sedimentary processes in the study area during the Quaternary. In particular, the physical properties of Unit S2 do not show transitional characteristics between Units S1 and S3, although it belongs to the transition zone in sequence order. This finding is attributed to the fact that compared with the sediments of Units S1 and S3, Unit S2 is composed of more coarse-grained sediments with abundant shell fragments.