2003 Vol. 28, No. 1
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2003, 28(1): 1-5.
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Abstract:
The discovery of 10 prehistoric man sites was the beginning research on the prehistoric man and their activities in the Duolun area that is in southeastern farming animal husbandry zigzag zone of North China. There were 2 892 artifacts discovered in the area and including chopping tools, grinding tools and many fragments of potteries. The shapes and the assembling characteristics of those artifacts shows that the cultural periods of the 10 sites were from the early Neolithic to the middle Neolithic, about 10~6 kaB.P.. During the early phase of that time, the prehistoric man in the area lived on gathering and hunting, and during the late phase, the appearance of the tools for tilth such as a stone hoe indicated the birth of the original farming. However, these prehistoric man's activities were fairly affected by ecologic environment that would control the economic and cultural development during the prehistoric period. On the other hand, with the intrinsic irrationality, the original farming would aggravate the vicious circle of ecologic environment in a certain extent.
The discovery of 10 prehistoric man sites was the beginning research on the prehistoric man and their activities in the Duolun area that is in southeastern farming animal husbandry zigzag zone of North China. There were 2 892 artifacts discovered in the area and including chopping tools, grinding tools and many fragments of potteries. The shapes and the assembling characteristics of those artifacts shows that the cultural periods of the 10 sites were from the early Neolithic to the middle Neolithic, about 10~6 kaB.P.. During the early phase of that time, the prehistoric man in the area lived on gathering and hunting, and during the late phase, the appearance of the tools for tilth such as a stone hoe indicated the birth of the original farming. However, these prehistoric man's activities were fairly affected by ecologic environment that would control the economic and cultural development during the prehistoric period. On the other hand, with the intrinsic irrationality, the original farming would aggravate the vicious circle of ecologic environment in a certain extent.
2003, 28(1): 6-10.
Abstract:
In order to meet the need of high precision stratigraphic correlation, especially of the correlation of condense deposits the black graptolitic shale, three types of sequence boundary are recognized based on integrated studied of bio, litho and chemo Stratigraphy, i. e., the Ⅰtype, Ⅱ type sequence boundaries and a special one in continuous deposits at the base of Tangyagraptus typicus sub zone marked by δ (13 C) anomaly, which divided the Wufeng Formation. into two sequences-sq1 and sq2. The sq1 are formed by 3 parasequences, namely Psq1, Psq2 and Psq3, and the sq2 by another 2 parasequences, Psq4 and Psq5 based on the study of δ (Ce) anomaly. Consequently the precision of stratigraphic subdivision and correlation is improved.
In order to meet the need of high precision stratigraphic correlation, especially of the correlation of condense deposits the black graptolitic shale, three types of sequence boundary are recognized based on integrated studied of bio, litho and chemo Stratigraphy, i. e., the Ⅰtype, Ⅱ type sequence boundaries and a special one in continuous deposits at the base of Tangyagraptus typicus sub zone marked by δ (13 C) anomaly, which divided the Wufeng Formation. into two sequences-sq1 and sq2. The sq1 are formed by 3 parasequences, namely Psq1, Psq2 and Psq3, and the sq2 by another 2 parasequences, Psq4 and Psq5 based on the study of δ (Ce) anomaly. Consequently the precision of stratigraphic subdivision and correlation is improved.
2003, 28(1): 11-16.
Abstract:
The petrologic geochemistry and isotopic chronology of the eclogites imply most of the eclogites in the northern Dabie Mountains produced from the Triassic Yangtze subducted continental crust (lower crust formed during the deep subduction) and the metamorphosed mafic-untramafic belt with eclogite, marble and meta-peridotite blocks around the Mozitan-Xiaotian fault zone may represent the meta tectonic melange produced during the active subduction of an ancient oceanic slab and subsequent collision between the Yangtze and North China continental plates. The cooling history of the eclogites from about 900 ℃ to 300 ℃ can be subdivided into three stages: one isothermal stage and two rapid cooling stages. The initial stage during (230±6) Ma and ca 210 Ma was a near-isothermal or temperature rise process corresponding to the retrograded metamorphism of granulite facies with a rapid uplift of about 4 mm/a, then two fast cooling stages occurred with cooling rate of about 10 ℃/Ma (210 Ma to (172±3) Ma) and about 4 ℃/Ma ((172±3) Ma to 130 Ma). After the ultra-high pressure metamorphism of eclogite facies, relatively slower uplift rate and cooling rate and high-T overprinting of granulite facies metamorphism is the major difference of the eclogites in northern Dabie Mountains from those in southern Dabie Mountains.
The petrologic geochemistry and isotopic chronology of the eclogites imply most of the eclogites in the northern Dabie Mountains produced from the Triassic Yangtze subducted continental crust (lower crust formed during the deep subduction) and the metamorphosed mafic-untramafic belt with eclogite, marble and meta-peridotite blocks around the Mozitan-Xiaotian fault zone may represent the meta tectonic melange produced during the active subduction of an ancient oceanic slab and subsequent collision between the Yangtze and North China continental plates. The cooling history of the eclogites from about 900 ℃ to 300 ℃ can be subdivided into three stages: one isothermal stage and two rapid cooling stages. The initial stage during (230±6) Ma and ca 210 Ma was a near-isothermal or temperature rise process corresponding to the retrograded metamorphism of granulite facies with a rapid uplift of about 4 mm/a, then two fast cooling stages occurred with cooling rate of about 10 ℃/Ma (210 Ma to (172±3) Ma) and about 4 ℃/Ma ((172±3) Ma to 130 Ma). After the ultra-high pressure metamorphism of eclogite facies, relatively slower uplift rate and cooling rate and high-T overprinting of granulite facies metamorphism is the major difference of the eclogites in northern Dabie Mountains from those in southern Dabie Mountains.
2003, 28(1): 17-20.
Abstract:
Geothermic and astrolithological studies indicated the exponential attenuation of the Earth's radioelement consistency along the depth. The explanation to this fact remains an enigma in geoscience. Through the investigation of the Earth's gas discharge, we discovered that this process have brought radioelements to the upper layer and the surface of the Earth. The same process also happened in other earthlike planets and planetoids and the older the lesser the radioelements at the planet interior. All prevailing geodynamics theories are based on the mechanism of Earth’s interior thermal dynamics. But the lack of interior radioelements of the Earth heckles this thermal mechanism.
Geothermic and astrolithological studies indicated the exponential attenuation of the Earth's radioelement consistency along the depth. The explanation to this fact remains an enigma in geoscience. Through the investigation of the Earth's gas discharge, we discovered that this process have brought radioelements to the upper layer and the surface of the Earth. The same process also happened in other earthlike planets and planetoids and the older the lesser the radioelements at the planet interior. All prevailing geodynamics theories are based on the mechanism of Earth’s interior thermal dynamics. But the lack of interior radioelements of the Earth heckles this thermal mechanism.
2003, 28(1): 21-25.
Abstract:
The absorbability of 13X zeolite on Ni2+ in wastewater was experimentally studied. The absorption rate, isotherms, capacity and effects of such factors on the absorbability as pH value, Ni2+ concentration in the wastewater, temperature, time and dosage of wastewater were characterized separately. The mechanism for adsorption of 13X zeolite on Ni2+ was also studied. The results show that at ambient temperature, the adsorption capacity of 13X zeolite on Ni2+ in wastewater was 49.7 mg/g zeolite in 15 minutes. The adsorption isotherm for the process exhibits Langmiur behavior, and the ion exchange and surface complex were suggested to be the major adsorption mechanisms in the experiments.
The absorbability of 13X zeolite on Ni2+ in wastewater was experimentally studied. The absorption rate, isotherms, capacity and effects of such factors on the absorbability as pH value, Ni2+ concentration in the wastewater, temperature, time and dosage of wastewater were characterized separately. The mechanism for adsorption of 13X zeolite on Ni2+ was also studied. The results show that at ambient temperature, the adsorption capacity of 13X zeolite on Ni2+ in wastewater was 49.7 mg/g zeolite in 15 minutes. The adsorption isotherm for the process exhibits Langmiur behavior, and the ion exchange and surface complex were suggested to be the major adsorption mechanisms in the experiments.
2003, 28(1): 26-30.
Abstract:
Gold (Ⅲ)-chloride and gold (Ⅰ)-thiosulfate adsorption by various minerals and ores were experimented and studied in the paper. The adsorption of AuCl4- by minerals is much higher than Au(S2O3)23-. The adsorption is montmorillonite > kaolinite > illite for clay minerals, and pyrite > goethite > limonite for iron-bearing minerals. H2O2 containing in meteoric water is a catalyst for oxidation or reduction of gold, pyrite and other minerals, so that it can speed up weathering process and Au dissolution and migration under supergene conditions. The meteoric water can, to some extent, leach gold in laterite, and the leaching capacity is controlled by compositions of the leached rocks and minerals. Meteoric water, KCl, oxalic acid, citric acid, hypo and other solutions are also able to leach some gold in laterite, but their leaching capacities are quite different from one another even for same sample. The lateritic gold deposits were produced under the acidic, oxidizing and Cl-, SO42- rich hydro-geochemical environment. Gold migrated as sulpho-sulphate complex, chloride complex and their hydrates and the key factors were the oxidation of sulpho sulphate complex anions and the subsequent reduction in the lower part of the weathering crusts to make Au-bearing complexes unstable and then to make the released gold concentrated, precipitated or absorbed by other minerals. The adsorption of gold by minerals plays an important role during minerogenetic process of lateritic gold deposits.
Gold (Ⅲ)-chloride and gold (Ⅰ)-thiosulfate adsorption by various minerals and ores were experimented and studied in the paper. The adsorption of AuCl4- by minerals is much higher than Au(S2O3)23-. The adsorption is montmorillonite > kaolinite > illite for clay minerals, and pyrite > goethite > limonite for iron-bearing minerals. H2O2 containing in meteoric water is a catalyst for oxidation or reduction of gold, pyrite and other minerals, so that it can speed up weathering process and Au dissolution and migration under supergene conditions. The meteoric water can, to some extent, leach gold in laterite, and the leaching capacity is controlled by compositions of the leached rocks and minerals. Meteoric water, KCl, oxalic acid, citric acid, hypo and other solutions are also able to leach some gold in laterite, but their leaching capacities are quite different from one another even for same sample. The lateritic gold deposits were produced under the acidic, oxidizing and Cl-, SO42- rich hydro-geochemical environment. Gold migrated as sulpho-sulphate complex, chloride complex and their hydrates and the key factors were the oxidation of sulpho sulphate complex anions and the subsequent reduction in the lower part of the weathering crusts to make Au-bearing complexes unstable and then to make the released gold concentrated, precipitated or absorbed by other minerals. The adsorption of gold by minerals plays an important role during minerogenetic process of lateritic gold deposits.
2003, 28(1): 31-40.
Abstract:
The natural philosophical conception that" the geological process and spatio-temporal structure are the essence and crux of geological phenomena" proposed by the author can be used to classify the geological science as four major academic disciplines: the composition and structure of the earth materials, the geological process, the geological field and the evolution of the geosystem. These four major academic disciplines correspond to the nine important basic geological issues and associated complex theoretical problems (Table 2). In this paper, the author applies the complex theory of geological science"the dynamicsof the self-organized critical processof geological process— the fractal growth of geosystems at the edge of chaos" proposed by the author himself to the research into the nine important basic geological issues, with an emphasis on the relatively deep and brief analysis of the nature, theory and research method of the major basic theoretical problems. The purpose of the paper is to understand the geological sciences, old and renewed frequently, from the new pointof view of the complexity of geosystem considered as the basic problem of geological sciences, to raise the study of basic geological problems to the level of the nolinear science and the theory of complexity and to complete the transformation of the geological science into a precise science, with an expectation to make a breakthrough in geological process.
The natural philosophical conception that" the geological process and spatio-temporal structure are the essence and crux of geological phenomena" proposed by the author can be used to classify the geological science as four major academic disciplines: the composition and structure of the earth materials, the geological process, the geological field and the evolution of the geosystem. These four major academic disciplines correspond to the nine important basic geological issues and associated complex theoretical problems (Table 2). In this paper, the author applies the complex theory of geological science"the dynamicsof the self-organized critical processof geological process— the fractal growth of geosystems at the edge of chaos" proposed by the author himself to the research into the nine important basic geological issues, with an emphasis on the relatively deep and brief analysis of the nature, theory and research method of the major basic theoretical problems. The purpose of the paper is to understand the geological sciences, old and renewed frequently, from the new pointof view of the complexity of geosystem considered as the basic problem of geological sciences, to raise the study of basic geological problems to the level of the nolinear science and the theory of complexity and to complete the transformation of the geological science into a precise science, with an expectation to make a breakthrough in geological process.
2003, 28(1): 41-46.
Abstract:
Fluorite is main vein mineral in Maoniuping REE deposit, whose formation ran through the whole mineralization process. So the isotopic study plays an important role in probing the source of fluorite and REE ore-forming fluid. The Sr, Nd isotopic composition of 6 fluorite samples from Maoniuping orefield are similar. According to Sr, Nd isotopic data of the wall rocks (carbonatite-syenite, granite), it is shown: that different REE distribution fluorites from different colors and ore type are the products of the same source; REE ore-forming fluids come from the enriched mantle and are closely related with magma action of carbonatite-syenite.
Fluorite is main vein mineral in Maoniuping REE deposit, whose formation ran through the whole mineralization process. So the isotopic study plays an important role in probing the source of fluorite and REE ore-forming fluid. The Sr, Nd isotopic composition of 6 fluorite samples from Maoniuping orefield are similar. According to Sr, Nd isotopic data of the wall rocks (carbonatite-syenite, granite), it is shown: that different REE distribution fluorites from different colors and ore type are the products of the same source; REE ore-forming fluids come from the enriched mantle and are closely related with magma action of carbonatite-syenite.
2003, 28(1): 47-53.
Abstract:
The study of supercontinent-breakup is a modern frontier project of earth science. Based on the lithochemistry, the trace element, REE and Sm-Nd isotope characteristics of the Precambrian metamorphic volcanic rocks of Tiekelike belt in Southern Tarim plate, this paper studies the tectonic events for the Meso-Proterozoic breakup of paleo-Tarim plate. The meta-volcanic rocks were composed of meta-rhyolite (the lower part) and meta-basalt interspersed by thin-layered marble (the upper part). The basalt has low w(SiO2) arranging from 43.8% to 49.26% and averaging 47.29%, it has high alkaline and w(Na2O+K2O) is between 2.6% and 4.9%. The lower basalt has w(Na2O)/w(K2O) arranging from 0.54 to 1.50 and belongs to shoshinite which has high ∑REE and LREE, its w(La)n/w(Yb)n averages 3.45 and δ(Eu) is between 0.69 and 0.91 which shows middle negative anomality. The upper basalt has w(Na2O)/w(K2O) arranging from 5.11 to 17.89 and belongs to tholeiite, it has low ∑REE, δ (Eu) is between 0.82 and 1.13, its REE spider pattern (normalized by C1 chondrite) is similar with that of the oceanic tholeiite, its trace elements shows characteristics of oceanic tholeiite and the lower basalt is similar with that of intro-plate basalt. Sm-Nd isochron of the upper basalt is (1 200±82.3) Ma. Concluded on above studies, we put forward that the Precambrian metamorphic volcanic rocks recorded the whole breakup tectonic course in Meso-Proterozoic of the southern paleo-Tarim plate.
The study of supercontinent-breakup is a modern frontier project of earth science. Based on the lithochemistry, the trace element, REE and Sm-Nd isotope characteristics of the Precambrian metamorphic volcanic rocks of Tiekelike belt in Southern Tarim plate, this paper studies the tectonic events for the Meso-Proterozoic breakup of paleo-Tarim plate. The meta-volcanic rocks were composed of meta-rhyolite (the lower part) and meta-basalt interspersed by thin-layered marble (the upper part). The basalt has low w(SiO2) arranging from 43.8% to 49.26% and averaging 47.29%, it has high alkaline and w(Na2O+K2O) is between 2.6% and 4.9%. The lower basalt has w(Na2O)/w(K2O) arranging from 0.54 to 1.50 and belongs to shoshinite which has high ∑REE and LREE, its w(La)n/w(Yb)n averages 3.45 and δ(Eu) is between 0.69 and 0.91 which shows middle negative anomality. The upper basalt has w(Na2O)/w(K2O) arranging from 5.11 to 17.89 and belongs to tholeiite, it has low ∑REE, δ (Eu) is between 0.82 and 1.13, its REE spider pattern (normalized by C1 chondrite) is similar with that of the oceanic tholeiite, its trace elements shows characteristics of oceanic tholeiite and the lower basalt is similar with that of intro-plate basalt. Sm-Nd isochron of the upper basalt is (1 200±82.3) Ma. Concluded on above studies, we put forward that the Precambrian metamorphic volcanic rocks recorded the whole breakup tectonic course in Meso-Proterozoic of the southern paleo-Tarim plate.
2003, 28(1): 54-60.
Abstract:
Thrust structure widely developed in pre-Tertiary basement in south area of Huanghua basin. There are 6 structural styles in section which includes (1) snakehead and imbricate fan, (2) stack antiform, (3) duplex, (4) blind thrust in low angle or interbeds, (5) triangle zone and (6) high-angle thrust-domino. In the plane view, there are almost 5 parallel thrust zones striking in NE-NNE. The names are given respectively by (1) Cangdong thrust zone, (2) Kongxi thrust zone, (3) Wumaying thrust zone (4) Xuhei thrust zone and Chenxi thrust zone from west to east. In the west part, the thrust structure dominates the styles of snakehead, imbricate fan and stack antiform. In the middle part, the thrust structure dominates the styles of duplex, blind thrust in low angle or interbeds and pop-up and triangle zone. In the east part, the thrust structure dominates the styles of thrust-domino. Most of the thrust faults are dip to SEE (southeast-east) and the structural styles show the detachment of the thrust faults become deeper toward southeast. Possibly, all of the thrusts linked a large-scale thrust system whose direction is from SE-SEE to NW-NWW. The strata involved the thrust system mainly include Paleaozoic group and Lower-Middle Triassic but some leading thrusts have put in the Jurassic. We confer the thrust system was formed before Jurassic and after Triassic, and progressive thrust happened during Early-Middle Jurassic. The thrust system superposed extensional and right-lateral strike-slip tectonics during Cenozoic. Some sections of Cangdong fault which was controlling the formation of Huanghua basin during Tertiary were thrust faults during pre-Tertiary.
Thrust structure widely developed in pre-Tertiary basement in south area of Huanghua basin. There are 6 structural styles in section which includes (1) snakehead and imbricate fan, (2) stack antiform, (3) duplex, (4) blind thrust in low angle or interbeds, (5) triangle zone and (6) high-angle thrust-domino. In the plane view, there are almost 5 parallel thrust zones striking in NE-NNE. The names are given respectively by (1) Cangdong thrust zone, (2) Kongxi thrust zone, (3) Wumaying thrust zone (4) Xuhei thrust zone and Chenxi thrust zone from west to east. In the west part, the thrust structure dominates the styles of snakehead, imbricate fan and stack antiform. In the middle part, the thrust structure dominates the styles of duplex, blind thrust in low angle or interbeds and pop-up and triangle zone. In the east part, the thrust structure dominates the styles of thrust-domino. Most of the thrust faults are dip to SEE (southeast-east) and the structural styles show the detachment of the thrust faults become deeper toward southeast. Possibly, all of the thrusts linked a large-scale thrust system whose direction is from SE-SEE to NW-NWW. The strata involved the thrust system mainly include Paleaozoic group and Lower-Middle Triassic but some leading thrusts have put in the Jurassic. We confer the thrust system was formed before Jurassic and after Triassic, and progressive thrust happened during Early-Middle Jurassic. The thrust system superposed extensional and right-lateral strike-slip tectonics during Cenozoic. Some sections of Cangdong fault which was controlling the formation of Huanghua basin during Tertiary were thrust faults during pre-Tertiary.
2003, 28(1): 61-66.
Abstract:
Underpressure system developed in the Shiwu depression of Songliao basin with measured formation pressure gradient ranging between 0.005 MPa/m to 0.008 MPa/m. This research result shows that the genetic mechanism of abnormal low pressure attributes to reduction of paleothermal gradients, uplift and erosion during Eocene period. Moreover, gas diffusions also affect the formation of underpressure system at local part. This system at present indicates the evolution process from overpressure to underpressure, which controls fluid flow and hydrocarbon migration in different stages of the depression. Hence, oil pools generating at early stage occur at the basin margin, and gas pools generating at late stage at central part of the Shiwu depression, Songliao basin.
Underpressure system developed in the Shiwu depression of Songliao basin with measured formation pressure gradient ranging between 0.005 MPa/m to 0.008 MPa/m. This research result shows that the genetic mechanism of abnormal low pressure attributes to reduction of paleothermal gradients, uplift and erosion during Eocene period. Moreover, gas diffusions also affect the formation of underpressure system at local part. This system at present indicates the evolution process from overpressure to underpressure, which controls fluid flow and hydrocarbon migration in different stages of the depression. Hence, oil pools generating at early stage occur at the basin margin, and gas pools generating at late stage at central part of the Shiwu depression, Songliao basin.
2003, 28(1): 67-70.
Abstract:
Reservoir sandstones have big pore space; wide throat size and high permeability in Guantao Formation, Gudao Oilfield. Reservoir pore textures can be divided into 6 types. The main clay minerals are I/S mixed and kaolinite in fine grain size sandstones. Water sensibility and flow sensibilities exist in reservoir. Comparing the very high water cut stage with early and middle stage of oilfield development, sandstone's permeability increases several times, and the contents of clay and immovable water decrease obviously. Reservoir petrophysical parameters were different in 4 micro-facies units controlled by fluvial facies in Gudao oilfield.
Reservoir sandstones have big pore space; wide throat size and high permeability in Guantao Formation, Gudao Oilfield. Reservoir pore textures can be divided into 6 types. The main clay minerals are I/S mixed and kaolinite in fine grain size sandstones. Water sensibility and flow sensibilities exist in reservoir. Comparing the very high water cut stage with early and middle stage of oilfield development, sandstone's permeability increases several times, and the contents of clay and immovable water decrease obviously. Reservoir petrophysical parameters were different in 4 micro-facies units controlled by fluvial facies in Gudao oilfield.
2003, 28(1): 71-77.
Abstract:
This paper focuses on the study of the pool forming periods of the hydrocarbon by means of organic geochemistry. The correlation of petroleum sources shows that Jurassic Badaowan Formation is taken as main hydrocarbon source bed, Triassic is as the second source. Firstly, the hydrocarbon migrated laterally at short distance, then into Sangonghe and Xishanyao formations along the path of faults. This basin had undergone two periods of producing hydrocarbon, the main period of producing hydrocarbon is the end of Jurassic, secondly is the late of Tertiary. The distribution, homogenization temperature and components of fluid inclusions, dating of anthigenic illite, and maturity of hydrocarbon in the reservoir reveal two periods of pool forming in the Late-Middle Jurassic of the Yanqi basin, the first event for the generation, migration and accumulation of low maturity hydrocarbon happened during the late Jurassic Badaowan Formation, and the second event for maturity hydrocarbon happened during the end of Jurassic. The fluid inclusions and the isotope chronology of anthigenic illite in the reservoir haven't recorded the producing hydrocarbon and pool forming during the late of Tertiary. Main pool formations took place in the late of Jurassic, and has been adjusted with finality during the late of Tertiary.
This paper focuses on the study of the pool forming periods of the hydrocarbon by means of organic geochemistry. The correlation of petroleum sources shows that Jurassic Badaowan Formation is taken as main hydrocarbon source bed, Triassic is as the second source. Firstly, the hydrocarbon migrated laterally at short distance, then into Sangonghe and Xishanyao formations along the path of faults. This basin had undergone two periods of producing hydrocarbon, the main period of producing hydrocarbon is the end of Jurassic, secondly is the late of Tertiary. The distribution, homogenization temperature and components of fluid inclusions, dating of anthigenic illite, and maturity of hydrocarbon in the reservoir reveal two periods of pool forming in the Late-Middle Jurassic of the Yanqi basin, the first event for the generation, migration and accumulation of low maturity hydrocarbon happened during the late Jurassic Badaowan Formation, and the second event for maturity hydrocarbon happened during the end of Jurassic. The fluid inclusions and the isotope chronology of anthigenic illite in the reservoir haven't recorded the producing hydrocarbon and pool forming during the late of Tertiary. Main pool formations took place in the late of Jurassic, and has been adjusted with finality during the late of Tertiary.
2003, 28(1): 78-86.
Abstract:
Based on mudstone sonic log and measured fluid pressure, the paper analyzes the fluid pressure systems and the controlling factors of pressure system structures and distributions. According to the calculated pressure-depth plot of drills, we can recognize two pressure systems. The upper is normal pressure system, and the lower is abnormal system. The pressure sections and plane maps show that there exist three ring pressure systems in Dongying depression. The inner ring is overpressured system. The middle ring is highly pressured system. The external ring is normal-subnormal pressured system. The highly pressured and overpressured system made up a sealed compartment complex. Because the overpressured system includes the active source rock in the third and forth member of Shahejie Formation, the source rock compartment complex (SR-OPCC) is named here. The pressure conduit systems in the abnormal pressured fluid compartments separate the SR-OPCC into many smaller, nested subcompartments, which include permeable sandstone beds, faults and salt tectonics. So the model of the overpressured compartment-pressure conduit system-overpressured compartment is summarized in the paper. The SR-OPCC has profound and lasting effects on the migration and accumulation of petroleum in Dongying depression.
Based on mudstone sonic log and measured fluid pressure, the paper analyzes the fluid pressure systems and the controlling factors of pressure system structures and distributions. According to the calculated pressure-depth plot of drills, we can recognize two pressure systems. The upper is normal pressure system, and the lower is abnormal system. The pressure sections and plane maps show that there exist three ring pressure systems in Dongying depression. The inner ring is overpressured system. The middle ring is highly pressured system. The external ring is normal-subnormal pressured system. The highly pressured and overpressured system made up a sealed compartment complex. Because the overpressured system includes the active source rock in the third and forth member of Shahejie Formation, the source rock compartment complex (SR-OPCC) is named here. The pressure conduit systems in the abnormal pressured fluid compartments separate the SR-OPCC into many smaller, nested subcompartments, which include permeable sandstone beds, faults and salt tectonics. So the model of the overpressured compartment-pressure conduit system-overpressured compartment is summarized in the paper. The SR-OPCC has profound and lasting effects on the migration and accumulation of petroleum in Dongying depression.
2003, 28(1): 87-96.
Abstract:
The narrowness and confusion of demarcating time between Archean and Proterozoic have kept deepening research on the early geology within great limits. Through determination demarcating and transiting criteria, the transformation of geo-dynamics system between Archean and Proterozoic can be divided into four types: transformation from compressional to extensional system, from vertical to horizontal, of principal stress, from mantle plume to plate tectonics. The relatively outcomes which formed within 0.3~0.5 billions year of transformations includes eucaryote, radioelements, magma and ores. The partition between Archean and Proterozoic should have a transiting line, that can be limited in 2.20~2.80 Ga. The partition has close relation with major geological events, and this work brings a new edification to ore-formation in depth.
The narrowness and confusion of demarcating time between Archean and Proterozoic have kept deepening research on the early geology within great limits. Through determination demarcating and transiting criteria, the transformation of geo-dynamics system between Archean and Proterozoic can be divided into four types: transformation from compressional to extensional system, from vertical to horizontal, of principal stress, from mantle plume to plate tectonics. The relatively outcomes which formed within 0.3~0.5 billions year of transformations includes eucaryote, radioelements, magma and ores. The partition between Archean and Proterozoic should have a transiting line, that can be limited in 2.20~2.80 Ga. The partition has close relation with major geological events, and this work brings a new edification to ore-formation in depth.
2003, 28(1): 97-101.
Abstract:
Water-lily plants are key group on study of the flowering plant phylogeny. The internal transcribed spacers (ITS) and the 5.8S coding region of nuclear ribosomal DNA (nrDNA) of seven taxa were sequenced to study molecular phylogeny and evolution of Nymphaeales sensu lato. The ITS phylogenetic trees were constructed based on the sequences and a combined data set with sequences from GenBank. The results obtained from ITS sequences also supported that the genus Ceratophyllum could be considered the ancestral group in the order, as the results of most molecular systematic studies.
Water-lily plants are key group on study of the flowering plant phylogeny. The internal transcribed spacers (ITS) and the 5.8S coding region of nuclear ribosomal DNA (nrDNA) of seven taxa were sequenced to study molecular phylogeny and evolution of Nymphaeales sensu lato. The ITS phylogenetic trees were constructed based on the sequences and a combined data set with sequences from GenBank. The results obtained from ITS sequences also supported that the genus Ceratophyllum could be considered the ancestral group in the order, as the results of most molecular systematic studies.
2003, 28(1): 102-106.
Abstract:
The 2-D inversion is the best method in the interpretation of DC resistivity sounding profiles data owing to its high speed, but the 3-D inversion, by contrast, needs more measured data and more computer time. Through the 2-D inversional study of several 3-D models, we know that for the good conductor ore-body without strike, there is some deflection between the center of real ore-body and the center of anomaly enclosed by the 2-D inversion, however, the anomaly can still reflect the true shape and the center position of the ore-body in the main. When the ore-body has certain lengths in strike, the effect of 2-D inversion is good to it, no matter its resistivity is high or low.
The 2-D inversion is the best method in the interpretation of DC resistivity sounding profiles data owing to its high speed, but the 3-D inversion, by contrast, needs more measured data and more computer time. Through the 2-D inversional study of several 3-D models, we know that for the good conductor ore-body without strike, there is some deflection between the center of real ore-body and the center of anomaly enclosed by the 2-D inversion, however, the anomaly can still reflect the true shape and the center position of the ore-body in the main. When the ore-body has certain lengths in strike, the effect of 2-D inversion is good to it, no matter its resistivity is high or low.
2003, 28(1): 107-110.
Abstract:
In April 9, 2000, the huge landslide occurred in Yigong River in pomi in Tibet, the volume of the landslide was over 3×108 m3. It was the second landslide occurred in the same gully during the last 100 years. Based on the analysis of satellite remote sensing images and data of stratum, structure, earthquakes and meteorology, the reasons for the occurrence of landslides were discussed. It has been shown that occurrence of the landslide were controlled by the combination of geological structure, stratum character, neo-tectonism and meteorological conditions. The gully is now in the condition of material and energy accumulation, landslide will probably occur in future.
In April 9, 2000, the huge landslide occurred in Yigong River in pomi in Tibet, the volume of the landslide was over 3×108 m3. It was the second landslide occurred in the same gully during the last 100 years. Based on the analysis of satellite remote sensing images and data of stratum, structure, earthquakes and meteorology, the reasons for the occurrence of landslides were discussed. It has been shown that occurrence of the landslide were controlled by the combination of geological structure, stratum character, neo-tectonism and meteorological conditions. The gully is now in the condition of material and energy accumulation, landslide will probably occur in future.
