1997 Vol. 15, No. S1
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Display Method:
1997, 15(S1): 1-7.
Abstract:
The sedimentological analysis of the Chishan Formation is the result of the detailed, bed-by-bed study of the standard pro-file of Chishan Formation in Chishan Mountain, Jurong County, Jiangsu. Considering lithologies are diverse and according to thegenetic type, six recurring lithophases are distinguished as follows:Lithophase 1 .Purplish red fine calcareous feldspathic graywacke.Lithophase 2. Purplish red fossiliferous calcareous clay siltite or silty claystoneLithophase 3: rPurplish red thin bedded silty clay dolomite (or dolomitic fine-silty sandstone) with polygonal fracture.Lithophase 4. Bricky red fine feldspathic quartz sandstone with large-scale and high-angle cross-bedding.Lithophase 5. Purplish red thick bedded medium-fine feldspathic quartz sandstone with plane bed lamination, intercalatingmuddy flate gravel conglomerate and thin bedded gravelstone.Lithophase 6. Bricky red lenticular unequigranular graywacke, fine feldspathic quartz sandstone and silty claystone,whichconsist of hemicycles with fining-upward grain size.The Chishan Formation can be subdivided into two members. The lower member consists dominantly of lithophases 1,2 and3 which make up hemicycles. The upper member is mainly composed of lithophases 4,6. According to the features of the sedimen-tary structure and texture and lithophase associations of Chishan Formation, the sedimentary environment of the lower member isexplained the desert lake or playa and the upper member interpreted aeolian desert sea.In this paper, it is discussed that the bounding surfaces within the aeolian sandstones with large scale and high-angle cross-bedding (lithophase 4), discribed the sedimentary characteristics of the first-order surfaces (Stokes surfaces) and inquired intothe depositional tectonic setting of the Chishan Formation. We consider that the Late Cretaceous Chishan Formation formed duringthe periods from slowly thermal cooling subsidence to shrinking of the Subei Basin.
The sedimentological analysis of the Chishan Formation is the result of the detailed, bed-by-bed study of the standard pro-file of Chishan Formation in Chishan Mountain, Jurong County, Jiangsu. Considering lithologies are diverse and according to thegenetic type, six recurring lithophases are distinguished as follows:Lithophase 1 .Purplish red fine calcareous feldspathic graywacke.Lithophase 2. Purplish red fossiliferous calcareous clay siltite or silty claystoneLithophase 3: rPurplish red thin bedded silty clay dolomite (or dolomitic fine-silty sandstone) with polygonal fracture.Lithophase 4. Bricky red fine feldspathic quartz sandstone with large-scale and high-angle cross-bedding.Lithophase 5. Purplish red thick bedded medium-fine feldspathic quartz sandstone with plane bed lamination, intercalatingmuddy flate gravel conglomerate and thin bedded gravelstone.Lithophase 6. Bricky red lenticular unequigranular graywacke, fine feldspathic quartz sandstone and silty claystone,whichconsist of hemicycles with fining-upward grain size.The Chishan Formation can be subdivided into two members. The lower member consists dominantly of lithophases 1,2 and3 which make up hemicycles. The upper member is mainly composed of lithophases 4,6. According to the features of the sedimen-tary structure and texture and lithophase associations of Chishan Formation, the sedimentary environment of the lower member isexplained the desert lake or playa and the upper member interpreted aeolian desert sea.In this paper, it is discussed that the bounding surfaces within the aeolian sandstones with large scale and high-angle cross-bedding (lithophase 4), discribed the sedimentary characteristics of the first-order surfaces (Stokes surfaces) and inquired intothe depositional tectonic setting of the Chishan Formation. We consider that the Late Cretaceous Chishan Formation formed duringthe periods from slowly thermal cooling subsidence to shrinking of the Subei Basin.
1997, 15(S1): 16-23.
Abstract:
The Tuha basin is a typical coal-derived oil-gas basin. Through analyzing the geological and geochemical conditions formingcoal-derived oil in this basin, the coal-derived oil pool is rnnsidered to be formed under a specially designated geological condition.(1) The development of source rocks and reservoir of coal measures is controlled by the tectonic evolution of basin. (2) Low-ma-lure source materials are favorable for the expulsion of h州rocarbons. ( 3 ) Redox environments of coal-forming swamp and coal-forming plants result in the difference of hydrogen-rich degree in coal. Lower delta plain and interdistributary bay swamps are fa-vorable for the development of coal-derived hydrocarbon, and running water swamp facies is the most favorable facies zone for hy-drocarbon generation from coal. (4) Appropriate paleogeothermal gradient and inherited development of basin is advantageous tomaturation of source rock, and the development of overlying lake deposit is beneficial to the preservation of the expulsive hydrocar-boas from coalbed. (5) Suitable tectonic compressing is favorable for the expulsion and migration of coal-derived oil.
The Tuha basin is a typical coal-derived oil-gas basin. Through analyzing the geological and geochemical conditions formingcoal-derived oil in this basin, the coal-derived oil pool is rnnsidered to be formed under a specially designated geological condition.(1) The development of source rocks and reservoir of coal measures is controlled by the tectonic evolution of basin. (2) Low-ma-lure source materials are favorable for the expulsion of h州rocarbons. ( 3 ) Redox environments of coal-forming swamp and coal-forming plants result in the difference of hydrogen-rich degree in coal. Lower delta plain and interdistributary bay swamps are fa-vorable for the development of coal-derived hydrocarbon, and running water swamp facies is the most favorable facies zone for hy-drocarbon generation from coal. (4) Appropriate paleogeothermal gradient and inherited development of basin is advantageous tomaturation of source rock, and the development of overlying lake deposit is beneficial to the preservation of the expulsive hydrocar-boas from coalbed. (5) Suitable tectonic compressing is favorable for the expulsion and migration of coal-derived oil.
1997, 15(S1): 35-40.
Abstract:
There is a set of marine-facies sedimentary series which are mainly composed of carbonate rock for middle-upper Proterozoic and lower Palaeo-zoic sub-erathem of libel depression. The sedimentary formation have many minerals which are formed by crystallization and recrystallization such ascalcite, fluorite, quartz, barite ect. Through making a systematic study to fluid inclusions characteristics in these minerals, there are six types hy-drocarbon inclusions and three kinds aqueous inclusions have been differentiated. These fluid inclusions separately formed by two immiscible fluid oil-gas and oil field water. During the two immiscible fluid migration, oil field water exist within it妙continuou-v phase, and oil-gas妙dispersed phase(drop, bubble). In these fluid inclusions, the vapor volume of vapor-liquid aqueous inclusions are between 1-10%.and it's salinity between I.73-9.86%( NaCI), and average is 4. 72 % ( NaCl), showing that it came from paleo-seawater. The homogenization temperature of the aqueous inclusions is inthe range 47-173 C，and the homogenized phase is liquid phase which represents the lowerest formation temperature for oil-gas migration and re-servior in the depression. The hydrocarbon inclusions are the direct sign of oil-gas primary and secondary migration, in which the vapor volume ofoil-gas hydrocarbon inclusions is in the range 2-10%，and its homogenization temperature is between 41-186℃ with the oil homogenized phaseshowing that oil-gas migration and reservoir was in oil phase. When forming temperature is lower, the homogenization temperature of hydrocarboninclusion is lower than aqueous inclusion. But when the temperature is higher, the homogenization temperature of aqueous inclusion is lower than hy-drocarbon inclusion. According to the strata sequence of middle-upper Proterozoic and lower Palaeozoic sub-erathem in Jibei depression, the mean homogenizationtemperature of fluid inclusion is higher in the top and bottom of strata, and lower in the middle strata. This is because that there are giant thick-bed-ed volcanic rock covering it. The homogenization temperature of the same foramtion are obviously different in the different parts of the depression,but the direction of oil-gas migration show that is from high temperature to low temperature. In addtion, according to the type and quantity of hydrocarbon inclusions in the different layers, we deduce that the main oil-gas reservoir are Tieling formation, Wumishan formation of middle-upper Proterozoic suberathem and Ordovician system.
There is a set of marine-facies sedimentary series which are mainly composed of carbonate rock for middle-upper Proterozoic and lower Palaeo-zoic sub-erathem of libel depression. The sedimentary formation have many minerals which are formed by crystallization and recrystallization such ascalcite, fluorite, quartz, barite ect. Through making a systematic study to fluid inclusions characteristics in these minerals, there are six types hy-drocarbon inclusions and three kinds aqueous inclusions have been differentiated. These fluid inclusions separately formed by two immiscible fluid oil-gas and oil field water. During the two immiscible fluid migration, oil field water exist within it妙continuou-v phase, and oil-gas妙dispersed phase(drop, bubble). In these fluid inclusions, the vapor volume of vapor-liquid aqueous inclusions are between 1-10%.and it's salinity between I.73-9.86%( NaCI), and average is 4. 72 % ( NaCl), showing that it came from paleo-seawater. The homogenization temperature of the aqueous inclusions is inthe range 47-173 C，and the homogenized phase is liquid phase which represents the lowerest formation temperature for oil-gas migration and re-servior in the depression. The hydrocarbon inclusions are the direct sign of oil-gas primary and secondary migration, in which the vapor volume ofoil-gas hydrocarbon inclusions is in the range 2-10%，and its homogenization temperature is between 41-186℃ with the oil homogenized phaseshowing that oil-gas migration and reservoir was in oil phase. When forming temperature is lower, the homogenization temperature of hydrocarboninclusion is lower than aqueous inclusion. But when the temperature is higher, the homogenization temperature of aqueous inclusion is lower than hy-drocarbon inclusion. According to the strata sequence of middle-upper Proterozoic and lower Palaeozoic sub-erathem in Jibei depression, the mean homogenizationtemperature of fluid inclusion is higher in the top and bottom of strata, and lower in the middle strata. This is because that there are giant thick-bed-ed volcanic rock covering it. The homogenization temperature of the same foramtion are obviously different in the different parts of the depression,but the direction of oil-gas migration show that is from high temperature to low temperature. In addtion, according to the type and quantity of hydrocarbon inclusions in the different layers, we deduce that the main oil-gas reservoir are Tieling formation, Wumishan formation of middle-upper Proterozoic suberathem and Ordovician system.
1997, 15(S1): 46-50.
Abstract:
The paper discusses the clay mineral distribution and evolution of argillaceous rock in sedimentary basins from view of tectonicgeology. It's considered that tectonic backgrounds and movements are the basical factors controlling clay minerals of argillaceousrocks in sedimentary basins. This explains more reasonably the differences of clay mineral compositional characteristics of argilla-ceous rocks between petroleum basins in the east and west China. Furthermore, it explains a special kind of clay mineral assem-blage generally existed in western Tertiary argillaccous rocks, in which the clay minerals are mainly composed of illite and chloritebut the diagenetic grade is very low.
The paper discusses the clay mineral distribution and evolution of argillaceous rock in sedimentary basins from view of tectonicgeology. It's considered that tectonic backgrounds and movements are the basical factors controlling clay minerals of argillaceousrocks in sedimentary basins. This explains more reasonably the differences of clay mineral compositional characteristics of argilla-ceous rocks between petroleum basins in the east and west China. Furthermore, it explains a special kind of clay mineral assem-blage generally existed in western Tertiary argillaccous rocks, in which the clay minerals are mainly composed of illite and chloritebut the diagenetic grade is very low.
1997, 15(S1): 57-63.
Abstract:
In this paper, 197 samples were gathered from a 820cm profile at Dongganchi of Fangshan in Beijing, and the pollen assem-blages, charcoal, loss-on-ignition were obtained, Based on the investigations of pollen assemblages, charcoal, and loss-on-ignitionand comparison with the pollen assemblages of west profile at Dongganchi, Fenzhang profile and Gaoiizhang profile, the differenceslandform units and in different sedimentary environments pollen deposits were discussed. For example, the east and west profiles ofDongganchi are located between two proluvial fans, Fenzhang profile of Fanshan is located in the front of marginal depressions ofproluvial fan, and Gaolizhang profile is located in, alluvial plain. So the primary reason of the decrease of pollen-spore concentration,charcoal and loss-on-ignitions in east and west profiles of Dongganchi since 7000a B. P. was given. An important information couldbe provided for further studies of paleovegetation and paleoclimate research by this.
In this paper, 197 samples were gathered from a 820cm profile at Dongganchi of Fangshan in Beijing, and the pollen assem-blages, charcoal, loss-on-ignition were obtained, Based on the investigations of pollen assemblages, charcoal, and loss-on-ignitionand comparison with the pollen assemblages of west profile at Dongganchi, Fenzhang profile and Gaoiizhang profile, the differenceslandform units and in different sedimentary environments pollen deposits were discussed. For example, the east and west profiles ofDongganchi are located between two proluvial fans, Fenzhang profile of Fanshan is located in the front of marginal depressions ofproluvial fan, and Gaolizhang profile is located in, alluvial plain. So the primary reason of the decrease of pollen-spore concentration,charcoal and loss-on-ignitions in east and west profiles of Dongganchi since 7000a B. P. was given. An important information couldbe provided for further studies of paleovegetation and paleoclimate research by this.
1997, 15(S1): 70-75.
Abstract:
The gas source rocks in this area are mainly grey mud deposited in inner sublittoral enviornment and grey-greyish black muddeposited in flood land environment influenced by sea water. Shallow-sea facies gas source rock deposited in weak reduction-reduc-lion environment, and flood land facies gas source rock deposited in light reduction-high reduction environment. On the whole, thelatter has higher reductibility and stronger gas-yielding capacity than the former, and which in the north is higher or stronger thanthat in the south of Zhejiang province. Formation of the biogas were controlled by seven main factors, namely depositional environ-went, depositional time, paleoclimate, sea level change, crustal subsidence, rate of deposition and water medium. It's favorableinfluence to mass production and enrichment of biogas in flood land facies gas source rock, when these factors interact and influenceeach other.
The gas source rocks in this area are mainly grey mud deposited in inner sublittoral enviornment and grey-greyish black muddeposited in flood land environment influenced by sea water. Shallow-sea facies gas source rock deposited in weak reduction-reduc-lion environment, and flood land facies gas source rock deposited in light reduction-high reduction environment. On the whole, thelatter has higher reductibility and stronger gas-yielding capacity than the former, and which in the north is higher or stronger thanthat in the south of Zhejiang province. Formation of the biogas were controlled by seven main factors, namely depositional environ-went, depositional time, paleoclimate, sea level change, crustal subsidence, rate of deposition and water medium. It's favorableinfluence to mass production and enrichment of biogas in flood land facies gas source rock, when these factors interact and influenceeach other.
1997, 15(S1): 82-85.
Abstract:
The study results indicated that the light hydrocarbons are mainly produced from the pinus pollen between 300~500℃，maximum at 350~450℃. When temperature is lower than 200℃，there are only traces of the light hydrocarbons produced.Higher 550℃，the light hydrocarbons are far less because of stronger thermal degradation. The light hydrocarbons consist offour components. The main component is aromatic serial compounde which consist of 1~4 aromatic rings. The aromatic com-ponent in the total light hydrocarbons is about 55. 17~65. 20%when the temperature is lower than 450℃. Hower,at over550℃ the light hydrocarbons consist almost all of aromatic compounds. The other components in the light hydrocarbons arenormal alkanes. alkyl cyclohexanes & alkyl cyclopentanes and long-chain fatty acid (or ester) serial compounds. Thesebiomarkers have been identified from oils, coals and other sedimentary organic matters which the main organic source are theterrestrial higher plants. So, this paper will provide the important imformations in recognising the hydrocarbon source tom-pounds of terrestrially crude oils (gases) and in the theory of the productive hydrocarbons during thermal maturation.
The study results indicated that the light hydrocarbons are mainly produced from the pinus pollen between 300~500℃，maximum at 350~450℃. When temperature is lower than 200℃，there are only traces of the light hydrocarbons produced.Higher 550℃，the light hydrocarbons are far less because of stronger thermal degradation. The light hydrocarbons consist offour components. The main component is aromatic serial compounde which consist of 1~4 aromatic rings. The aromatic com-ponent in the total light hydrocarbons is about 55. 17~65. 20%when the temperature is lower than 450℃. Hower,at over550℃ the light hydrocarbons consist almost all of aromatic compounds. The other components in the light hydrocarbons arenormal alkanes. alkyl cyclohexanes & alkyl cyclopentanes and long-chain fatty acid (or ester) serial compounds. Thesebiomarkers have been identified from oils, coals and other sedimentary organic matters which the main organic source are theterrestrial higher plants. So, this paper will provide the important imformations in recognising the hydrocarbon source tom-pounds of terrestrially crude oils (gases) and in the theory of the productive hydrocarbons during thermal maturation.
1997, 15(S1): 91-95.
Abstract:
Bio-reef-chert Suite is an important rock assemblage for controlling Dajiangping superlarge pyrite deposits, Fankou super-large lead-zinc deposits and Changkeng superlarge gold-silver deposits. It is formed as a fixed and ordered suite at space andtime, rnmposed of carbonate rocks of reef facies, hydrothermal sedimentary rocks (ores), fine detrital rocks intercalated bandedmudlimestone, synchronous volcanic rocks, tuffaceous rocks and volcanic veins in the isostrata in mining area or in the neighbordistrict. It is also the comprehensive products of normal sedimentary process, biological process in basin, hydrothermal sedimentaryprows under basin base and magmatic process in the deep of lithosphere, when basin evoluted at a special stage in a special geologi-cal setting.
Bio-reef-chert Suite is an important rock assemblage for controlling Dajiangping superlarge pyrite deposits, Fankou super-large lead-zinc deposits and Changkeng superlarge gold-silver deposits. It is formed as a fixed and ordered suite at space andtime, rnmposed of carbonate rocks of reef facies, hydrothermal sedimentary rocks (ores), fine detrital rocks intercalated bandedmudlimestone, synchronous volcanic rocks, tuffaceous rocks and volcanic veins in the isostrata in mining area or in the neighbordistrict. It is also the comprehensive products of normal sedimentary process, biological process in basin, hydrothermal sedimentaryprows under basin base and magmatic process in the deep of lithosphere, when basin evoluted at a special stage in a special geologi-cal setting.
1997, 15(S1): 102-105.
Abstract:
Secondary porosity caused by dissolution of primary skeleton grains and chemical cements is the most important petroleumstorage spaces in deep burial elastic reservoirs. Lithic arkose is the main component of Triassic reservoir sandstones in the Tarimbasin ; carbonate cement in the reservoir ranges from 5 % to 35 %，and in the Tertiary of the Jizhong Depression the common reser-voir rock is arkose, of which carbonate cement is between 3 % and 35 %.The feldspathic grains and carbonate cement provide 6a-sic materials for the formation of solution porosity. Cores taken from below 3500m in Jizhong Depression show the maximumporosity < 20 % and maximum permeability<100 x 10-3pm2. Most of the samples have porosity<10 % and permeability<10x10-3pm2;In the Tarim basin the Triassic sandstone reservoirs buried deeper than 5000m still have maximum porosity > 20 %and permeability 1000 x 10-3pm2. Production shows that when elastic reservoir buried deeper than 3500m in Jizhong Depressionthe fluid production is always less than 1002/d; while in the Tarim Basin when buried below 5000m, Tertiary elastic reservoirs stillhave an oil production of 500t/d and gas 100000m3/d. This paper compares the deep burial elastic reservoirs in the Tertiary of theJizhong Depression with the Triassic of Tarim Basin and discusses the factors affecting the porosity evolution in deep burial situa-lion. Geotemperature and multiple hydrocarbon sources are the main factors that bring about the difference of reservoir storage ca-pacify in deep burial elastic reservoirs in the Jizhong Depression and the Tarim Basin.
Secondary porosity caused by dissolution of primary skeleton grains and chemical cements is the most important petroleumstorage spaces in deep burial elastic reservoirs. Lithic arkose is the main component of Triassic reservoir sandstones in the Tarimbasin ; carbonate cement in the reservoir ranges from 5 % to 35 %，and in the Tertiary of the Jizhong Depression the common reser-voir rock is arkose, of which carbonate cement is between 3 % and 35 %.The feldspathic grains and carbonate cement provide 6a-sic materials for the formation of solution porosity. Cores taken from below 3500m in Jizhong Depression show the maximumporosity < 20 % and maximum permeability<100 x 10-3pm2. Most of the samples have porosity<10 % and permeability<10x10-3pm2;In the Tarim basin the Triassic sandstone reservoirs buried deeper than 5000m still have maximum porosity > 20 %and permeability 1000 x 10-3pm2. Production shows that when elastic reservoir buried deeper than 3500m in Jizhong Depressionthe fluid production is always less than 1002/d; while in the Tarim Basin when buried below 5000m, Tertiary elastic reservoirs stillhave an oil production of 500t/d and gas 100000m3/d. This paper compares the deep burial elastic reservoirs in the Tertiary of theJizhong Depression with the Triassic of Tarim Basin and discusses the factors affecting the porosity evolution in deep burial situa-lion. Geotemperature and multiple hydrocarbon sources are the main factors that bring about the difference of reservoir storage ca-pacify in deep burial elastic reservoirs in the Jizhong Depression and the Tarim Basin.
1997, 15(S1): 114-119.
Abstract:
Diagenetic field analysis have rapid and valid guide significance for regional reservoir prediction and evaluation. The Nanpu de-pression (continental area) is separated into two grade-2 fault blocks. The upbip block (Gaoshanpu-Liuzhan) have undergone twotimes of inorganic-organic diagenesis processes, in relation to two times of evident subsidence burial, and is characterized by abnor-coal high pressure ( compartment) in intermediated-deep burial ( 2700~3450m), as well as indirect freshening alteration in theshallow part resulted from meteoric infiltration. On the other hand, the downthrown block (Beipu-Laoyiemiao) is characterized bycontinual subsidence burial, which provided available conditions for thermo-fluid flow and related abnormal high pressure compart-went development in deep burial part(> 3400m). The diagenetic field separation between the two fault blocks has important controls on reservoir diagenesis framework and se-quences of the Lower Tertiary, in which some relations are discussed and applied to quantitative and semi-quantitative prediction ofburial depths of reservoir diagenesis belts in the blocks. It was found that reservoir burial depth in the downthrown block is gener-ally 200~500m larger than one in the updip block for the same diagenesis belt. In addition, it is also discussed that diagenetic sequences, characterized by chlorite-carbonate-analcime authigenetic assemblagein the Gaoshanpu and carbonate illite-quartz authigenetic assemblage in the Beipu, were related to cation-rich and cation-poor typesof primary sediment and pore water chemistry, respectively.
Diagenetic field analysis have rapid and valid guide significance for regional reservoir prediction and evaluation. The Nanpu de-pression (continental area) is separated into two grade-2 fault blocks. The upbip block (Gaoshanpu-Liuzhan) have undergone twotimes of inorganic-organic diagenesis processes, in relation to two times of evident subsidence burial, and is characterized by abnor-coal high pressure ( compartment) in intermediated-deep burial ( 2700~3450m), as well as indirect freshening alteration in theshallow part resulted from meteoric infiltration. On the other hand, the downthrown block (Beipu-Laoyiemiao) is characterized bycontinual subsidence burial, which provided available conditions for thermo-fluid flow and related abnormal high pressure compart-went development in deep burial part(> 3400m). The diagenetic field separation between the two fault blocks has important controls on reservoir diagenesis framework and se-quences of the Lower Tertiary, in which some relations are discussed and applied to quantitative and semi-quantitative prediction ofburial depths of reservoir diagenesis belts in the blocks. It was found that reservoir burial depth in the downthrown block is gener-ally 200~500m larger than one in the updip block for the same diagenesis belt. In addition, it is also discussed that diagenetic sequences, characterized by chlorite-carbonate-analcime authigenetic assemblagein the Gaoshanpu and carbonate illite-quartz authigenetic assemblage in the Beipu, were related to cation-rich and cation-poor typesof primary sediment and pore water chemistry, respectively.
1997, 15(S1): 127-131.
Abstract:
Minghe basin is one of the typical continental basins containning coal,oil and gas. The study area-Yaojie region is an inter-mountain river valley depression, where there are the fluvial sediments of 600m in thickness in late Jurassic strata. On the basis ofthe previous biostratigraphical research, this paper researches the evolutionary characteristics of sedimentary facies of XiangtangFormatin of Jurassic system in Yaojie region, Minhe basin by means of the method of markov chain mathematical mock. There-fore, the evolutionary characteristics of the sedimentary facies have been understood. Xiangtang Formation is divivided into three sections J3x1,J3x2,J3x3 according to charateristics of rocks, constructures, sedi-mentary structure etc. 13 kinds of rock element has been recognized in the Formation, which consist of several facies sequence bytranforming and combinating each other. Every facies sequence represents a kind of law of sequence which reflects the sedimentaryprocess and environment, thus, it can be served as an important factor to analyze sedimentary facies and small facies. The researchresults are as belows: J3x1 section's alluvial-fan facies; the channel, which developed a macro-unconvex eroded basis, was filled by greyish greenmassive conglomerate and sandy conglomerate lens, which is interpreted as the ephemeral channel on alluvial fan top. Middle partis the interbeds of greyish green plate shaped middle-fine sandstone which contains gravels with thinner mudstone, representing issediments formed between both cnannel of alluvian fan. Upper part greyish green purple thinner mudstone beds containning thin-ner sandstone beds were deposited in alluvial plain. Lower J3x2 section's braided river facies: Channel sandy bars developed very well, but the sediments of floody plain smalt fa-ties is poor. The sandy rudite,sandstone containing gravels and standstone with trough cross bedding is the main sediments, andthe structures of scours and filling occurs frequently in lower part. Charateristics of probability cumulative curve show water is shal-low with a high-speed flow. Upper J3x2 section's alluvial fan facies: Rythmite bed of pale sandstone and mudstone take over the main proportion, and thedeposits of the alluvial fan plain occupy the majority of all facies, which shows the characteristics of alluvial fan's deposits in frontof fault in basin. J3x3 section's meandering river facies: the deposits of levee and flood plain developed extremely well, of which sediments aremostly fine. The structures of sediments filling in channel are mainly plate cross beddings, and the probability cumulative curve ofsandstone of point bar shows out low sections of heap-supspend. Levee sediments are rythmite interbed of which probability cu-mulitive curve is a single line type, and suspend composition takes over 9096.Above that are the flood plain sediments which con-sist of the great set of mudstone.fine sandy mudstone and poor coal beds.
Minghe basin is one of the typical continental basins containning coal,oil and gas. The study area-Yaojie region is an inter-mountain river valley depression, where there are the fluvial sediments of 600m in thickness in late Jurassic strata. On the basis ofthe previous biostratigraphical research, this paper researches the evolutionary characteristics of sedimentary facies of XiangtangFormatin of Jurassic system in Yaojie region, Minhe basin by means of the method of markov chain mathematical mock. There-fore, the evolutionary characteristics of the sedimentary facies have been understood. Xiangtang Formation is divivided into three sections J3x1,J3x2,J3x3 according to charateristics of rocks, constructures, sedi-mentary structure etc. 13 kinds of rock element has been recognized in the Formation, which consist of several facies sequence bytranforming and combinating each other. Every facies sequence represents a kind of law of sequence which reflects the sedimentaryprocess and environment, thus, it can be served as an important factor to analyze sedimentary facies and small facies. The researchresults are as belows: J3x1 section's alluvial-fan facies; the channel, which developed a macro-unconvex eroded basis, was filled by greyish greenmassive conglomerate and sandy conglomerate lens, which is interpreted as the ephemeral channel on alluvial fan top. Middle partis the interbeds of greyish green plate shaped middle-fine sandstone which contains gravels with thinner mudstone, representing issediments formed between both cnannel of alluvian fan. Upper part greyish green purple thinner mudstone beds containning thin-ner sandstone beds were deposited in alluvial plain. Lower J3x2 section's braided river facies: Channel sandy bars developed very well, but the sediments of floody plain smalt fa-ties is poor. The sandy rudite,sandstone containing gravels and standstone with trough cross bedding is the main sediments, andthe structures of scours and filling occurs frequently in lower part. Charateristics of probability cumulative curve show water is shal-low with a high-speed flow. Upper J3x2 section's alluvial fan facies: Rythmite bed of pale sandstone and mudstone take over the main proportion, and thedeposits of the alluvial fan plain occupy the majority of all facies, which shows the characteristics of alluvial fan's deposits in frontof fault in basin. J3x3 section's meandering river facies: the deposits of levee and flood plain developed extremely well, of which sediments aremostly fine. The structures of sediments filling in channel are mainly plate cross beddings, and the probability cumulative curve ofsandstone of point bar shows out low sections of heap-supspend. Levee sediments are rythmite interbed of which probability cu-mulitive curve is a single line type, and suspend composition takes over 9096.Above that are the flood plain sediments which con-sist of the great set of mudstone.fine sandy mudstone and poor coal beds.
1997, 15(S1): 138-141.
Abstract:
The Saturate components characteristics and its' stable carbon isotope composition of individual n-alkanes of Fuling For-mation immature source rock from Jinghu sag in SuBei Basin have been studied in detail by means of GC, GC-MS and GC-C-MS. As a result，the content of steranes (especially aaa(20R)-C20sterane) of saturate is very abundant. There are threemajor peaks in the distribution of normal alkanes. The highest peak is C22 or C20 normal alkane. According to the study of themaceral composition and the variation in stable carbon isotope of individual hydrocarbons, it is proposed that middle molecularweight (nC19-nC22) normal alkanes are derived from bacteria and algae and steranes (including abundent Cz9 sterane) mainlycome from algae.
The Saturate components characteristics and its' stable carbon isotope composition of individual n-alkanes of Fuling For-mation immature source rock from Jinghu sag in SuBei Basin have been studied in detail by means of GC, GC-MS and GC-C-MS. As a result，the content of steranes (especially aaa(20R)-C20sterane) of saturate is very abundant. There are threemajor peaks in the distribution of normal alkanes. The highest peak is C22 or C20 normal alkane. According to the study of themaceral composition and the variation in stable carbon isotope of individual hydrocarbons, it is proposed that middle molecularweight (nC19-nC22) normal alkanes are derived from bacteria and algae and steranes (including abundent Cz9 sterane) mainlycome from algae.
1997, 15(S1): 147-151.
Abstract:
Based on the sporo-pollen analyses of the core samples of Corehole 83-CK1 from the Qagan Salt Lake in the Eren Basin ofthe Inner Mongolia, the sporo-pollen diagram were divided into four palynofloral zones, i. e. Zone I，Zone II，Zone lII，andZone Ⅳ in this paper. In accordance with the characteristics of the sporo-pollen assemblages, the problems on the vegetational evo-lution and the paleoclimatic changes in the past 18 ka as well as the sedimentary environment of salt lake were discussed. Ages ofthe sedimentary section of Corehole 83-CKl are based on14C dating. The results of this study indicate that the late stage of LatePleistocene Epoch (18-15 ka BP) and the early stage of Holocene Epoch (10-5 ka BP) with relatively wet and warm climaticconditions should be the preparatory stages for the formation of saline deposits; the last stage of Late Pleistocene Epoch (15-10 kaBP) and the late stage of Holocene Epoch (S ka BP to the present) with dry and cold climatic conditions should be the main stagesfor the formation and evolution of saline deposits in the Inner Mongolia
Based on the sporo-pollen analyses of the core samples of Corehole 83-CK1 from the Qagan Salt Lake in the Eren Basin ofthe Inner Mongolia, the sporo-pollen diagram were divided into four palynofloral zones, i. e. Zone I，Zone II，Zone lII，andZone Ⅳ in this paper. In accordance with the characteristics of the sporo-pollen assemblages, the problems on the vegetational evo-lution and the paleoclimatic changes in the past 18 ka as well as the sedimentary environment of salt lake were discussed. Ages ofthe sedimentary section of Corehole 83-CKl are based on14C dating. The results of this study indicate that the late stage of LatePleistocene Epoch (18-15 ka BP) and the early stage of Holocene Epoch (10-5 ka BP) with relatively wet and warm climaticconditions should be the preparatory stages for the formation of saline deposits; the last stage of Late Pleistocene Epoch (15-10 kaBP) and the late stage of Holocene Epoch (S ka BP to the present) with dry and cold climatic conditions should be the main stagesfor the formation and evolution of saline deposits in the Inner Mongolia
1997, 15(S1): 157-162.
Abstract:
Qinghai lake is a plateau inland intermountain rift-subsidence Iake basin developped since quaternary. The development andevolution of the lake basin have experienced four stages, that is, the rift period, the lake and river coexistence period, the mostflourishing development period and the shrivel period. The distribution of the sedimentary facies is controlled by climate, sedimentsource, rivers, topography and tectonic evolution histories, which is charactered by intermountain rift-subsidence and near sedi-ment source deposition. Along the long axis direction of the basin, the sedimentary deposit system of braided river, meanderingriver, delta, subaqueous channel and deep water lacustrine facies are developed at the west end, whereas at the east end of thebasin mainly distributed the aeolian and lagoon deposits. In the areas along the short axis direction of the basin, the systems of in-termontain fluvial, braided river, diluvial fan, fan-delta and shallow lake shore facies are deposited. The south bank is relativelysteeper, where mainly formed several large and small alluvial fan or aprons. In shallow lake shore areas, sedimentary deposits oflongshore bar, sand spit, shingle beach, sand beach, mudflat, swamp and lakebay facies are well developed. Compared with otherlakes in China and abroad, the deposits in Qinghai lake are featured by their better developed aeolian, subaqueous fluvial and long-shore bar facies. Based on field survey, sampling anisys and comprehensive research the paper discusses its development, regional tectonics mi-lieu, lake environment, sedimentation, sedimentary facies, and structure-sediment evolution of lake basin.
Qinghai lake is a plateau inland intermountain rift-subsidence Iake basin developped since quaternary. The development andevolution of the lake basin have experienced four stages, that is, the rift period, the lake and river coexistence period, the mostflourishing development period and the shrivel period. The distribution of the sedimentary facies is controlled by climate, sedimentsource, rivers, topography and tectonic evolution histories, which is charactered by intermountain rift-subsidence and near sedi-ment source deposition. Along the long axis direction of the basin, the sedimentary deposit system of braided river, meanderingriver, delta, subaqueous channel and deep water lacustrine facies are developed at the west end, whereas at the east end of thebasin mainly distributed the aeolian and lagoon deposits. In the areas along the short axis direction of the basin, the systems of in-termontain fluvial, braided river, diluvial fan, fan-delta and shallow lake shore facies are deposited. The south bank is relativelysteeper, where mainly formed several large and small alluvial fan or aprons. In shallow lake shore areas, sedimentary deposits oflongshore bar, sand spit, shingle beach, sand beach, mudflat, swamp and lakebay facies are well developed. Compared with otherlakes in China and abroad, the deposits in Qinghai lake are featured by their better developed aeolian, subaqueous fluvial and long-shore bar facies. Based on field survey, sampling anisys and comprehensive research the paper discusses its development, regional tectonics mi-lieu, lake environment, sedimentation, sedimentary facies, and structure-sediment evolution of lake basin.
1997, 15(S1): 8-15.
Abstract:
Systematic analyses on the seafloor surface sediments of the north Okinawa Trough were carried out to seek for geochemicalindexes respectively representing terrigenous, volcanic and biogenic sediments. Research results showed that SiO2 was riched in thezone of the outer shelf edge and shelf break where the terrigenous sediments and relict sediments were dominant. A12O3and Na20contents were the indexes representing volcanic materials, and Ca0 or total carbonate indicating the biogenic deposits. In addition,MgO, Fe203, Ti02, K2O2MnO1 P2O5, LOI (loss by ignition) and most trace metals, such as Rb, $a, Zn and Cr were compara-tively enriched in the fine sediments. Stronsium concentration had close relationship with proportion of the biogenic components inthe sediments. Distributions of most chemical rnmponents presented a pattern which was devided into the east area and west area by the mid-dle axis line of the Okinawa Trough, suggesting important differences existing between the two areas in the both sediment resourceand sedimentary environment. The middle axis line of the trough was a natural boundary in sedimentology.
Systematic analyses on the seafloor surface sediments of the north Okinawa Trough were carried out to seek for geochemicalindexes respectively representing terrigenous, volcanic and biogenic sediments. Research results showed that SiO2 was riched in thezone of the outer shelf edge and shelf break where the terrigenous sediments and relict sediments were dominant. A12O3and Na20contents were the indexes representing volcanic materials, and Ca0 or total carbonate indicating the biogenic deposits. In addition,MgO, Fe203, Ti02, K2O2MnO1 P2O5, LOI (loss by ignition) and most trace metals, such as Rb, $a, Zn and Cr were compara-tively enriched in the fine sediments. Stronsium concentration had close relationship with proportion of the biogenic components inthe sediments. Distributions of most chemical rnmponents presented a pattern which was devided into the east area and west area by the mid-dle axis line of the Okinawa Trough, suggesting important differences existing between the two areas in the both sediment resourceand sedimentary environment. The middle axis line of the trough was a natural boundary in sedimentology.
1997, 15(S1): 24-29.
Abstract:
The characteristics of organic matter in permafrost bog sediments of Qinghai-Xizang (Tibet) Plateau may provide special in-formation on geochemistry and environment history. In this work, sedimentary facies and organic matter of shallow frozen lacus-trine sediments from a depth of 1 .4m, which is the upper limit of permafrost to 4. 5m have been studied systematically. In thisprofile, clay, silt and fine sand layers occur alternatively. The layers of clay contain the highest content of organic matter and thoseof fine sand contain the least. The important characteristics of organic matter in these frosted bog deposits are shown as follows; 1)the organic matter was of simple source which came from local grasses and subjected to little effect of sedimentation; 2) the compo-nents were relatively stable once after frozen in the sediments. In this profile, the Corg and HI range from 0.11 to 4. 77 and 0 to369 in the section of 20 to 40cm respectively and the contents of extracts vary from 108 to 3630ppm. In soluble extracts, contentof alkane, aromatic, non-hydrocarbon and asphaltene groups are from 0.21 to 15.6296，0 . 79 to 19 . 2 96，3. 8 to 46. 55 96 and 2 .0 to 26.996 respectively. In section from 20 to 40cm, the Corg, HI(hydrogen index), content of extracts by CH222 andmethanol (8:2), groups of extracts have the same variations with the depth and,can imply the paleoenvironmental changes. TheOEP and Pr/Ph high than 2 and 1 respectively, Indicating that the sedimentary environment was in oxidation. The distribution ofditerpane and hopane vary clearly with the depth and may be a good indicator to environment. Especially, the biomarkers such aspigment and diterpane may help reconstruct the paleoenvironment and imply the change of environment
The characteristics of organic matter in permafrost bog sediments of Qinghai-Xizang (Tibet) Plateau may provide special in-formation on geochemistry and environment history. In this work, sedimentary facies and organic matter of shallow frozen lacus-trine sediments from a depth of 1 .4m, which is the upper limit of permafrost to 4. 5m have been studied systematically. In thisprofile, clay, silt and fine sand layers occur alternatively. The layers of clay contain the highest content of organic matter and thoseof fine sand contain the least. The important characteristics of organic matter in these frosted bog deposits are shown as follows; 1)the organic matter was of simple source which came from local grasses and subjected to little effect of sedimentation; 2) the compo-nents were relatively stable once after frozen in the sediments. In this profile, the Corg and HI range from 0.11 to 4. 77 and 0 to369 in the section of 20 to 40cm respectively and the contents of extracts vary from 108 to 3630ppm. In soluble extracts, contentof alkane, aromatic, non-hydrocarbon and asphaltene groups are from 0.21 to 15.6296，0 . 79 to 19 . 2 96，3. 8 to 46. 55 96 and 2 .0 to 26.996 respectively. In section from 20 to 40cm, the Corg, HI(hydrogen index), content of extracts by CH222 andmethanol (8:2), groups of extracts have the same variations with the depth and,can imply the paleoenvironmental changes. TheOEP and Pr/Ph high than 2 and 1 respectively, Indicating that the sedimentary environment was in oxidation. The distribution ofditerpane and hopane vary clearly with the depth and may be a good indicator to environment. Especially, the biomarkers such aspigment and diterpane may help reconstruct the paleoenvironment and imply the change of environment
1997, 15(S1): 41-45.
Abstract:
Ruyang Group in the western Henan can be divided into six third-order sequences. These sequences are made of some high-frequency sequence. The sequence 6 in them contains 9 parasequences sets and more than 36 parasequence. A parasoquence consistsof various sedimentary facies having upward-shallowing sequence, and is bounded by hiatus. The grain size is upward-coarseningand bed is upward thicking in parasequence. Geochemical data show As, Sb decrease and &13C increase in upward-shallowing se-quence. The character of the parasequence has relationship with to the sea-level change.
Ruyang Group in the western Henan can be divided into six third-order sequences. These sequences are made of some high-frequency sequence. The sequence 6 in them contains 9 parasequences sets and more than 36 parasequence. A parasoquence consistsof various sedimentary facies having upward-shallowing sequence, and is bounded by hiatus. The grain size is upward-coarseningand bed is upward thicking in parasequence. Geochemical data show As, Sb decrease and &13C increase in upward-shallowing se-quence. The character of the parasequence has relationship with to the sea-level change.
1997, 15(S1): 51-56.
Abstract:
A 10km long section composed of 39 drilling holes in the central Jiangsu is examined to reconstruct the history of the coastaldevelopment and environmental evolution. There appears some evidences that modern tidal flat in central Jiangsu developed fromHolocene tidal sand ridges in the past centuries. A hiatus of sedimentation occurred between 20 and 10 ka BP. because of the lowerstand of sea level. Tidal flat occured in the modern coastal zone or nearshore during 30-20 ka BP.
A 10km long section composed of 39 drilling holes in the central Jiangsu is examined to reconstruct the history of the coastaldevelopment and environmental evolution. There appears some evidences that modern tidal flat in central Jiangsu developed fromHolocene tidal sand ridges in the past centuries. A hiatus of sedimentation occurred between 20 and 10 ka BP. because of the lowerstand of sea level. Tidal flat occured in the modern coastal zone or nearshore during 30-20 ka BP.
1997, 15(S1): 64-69.
Abstract:
The general characteristics of lacustrine carbonate source rocks are discussed in this paper, where the lacustrine carbonate ofHetaoyuan Formation, Tertiary, Biyang Depression, was taken as an example. That the composition characteristics, the contentsof organic matters, the transformative rate of hydrocarbons and the type of organic matters show that lacustrine carbonate sourcerocks are rich in oil-generating material, and the convincible oil-source rock correlation material indicates that lacustrine carbonatesnot only can generate oils, but also be the source rocks of commercial oils.
The general characteristics of lacustrine carbonate source rocks are discussed in this paper, where the lacustrine carbonate ofHetaoyuan Formation, Tertiary, Biyang Depression, was taken as an example. That the composition characteristics, the contentsof organic matters, the transformative rate of hydrocarbons and the type of organic matters show that lacustrine carbonate sourcerocks are rich in oil-generating material, and the convincible oil-source rock correlation material indicates that lacustrine carbonatesnot only can generate oils, but also be the source rocks of commercial oils.
1997, 15(S1): 76-81.
Abstract:
The Differential Thermal-Gas Chromatography is a kind of pyrolitic analytic equipments which can obtain a lot of usefull in-formation on maturity, types of source materials and potential of gas and petroleum generation from different kinds of geologicalsamples by means of changes of pyrolitic gas compositions and total gas amounts produced during heating processes at different tem-perature points. In Cambrian-Ordovician carbonate rocks of Tarim Basin and Tangshan district, ethanes are the major peaks in pyroliticgaseous hydrocarbons from 550℃ or so to 700,0 temperature point range, whereas in Palaeozoic mudstones of Tarim Basin, ter-restrial kerogens of different periods (Permian, Jurrassic and Tertiary) of Zhungeer Basin, and two terrestrial coals with differentranks ( Ro = 0. 36 %，2.32% respectively), urethanes are the major peaks from 500℃ to 600℃ range. The difference in the py-rolytic gaseous hydrocarbon compositions betweennn carbonate rocks and other geological samples mentioned above is mainly causedby contributions of enclosed organic matter to pyrolitic gaseous h州rocarbons of carbonate rocks. By means of comparison with total gas amounts at different temperature points of the terrestrial kerogens of Zhungeer Basin,and coals, it is found that the Cambrian-Ordovician carbonate source rocks still have certain hydrocarbon generation potential at700℃ high temperature point, again showing contributions of enclosed organic matter in carbonate rocks to hydrocarbon generationat late stage. By means of comparison between transformation ratios (S1/(S1+S2))from Rock-Eval and total gas amounts produced fromper gram organic carbon during eleven temperature points from 1000C to 7000C，thd Cambrian-C!rdovician carbonate rocks ofTarim Basin have higher maturity than those of Tangshan district, which is consistent with geological history of the two districtsduring Early Palaeozoic Era.
The Differential Thermal-Gas Chromatography is a kind of pyrolitic analytic equipments which can obtain a lot of usefull in-formation on maturity, types of source materials and potential of gas and petroleum generation from different kinds of geologicalsamples by means of changes of pyrolitic gas compositions and total gas amounts produced during heating processes at different tem-perature points. In Cambrian-Ordovician carbonate rocks of Tarim Basin and Tangshan district, ethanes are the major peaks in pyroliticgaseous hydrocarbons from 550℃ or so to 700,0 temperature point range, whereas in Palaeozoic mudstones of Tarim Basin, ter-restrial kerogens of different periods (Permian, Jurrassic and Tertiary) of Zhungeer Basin, and two terrestrial coals with differentranks ( Ro = 0. 36 %，2.32% respectively), urethanes are the major peaks from 500℃ to 600℃ range. The difference in the py-rolytic gaseous hydrocarbon compositions betweennn carbonate rocks and other geological samples mentioned above is mainly causedby contributions of enclosed organic matter to pyrolitic gaseous h州rocarbons of carbonate rocks. By means of comparison with total gas amounts at different temperature points of the terrestrial kerogens of Zhungeer Basin,and coals, it is found that the Cambrian-Ordovician carbonate source rocks still have certain hydrocarbon generation potential at700℃ high temperature point, again showing contributions of enclosed organic matter in carbonate rocks to hydrocarbon generationat late stage. By means of comparison between transformation ratios (S1/(S1+S2))from Rock-Eval and total gas amounts produced fromper gram organic carbon during eleven temperature points from 1000C to 7000C，thd Cambrian-C!rdovician carbonate rocks ofTarim Basin have higher maturity than those of Tangshan district, which is consistent with geological history of the two districtsduring Early Palaeozoic Era.
1997, 15(S1): 86-90.
Abstract:
This paper describes in detail SEDBA (A Global Database in Sedimentary Petrology) and the characteristics and functions ofits management software FOX SEDBA, as well as the method using the software development tools to construct FOX SEDBA.FOX SEDBA is completely menu-driving system and can provide a good interface for users. It allows for data entry, editing, in-query, retrieval, print out and graph. As the system is advanced and the retrieval functions are powerful and flexible, the SEDBAdatabase will play an important role in the present geosciences.
This paper describes in detail SEDBA (A Global Database in Sedimentary Petrology) and the characteristics and functions ofits management software FOX SEDBA, as well as the method using the software development tools to construct FOX SEDBA.FOX SEDBA is completely menu-driving system and can provide a good interface for users. It allows for data entry, editing, in-query, retrieval, print out and graph. As the system is advanced and the retrieval functions are powerful and flexible, the SEDBAdatabase will play an important role in the present geosciences.
1997, 15(S1): 96-101.
Abstract:
According to the results of multidisciplinary analyses with different methods, we found that there were at least four hiatuses ina sediment core taken from CC Zone in North Pacific. These hiatuses are as follows: Holocene, Middle Pleistocene, UpperPliocene and Middle Miocene. The main cause of these hiatuses is the Antactic Bottom Water (AABW). There were three layers of polymetallic nodules in this sediment core. They were the surface nodules, the buried nodules inthe depth of 28cm and 320cm in the mre respectively. These nodules were different in the size, chemical composition, mineralphases and age, but the origin of these nodules were all related to the hiatus in 320cm of the core which began at 1.2 X 107a BP.
According to the results of multidisciplinary analyses with different methods, we found that there were at least four hiatuses ina sediment core taken from CC Zone in North Pacific. These hiatuses are as follows: Holocene, Middle Pleistocene, UpperPliocene and Middle Miocene. The main cause of these hiatuses is the Antactic Bottom Water (AABW). There were three layers of polymetallic nodules in this sediment core. They were the surface nodules, the buried nodules inthe depth of 28cm and 320cm in the mre respectively. These nodules were different in the size, chemical composition, mineralphases and age, but the origin of these nodules were all related to the hiatus in 320cm of the core which began at 1.2 X 107a BP.
1997, 15(S1): 106-113.
Abstract:
The Lower Silurian Series in the Chuandongnan-Qingbei area of China is well Groped out and contains abundant fossils. Theauthors have discovered reefs spreading in varying degrees on the layer through field trip and research Qijing Guanyinqiao ofChongqing, Puodu and its neighbouring area. Reef Typifing point, dune, strata grew into the middle-lower layer of Shiniulan for-mation (equal to middle llandovery ).Reef-building biota is mainly composed of Tabulata，Tetracorallia，Stromatoporida.Biodetritus bank and knotty limestone formed reef bottom. Reef growing and spreading was restricted by palaeoenvironment. Theshallow slope zone nearing Qianzhong uplift is favorable to reef development.
The Lower Silurian Series in the Chuandongnan-Qingbei area of China is well Groped out and contains abundant fossils. Theauthors have discovered reefs spreading in varying degrees on the layer through field trip and research Qijing Guanyinqiao ofChongqing, Puodu and its neighbouring area. Reef Typifing point, dune, strata grew into the middle-lower layer of Shiniulan for-mation (equal to middle llandovery ).Reef-building biota is mainly composed of Tabulata，Tetracorallia，Stromatoporida.Biodetritus bank and knotty limestone formed reef bottom. Reef growing and spreading was restricted by palaeoenvironment. Theshallow slope zone nearing Qianzhong uplift is favorable to reef development.
1997, 15(S1): 120-126.
Abstract:
The paper has studied the sedimentary evolution history, depositional system and sedimentary fades of deep reservoir in Liao-he Basin by using sedimentology combining with log facies and seismic facies as well as various reservoir forecasting methods to re-veal the depositional feature and sandbody spatial distribution of deep reservoir bed, analysed the reservoir characteristics of sectionSha 3 turbidite sandbody and Sha 2-Sha 4 fan-delta sandbody, and predicted favorable facies belts. The conclusion of the researchis that sublacustrine fan reservoir is of a little high porosity and general low permeability, and the petrophysical properties of sectionSha 2 fan-delta frontal reservoir is batter than that of section Sha 3 turbidity reservoir at the same depth. Finally, the sedimentrymodel and depositional feature of deep reservoir in west depression, Liaohe Basin has been summarized.
The paper has studied the sedimentary evolution history, depositional system and sedimentary fades of deep reservoir in Liao-he Basin by using sedimentology combining with log facies and seismic facies as well as various reservoir forecasting methods to re-veal the depositional feature and sandbody spatial distribution of deep reservoir bed, analysed the reservoir characteristics of sectionSha 3 turbidite sandbody and Sha 2-Sha 4 fan-delta sandbody, and predicted favorable facies belts. The conclusion of the researchis that sublacustrine fan reservoir is of a little high porosity and general low permeability, and the petrophysical properties of sectionSha 2 fan-delta frontal reservoir is batter than that of section Sha 3 turbidity reservoir at the same depth. Finally, the sedimentrymodel and depositional feature of deep reservoir in west depression, Liaohe Basin has been summarized.
1997, 15(S1): 132-137.
Abstract:
40 kerogen samples were collected from 12 regions ( basins) in China. Three of them have been heated for 40 hours at 8 differ-ent temperatures from 250℃ to 700℃.respectively. And 24 heated kerogen samples have been obtained. All these 64 kerogensamples were analysed for their carbon isotopic compositions and 50 of them were analysed for their hydrogen isotopic compositionsA few of the samples were analysed for the C, H, O, N elemental compositions. The carbon isotope compositions of the analysedkerogens range from -23. 0 to -31.2‰(PDB), the hydrogen isotopic compositions of the kerogens range from -94 to-159‰(SMOW ).The research indicated that: 1 .in the terrestrial depositional environments, the carbon isotope composition of kerogenis mainly controlled by the types of kerogen, i. e. the sapropelic type of kerogen has lighter carbon isotope composition (13C<-28.0‰ ) , and the humic type of kerogen has heavier carbon isotope composition ( 13C> -26.0‰) , and the sapropelic-humic or hu-mic-sapropelic types of kerogens have the carbon isotope compositions ranging from -26. 0 to -28. 0‰.2. The effect of the thermalmaturation on the carbon isotope composition of kerogen is not obvious in the oil and gas generation maturation stage. On the con-trary, the H/C atomic ratio of kerogen decreases with the increasing maturity of source rocks. Consequently, in the higher thermalmaturation stage, the carbon isotope composition of kerogen is more effective than the H/C atomic ratio of kerogen to differentiatethe types of kerogens. 3. The hdyrogen isotope composition of kerogen mainly reflects the salinity of the depositional medium inwhich the source rocks were deposited. The kerogens of the source rocks deposited in the fresh water environments have the hydro-gen isotope compositions lighter than-130‰, and the kerogens of the source rocks deposited in the brackish to salt water environ-menu have the hydrogen isotope compositions heavier than-130‰
40 kerogen samples were collected from 12 regions ( basins) in China. Three of them have been heated for 40 hours at 8 differ-ent temperatures from 250℃ to 700℃.respectively. And 24 heated kerogen samples have been obtained. All these 64 kerogensamples were analysed for their carbon isotopic compositions and 50 of them were analysed for their hydrogen isotopic compositionsA few of the samples were analysed for the C, H, O, N elemental compositions. The carbon isotope compositions of the analysedkerogens range from -23. 0 to -31.2‰(PDB), the hydrogen isotopic compositions of the kerogens range from -94 to-159‰(SMOW ).The research indicated that: 1 .in the terrestrial depositional environments, the carbon isotope composition of kerogenis mainly controlled by the types of kerogen, i. e. the sapropelic type of kerogen has lighter carbon isotope composition (13C<-28.0‰ ) , and the humic type of kerogen has heavier carbon isotope composition ( 13C> -26.0‰) , and the sapropelic-humic or hu-mic-sapropelic types of kerogens have the carbon isotope compositions ranging from -26. 0 to -28. 0‰.2. The effect of the thermalmaturation on the carbon isotope composition of kerogen is not obvious in the oil and gas generation maturation stage. On the con-trary, the H/C atomic ratio of kerogen decreases with the increasing maturity of source rocks. Consequently, in the higher thermalmaturation stage, the carbon isotope composition of kerogen is more effective than the H/C atomic ratio of kerogen to differentiatethe types of kerogens. 3. The hdyrogen isotope composition of kerogen mainly reflects the salinity of the depositional medium inwhich the source rocks were deposited. The kerogens of the source rocks deposited in the fresh water environments have the hydro-gen isotope compositions lighter than-130‰, and the kerogens of the source rocks deposited in the brackish to salt water environ-menu have the hydrogen isotope compositions heavier than-130‰
1997, 15(S1): 142-146.
Abstract:
23 clastic sediments were treated with 6 steps of sequential extraction in 91-Ⅳ4 core of Qarhan Salt Lake, the proportion of9 kinds of element in 6 geochemical phases indicates; remain fraction>carbonate phase>moderate reducible phase, easy reduciblephase>excangeable fraction>organic fraction; the distribution law of each element in 91-Ⅳ4 core reflects the climate conditionswhen sediments formed.
23 clastic sediments were treated with 6 steps of sequential extraction in 91-Ⅳ4 core of Qarhan Salt Lake, the proportion of9 kinds of element in 6 geochemical phases indicates; remain fraction>carbonate phase>moderate reducible phase, easy reduciblephase>excangeable fraction>organic fraction; the distribution law of each element in 91-Ⅳ4 core reflects the climate conditionswhen sediments formed.
1997, 15(S1): 152-156.
Abstract:
In this paper, Organic geochemistry of sinking material of the atmosphere and airborne particulates in Lanzhou was studied.The result show that sinking materal of the atmosphere in L.anzhou contain higher organic matter. n-Alkanes in sinking materat,with low odd-over-even predominance, are dominated by short chain component. Saturated n-fatty acids in sinking materaland airborne particulates have a strong even-over-odd predominance and short saturated n-fatty acids are major component.Unsaturated and iso-fatty acids are present in low abundance. Distuibution of n-alkanes and fatty acid indicate that organic mat-ter in sinking material of the atmosphere and airborne patricuiates in Lanzhou are derived mainly from fossil fuel contamination andpartly from vascular plants and mieroorganisms
In this paper, Organic geochemistry of sinking material of the atmosphere and airborne particulates in Lanzhou was studied.The result show that sinking materal of the atmosphere in L.anzhou contain higher organic matter. n-Alkanes in sinking materat,with low odd-over-even predominance, are dominated by short chain component. Saturated n-fatty acids in sinking materaland airborne particulates have a strong even-over-odd predominance and short saturated n-fatty acids are major component.Unsaturated and iso-fatty acids are present in low abundance. Distuibution of n-alkanes and fatty acid indicate that organic mat-ter in sinking material of the atmosphere and airborne patricuiates in Lanzhou are derived mainly from fossil fuel contamination andpartly from vascular plants and mieroorganisms
