Surface sediment data acquired by the grab sampling technique were used in the present study to produce a high-resolution and full coverage surface grain-size mapping. The objective is to test whether the hypothetical...Surface sediment data acquired by the grab sampling technique were used in the present study to produce a high-resolution and full coverage surface grain-size mapping. The objective is to test whether the hypothetically natural relationship between the surface sediment distribution and complex bathymetry could be used to improve the quality of surface sediment patches mapping. This is based on our hypothesis that grain-size characteristics of the ridge surface sediments must be intrinsically related to the hydrodynamic condition, i.e. storm-induced currents and the geometry of the seabed morphology. The median grain-size data were obtained from grab samples with inclusive bathymetric point recorded at 713 locations on the high-energy and shallow shelf of the Spiekeroog Barrier Island at the German Bight of the Southern North Sea. The area features two-parallel shoreface-connected ridges which is situated obliquely WNW-SSE oriented and mostly sandy in texture. We made use the median grain-size (d50) as the predictand and the bathymetry as the covariable to produce a high-resolution raster map of median grain-size distribution using the Cokriging interpolation. From the cross-validation of the estimated median grain-size data with the measured ones, it is clear that the gradient of the linear regression line for Cokriging is leaning closer towards the theoretical perfect-correlation line (45°) compared to that for Anisotropy Kriging. The interpolation result with Cokriging shows more realistic estimates on the unknown points of the median grain-size and gave detail to surface sediment patchiness, which spatial scale is more or less in agreement with previous studies. In addition to the moderate correlation obtained from the Pearson correlation (r = 0.44), the cross-variogram shows a more precise nature of their spatial correlation, which is physically meaningful for the interpolation process. The present study partially contributes to the framework of habitat mapping and nature protection that is to fill the gaps 展开更多
In the developed world,governance of marine ecological environment is the important part of the national ecological and economic outcome.The Yellow Sea is one of large marine ecosystems in the seas of East Asia,which ...In the developed world,governance of marine ecological environment is the important part of the national ecological and economic outcome.The Yellow Sea is one of large marine ecosystems in the seas of East Asia,which is an extension of one of the largest continental shelf areas,and forms a huge but shallow sediment body in its south area which is geographically unique in the world.As a region with the most fragile natural environment,unparalleled global ecological significance and the most urgent protection needs,the Yellow Sea ecological zone is becoming a common concern of countries around the Yellow Sea and beyond,such as tidal flats and the staging migratory birds(Murray et al.,2015).展开更多
This study is focused on sedimentary environments, facies distribution, and sequence stratigraphy. The facies and sequence stratigraphic analyses of the Bahram Formation（middleelate Devonian） in southcentral Iran ar...This study is focused on sedimentary environments, facies distribution, and sequence stratigraphy. The facies and sequence stratigraphic analyses of the Bahram Formation（middleelate Devonian） in southcentral Iran are based on two measured stratigraphic sections in the southern Tabas block. The Bahram Formation overlies red sandstones Padeha Formation in sections Hutk and Sardar and is overlain by Carboniferous carbonate deposits of Hutk Formation paraconformably, with a thickness of 354 and386 m respectively. Mixed siliciclastic and carbonate sediments are present in this succession. The field observations and laboratory studies were used to identify 14 micro/petrofacies, which can be grouped into 5 depositional environments： shore, tidal flat, lagoon, shoal and shallow open marine. A mixed carbonate-detrital shallow shelf is suggested for the depositional environment of the Bahram Formation which deepens to the east（Sardar section） and thins in southern locations（Hutk section）. Three 3rdorder cyclic siliciclastic and carbonate sequences in the Bahram Formation and one sequence shared with the overlying joint with Hutk Formation are identified, on the basis of shallowing upward patterns in the micro/pertofacies.展开更多
Quaternary buried ancient river channels are widespread in the shallow-level sediments of the northern shelf of the South China Sea. The sedimentary sequence mainly of fluvial deposits comprise an important component ...Quaternary buried ancient river channels are widespread in the shallow-level sediments of the northern shelf of the South China Sea. The sedimentary sequence mainly of fluvial deposits comprise an important component part of the low-stand system tract and transgressive system tract in the study region. The plannar variation and spatial association of the sedimentary features such as incised valley fillings, deltaic foreset wedges and block slides of shelf-marginal fans reflect the palaeogeographic environment during the fall of the regional sea level in the northern part of the South China Sea. Based on the high-resolution seismic reflection data and gelogical data from boreholes, the present paper makes an integrated interpretation of the Quaternary ancient river channels in the shallow sediments of the study area, studies the sedimentary features of the ancient channels such as their spatial distribution, seismic facies reflection indicators, sedimentary facies and sand -body types, and discusses their formational setting and evolutionary model, with the main purpose to render a service to the hydrocarbon resources exploration and development and marine engineering in the northern shelf of the South China Sea.展开更多
Conodonts are elements of a feeding apparatus of jawless eel-like animals belonging to the clade Vertebrata.They are very important microfossils,ubiquitous in the Paleozoic and Early Mesozoic marine sequences,and they...Conodonts are elements of a feeding apparatus of jawless eel-like animals belonging to the clade Vertebrata.They are very important microfossils,ubiquitous in the Paleozoic and Early Mesozoic marine sequences,and they occurred in different habitats,from deep-ocean to shallow-shelf waters.展开更多
Some carbonate concretion samples were collected in 1983 from the continental slope of the East China Sea at 29°08′N, 127°30′E, depth 240m. Their morphology, mineral composition and texture are markedly di...Some carbonate concretion samples were collected in 1983 from the continental slope of the East China Sea at 29°08′N, 127°30′E, depth 240m. Their morphology, mineral composition and texture are markedly different from those of the calcareous concretions occurring in the shallow shelf. The latter are formed in continental environment, while展开更多
Authigenic ferromanganese carbonates were first discovered in some shallow and hemipelagic areas by scientists abroad.These minerals have also been found on the offshore along China, especially in the South China Sea ...Authigenic ferromanganese carbonates were first discovered in some shallow and hemipelagic areas by scientists abroad.These minerals have also been found on the offshore along China, especially in the South China Sea (such as the Beibu Bay, the Sanya Bay and the continental shelf). Though the abundance of the carbonates展开更多
The formation of Recent shallow seas is an outcome of the latest transgression. Thus we propose the term 'shelf transgression' to include the different kinds of nomenclature used in designating and correlating...The formation of Recent shallow seas is an outcome of the latest transgression. Thus we propose the term 'shelf transgression' to include the different kinds of nomenclature used in designating and correlating world-wide Holocene transgressions. Shelf transgression has not only led to the formation of Recent shallow seas of the world, but also had profound effects on the development of modern coasts and estuaries, and hence is directly related to problems of construction of coastal engineering展开更多
文摘Surface sediment data acquired by the grab sampling technique were used in the present study to produce a high-resolution and full coverage surface grain-size mapping. The objective is to test whether the hypothetically natural relationship between the surface sediment distribution and complex bathymetry could be used to improve the quality of surface sediment patches mapping. This is based on our hypothesis that grain-size characteristics of the ridge surface sediments must be intrinsically related to the hydrodynamic condition, i.e. storm-induced currents and the geometry of the seabed morphology. The median grain-size data were obtained from grab samples with inclusive bathymetric point recorded at 713 locations on the high-energy and shallow shelf of the Spiekeroog Barrier Island at the German Bight of the Southern North Sea. The area features two-parallel shoreface-connected ridges which is situated obliquely WNW-SSE oriented and mostly sandy in texture. We made use the median grain-size (d50) as the predictand and the bathymetry as the covariable to produce a high-resolution raster map of median grain-size distribution using the Cokriging interpolation. From the cross-validation of the estimated median grain-size data with the measured ones, it is clear that the gradient of the linear regression line for Cokriging is leaning closer towards the theoretical perfect-correlation line (45°) compared to that for Anisotropy Kriging. The interpolation result with Cokriging shows more realistic estimates on the unknown points of the median grain-size and gave detail to surface sediment patchiness, which spatial scale is more or less in agreement with previous studies. In addition to the moderate correlation obtained from the Pearson correlation (r = 0.44), the cross-variogram shows a more precise nature of their spatial correlation, which is physically meaningful for the interpolation process. The present study partially contributes to the framework of habitat mapping and nature protection that is to fill the gaps
基金The National Key Research and Development Project of China under contract No.2019YFC1407805the UNDP/GEF YSLME PhaseⅡProject。
文摘In the developed world,governance of marine ecological environment is the important part of the national ecological and economic outcome.The Yellow Sea is one of large marine ecosystems in the seas of East Asia,which is an extension of one of the largest continental shelf areas,and forms a huge but shallow sediment body in its south area which is geographically unique in the world.As a region with the most fragile natural environment,unparalleled global ecological significance and the most urgent protection needs,the Yellow Sea ecological zone is becoming a common concern of countries around the Yellow Sea and beyond,such as tidal flats and the staging migratory birds(Murray et al.,2015).
基金a part of project of the Hormozgan University and two master theses of the senior author, which is supported by the Department of Geology at Hormozgan University of Bandar Abbas, Iran
文摘This study is focused on sedimentary environments, facies distribution, and sequence stratigraphy. The facies and sequence stratigraphic analyses of the Bahram Formation（middleelate Devonian） in southcentral Iran are based on two measured stratigraphic sections in the southern Tabas block. The Bahram Formation overlies red sandstones Padeha Formation in sections Hutk and Sardar and is overlain by Carboniferous carbonate deposits of Hutk Formation paraconformably, with a thickness of 354 and386 m respectively. Mixed siliciclastic and carbonate sediments are present in this succession. The field observations and laboratory studies were used to identify 14 micro/petrofacies, which can be grouped into 5 depositional environments： shore, tidal flat, lagoon, shoal and shallow open marine. A mixed carbonate-detrital shallow shelf is suggested for the depositional environment of the Bahram Formation which deepens to the east（Sardar section） and thins in southern locations（Hutk section）. Three 3rdorder cyclic siliciclastic and carbonate sequences in the Bahram Formation and one sequence shared with the overlying joint with Hutk Formation are identified, on the basis of shallowing upward patterns in the micro/pertofacies.
基金The present paper represents the result of a scientific research subject of the UNDP-assisted Project "Marine Engineering Geological Investigation of the Pearl River Mouth Basin in the Northern Party of the South China Sea" (Project No. UNDP.CPR/85/044)
文摘Quaternary buried ancient river channels are widespread in the shallow-level sediments of the northern shelf of the South China Sea. The sedimentary sequence mainly of fluvial deposits comprise an important component part of the low-stand system tract and transgressive system tract in the study region. The plannar variation and spatial association of the sedimentary features such as incised valley fillings, deltaic foreset wedges and block slides of shelf-marginal fans reflect the palaeogeographic environment during the fall of the regional sea level in the northern part of the South China Sea. Based on the high-resolution seismic reflection data and gelogical data from boreholes, the present paper makes an integrated interpretation of the Quaternary ancient river channels in the shallow sediments of the study area, studies the sedimentary features of the ancient channels such as their spatial distribution, seismic facies reflection indicators, sedimentary facies and sand -body types, and discusses their formational setting and evolutionary model, with the main purpose to render a service to the hydrocarbon resources exploration and development and marine engineering in the northern shelf of the South China Sea.
文摘Conodonts are elements of a feeding apparatus of jawless eel-like animals belonging to the clade Vertebrata.They are very important microfossils,ubiquitous in the Paleozoic and Early Mesozoic marine sequences,and they occurred in different habitats,from deep-ocean to shallow-shelf waters.
文摘Some carbonate concretion samples were collected in 1983 from the continental slope of the East China Sea at 29°08′N, 127°30′E, depth 240m. Their morphology, mineral composition and texture are markedly different from those of the calcareous concretions occurring in the shallow shelf. The latter are formed in continental environment, while
文摘Authigenic ferromanganese carbonates were first discovered in some shallow and hemipelagic areas by scientists abroad.These minerals have also been found on the offshore along China, especially in the South China Sea (such as the Beibu Bay, the Sanya Bay and the continental shelf). Though the abundance of the carbonates
文摘The formation of Recent shallow seas is an outcome of the latest transgression. Thus we propose the term 'shelf transgression' to include the different kinds of nomenclature used in designating and correlating world-wide Holocene transgressions. Shelf transgression has not only led to the formation of Recent shallow seas of the world, but also had profound effects on the development of modern coasts and estuaries, and hence is directly related to problems of construction of coastal engineering
