Sedimentary successions and internal structure of the coastal barrier-lagoon system of Boao, eastern Hainan Island were studied through utilizing data from test holes and trenches and ground-penetrating-radar (GPR) pr...Sedimentary successions and internal structure of the coastal barrier-lagoon system of Boao, eastern Hainan Island were studied through utilizing data from test holes and trenches and ground-penetrating-radar (GPR) profiles. During late Pleistocene, fluvial and delta plains developed over an unevenly eroded bedrock during low sea level stand, followed by the formation of littoral and lagoon facies and defined coastal barrier-lagoon-estuary system during the post-glacial uppermost Pleistocene-lower Holocene eustatic rise of the sea level, and the upper Holocene high stand. GPR results show that Yudaitan, a sandy coastal bar backed by a low-laying land (shoal) just east of the active lagoon, is a continuous, parallel and slightly-wavy reflectors indicating homogeneous sandy or sandy gravel sediments, and inclined reflectors partly caused by progradation and accumulation of beach sand and gravel. Quasi-continuous, hummocky and chaotic reflectors from the shoal of Nangang village correspond to mixed accumulation of sands and clay. This research indicates the GPR is a non-intrusive, rapid, and economical method for high-resolution profiling of subsurface sediments in sandy gravelly coast.展开更多
Study of internal-wave and internal-tide deposits is a very young research field in deep-water sedimentology. It has been just twenty years since the first example of internal-wave and internal-tide deposits was ident...Study of internal-wave and internal-tide deposits is a very young research field in deep-water sedimentology. It has been just twenty years since the first example of internal-wave and internal-tide deposits was identified in the stratigraphic record. Since that time, Chinese scholars have made unremitting efforts and gained some significant research achievements in this field. This paper briefly outlines the history and main achievements of research of internal-wave and internal-tide deposits in China, describes depositional charac-teristics, sedimentary successions, types of lithofacies, and depositional models of internal-wave and internal-tide deposits identified mainly from ancient strata, and summarizes the existing problems in this research field. New advances in marine physics should be applied to research of the subject of internal-wave and internal-tide deposition, whereas the sedimentary characteristics of internal-wave and internal-tide deposits may be used to deduce the physical processes of their creation. Flume experiments on internal-wave and internal-tide deposition should also be put in practice as often as possible, so that the mechanisms of internal-wave and internal-tide deposition can be explored.展开更多
基金Project of cooperation between China and Canada, CIDA Project, No. CCHEP 282/19736
文摘Sedimentary successions and internal structure of the coastal barrier-lagoon system of Boao, eastern Hainan Island were studied through utilizing data from test holes and trenches and ground-penetrating-radar (GPR) profiles. During late Pleistocene, fluvial and delta plains developed over an unevenly eroded bedrock during low sea level stand, followed by the formation of littoral and lagoon facies and defined coastal barrier-lagoon-estuary system during the post-glacial uppermost Pleistocene-lower Holocene eustatic rise of the sea level, and the upper Holocene high stand. GPR results show that Yudaitan, a sandy coastal bar backed by a low-laying land (shoal) just east of the active lagoon, is a continuous, parallel and slightly-wavy reflectors indicating homogeneous sandy or sandy gravel sediments, and inclined reflectors partly caused by progradation and accumulation of beach sand and gravel. Quasi-continuous, hummocky and chaotic reflectors from the shoal of Nangang village correspond to mixed accumulation of sands and clay. This research indicates the GPR is a non-intrusive, rapid, and economical method for high-resolution profiling of subsurface sediments in sandy gravelly coast.
基金funded by the National Natural Science Foundation of China (No.40672071 and 41072086)the Research Fund for the Doctoral Program of Higher Education in China (No.20104220110002)
文摘Study of internal-wave and internal-tide deposits is a very young research field in deep-water sedimentology. It has been just twenty years since the first example of internal-wave and internal-tide deposits was identified in the stratigraphic record. Since that time, Chinese scholars have made unremitting efforts and gained some significant research achievements in this field. This paper briefly outlines the history and main achievements of research of internal-wave and internal-tide deposits in China, describes depositional charac-teristics, sedimentary successions, types of lithofacies, and depositional models of internal-wave and internal-tide deposits identified mainly from ancient strata, and summarizes the existing problems in this research field. New advances in marine physics should be applied to research of the subject of internal-wave and internal-tide deposition, whereas the sedimentary characteristics of internal-wave and internal-tide deposits may be used to deduce the physical processes of their creation. Flume experiments on internal-wave and internal-tide deposition should also be put in practice as often as possible, so that the mechanisms of internal-wave and internal-tide deposition can be explored.
