Rivers often witness non-uniform bed load sedim ent transport. For a long tim e, non-uniform bed load transport has been assum ed to be at capacity regime determined exclusively by local flow. Yet whether the capacity...Rivers often witness non-uniform bed load sedim ent transport. For a long tim e, non-uniform bed load transport has been assum ed to be at capacity regime determined exclusively by local flow. Yet whether the capacity assumption for non-uniform bed load transport is justified remains poorly understood. Here, the relative time scale of non-uniform bed load transport is evaluated and non-capacity and capacity models are compared for both aggradation and degradation cases with observed data. As characterized by its relative time scale, the adaptation of non-uniform bed load to capacity regime should be fulfilled quickly. However, changes in the flow and sedim ent inputs from upstream or tributaries hinder the adaptation. Also, the adaptation to capacity regime is size dependent, the finer the sediment size the slower the adaptation is, and vice versa. It is shown that the capacity model may entail considerable errors compared to the non-capacity model. For modelling of non-uniform bed load, non-capacity modelling is recommended, in which the temporal and spatial scales required for adaptation are explicitly appreciated.展开更多
Suspended particulate barite crystals were detected in the water columns at four different stations near the 90°E ridge in the Indian Ocean.Four distinct morphological types of marine barites were distinguished:e...Suspended particulate barite crystals were detected in the water columns at four different stations near the 90°E ridge in the Indian Ocean.Four distinct morphological types of marine barites were distinguished:euhedral-subhedral crystals,oval or round crystals,rhombic crystals,and irregular crystals.The barite crystals in the study area are typically fine,with a dominant size of 1–3μm.The vertical distribution of barites is significantly affected by the formation and sedimentation processes.Barites begin to appear at a depth of 30 m and are formed primarily from the surface to the depth of 2000m with a concentration peak at the depth of 200m,where particles are coarser than those in the other layers.The barites begin to settle and dissolve once formed in the water column,resulting in finer barite particles and lower particle concentrations.The formation of barite crystals is related to biological processes associated with the decomposition of barium-rich skeletons in the microenvironment of decaying organic matter that is affected by the primary productivity and dissolved oxygen content in the water column.The dissolving process of barite crystals showed similar variation with the concentration of dissolved barium in ocean water,and the substitution of strontium for barite in crystals promotes the selective dissolution of barite and exerts an important impact on its morphology.It is approximately 33%of barites in the amount and 22%in the concentration to settle to the bottom of the water column compared to that observed in the main barite formation zone.展开更多
Based on the investigation data of PHC content in Jiaozhou Bay, China during 1980 -1981, the distribution of PHC content in the bottom water of Jiaozhou Bay was analyzed. The results showed that PHC content in the bot...Based on the investigation data of PHC content in Jiaozhou Bay, China during 1980 -1981, the distribution of PHC content in the bottom water of Jiaozhou Bay was analyzed. The results showed that PHC content in the bottom water of Jiaozhou Bay varied from 0.028 to 0.147 mg/L. from April to November （except for May） during 1980 -1981, indicating that the bottom water was polluted slightly by PHC. PHC content was affect- ed by the vertical water body effect, so that the minimum of PHC content in the bottom water changed stably. In addition, there were no obvious seasonal variations in PHC content in the bottom water. It reveals that PHC brought by human activity was more than that transported by rivers, so PHC pollution caused by human activity was serious. From the inside water to the outside water, PHC content decreased gradually in April and Au- gust but increased in November, showing the sedimentation process of PHC. The sedimentation process of PHC showed the migration paths of PHC in Jiaozhou Bay in time and space.展开更多
In this paper,the technology of wave process method for sedimentation is first adopted in the research of the foreland thrust fault of Micang Mountain with respect of oil and reservoir’s formation and tectonic and se...In this paper,the technology of wave process method for sedimentation is first adopted in the research of the foreland thrust fault of Micang Mountain with respect of oil and reservoir’s formation and tectonic and sedimentary evolution.From the fluctuation characteristics,we could make conclusions in the foreland thrust belt of Micang Mountain that,there existed 2 first-order sedimentary cycles(220 Ma),corresponding to Caledonian-Hercynian and Indo-Chinese-Yanshan-Himalayan tectonic cycles respec-tively;there existed 4 second-order sedimentary cycles(10 Ma),corresponding to two sedimentation peak period and two denudation peak periods in research zone;there existed 12 third-order sedimen-tary cycles(35 Ma)and 21 fourth-sedimentary cycles(20 Ma).These 33 cycles in the research zone corresponded to the sedimentation-denudation process in different periods,furthermore,their fluctua-tion characteristics bore the genetic relationship with the development law of source,reservoir and cap rocks:the source rock had the tendency to develop at the turning part between wave crest and wave trough,or at the superposition of wave turning part in different periods,presenting like"X";most res-ervoir rocks developed at the place of wave peak;the development of cap rock was located in the wave trough on the right of sedimentation-denudation datum line.As a result,through the application of wave process method for sedimentation,we could rediscover the understanding of the tectonic and sedimentary evolution from another prospective,meanwhile,it enables to make prediction about the development rule of source,reservoir and cap rocks,which means a significant importance to the re-search of oil and reservoir’s forming condition.展开更多
基金funded by the N atural Science Foundation of China (G rants No. 11172217, 51279144 and 11432015)Chinese Academy of Sciences (G rant No. KZZDEW -05-01-03)
文摘Rivers often witness non-uniform bed load sedim ent transport. For a long tim e, non-uniform bed load transport has been assum ed to be at capacity regime determined exclusively by local flow. Yet whether the capacity assumption for non-uniform bed load transport is justified remains poorly understood. Here, the relative time scale of non-uniform bed load transport is evaluated and non-capacity and capacity models are compared for both aggradation and degradation cases with observed data. As characterized by its relative time scale, the adaptation of non-uniform bed load to capacity regime should be fulfilled quickly. However, changes in the flow and sedim ent inputs from upstream or tributaries hinder the adaptation. Also, the adaptation to capacity regime is size dependent, the finer the sediment size the slower the adaptation is, and vice versa. It is shown that the capacity model may entail considerable errors compared to the non-capacity model. For modelling of non-uniform bed load, non-capacity modelling is recommended, in which the temporal and spatial scales required for adaptation are explicitly appreciated.
基金supported by the COMRA Major Project(No.DY135-S1-01-09)the Opening Foundation of Key Laboratory of Submarine Geosciences and Prospecting Techniques,Ocean University of China(No.SGPT-2019OF-02).
文摘Suspended particulate barite crystals were detected in the water columns at four different stations near the 90°E ridge in the Indian Ocean.Four distinct morphological types of marine barites were distinguished:euhedral-subhedral crystals,oval or round crystals,rhombic crystals,and irregular crystals.The barite crystals in the study area are typically fine,with a dominant size of 1–3μm.The vertical distribution of barites is significantly affected by the formation and sedimentation processes.Barites begin to appear at a depth of 30 m and are formed primarily from the surface to the depth of 2000m with a concentration peak at the depth of 200m,where particles are coarser than those in the other layers.The barites begin to settle and dissolve once formed in the water column,resulting in finer barite particles and lower particle concentrations.The formation of barite crystals is related to biological processes associated with the decomposition of barium-rich skeletons in the microenvironment of decaying organic matter that is affected by the primary productivity and dissolved oxygen content in the water column.The dissolving process of barite crystals showed similar variation with the concentration of dissolved barium in ocean water,and the substitution of strontium for barite in crystals promotes the selective dissolution of barite and exerts an important impact on its morphology.It is approximately 33%of barites in the amount and 22%in the concentration to settle to the bottom of the water column compared to that observed in the main barite formation zone.
基金Supported by the Doctoral Degree Construction Library of Guizhou Minzu UniversitySupporting Plan Project for New Century Excellent Talents by Ministry of Education(NCET-12-0659)+5 种基金National Natural Science Foundation of China(31560107)Major Project of Science and Technology of Guizhou Province([2004]6007-01)Guizhou R&D Program for Social Development([2014]3036)Scientific Research Project for Introduction of Talents of Guizhou Minzu University([2014]02)Natural Scientific Research Project of Education Department of Guizhou Province,China(KY[2014]266)Joint Foundation of Science and Technology Department of Guizhou Province,China(LH[2014]7376)
文摘Based on the investigation data of PHC content in Jiaozhou Bay, China during 1980 -1981, the distribution of PHC content in the bottom water of Jiaozhou Bay was analyzed. The results showed that PHC content in the bottom water of Jiaozhou Bay varied from 0.028 to 0.147 mg/L. from April to November （except for May） during 1980 -1981, indicating that the bottom water was polluted slightly by PHC. PHC content was affect- ed by the vertical water body effect, so that the minimum of PHC content in the bottom water changed stably. In addition, there were no obvious seasonal variations in PHC content in the bottom water. It reveals that PHC brought by human activity was more than that transported by rivers, so PHC pollution caused by human activity was serious. From the inside water to the outside water, PHC content decreased gradually in April and Au- gust but increased in November, showing the sedimentation process of PHC. The sedimentation process of PHC showed the migration paths of PHC in Jiaozhou Bay in time and space.
基金Supported by National Basic Research Program of China(Grant No.2005CB422107)
文摘In this paper,the technology of wave process method for sedimentation is first adopted in the research of the foreland thrust fault of Micang Mountain with respect of oil and reservoir’s formation and tectonic and sedimentary evolution.From the fluctuation characteristics,we could make conclusions in the foreland thrust belt of Micang Mountain that,there existed 2 first-order sedimentary cycles(220 Ma),corresponding to Caledonian-Hercynian and Indo-Chinese-Yanshan-Himalayan tectonic cycles respec-tively;there existed 4 second-order sedimentary cycles(10 Ma),corresponding to two sedimentation peak period and two denudation peak periods in research zone;there existed 12 third-order sedimen-tary cycles(35 Ma)and 21 fourth-sedimentary cycles(20 Ma).These 33 cycles in the research zone corresponded to the sedimentation-denudation process in different periods,furthermore,their fluctua-tion characteristics bore the genetic relationship with the development law of source,reservoir and cap rocks:the source rock had the tendency to develop at the turning part between wave crest and wave trough,or at the superposition of wave turning part in different periods,presenting like"X";most res-ervoir rocks developed at the place of wave peak;the development of cap rock was located in the wave trough on the right of sedimentation-denudation datum line.As a result,through the application of wave process method for sedimentation,we could rediscover the understanding of the tectonic and sedimentary evolution from another prospective,meanwhile,it enables to make prediction about the development rule of source,reservoir and cap rocks,which means a significant importance to the re-search of oil and reservoir’s forming condition.
