Several argillaceous platforms lie along the Yellow River(YR) of the eastern Guide Basin, northeastern Tibetan Plateau, and their compositions, formation processes, and geomorphic evolution remain debated. Using fie...Several argillaceous platforms lie along the Yellow River(YR) of the eastern Guide Basin, northeastern Tibetan Plateau, and their compositions, formation processes, and geomorphic evolution remain debated. Using field survey data, sample testing, and high-resolution remote sensing images, the evolution of the Erlian mudflow fans are analyzed. The data show significant differences between fans on either side of the YR. On the right bank, fans are dilute debris flows consisting of sand and gravel. On the left bank, fans are viscosity mudflows consisting of red clay. The composition and formation processes of the left bank platforms indicate a rainfall-induced pluvial landscape. Fan evolution can be divided into two stages: early-stage fans pre-date 16 ka B.P., and formed during the last deglaciation; late-stage fans post-date 8 ka B.P.. Both stages were induced by climate change. The data indicate that during the Last Glacial Maximum, the northeastern Tibetan Plateau experienced a cold and humid climate characterized by high rainfall. From 16–8 ka, the YR cut through the Erlian early mudflow fan, resulting in extensive erosion. Since 8 ka, the river channel has migrated south by at least 1.25 km, and late stage mudflow fan formation has occurred.展开更多
A turbidite fan in the Eocene upper Wenchang Formation in the Enping Sag, Pearl River Mouth Basin (PRMB) has been studied using seismic, logging and borehole data. The fan is characterized by parallel progradation o...A turbidite fan in the Eocene upper Wenchang Formation in the Enping Sag, Pearl River Mouth Basin (PRMB) has been studied using seismic, logging and borehole data. The fan is characterized by parallel progradation on the dip seismic profile and is mound-shaped or lenticular-shaped on the strike seismic profile. The study of the core and logging data from well EP17-3-1, which is located in the front side of the turbidite fan, shows that this fan is a set of normal grading sand beds, interbedded within thick dark grey mudstones of semi-deep to deep lake deposits in the Wenchang Formation. The fan is interpreted as a sand/mud-rich turbidite fan that has an area of over 140 km2 and a maximum thickness of over 340 m. Combined with a study of the regional geological background and previous provenance analysis of the Eocene Wenchang Formation, the main potential provenances for the turbidite fan are considered to be the Panyu low-uplift and northern fault terrace zone. The Enping Sag is considered to be a half graben-like basin whose north side is faulted and whose south side is overlapped. Basement subsidence in the Eocene was mainly controlled by boundary faults which dip relatively steeply on the north side, causing the subsidence center of the Enping Sag in this stage to be close to the north boundary faults. Sustained faults developed in the Enping Sag during the Eocene caused an increase of the relative height difference between the north and the south uplift zone in the Enping Sag. Affected by the second episode of the Zhuqiong movement (39-36 Ma) in late Eocene, sediments which had accumulated on the Panyu low-uplift zone were triggered and moved toward the subsidence center of the Enping Sag and formed the turbidite fan. The second episode of the Zhuqiong movement is the most important triggering factor for the formation of the turbidite fan in the Wenchang Formation. Seismic attribute characterization shows that the low frequency energy is enhanced and high frequency energy is weakened when seismic waves propagate through the oil-bearing zone in this fan. Amplitude versus offset (AVO) anomalies are observed in the seismic data and abnormally high pressure is encountered. The turbidite fan in the Wenchang Formation has provided important information for sedimentary evolution in deep layers of the Enping Sag and pointed to a new direction for the hydrocarbon exploration in the study area.展开更多
In the river systems, the environmental change always undergoes a process from quantitative to qualitative change. The upper limit of the qualitative change is called threshold. When the process reaches or goes beyond...In the river systems, the environmental change always undergoes a process from quantitative to qualitative change. The upper limit of the qualitative change is called threshold. When the process reaches or goes beyond the limit, the original event series will be replaced by the other event series. Investigations show that the evolution of the Huanghe River alluvial fan and delta has also under gone a process from quantitative to qualitative change. The geometric forms in each process are roughly the same. This threshold of the geometric forms not only provides us a quantitative index for plotting the periodicity of the alluvial fan and delta, but also is of importance for estimation of the trend of natural environmental change.It is shown that there are three periodic alluvial fans of the Huanghe River since the middle Holocene and four periodic delta since 1855 A.D., the thresholds of their geometric forms are from 0.93 to 0.94 and from 1.2 to 1.21 respectively.The changing trend in the past and the展开更多
Vertical hydraulic gradient (VHG) provides detailed information on 3D groundwater flows in alluvial fans, but its regional mapping is complicated by a lack of piezometer nests and uncertainty in conventional well data...Vertical hydraulic gradient (VHG) provides detailed information on 3D groundwater flows in alluvial fans, but its regional mapping is complicated by a lack of piezometer nests and uncertainty in conventional well data. Especially, determining representative depth of well screen in each well is problematic. Here, a VHG map of the Toyohira River alluvial fan, Sapporo, Japan, is constructed based on groundwater table elevation (GTE), using available well-data of various screen lengths and depths. The water-level data after 1988, when subway constructions are mostly completed in the city, are divided into those of shallow wells (≤20 m deep), and those of deep wells (>20 m deep). First, the GTE map is generated by kriging interpolation of shallow well data with topographic drift. Next, the individual VHG value of each deep well is calculated using its top, middle, and bottom elevations of the screen depths, respectively. The VHG maps of three cases are then obtained using neighborhood kriging. The VHG map of the bottom screen depths has proven most valid by cross-validation. The VHG map better visualizes that downward flows of groundwater are predominant over the fan. Positive area of VHG is mostly vanished around the fan-toe, indicating urbanization effect such as artificial withdrawals. A negative peak of VHG corresponds to recharge area, and is seen along the distinct losing section in the river. The negative peak also expands upstream to the fan-apex where a basement is suddenly depressed.展开更多
Eleven lithofacies and five lithofacies associations were indentified in the Miocene Zhujiang Formation on the basis of detailed core analysis. It could he determined that three depositional types developed, namely su...Eleven lithofacies and five lithofacies associations were indentified in the Miocene Zhujiang Formation on the basis of detailed core analysis. It could he determined that three depositional types developed, namely submarine fan, basin and deep-water traction current. Six microfacies were further recognized within the fan, including main channels in the inner fan, distributary channels in the middle fan, inter-channels, levees and the outer fan. The lower Zhujiang Formation, mainly sandstone associations, was inner fan and inner-middle fan deposits of the basin fan and the slope fan. The middle part, mainly mudstone associations, was outer fan deposits. With the transgression, the submarine fan was finally replaced by the basinal pelagic deposits which were dominated by mudstone associations, siltstone associations, and deep-water limestone associations. During the weak gravity flow activity, the lower channels, the middle-upper outer fans and basin deposits were strongly modified by the deep-water traction current. The identification of the deep-water traction deposition in Miocene Zhujiang Formation would be of great importance. It could be inferred that the deep- water traction current had been existing after the shelf-break formation since the Late Oligocene (23.8 Ma) in the Baiyun sag, influencing and controlling the sediment composition, the distribution, and depositional processes. It would provide great enlightenment to the paleo-oceanic current circulation in the northern South China Sea.展开更多
The concept and characteristics of fluvial fan are elucidated through literature review and case analysis.Firstly,the concept and terminology of fluvial fan are introduced.Secondly,the progress and controversy on the ...The concept and characteristics of fluvial fan are elucidated through literature review and case analysis.Firstly,the concept and terminology of fluvial fan are introduced.Secondly,the progress and controversy on the formation mechanism,analysis methods and sedimentary models of fluvial fan are elaborated,and fluvial fan is compared with alluvial fan,river and lacustrine delta.Finally,ten identification signs of the fluvial fan are proposed.It is found through the study that development and scale of fluvial fan are affected by external factors such as climate,tectonic,provenance and wind field.The facies and lithofacies association inside the fan are controlled by the activity of the internal channel.It is pointed that fluvial fans are widely distributed in the world not only today but also in the geological history.The occurrence of fluvial fan will change the traditional continental deposition system dominated by alluvial fan-river-lacustrine.Meanwhile,the research of fluvial fan will be of great significance in the fields of sedimentology and oil and gas exploration.展开更多
The coupling relationship between shelf-edge deltas and deep-water fan sand bodies is a hot and cutting-edge field of international sedimentology and deep-water oil and gas exploration.Based on the newly acquired high...The coupling relationship between shelf-edge deltas and deep-water fan sand bodies is a hot and cutting-edge field of international sedimentology and deep-water oil and gas exploration.Based on the newly acquired high-resolution 3D seismic,logging and core data of Pearl River Mouth Basin(PRMB),this paper dissected the shelf-edge delta to deep-water fan(SEDDF)depositional system in the Oligocene Zhuhai Formation of Paleogene in south subsag of Baiyun Sag,and revealed the complex coupling relationship from the continental shelf edge to deep-water fan sedimentation and its genetic mechanisms.The results show that during the deposition of the fourth to first members of the Zhuhai Formation,the scale of the SEDDF depositional system in the study area showed a pattern of first increasing and then decreasing,with deep-water fan developed in the third to first members and the largest plane distribution scale developed in the late stage of the second member.Based on the development of SEDDF depositional system along the source direction,three types of coupling relationships are divided,namely,deltas that are linked downdip to fans,deltas that lack downdip fans and fans that lack updip coeval deltas,with different depositional characteristics and genetic mechanisms.(1)Deltas that are linked downdip to fans:with the development of shelf-edge deltas in the shelf area and deep-water fans in the downdip slope area,and the strong source supply and relative sea level decline are the two key factors which control the development of this type of source-to-sink(S2S).The development of channels on the continental shelf edge is conducive to the formation of this type of S2S system even with weak source supply and high sea level.(2)Deltas that lack downdip fans:with the development of shelf edge deltas in shelf area,while deep water fans are not developed in the downdip slope area.The lack of“sources”and“channels”,and fluid transformation are the three main reasons for the formation of this type of S2S system.(3)Fans that lack updip coeval deltas:with the development of deep-water fans in continental slope area and the absence of updip coeval shelf edge deltas,which is jointly controlled by the coupling of fluid transformation at the shelf edge and the“channels”in the continental slope area.展开更多
Tigris and Euphrates are the main rivers in Iraq. The former has 5 main tributaries while the latter has no tributaries within Iraq. All these rivers exhibit meandering and/or shifting of their courses due to many rea...Tigris and Euphrates are the main rivers in Iraq. The former has 5 main tributaries while the latter has no tributaries within Iraq. All these rivers exhibit meandering and/or shifting of their courses due to many reasons;such as mass movements and alluvial fan's development. The meandering and shifting of river courses due to mass movements is dealt with in this study. Many examples are given from different parts of Iraq within different rivers and streams. In each case, the geology of the involved area is described;the reasons of the shifting and/or meandering of the river course are given. GIS technique was used to determine the coverage of the involved area. Landsat, Google Earth and DEM images were used to indicate the suffered areas from shifting and meandering of the rivers and streams. When possible, age of the shifting and/or meandering of the river and stream courses was estimated;using exposure age determination;mainly depending on the presence of river terraces, erosional forms, vegetation cover and the maturity of the involved area. Some of the given examples of shifting of river courses were found to be still active;others are inactive. In many cases, indications for very large mass movement phenomena were seen. Moreover, some of the large involved areas are highly populated, others includes few houses and/ or farms. The majority of the meanders are developed due to mass movement phenomena;others are caused by alluvial fans and/or tectonic features, lime plunging of anticlines.展开更多
The U. S. National Aeronautics and Space Administration(NASA) has archived thousands of satellite images of density plumes in its online publishing outlet called 'Earth Observatory' since 1999. Although these ...The U. S. National Aeronautics and Space Administration(NASA) has archived thousands of satellite images of density plumes in its online publishing outlet called 'Earth Observatory' since 1999. Although these images are in the public domain, there has not been any systematic compilation of configurations of density plumes associated with various sedimentary environments and processes. This article, based on 45 case studies covering 21 major rivers(e.g., Amazon, Betsiboka, Congo [Zaire], Copper, Hugli [Ganges], Mackenzie, Mississippi, Niger, Nile, Rhone, Rio de la Plata, Yellow, Yangtze, Zambezi, etc.) and six different depositional environments(i.e., marine, lacustrine, estuarine, lagoon, bay, and reef), is the first attempt in illustrating natural variability of configurations of density plumes in modern environments. There are, at least, 24 configurations of density plumes. An important finding of this study is that density plumes are controlled by a plethora of 18 oceanographic, meteorological, and other external factors. Examples are: 1) Yellow River in China by tidal shear front and by a change in river course; 2) Yangtze River in China by shelf currents and vertical mixing by tides in winter months; 3) Rio de la Plata Estuary in Argentina and Uruguay by Ocean currents; 4) San Francisco Bay in California by tidal currents; 5) Gulf of Manner in the Indian Ocean by monsoonal currents; 6) Egypt in Red Sea by Eolian dust; 7) U.S. Atlantic margin by cyclones; 8) Sri Lanka by tsunamis; 9) Copper River in Alaska by high-gradient braid delta; 10) Lake Erie by seiche; 11) continental margin off Namibia by upwelling; 12) Bering Sea by phytoplankton; 13) the Great Bahama Bank in the Atlantic Ocean by fish activity; 14) Indonesia by volcanic activity; 15) Greenland by glacial melt; 16) South Pacific Ocean by coral reef; 17) Carolina continental Rise by pockmarks; and 18) Otsuchi Bay in Japan by internal bore. The prevailing trend in promoting a single type of river-flood triggered hyperpycnal flow is flawed because there are 16 types of hyperpycnal flows. River-flood derived hyperpycnal flows are muddy in texture and they occur close to the shoreline in inner shelf environments. Hyperpycnal flows are not viable transport mechanisms of sand and gravel across the shelf into the deep sea. The available field observations suggest that they do not form meter-thick sand layers in deep water settings. For the above reasons, river-flood triggered hyperpycnites are considered unsuitable for serving as petroleum reservoirs in deep-water environments until proven otherwise.展开更多
基金financially supported by the National Nature Science Foundation of China under Grant No.41372333,41172158China Geological Survey(grant No.1212011220123)
文摘Several argillaceous platforms lie along the Yellow River(YR) of the eastern Guide Basin, northeastern Tibetan Plateau, and their compositions, formation processes, and geomorphic evolution remain debated. Using field survey data, sample testing, and high-resolution remote sensing images, the evolution of the Erlian mudflow fans are analyzed. The data show significant differences between fans on either side of the YR. On the right bank, fans are dilute debris flows consisting of sand and gravel. On the left bank, fans are viscosity mudflows consisting of red clay. The composition and formation processes of the left bank platforms indicate a rainfall-induced pluvial landscape. Fan evolution can be divided into two stages: early-stage fans pre-date 16 ka B.P., and formed during the last deglaciation; late-stage fans post-date 8 ka B.P.. Both stages were induced by climate change. The data indicate that during the Last Glacial Maximum, the northeastern Tibetan Plateau experienced a cold and humid climate characterized by high rainfall. From 16–8 ka, the YR cut through the Erlian early mudflow fan, resulting in extensive erosion. Since 8 ka, the river channel has migrated south by at least 1.25 km, and late stage mudflow fan formation has occurred.
基金supported by the China National Science and Technology Project (2011ZX05025-006)
文摘A turbidite fan in the Eocene upper Wenchang Formation in the Enping Sag, Pearl River Mouth Basin (PRMB) has been studied using seismic, logging and borehole data. The fan is characterized by parallel progradation on the dip seismic profile and is mound-shaped or lenticular-shaped on the strike seismic profile. The study of the core and logging data from well EP17-3-1, which is located in the front side of the turbidite fan, shows that this fan is a set of normal grading sand beds, interbedded within thick dark grey mudstones of semi-deep to deep lake deposits in the Wenchang Formation. The fan is interpreted as a sand/mud-rich turbidite fan that has an area of over 140 km2 and a maximum thickness of over 340 m. Combined with a study of the regional geological background and previous provenance analysis of the Eocene Wenchang Formation, the main potential provenances for the turbidite fan are considered to be the Panyu low-uplift and northern fault terrace zone. The Enping Sag is considered to be a half graben-like basin whose north side is faulted and whose south side is overlapped. Basement subsidence in the Eocene was mainly controlled by boundary faults which dip relatively steeply on the north side, causing the subsidence center of the Enping Sag in this stage to be close to the north boundary faults. Sustained faults developed in the Enping Sag during the Eocene caused an increase of the relative height difference between the north and the south uplift zone in the Enping Sag. Affected by the second episode of the Zhuqiong movement (39-36 Ma) in late Eocene, sediments which had accumulated on the Panyu low-uplift zone were triggered and moved toward the subsidence center of the Enping Sag and formed the turbidite fan. The second episode of the Zhuqiong movement is the most important triggering factor for the formation of the turbidite fan in the Wenchang Formation. Seismic attribute characterization shows that the low frequency energy is enhanced and high frequency energy is weakened when seismic waves propagate through the oil-bearing zone in this fan. Amplitude versus offset (AVO) anomalies are observed in the seismic data and abnormally high pressure is encountered. The turbidite fan in the Wenchang Formation has provided important information for sedimentary evolution in deep layers of the Enping Sag and pointed to a new direction for the hydrocarbon exploration in the study area.
文摘In the river systems, the environmental change always undergoes a process from quantitative to qualitative change. The upper limit of the qualitative change is called threshold. When the process reaches or goes beyond the limit, the original event series will be replaced by the other event series. Investigations show that the evolution of the Huanghe River alluvial fan and delta has also under gone a process from quantitative to qualitative change. The geometric forms in each process are roughly the same. This threshold of the geometric forms not only provides us a quantitative index for plotting the periodicity of the alluvial fan and delta, but also is of importance for estimation of the trend of natural environmental change.It is shown that there are three periodic alluvial fans of the Huanghe River since the middle Holocene and four periodic delta since 1855 A.D., the thresholds of their geometric forms are from 0.93 to 0.94 and from 1.2 to 1.21 respectively.The changing trend in the past and the
文摘Vertical hydraulic gradient (VHG) provides detailed information on 3D groundwater flows in alluvial fans, but its regional mapping is complicated by a lack of piezometer nests and uncertainty in conventional well data. Especially, determining representative depth of well screen in each well is problematic. Here, a VHG map of the Toyohira River alluvial fan, Sapporo, Japan, is constructed based on groundwater table elevation (GTE), using available well-data of various screen lengths and depths. The water-level data after 1988, when subway constructions are mostly completed in the city, are divided into those of shallow wells (≤20 m deep), and those of deep wells (>20 m deep). First, the GTE map is generated by kriging interpolation of shallow well data with topographic drift. Next, the individual VHG value of each deep well is calculated using its top, middle, and bottom elevations of the screen depths, respectively. The VHG maps of three cases are then obtained using neighborhood kriging. The VHG map of the bottom screen depths has proven most valid by cross-validation. The VHG map better visualizes that downward flows of groundwater are predominant over the fan. Positive area of VHG is mostly vanished around the fan-toe, indicating urbanization effect such as artificial withdrawals. A negative peak of VHG corresponds to recharge area, and is seen along the distinct losing section in the river. The negative peak also expands upstream to the fan-apex where a basement is suddenly depressed.
基金granted by the National Science and Technology Major Project of the Ministry of Science and Technology of China(Grant No.2008ZX05056-02-02)
文摘Eleven lithofacies and five lithofacies associations were indentified in the Miocene Zhujiang Formation on the basis of detailed core analysis. It could he determined that three depositional types developed, namely submarine fan, basin and deep-water traction current. Six microfacies were further recognized within the fan, including main channels in the inner fan, distributary channels in the middle fan, inter-channels, levees and the outer fan. The lower Zhujiang Formation, mainly sandstone associations, was inner fan and inner-middle fan deposits of the basin fan and the slope fan. The middle part, mainly mudstone associations, was outer fan deposits. With the transgression, the submarine fan was finally replaced by the basinal pelagic deposits which were dominated by mudstone associations, siltstone associations, and deep-water limestone associations. During the weak gravity flow activity, the lower channels, the middle-upper outer fans and basin deposits were strongly modified by the deep-water traction current. The identification of the deep-water traction deposition in Miocene Zhujiang Formation would be of great importance. It could be inferred that the deep- water traction current had been existing after the shelf-break formation since the Late Oligocene (23.8 Ma) in the Baiyun sag, influencing and controlling the sediment composition, the distribution, and depositional processes. It would provide great enlightenment to the paleo-oceanic current circulation in the northern South China Sea.
基金Supported by the China National Science and Technology Major Project(2017ZX05009-002)
文摘The concept and characteristics of fluvial fan are elucidated through literature review and case analysis.Firstly,the concept and terminology of fluvial fan are introduced.Secondly,the progress and controversy on the formation mechanism,analysis methods and sedimentary models of fluvial fan are elaborated,and fluvial fan is compared with alluvial fan,river and lacustrine delta.Finally,ten identification signs of the fluvial fan are proposed.It is found through the study that development and scale of fluvial fan are affected by external factors such as climate,tectonic,provenance and wind field.The facies and lithofacies association inside the fan are controlled by the activity of the internal channel.It is pointed that fluvial fans are widely distributed in the world not only today but also in the geological history.The occurrence of fluvial fan will change the traditional continental deposition system dominated by alluvial fan-river-lacustrine.Meanwhile,the research of fluvial fan will be of great significance in the fields of sedimentology and oil and gas exploration.
基金Supported by the National Natural Science Foundation of China(91528303)CNOOC Technology Project(2021-KT-YXKY-05).
文摘The coupling relationship between shelf-edge deltas and deep-water fan sand bodies is a hot and cutting-edge field of international sedimentology and deep-water oil and gas exploration.Based on the newly acquired high-resolution 3D seismic,logging and core data of Pearl River Mouth Basin(PRMB),this paper dissected the shelf-edge delta to deep-water fan(SEDDF)depositional system in the Oligocene Zhuhai Formation of Paleogene in south subsag of Baiyun Sag,and revealed the complex coupling relationship from the continental shelf edge to deep-water fan sedimentation and its genetic mechanisms.The results show that during the deposition of the fourth to first members of the Zhuhai Formation,the scale of the SEDDF depositional system in the study area showed a pattern of first increasing and then decreasing,with deep-water fan developed in the third to first members and the largest plane distribution scale developed in the late stage of the second member.Based on the development of SEDDF depositional system along the source direction,three types of coupling relationships are divided,namely,deltas that are linked downdip to fans,deltas that lack downdip fans and fans that lack updip coeval deltas,with different depositional characteristics and genetic mechanisms.(1)Deltas that are linked downdip to fans:with the development of shelf-edge deltas in the shelf area and deep-water fans in the downdip slope area,and the strong source supply and relative sea level decline are the two key factors which control the development of this type of source-to-sink(S2S).The development of channels on the continental shelf edge is conducive to the formation of this type of S2S system even with weak source supply and high sea level.(2)Deltas that lack downdip fans:with the development of shelf edge deltas in shelf area,while deep water fans are not developed in the downdip slope area.The lack of“sources”and“channels”,and fluid transformation are the three main reasons for the formation of this type of S2S system.(3)Fans that lack updip coeval deltas:with the development of deep-water fans in continental slope area and the absence of updip coeval shelf edge deltas,which is jointly controlled by the coupling of fluid transformation at the shelf edge and the“channels”in the continental slope area.
文摘Tigris and Euphrates are the main rivers in Iraq. The former has 5 main tributaries while the latter has no tributaries within Iraq. All these rivers exhibit meandering and/or shifting of their courses due to many reasons;such as mass movements and alluvial fan's development. The meandering and shifting of river courses due to mass movements is dealt with in this study. Many examples are given from different parts of Iraq within different rivers and streams. In each case, the geology of the involved area is described;the reasons of the shifting and/or meandering of the river course are given. GIS technique was used to determine the coverage of the involved area. Landsat, Google Earth and DEM images were used to indicate the suffered areas from shifting and meandering of the rivers and streams. When possible, age of the shifting and/or meandering of the river and stream courses was estimated;using exposure age determination;mainly depending on the presence of river terraces, erosional forms, vegetation cover and the maturity of the involved area. Some of the given examples of shifting of river courses were found to be still active;others are inactive. In many cases, indications for very large mass movement phenomena were seen. Moreover, some of the large involved areas are highly populated, others includes few houses and/ or farms. The majority of the meanders are developed due to mass movement phenomena;others are caused by alluvial fans and/or tectonic features, lime plunging of anticlines.
文摘The U. S. National Aeronautics and Space Administration(NASA) has archived thousands of satellite images of density plumes in its online publishing outlet called 'Earth Observatory' since 1999. Although these images are in the public domain, there has not been any systematic compilation of configurations of density plumes associated with various sedimentary environments and processes. This article, based on 45 case studies covering 21 major rivers(e.g., Amazon, Betsiboka, Congo [Zaire], Copper, Hugli [Ganges], Mackenzie, Mississippi, Niger, Nile, Rhone, Rio de la Plata, Yellow, Yangtze, Zambezi, etc.) and six different depositional environments(i.e., marine, lacustrine, estuarine, lagoon, bay, and reef), is the first attempt in illustrating natural variability of configurations of density plumes in modern environments. There are, at least, 24 configurations of density plumes. An important finding of this study is that density plumes are controlled by a plethora of 18 oceanographic, meteorological, and other external factors. Examples are: 1) Yellow River in China by tidal shear front and by a change in river course; 2) Yangtze River in China by shelf currents and vertical mixing by tides in winter months; 3) Rio de la Plata Estuary in Argentina and Uruguay by Ocean currents; 4) San Francisco Bay in California by tidal currents; 5) Gulf of Manner in the Indian Ocean by monsoonal currents; 6) Egypt in Red Sea by Eolian dust; 7) U.S. Atlantic margin by cyclones; 8) Sri Lanka by tsunamis; 9) Copper River in Alaska by high-gradient braid delta; 10) Lake Erie by seiche; 11) continental margin off Namibia by upwelling; 12) Bering Sea by phytoplankton; 13) the Great Bahama Bank in the Atlantic Ocean by fish activity; 14) Indonesia by volcanic activity; 15) Greenland by glacial melt; 16) South Pacific Ocean by coral reef; 17) Carolina continental Rise by pockmarks; and 18) Otsuchi Bay in Japan by internal bore. The prevailing trend in promoting a single type of river-flood triggered hyperpycnal flow is flawed because there are 16 types of hyperpycnal flows. River-flood derived hyperpycnal flows are muddy in texture and they occur close to the shoreline in inner shelf environments. Hyperpycnal flows are not viable transport mechanisms of sand and gravel across the shelf into the deep sea. The available field observations suggest that they do not form meter-thick sand layers in deep water settings. For the above reasons, river-flood triggered hyperpycnites are considered unsuitable for serving as petroleum reservoirs in deep-water environments until proven otherwise.