1990 Vol. 8, No. 1
column
Display Method:
1990, 8(1): 3-17.
Abstract:
The stalble isotope composition of primary fluid inclusions in a crystal represents the isotopic composition of the liquid in which that crystal formed. By studying the isotope composition of the primary fluid inclusions in evaporite minerals from ancient lake deposits, we can explore the history of ancient salt lakes. An analysis of the hydrogen and oxygen isotopic ratios of primary halite fluid inclusions was conducted in a long core, (about 47m) on the north shore of Dabusun Lake, Charhan saline pan, Qaidem basin, China.Brine samples were also collected in the vicinity of Dabusun lake. An analytical method suitable for micro-water samples, including fluid inclusions (typically less than 8 mg) has been established.The method involves reaction of water with zinc to produce H2and water with guanidinc hydrochloride to produce CO2. The standard deviation of the guanidine hydrochloride method is ± 0.15- ± 0.30‰ in water samples and ± 0.61‰ in samples from fluid inclusions.The standard deviation of the zinc method for fluid inclusion samples is ± 4.8‰. The texture of halite and the stable isotopic relationships of primary halite fluid inclusions in a long core show that the history of Charhan Lake (from about 50, 000 years ago to now) can be divided into 3 evolution periods with different salt- forming environments: the relatively stable desiccation period (50, 000-30, 000a.B.P), the fluctuation desiccation period with low temperature (30, 000-15, 000 a.B.P.) and the fluctuation desiccation period with temperture increasing (from 15, 000 a.B.P. to now) For all three periods there appear to have been minor fluctuations between fresh and saline water, the lake never became dried, but there appear to have been sudden changes on salt-florming environment between these periods. Modern Dabusun Lake originated as a dissolution lake, like the newborn (1967) West Dabusun Lake, however, Dabusun Lake is concentrataed enough to form potash salts on its northern shore.The water supply to the modern Charhan saline pan is dominated by meteoric water (mainly from the Kunlun Mountains to the south), however, smaller amounts of oil field brines do flow to the surface along the north edge of the Charhan saline pan.
The stalble isotope composition of primary fluid inclusions in a crystal represents the isotopic composition of the liquid in which that crystal formed. By studying the isotope composition of the primary fluid inclusions in evaporite minerals from ancient lake deposits, we can explore the history of ancient salt lakes. An analysis of the hydrogen and oxygen isotopic ratios of primary halite fluid inclusions was conducted in a long core, (about 47m) on the north shore of Dabusun Lake, Charhan saline pan, Qaidem basin, China.Brine samples were also collected in the vicinity of Dabusun lake. An analytical method suitable for micro-water samples, including fluid inclusions (typically less than 8 mg) has been established.The method involves reaction of water with zinc to produce H2and water with guanidinc hydrochloride to produce CO2. The standard deviation of the guanidine hydrochloride method is ± 0.15- ± 0.30‰ in water samples and ± 0.61‰ in samples from fluid inclusions.The standard deviation of the zinc method for fluid inclusion samples is ± 4.8‰. The texture of halite and the stable isotopic relationships of primary halite fluid inclusions in a long core show that the history of Charhan Lake (from about 50, 000 years ago to now) can be divided into 3 evolution periods with different salt- forming environments: the relatively stable desiccation period (50, 000-30, 000a.B.P), the fluctuation desiccation period with low temperature (30, 000-15, 000 a.B.P.) and the fluctuation desiccation period with temperture increasing (from 15, 000 a.B.P. to now) For all three periods there appear to have been minor fluctuations between fresh and saline water, the lake never became dried, but there appear to have been sudden changes on salt-florming environment between these periods. Modern Dabusun Lake originated as a dissolution lake, like the newborn (1967) West Dabusun Lake, however, Dabusun Lake is concentrataed enough to form potash salts on its northern shore.The water supply to the modern Charhan saline pan is dominated by meteoric water (mainly from the Kunlun Mountains to the south), however, smaller amounts of oil field brines do flow to the surface along the north edge of the Charhan saline pan.
1990, 8(1): 28-34.
Abstract:
The Qigufield is located in the depression formed during the Jurassic period and in the southern ma -gin of the Junggar basin. Usually the vitrinite content is the most in macerals of coal and dark mudstonc but the exinite content is more than 20% in the two coalbed, the matrix vitrinite enriching hydrogen s principal in the vitrinite group, which is of great advantage to liquid hydrocarbon being generated in coal measure strata of the depression. The (S1+S2) values analyzed by Rock Eval range from 130 to 164 mg/ g in the gas coal and 99.25% mg/ g in the brown coal from the Xishanyao group (J2x), and those values range between 72:6 and 99.7 mg / g in the dark mudstonc from the Badaowan group (J1b) . They suggest that both coal and mudstone have a better oil-generated productivity. The brown coal (J2x) en -riches vitrinite as high as 90.37% in Sikcshu, Wushu, from the thermoanalogue- change illustration, it can be seen that the oil flow out when R ° values are 0.45 to 1.2%, and the highest peak generated oil is at the stage of R ° ranging from 0.8 to 0.9%., this shows that the vitrinite can not only generate gas but also is a better source material. Generally the content of organic matter from the Jurassic system is less, than 30% in the southern margin of the Junggar basin, and the dcpositional thickness of mudstone is very great, which shows that the potentiality of hydrocarbon generation is high. The vitrinite still dominates in mudstones, and the exinite content reaches 30% and over in macerals of some mudstone, and therefore the dark mudstone of the Jurassic system also is a better oil-generated source material. Judged by the distribution characteristics of biomarkcrs, the crude oil of Qigufield is related to coat and dark mudstone from Xishanyao (J2x) and Badaowan (J1b) group, and the crude oil belong to coal-type oil. The richer C19 to C20 abietic, pimaric tricyclic diterpane and phyllocladane tetracyclic diterpane compounds are detected, which suggests the input of richer terrigenous higher plant. Besides C27 to C32 pentacyclic triterpenoids are also inspected in the crude oil and source rock, and the abundance of 17α (H) 21 β (H) - hopane is the highest in them. The Qigu crude oil is also similar to the Jurassic mudstone in the sterane distribution characteristics, the C29- stigmastane is dominant, C28-ergostane content is low, C27- cholestane is trace, and their distribution concentrates on the same area in the triangular diagram. A series of C27, C29, C30 8.14-secohopane is also determined in the crude oil, they are the products which thermodynamic affect leads the fragile C8-14bond of hopane skeleton to be opened. This series of biomarker is also derived from coal measure strata. Compared the carbon isotopic composition of the coal, mudstone and crude oil, the δ~13C is -24.7 to -32.3‰, -26.6 to -36.5‰ and -25.5 to -29.9‰ respectively. They have a better consistent. On the basis of study on the values of Σ diasterane / Σ sterane, C29α α αS / R+S, C31αβS / S+R, T3/ Tm, OEP and R ° in source rock and crude oil, authors know that petroleum is generated at the low-mature stage of diagenetic process.
The Qigufield is located in the depression formed during the Jurassic period and in the southern ma -gin of the Junggar basin. Usually the vitrinite content is the most in macerals of coal and dark mudstonc but the exinite content is more than 20% in the two coalbed, the matrix vitrinite enriching hydrogen s principal in the vitrinite group, which is of great advantage to liquid hydrocarbon being generated in coal measure strata of the depression. The (S1+S2) values analyzed by Rock Eval range from 130 to 164 mg/ g in the gas coal and 99.25% mg/ g in the brown coal from the Xishanyao group (J2x), and those values range between 72:6 and 99.7 mg / g in the dark mudstonc from the Badaowan group (J1b) . They suggest that both coal and mudstone have a better oil-generated productivity. The brown coal (J2x) en -riches vitrinite as high as 90.37% in Sikcshu, Wushu, from the thermoanalogue- change illustration, it can be seen that the oil flow out when R ° values are 0.45 to 1.2%, and the highest peak generated oil is at the stage of R ° ranging from 0.8 to 0.9%., this shows that the vitrinite can not only generate gas but also is a better source material. Generally the content of organic matter from the Jurassic system is less, than 30% in the southern margin of the Junggar basin, and the dcpositional thickness of mudstone is very great, which shows that the potentiality of hydrocarbon generation is high. The vitrinite still dominates in mudstones, and the exinite content reaches 30% and over in macerals of some mudstone, and therefore the dark mudstone of the Jurassic system also is a better oil-generated source material. Judged by the distribution characteristics of biomarkcrs, the crude oil of Qigufield is related to coat and dark mudstone from Xishanyao (J2x) and Badaowan (J1b) group, and the crude oil belong to coal-type oil. The richer C19 to C20 abietic, pimaric tricyclic diterpane and phyllocladane tetracyclic diterpane compounds are detected, which suggests the input of richer terrigenous higher plant. Besides C27 to C32 pentacyclic triterpenoids are also inspected in the crude oil and source rock, and the abundance of 17α (H) 21 β (H) - hopane is the highest in them. The Qigu crude oil is also similar to the Jurassic mudstone in the sterane distribution characteristics, the C29- stigmastane is dominant, C28-ergostane content is low, C27- cholestane is trace, and their distribution concentrates on the same area in the triangular diagram. A series of C27, C29, C30 8.14-secohopane is also determined in the crude oil, they are the products which thermodynamic affect leads the fragile C8-14bond of hopane skeleton to be opened. This series of biomarker is also derived from coal measure strata. Compared the carbon isotopic composition of the coal, mudstone and crude oil, the δ~13C is -24.7 to -32.3‰, -26.6 to -36.5‰ and -25.5 to -29.9‰ respectively. They have a better consistent. On the basis of study on the values of Σ diasterane / Σ sterane, C29α α αS / R+S, C31αβS / S+R, T3/ Tm, OEP and R ° in source rock and crude oil, authors know that petroleum is generated at the low-mature stage of diagenetic process.
1990, 8(1): 44-56.
Abstract:
The distributing law, contralling factors and source of Fe, Mn, Cu, Co, Ni, Pb, Zn, Cr, Mg, Ca, Al, Ti, K, Sr, Na, Corg. Si, N in 28 stations sediments were described in detail by the study method of the mathematical geology based of the data obtained during the second oceanic survey of the ferromanganse, nodules from the Pacific North region (7°-165° W), Main results are as follow: 1. There are characteristics for the abundance of chemical elements in sediments of study area as follow: a) .Major elements Si, Mg, N are similar and the trace elements Mn, Cu, Co, Ni, Zn and Ca are obviously enrichment, and Te, Al, Cr, Ti and Corg are poorer than that of the earth's crust, clay of the coast and the sediments of continental shelf. b) .Si, Al, Fe, Zn, K, Cr, Pb, Ti and N arc similar, and Mn, Cu, Co, Ni and Ca are obviously enrichment too, and Corg is poorer than that in sediments of the half deep sea and the ocean of the poor fcrromanganese nodules. c) .The content of Si, Al, K, Na, Mg, Ca and Cr in sediment arc obviously higher, and the trace elements Fe, Mn, Cu, Co, Ni, Pb and Sr, Ti are 1-2 quantity stager lower than that in ferromanganese nod nodules. d) .Mn, Cu, Co, Ni, in sediments are obviously enrichment and increased and the organic carbon is decreased, and the major elements are similar in the order of estuary-continental shelf-half deep sea - area of the poor fcrromanganese nodules- area of the enrichment ferromanganese nodules— ferromanganese nodules. 2.The distribution law of the elements in the surface sediment is similar for Fe, Mn, Cu, Co, Ni, Zn and K, Al, Ti their content in calcsiliceous ooze is lower than that in brown clay and siliceouse ooze, relatively, the content of elements in brown clay is higher than others.The distribution trend of Corg.N, Si and Na. are in agreement with the trace elements of Fe, Mn, but their content df elements in biological sediments is higher than that in brown and calcsiliceous ooze and the content elements in calcsiliceous ooze is lowest than others.The distribution of Ca, Sr and opposition with Fc, Corg.and the content of elemtnts in calcsilicenus is higher than that in brown clay and siliceous ooze. 3.The result of factor analysis shows that the distribution of elements in study area mainly is controlled by the three factors, that is ; 1) the adsorption of clay and colloid of the hydrate of Mn, Fe oxides; 2) the authigenic sedimentation of the processe of the biochemistry; 3) voicanism near to the strdy area and shale weathering in floor. The relationship between factors and elements indicates that Fe, Mn, Cu, Co, Ni, Zn, Cr and Mg, Al, Ti, K, mainly came from adsorption of clay; Corg.N, Sr, Na and Si, Ca, Sr mainly came from the sedimenation of processes of biochemistry; Pb mainly came from the calastic rook (volcanic clastic) and biological clastic.
The distributing law, contralling factors and source of Fe, Mn, Cu, Co, Ni, Pb, Zn, Cr, Mg, Ca, Al, Ti, K, Sr, Na, Corg. Si, N in 28 stations sediments were described in detail by the study method of the mathematical geology based of the data obtained during the second oceanic survey of the ferromanganse, nodules from the Pacific North region (7°-165° W), Main results are as follow: 1. There are characteristics for the abundance of chemical elements in sediments of study area as follow: a) .Major elements Si, Mg, N are similar and the trace elements Mn, Cu, Co, Ni, Zn and Ca are obviously enrichment, and Te, Al, Cr, Ti and Corg are poorer than that of the earth's crust, clay of the coast and the sediments of continental shelf. b) .Si, Al, Fe, Zn, K, Cr, Pb, Ti and N arc similar, and Mn, Cu, Co, Ni and Ca are obviously enrichment too, and Corg is poorer than that in sediments of the half deep sea and the ocean of the poor fcrromanganese nodules. c) .The content of Si, Al, K, Na, Mg, Ca and Cr in sediment arc obviously higher, and the trace elements Fe, Mn, Cu, Co, Ni, Pb and Sr, Ti are 1-2 quantity stager lower than that in ferromanganese nod nodules. d) .Mn, Cu, Co, Ni, in sediments are obviously enrichment and increased and the organic carbon is decreased, and the major elements are similar in the order of estuary-continental shelf-half deep sea - area of the poor fcrromanganese nodules- area of the enrichment ferromanganese nodules— ferromanganese nodules. 2.The distribution law of the elements in the surface sediment is similar for Fe, Mn, Cu, Co, Ni, Zn and K, Al, Ti their content in calcsiliceous ooze is lower than that in brown clay and siliceouse ooze, relatively, the content of elements in brown clay is higher than others.The distribution trend of Corg.N, Si and Na. are in agreement with the trace elements of Fe, Mn, but their content df elements in biological sediments is higher than that in brown and calcsiliceous ooze and the content elements in calcsiliceous ooze is lowest than others.The distribution of Ca, Sr and opposition with Fc, Corg.and the content of elemtnts in calcsilicenus is higher than that in brown clay and siliceous ooze. 3.The result of factor analysis shows that the distribution of elements in study area mainly is controlled by the three factors, that is ; 1) the adsorption of clay and colloid of the hydrate of Mn, Fe oxides; 2) the authigenic sedimentation of the processe of the biochemistry; 3) voicanism near to the strdy area and shale weathering in floor. The relationship between factors and elements indicates that Fe, Mn, Cu, Co, Ni, Zn, Cr and Mg, Al, Ti, K, mainly came from adsorption of clay; Corg.N, Sr, Na and Si, Ca, Sr mainly came from the sedimenation of processes of biochemistry; Pb mainly came from the calastic rook (volcanic clastic) and biological clastic.
1990, 8(1): 65-78.
Abstract:
Tonstem, Pianhnite and purple Kaolinite occur as intercalithes in the coal seams m the north area of Shanxi province and its neighbouring areas of the south area of Inner Mongolia and the east area of Shanxi province. The three kinds of clay rock intercalith are always located in the same horizon or the similar horizon, or closely associated with each other.They are all formed in swamp environment. Moreover the author considers that they are not only different in their source material but also in the pH value of water of the swamp in which they were deposited. In the north area of Shanxi province coal seam of Lower Permian-Upper Carboniferous can be divided into 1-9 layers from top to bottom which are often intercalated with tonstein. There are two opinion about the genesis of tonstein. One considers that it is formed by sedimentation of the-weathered-and-water-transported-materials of geneses and mediate acidic igneous rocks on the Paleo-continent near by .The other maintains that volcanic elastics is dropped into swamp and dissolved by water and. kaolinized by easyly seperatng out the dissolved elements to form as tonstein. Here the author holds another opinion, i.e., some tonstein are formed by colloid precipitation with ordering well and high crystalic coeficient Kaolinite and relics of high temperature quartz and sanidine which indicate the dominating of volcanic elastics over the terrestrial elastics in their source material. On the contrary the terrestrial elastics dominated tonstein (at the bottom of No 9 coal layer of the north area of Shanxi province) contain more or less clastic materials, such as sandy and silts quartz and microline and colloid clay particles. No high temperature quartz and sanidine are contained. And the former is pure, always intercalated in the middle of a coal layer. The later are not so pure and always occur as hanging or foot wall of a coal layer with a few exception. Pianlinite (A12O3 · 2SiO2H2O) is the other intercalith in coal seam in the north area of Shanxi province whose horizon corresponds to No 4 coal layer. It occurs as single layer or multi-layers. The author (1963) pointed out that it was formed by the alternating precipitation of SiO2and A12O3 in which prysmatic-low-temperature-euhedral-quartz could be seen. During diagenesis colloid water was squeezed out and the precipitates began to transform to meta-crystalized minerals of pianlinite then recry talized, possibly through allophane mage The formation condition of pianlinite is different from that of kaolinite lying n (I) p- I value of the swamp water: (2) the fine source material particle. The-weathered-fine-terrestrial-material, such as aphanilic and colloid clay transported by water to or the -erupted-fine-volcanic clastic-materials, such as vitreous elasties and crystal elastics dropped into strong acidic swamp (pH4) would be dissolved. When PH rised to 4.8 5 precipitates of A12O3 : SiO2 = 1 : 2 would be formed which turned to pianlinite throng allophane stage by gradually squeering out colloid water (allophane turned p(?) can be seen in Hun yuan area) during diagenesis. In resent years some geologists argue that such pianlinite and kaolonite rock (?) the natural burning of coal layer. Bui piamlinite and meta-kaolinite are different in ther propen Especially the organic materatin the dark pianlinite rock are oxidized at 325℃ white (?) of kaolinite takes place above 500℃ . Therefore organic material can not remain after (?) dewater ing In addition, enough oxygen is needed to cause coal-burning which can only appears abou the ground surface and surfaces in shaft because of the access of air The author, found Pranlini in Chaihe mining aren at the depth of 40m underground where no fractures could be seen and m-association of coal layer and pianlinile layer could be seen. And low-temperature- arysmatic dihedral-quartz was found with it All this menuened above make sure that pianlinite is no formed by the naturally burned coat. Purple kaolinite rock is mainly associated with No.4 coal layer of Shanxi Formation No 9 coal,ayer of the Talyuan Formition. There are two opmicsns about itls genesis(1)formeby primary scdimentation. (2) formed by weathering and residoal accumulaton the weathcrrng of coal. The author agrees with the two opinion but heconsiders that forme，also relatcd to organac acid leaching, recrystalization and orderczation of kaoim- tc:and the
Tonstem, Pianhnite and purple Kaolinite occur as intercalithes in the coal seams m the north area of Shanxi province and its neighbouring areas of the south area of Inner Mongolia and the east area of Shanxi province. The three kinds of clay rock intercalith are always located in the same horizon or the similar horizon, or closely associated with each other.They are all formed in swamp environment. Moreover the author considers that they are not only different in their source material but also in the pH value of water of the swamp in which they were deposited. In the north area of Shanxi province coal seam of Lower Permian-Upper Carboniferous can be divided into 1-9 layers from top to bottom which are often intercalated with tonstein. There are two opinion about the genesis of tonstein. One considers that it is formed by sedimentation of the-weathered-and-water-transported-materials of geneses and mediate acidic igneous rocks on the Paleo-continent near by .The other maintains that volcanic elastics is dropped into swamp and dissolved by water and. kaolinized by easyly seperatng out the dissolved elements to form as tonstein. Here the author holds another opinion, i.e., some tonstein are formed by colloid precipitation with ordering well and high crystalic coeficient Kaolinite and relics of high temperature quartz and sanidine which indicate the dominating of volcanic elastics over the terrestrial elastics in their source material. On the contrary the terrestrial elastics dominated tonstein (at the bottom of No 9 coal layer of the north area of Shanxi province) contain more or less clastic materials, such as sandy and silts quartz and microline and colloid clay particles. No high temperature quartz and sanidine are contained. And the former is pure, always intercalated in the middle of a coal layer. The later are not so pure and always occur as hanging or foot wall of a coal layer with a few exception. Pianlinite (A12O3 · 2SiO2H2O) is the other intercalith in coal seam in the north area of Shanxi province whose horizon corresponds to No 4 coal layer. It occurs as single layer or multi-layers. The author (1963) pointed out that it was formed by the alternating precipitation of SiO2and A12O3 in which prysmatic-low-temperature-euhedral-quartz could be seen. During diagenesis colloid water was squeezed out and the precipitates began to transform to meta-crystalized minerals of pianlinite then recry talized, possibly through allophane mage The formation condition of pianlinite is different from that of kaolinite lying n (I) p- I value of the swamp water: (2) the fine source material particle. The-weathered-fine-terrestrial-material, such as aphanilic and colloid clay transported by water to or the -erupted-fine-volcanic clastic-materials, such as vitreous elasties and crystal elastics dropped into strong acidic swamp (pH4) would be dissolved. When PH rised to 4.8 5 precipitates of A12O3 : SiO2 = 1 : 2 would be formed which turned to pianlinite throng allophane stage by gradually squeering out colloid water (allophane turned p(?) can be seen in Hun yuan area) during diagenesis. In resent years some geologists argue that such pianlinite and kaolonite rock (?) the natural burning of coal layer. Bui piamlinite and meta-kaolinite are different in ther propen Especially the organic materatin the dark pianlinite rock are oxidized at 325℃ white (?) of kaolinite takes place above 500℃ . Therefore organic material can not remain after (?) dewater ing In addition, enough oxygen is needed to cause coal-burning which can only appears abou the ground surface and surfaces in shaft because of the access of air The author, found Pranlini in Chaihe mining aren at the depth of 40m underground where no fractures could be seen and m-association of coal layer and pianlinile layer could be seen. And low-temperature- arysmatic dihedral-quartz was found with it All this menuened above make sure that pianlinite is no formed by the naturally burned coat. Purple kaolinite rock is mainly associated with No.4 coal layer of Shanxi Formation No 9 coal,ayer of the Talyuan Formition. There are two opmicsns about itls genesis(1)formeby primary scdimentation. (2) formed by weathering and residoal accumulaton the weathcrrng of coal. The author agrees with the two opinion but heconsiders that forme，also relatcd to organac acid leaching, recrystalization and orderczation of kaoim- tc:and the
1990, 8(1): 91-97.
Abstract:
The Permian of Talimu basin is one of the important layers to explore and develop oil and gas. Sard-stone is the most important reservoir rocks of oil and gas. By means of researching the feature of dia'gencsis of sandstone, we can probe into the evolutionary trend and distributive law of the pore Then, it may effectively guide us to explore and develop oil and gas. The Permian of Keping area in Xinjiang extensively shows the Lower Permian. The principal pan of the Lower Permian is a series of miscellaneous colour fragmentary rocks, and is a transitional sediment that contains intermittently marine layer. There was volcanic activity (basait). Before our researches, the sedimentary environment and facics of sandstone-this scries of miscc ia-neous colour fragmentary rocks of continental origin-had been researched by some people. Bui ihc diagenesis and secondary pores have not been done so far. We have been studying on sedimentary fanes and diagenesis and secondary pores of the layers by fieldwork, ' flakes of rock, colouration, grain-size, scanning electron microscope studies, cathodlumineccnce, X- ray diffraction analysis, etc. The phenomena of diagensis observed includes 1) dolomitization of aqualotysis; 2) cementation of early-calcite; 3) compaction and pressolution; 4) replacement; 5) formation of self-precipitation clay mineral; 6) corrosion of feldspar; 7) secondary and overgrowth quartz and feldspar, 8) filling of hydrocarborn; 9) dissolution indeep subground; 10) filling of dolomite and ferrodolomite; etc. The principle, feature, evolutionary order and its relation of diagenesis has been analysed and discussed in detail. Based on it we built a simple and ideal history of diagenesis. By the stueies of deagensis, we predict distributive law of undergroundporc and point out six ma ks to distinguish second arypores. The author divided roughly five types of secondary pores according to he contributing factors. It is concluded that 1), dissolution of calcareous cement; 2), dissolution and corrosion of replatement mineral; 3), dissolution of feldspar; 4), change of clay mineral; 5), fragmentation. The form, relative content and evolution of the secondary pores arc analysed and described. And it is shownwith the figures and tables. The author consider, on the basis of the sedimentation, that the diagenesis (The primary facto is the dissolution) is the most important affect in the formation of the secondary porein sand bodies. Ml that we do, to a certain extent, has guidable significance to explore and develop oi! and gas. In he meantime, we set forth our views that how to divide the sedimentary facies of the series of layer.
The Permian of Talimu basin is one of the important layers to explore and develop oil and gas. Sard-stone is the most important reservoir rocks of oil and gas. By means of researching the feature of dia'gencsis of sandstone, we can probe into the evolutionary trend and distributive law of the pore Then, it may effectively guide us to explore and develop oil and gas. The Permian of Keping area in Xinjiang extensively shows the Lower Permian. The principal pan of the Lower Permian is a series of miscellaneous colour fragmentary rocks, and is a transitional sediment that contains intermittently marine layer. There was volcanic activity (basait). Before our researches, the sedimentary environment and facics of sandstone-this scries of miscc ia-neous colour fragmentary rocks of continental origin-had been researched by some people. Bui ihc diagenesis and secondary pores have not been done so far. We have been studying on sedimentary fanes and diagenesis and secondary pores of the layers by fieldwork, ' flakes of rock, colouration, grain-size, scanning electron microscope studies, cathodlumineccnce, X- ray diffraction analysis, etc. The phenomena of diagensis observed includes 1) dolomitization of aqualotysis; 2) cementation of early-calcite; 3) compaction and pressolution; 4) replacement; 5) formation of self-precipitation clay mineral; 6) corrosion of feldspar; 7) secondary and overgrowth quartz and feldspar, 8) filling of hydrocarborn; 9) dissolution indeep subground; 10) filling of dolomite and ferrodolomite; etc. The principle, feature, evolutionary order and its relation of diagenesis has been analysed and discussed in detail. Based on it we built a simple and ideal history of diagenesis. By the stueies of deagensis, we predict distributive law of undergroundporc and point out six ma ks to distinguish second arypores. The author divided roughly five types of secondary pores according to he contributing factors. It is concluded that 1), dissolution of calcareous cement; 2), dissolution and corrosion of replatement mineral; 3), dissolution of feldspar; 4), change of clay mineral; 5), fragmentation. The form, relative content and evolution of the secondary pores arc analysed and described. And it is shownwith the figures and tables. The author consider, on the basis of the sedimentation, that the diagenesis (The primary facto is the dissolution) is the most important affect in the formation of the secondary porein sand bodies. Ml that we do, to a certain extent, has guidable significance to explore and develop oi! and gas. In he meantime, we set forth our views that how to divide the sedimentary facies of the series of layer.
1990, 8(1): 106-114.
Abstract:
Bohai Bay basin was apparently influenced by the oceanic climate due to the pacific Ocean' s progressing to China' s continent in Eogenc.Dongpu Depression in the basin had a subtropical climate, and was not far from the Pacific.Thus the powerful storm from the Pacific used to attack the area.At the same time, Dongpu Depression was a large open lake with gentle toporgraphy and the developed delta and shore beaches, which helped form storm flow and its deposits. Storm deposit or tcmpcstitc in the study area can be identified by: (1) abrupt top and sole contact, (2) wave-produced beddings, (3) low maturity in composition and relatively high naturity in texture, (4) biological Fodinichia and Fugichnia, (5) Bouma-like succession, and (6) abundant resedimented intrabasinal components. As a complete system, storm-flow dcpositional system consists of provenance facies, storm facies and turbidite one.Provenance lacies rclers to the beach and/ or delta supplying the storm now with suth-cicnt sandy source.The storm sedimentation facies, located between fair-weather (littoral lake) wave base and that of storm, can be subdivided into two units, proximal subfacies characterized by Sa, Sb and Sc in Bouma-like sequence and distal subfacies with Sabc and Sdc and lower sand / shale ratio.Storm waves were not available below the wave base of storm, where the unloading of storm-underflow formed deep-water storm-generated turbidite.It seems that the storm deposition followed the following ru es: (1) tempestite developed in the middle of the lake-regressive sequence during the evolution of the basm; (2) tempestite is intcrbcdcd with non-tempestite and takes a smaller proportion in strata records; and (3) storm deposit is surrounded by acltas and/ or beaches onshore and by turbidites (flood-formed) offshore. The discovery of ancient storm deposit is of great significance.Oscillation ripples common in pestite have been used to evaluate paleobathymetry quantitatively.As a result, the fair-weather wave base is about 5m, and the storm one around 15m.And what is more important is that tempestite in the area acts as type of reservior. It is further concluded that tempestite might be widely spread in the near-sea lake basins of coastal lake basins, for example, the Eogenc of Bohai Bay basin.
Bohai Bay basin was apparently influenced by the oceanic climate due to the pacific Ocean' s progressing to China' s continent in Eogenc.Dongpu Depression in the basin had a subtropical climate, and was not far from the Pacific.Thus the powerful storm from the Pacific used to attack the area.At the same time, Dongpu Depression was a large open lake with gentle toporgraphy and the developed delta and shore beaches, which helped form storm flow and its deposits. Storm deposit or tcmpcstitc in the study area can be identified by: (1) abrupt top and sole contact, (2) wave-produced beddings, (3) low maturity in composition and relatively high naturity in texture, (4) biological Fodinichia and Fugichnia, (5) Bouma-like succession, and (6) abundant resedimented intrabasinal components. As a complete system, storm-flow dcpositional system consists of provenance facies, storm facies and turbidite one.Provenance lacies rclers to the beach and/ or delta supplying the storm now with suth-cicnt sandy source.The storm sedimentation facies, located between fair-weather (littoral lake) wave base and that of storm, can be subdivided into two units, proximal subfacies characterized by Sa, Sb and Sc in Bouma-like sequence and distal subfacies with Sabc and Sdc and lower sand / shale ratio.Storm waves were not available below the wave base of storm, where the unloading of storm-underflow formed deep-water storm-generated turbidite.It seems that the storm deposition followed the following ru es: (1) tempestite developed in the middle of the lake-regressive sequence during the evolution of the basm; (2) tempestite is intcrbcdcd with non-tempestite and takes a smaller proportion in strata records; and (3) storm deposit is surrounded by acltas and/ or beaches onshore and by turbidites (flood-formed) offshore. The discovery of ancient storm deposit is of great significance.Oscillation ripples common in pestite have been used to evaluate paleobathymetry quantitatively.As a result, the fair-weather wave base is about 5m, and the storm one around 15m.And what is more important is that tempestite in the area acts as type of reservior. It is further concluded that tempestite might be widely spread in the near-sea lake basins of coastal lake basins, for example, the Eogenc of Bohai Bay basin.
1990, 8(1): 115-121.
Abstract:
Recently, carbonate tcmpstitcs have been discorvcry in some places of China .This paper will report terrigenous clastic tcmpcstitcs. Sedimentary structures of the Prccambrian trrigenous tcmpestitcs in Banbiansham, Taojiang arc Very clear. They arc charactcrizd by humorcky cross- stratification, differential stratification, rhythmic stratificalion and special bedding plane structure. Eight grade A rhythms that consist of massive beds and rhythmites may be divided in the section.The massive beds which arc more than 2 meters thick at the must tnd 0.5 meters at the least consist of argillic siltstone. there are some breccias arc sandstone and argilhte with complicated curved shapes.The massive bed was formed during a heavystorm stage——Original sed- iments were croded into different size by the storm flow then they were sedimcntatcd again. The rhymic beds may be subdivided into a lot of B grade rhythms which consitc of andstone and urgillite.Thc grade B rhythms is less than 20 centimeters.There arc cnvident eroded marks of under-water conditions between two rhythms.The rhythmitc is the result ofaltcrnate sedimentation during hghtcrstorm weather and fair weather stages. According to the sedimentary structures, from lower to upper, the eight A grade rhythms arc subdivided into slope storm turbidity cruucnt outcrshclf storm clastic How and shclf storm clastic flow deposits 1.The slope storm turbidity current deposit belongs to a low-density current one, it is characterized by convolute bedding and humorky crossstratification of landslip type, unstable rhythmis stratificatien lighter bottom erosion marks and by changeable factors in vertical sequence. 2. The outer- shelf storm clastic flow deposit belongs to a distal tempestite, Hummocty cross-stratifications in it arc commoner.and erosion marks between the rhythms are clear. 3.The shelf clastic flow deposit belongs to a proximal tempestitc.It is characterized by very common guuer casts with 16 cm high at the most on the bottom surface large ripple marks on the top surface, differential stratifications and hummocky cross-stratifications arc when developed. !n addition, some penecontemporancous structures such as convolute bedding, flame structure, primary fault and contemporaneous breccias arc common in the tempestites, although they are not typical of tempcstite.
Recently, carbonate tcmpstitcs have been discorvcry in some places of China .This paper will report terrigenous clastic tcmpcstitcs. Sedimentary structures of the Prccambrian trrigenous tcmpestitcs in Banbiansham, Taojiang arc Very clear. They arc charactcrizd by humorcky cross- stratification, differential stratification, rhythmic stratificalion and special bedding plane structure. Eight grade A rhythms that consist of massive beds and rhythmites may be divided in the section.The massive beds which arc more than 2 meters thick at the must tnd 0.5 meters at the least consist of argillic siltstone. there are some breccias arc sandstone and argilhte with complicated curved shapes.The massive bed was formed during a heavystorm stage——Original sed- iments were croded into different size by the storm flow then they were sedimcntatcd again. The rhymic beds may be subdivided into a lot of B grade rhythms which consitc of andstone and urgillite.Thc grade B rhythms is less than 20 centimeters.There arc cnvident eroded marks of under-water conditions between two rhythms.The rhythmitc is the result ofaltcrnate sedimentation during hghtcrstorm weather and fair weather stages. According to the sedimentary structures, from lower to upper, the eight A grade rhythms arc subdivided into slope storm turbidity cruucnt outcrshclf storm clastic How and shclf storm clastic flow deposits 1.The slope storm turbidity current deposit belongs to a low-density current one, it is characterized by convolute bedding and humorky crossstratification of landslip type, unstable rhythmis stratificatien lighter bottom erosion marks and by changeable factors in vertical sequence. 2. The outer- shelf storm clastic flow deposit belongs to a distal tempestite, Hummocty cross-stratifications in it arc commoner.and erosion marks between the rhythms are clear. 3.The shelf clastic flow deposit belongs to a proximal tempestitc.It is characterized by very common guuer casts with 16 cm high at the most on the bottom surface large ripple marks on the top surface, differential stratifications and hummocky cross-stratifications arc when developed. !n addition, some penecontemporancous structures such as convolute bedding, flame structure, primary fault and contemporaneous breccias arc common in the tempestites, although they are not typical of tempcstite.
1990, 8(1): 129-132.
Abstract:
The common wavemarks in strata are often deformed under theinfluence of diagenesis and its various later stage factors so that the indentiflcation of wave marks nature becomes difficult. The production of wavemark is controlled by underwater topography as well as sediments size of which argillic silt material is the best. It' s necessary to carefully recognize original wavemarks namely peaks well preserved ones while those which have been reproduced cannot be used to judge and conclude by its deformed peaks and if the base rock on which wavemarks formed is force-pressed. We should pay attation to the effects of tectonis stress exerted on wavemarks.
The common wavemarks in strata are often deformed under theinfluence of diagenesis and its various later stage factors so that the indentiflcation of wave marks nature becomes difficult. The production of wavemark is controlled by underwater topography as well as sediments size of which argillic silt material is the best. It' s necessary to carefully recognize original wavemarks namely peaks well preserved ones while those which have been reproduced cannot be used to judge and conclude by its deformed peaks and if the base rock on which wavemarks formed is force-pressed. We should pay attation to the effects of tectonis stress exerted on wavemarks.
1990, 8(1): 143-147.
Abstract:
The first flume experiment was completed by Gilbert (1914), who studied the sedimentary structures formed under a variety of flow conditions .In the 1960s, the investigations on flume laboratory were conducted extensively, the systematic researech report on flume experiments completede by Simons and Richardson evoked wide repercussion in sedimentary field. In the 1970s, the content of flume study was more extensive and more thorough. Moreover, other sedimentary modelling experiments were conducted too, such as experiments on turbidity currents, wind sedimentation tunnel experiments and windstorm sedimentation experiments. These experiments have pushed the theory of sedimentology forward. In the 1980s, sedimentary simulation experiments were transferred from qualitative into quantitative, from small flume expertiments into big basin modelling experiments. As the development of the theory of sedimentology and the necessity that science theory must be transferred into productive forces, attention on sedimentary simulation experiments should be paid to that the conditions of the experimentmust tend to simulate the natural conditions, the content should be transferred from qualitative and small flume study into quantitative and basin sedimentation system modelling, the purpose should be to bring pure theory into practical application. In 1989, Jianghan Petroleum Institute is planning to establish a big Fluvial- Lake System Sedimentation Modelling Laboratory, which will adopt the advanced scientific and technical system of automatic control, automatic test and measure, automatic operation and processing. The main purpose of the laboratory is to predict quantitatively the distribution, size and properties of sandstone body in terrigenous lake basin after it is completed. Moreover, it can provide sedimentologists with a place to go in for basic study of sedimentology.
The first flume experiment was completed by Gilbert (1914), who studied the sedimentary structures formed under a variety of flow conditions .In the 1960s, the investigations on flume laboratory were conducted extensively, the systematic researech report on flume experiments completede by Simons and Richardson evoked wide repercussion in sedimentary field. In the 1970s, the content of flume study was more extensive and more thorough. Moreover, other sedimentary modelling experiments were conducted too, such as experiments on turbidity currents, wind sedimentation tunnel experiments and windstorm sedimentation experiments. These experiments have pushed the theory of sedimentology forward. In the 1980s, sedimentary simulation experiments were transferred from qualitative into quantitative, from small flume expertiments into big basin modelling experiments. As the development of the theory of sedimentology and the necessity that science theory must be transferred into productive forces, attention on sedimentary simulation experiments should be paid to that the conditions of the experimentmust tend to simulate the natural conditions, the content should be transferred from qualitative and small flume study into quantitative and basin sedimentation system modelling, the purpose should be to bring pure theory into practical application. In 1989, Jianghan Petroleum Institute is planning to establish a big Fluvial- Lake System Sedimentation Modelling Laboratory, which will adopt the advanced scientific and technical system of automatic control, automatic test and measure, automatic operation and processing. The main purpose of the laboratory is to predict quantitatively the distribution, size and properties of sandstone body in terrigenous lake basin after it is completed. Moreover, it can provide sedimentologists with a place to go in for basic study of sedimentology.
1990, 8(1): 19-27.
Abstract:
Fushun oil shale was pyrolysed in Fischer Assay with heating rate of 5℃ / mm to different final temperatures ranged from 400 to 510℃ .The raw oil shale and the pyrolyzed solid residues were extracted by chloroform and demineralized by hydrochloric acid and hydrofluoric acid. The chemical structure of these kerogen concentrates was investigated using the high field (75.46 MHz) solid state C- 13 NMR spectroscopy with cross polarization and magic angle spinning. The Dixon TOSS technique combined with rotor spinning rate of 4 KHz suppressed the aromatic carbon spinning side-bands and provided satisfactory spectra of high resolution and low distortion. In the aliphatic carbon region, the peaks assigned to the terminal methyl carbons ( 14-16 ppm), the aromatic bonded methyl carbons ( 18-20 ppm), the ethelene carbons (28-30 ppm) and the shoulder (35-40 ppm) likely assigned to the alpha methelene or methine carbons bonded to the aromatic rings, are founded to be distinguished distinctly. The resolution of the aromatic carbon region is limited perhaps due to the anisotropy of the aromatic structure. Generally, the high field solid state C-13 NMR (CP / MAS+TOSS) spectroscopy provided a direct method for detecting and measuring the carbon distribution of kerogen. The aliphatic termimal methyl carbon is weakened graduately as the final temperature of degradation is increased, that implies it takes an active part in the oil and gas formation. On the contrary, the aromatic methyl carbons grow up from a shoulder in the original kerogen NMR spectra to a main peak of residue aliphatic carbons for the kerogens which had experienced the high degree thermal degradation. It supports the hypothesis that the beta bond scission is one of the essential reactions in the thermal degradation process. The most dominant resonance band of the original kerogen is the methelene carbons, which consume quickly throughout the process of oil and gas formation, and were depleted as the genaration of oil had finished. The broad band of aromatic carbons becomes a dominent peak in the spectrum as the process is going on. It is found that the yield of aromatic carbon in the whole process of degradation is kept nearly constant. Since the aromatic cluster of the original kerogen had been recognized in the previous studies to be primary composed of 3-5 kata-condensed rings, yet most aromatic components of shale oil have only single and double rings, it reasonable to assume that as the simple aromatics were formed by aromatization of aliphatics, they are rather easy to migrate as components of oil, and merely the intrinsical aromatic carbons were left in the degradated kerogens. It sounds to be an answer that why the conservation of aromatic carbon is not an individual feature in many thermal degradation experiments for different types of kerogens. In general, the aomatic carbons contribute little to the generation of hydrocarbons. Based on the NMR and ultimate analysis data of kerogens, a series of chemical structural parameters had been derived, including apparent carbon aromaticity, average carbon number of methelene groups and ring condensation index. They are correlated with the kelative oil yields of the derogens where the original kerogen oil yield was taken as unit. A straight line is plotted to show the relation between relative oil yields and apparent aliphatic carbon fractions. It intersects with the axis of aliphatic carbon fraction at 0.17, indicates that this portion of aliphatic carbon have not taken part with oil generation. Another straight line plotted with the sum of methelene and terminal methyl carbon fractions instead of the aliphatic carbon fraction reaches the origin point. It means that they are the exact matrix of oil.The relation of relative oil yields and average number of carbon atoms in methelene groups of carbon number larger than 5 possess of high potential in generating oil, and those of less than 3 are insignificant to the oil formation. The curve of ring condensation index evolution path depicts different reaction stages of
Fushun oil shale was pyrolysed in Fischer Assay with heating rate of 5℃ / mm to different final temperatures ranged from 400 to 510℃ .The raw oil shale and the pyrolyzed solid residues were extracted by chloroform and demineralized by hydrochloric acid and hydrofluoric acid. The chemical structure of these kerogen concentrates was investigated using the high field (75.46 MHz) solid state C- 13 NMR spectroscopy with cross polarization and magic angle spinning. The Dixon TOSS technique combined with rotor spinning rate of 4 KHz suppressed the aromatic carbon spinning side-bands and provided satisfactory spectra of high resolution and low distortion. In the aliphatic carbon region, the peaks assigned to the terminal methyl carbons ( 14-16 ppm), the aromatic bonded methyl carbons ( 18-20 ppm), the ethelene carbons (28-30 ppm) and the shoulder (35-40 ppm) likely assigned to the alpha methelene or methine carbons bonded to the aromatic rings, are founded to be distinguished distinctly. The resolution of the aromatic carbon region is limited perhaps due to the anisotropy of the aromatic structure. Generally, the high field solid state C-13 NMR (CP / MAS+TOSS) spectroscopy provided a direct method for detecting and measuring the carbon distribution of kerogen. The aliphatic termimal methyl carbon is weakened graduately as the final temperature of degradation is increased, that implies it takes an active part in the oil and gas formation. On the contrary, the aromatic methyl carbons grow up from a shoulder in the original kerogen NMR spectra to a main peak of residue aliphatic carbons for the kerogens which had experienced the high degree thermal degradation. It supports the hypothesis that the beta bond scission is one of the essential reactions in the thermal degradation process. The most dominant resonance band of the original kerogen is the methelene carbons, which consume quickly throughout the process of oil and gas formation, and were depleted as the genaration of oil had finished. The broad band of aromatic carbons becomes a dominent peak in the spectrum as the process is going on. It is found that the yield of aromatic carbon in the whole process of degradation is kept nearly constant. Since the aromatic cluster of the original kerogen had been recognized in the previous studies to be primary composed of 3-5 kata-condensed rings, yet most aromatic components of shale oil have only single and double rings, it reasonable to assume that as the simple aromatics were formed by aromatization of aliphatics, they are rather easy to migrate as components of oil, and merely the intrinsical aromatic carbons were left in the degradated kerogens. It sounds to be an answer that why the conservation of aromatic carbon is not an individual feature in many thermal degradation experiments for different types of kerogens. In general, the aomatic carbons contribute little to the generation of hydrocarbons. Based on the NMR and ultimate analysis data of kerogens, a series of chemical structural parameters had been derived, including apparent carbon aromaticity, average carbon number of methelene groups and ring condensation index. They are correlated with the kelative oil yields of the derogens where the original kerogen oil yield was taken as unit. A straight line is plotted to show the relation between relative oil yields and apparent aliphatic carbon fractions. It intersects with the axis of aliphatic carbon fraction at 0.17, indicates that this portion of aliphatic carbon have not taken part with oil generation. Another straight line plotted with the sum of methelene and terminal methyl carbon fractions instead of the aliphatic carbon fraction reaches the origin point. It means that they are the exact matrix of oil.The relation of relative oil yields and average number of carbon atoms in methelene groups of carbon number larger than 5 possess of high potential in generating oil, and those of less than 3 are insignificant to the oil formation. The curve of ring condensation index evolution path depicts different reaction stages of
1990, 8(1): 35-43.
Abstract:
The representative samples of continental shelf sediments from the Bohai Sea, Yellow Sea, East China Sea and South China Sea have been selected and the concentrations of 15 rare earth elements (REE) in these sediments have been mcasurde by X-ray fluorescent spectral analysis.Relative eucrs of the measurement are less than 10% .The results of stults show that the abundance of REE in continental shelf sediments of the China Seas is 156ppm, which is relatively close to that in Loess of China and Fujian granite, but different from that in Pacific sediments.It is evident that the REE have an" inherited" or "philo- continental" property.The average content of REE is controlled by sediment grain-size, that is, REE contents increase gradually with the decrease in grain size. REE distribution patterns demonstrate a distinctly negative slope, which means that the light rare earth element (LREE) concentrations are obviously larger than those of the heavy rare earth elements (HREE), indicating a typical characteristic of rare earth elements of the continental crust. Experiments show that REE mainly concentrate in the clay minerals (2u), and thye are not largely absorbed as cations by clay minerals, but mainly esist in crystal lattices of clay minerals as isomorph.Secondly, some of REE lie in heavy minerals.In regard to the correlation analysis and cluster analysis, the REE have a close relationship with most elements related with clay minerals, such as Al, Ti, K, Rb, Fe, etc.In contrast, the Ca and Sr.All mentioned above suggests that the rocks widely distributed in continent of China, which were weathered and transported, are the main soured of REE in continental shelf sediments of the China Seas.
The representative samples of continental shelf sediments from the Bohai Sea, Yellow Sea, East China Sea and South China Sea have been selected and the concentrations of 15 rare earth elements (REE) in these sediments have been mcasurde by X-ray fluorescent spectral analysis.Relative eucrs of the measurement are less than 10% .The results of stults show that the abundance of REE in continental shelf sediments of the China Seas is 156ppm, which is relatively close to that in Loess of China and Fujian granite, but different from that in Pacific sediments.It is evident that the REE have an" inherited" or "philo- continental" property.The average content of REE is controlled by sediment grain-size, that is, REE contents increase gradually with the decrease in grain size. REE distribution patterns demonstrate a distinctly negative slope, which means that the light rare earth element (LREE) concentrations are obviously larger than those of the heavy rare earth elements (HREE), indicating a typical characteristic of rare earth elements of the continental crust. Experiments show that REE mainly concentrate in the clay minerals (2u), and thye are not largely absorbed as cations by clay minerals, but mainly esist in crystal lattices of clay minerals as isomorph.Secondly, some of REE lie in heavy minerals.In regard to the correlation analysis and cluster analysis, the REE have a close relationship with most elements related with clay minerals, such as Al, Ti, K, Rb, Fe, etc.In contrast, the Ca and Sr.All mentioned above suggests that the rocks widely distributed in continent of China, which were weathered and transported, are the main soured of REE in continental shelf sediments of the China Seas.
1990, 8(1): 57-64.
Abstract:
The homologues of dehydroxyl-vitamin E (DHVE) and their isomers are determined in the light aromatics fraction of source rocks and crude oils in Qianjang depression, (Jianghan Salt Lake Basin, China ) which is the most complete distribution series of DHVE fornd in the geological body so far. DHVE come from VE by removing-OH group, and has three homologues: α, γ and δ types. According to the GC/ MS determination, it is found that every one of DHVE homologues has a pair of diastereomer-2R and 2S, These two configuration differ obversly in thermal stability because of their diference of the long side chain alkayl group in space arrangement. 2R-DHVE may be distroyed precedently under clay minerals catalysis and thermal stress effect, but 2S-DHVE is relatively more stable. DHVE exits mainly in immature-lower mature sedimentary organic matter (Ro0.6%), and there is higher content of 2R-DHVE in Ro 0.4% depth range. 2R-DHVE disappears and 2S-DHVE is predominent along with the increase of burial depth and the raise of temperature。 In the depth section, there is the stable alignment of δ γ α type or the transformed rela tion of α→γ→δ type among DHVE homoegues in source rocks and oils., δ / α, δ / γ and δ/ (α+γ) ratios show gradually increase trend in general change with depth of burial which indi cates mature degree of organic matter. Up to now, DHVE reported in geological body is mainly identified in gypseous salt sedimentary environment which is formed underdry scotching climate condition. Enough sunsb ing is more favourable to bio-photosynthesis, and so, both 1 lower livings and higher plants can synthesis abundent VE.Most sampls contain DHVE. They are gypseous, plastery, calcific mudstone with visiable plant trace, that locate at the Qianjiang depression margin in Jianghan Basin. Therefore it may be indicated that higher concentration of DHVE may be partly due to the contribution of conlinenbtal sources and the strong reduction nature and climate condition of saline environment that are more favourable to occuration preservation and transformation of VE and DHVE. The identification in sedimentary organic matter of DHVE shows that it is important composition of oil- generating matters. As a biomolecular fossil, DHVE may indicate sedimentary environment, mature degree of organic matter, and be another precursor of pristane and other isopenoid compounds. The appearance of DHVE in oils furnish more relia-bled evidence for existance of immature or lower mature oil, which has important theoretical value to further approching mechanism for organic matter to generate hydrocarbon.
The homologues of dehydroxyl-vitamin E (DHVE) and their isomers are determined in the light aromatics fraction of source rocks and crude oils in Qianjang depression, (Jianghan Salt Lake Basin, China ) which is the most complete distribution series of DHVE fornd in the geological body so far. DHVE come from VE by removing-OH group, and has three homologues: α, γ and δ types. According to the GC/ MS determination, it is found that every one of DHVE homologues has a pair of diastereomer-2R and 2S, These two configuration differ obversly in thermal stability because of their diference of the long side chain alkayl group in space arrangement. 2R-DHVE may be distroyed precedently under clay minerals catalysis and thermal stress effect, but 2S-DHVE is relatively more stable. DHVE exits mainly in immature-lower mature sedimentary organic matter (Ro0.6%), and there is higher content of 2R-DHVE in Ro 0.4% depth range. 2R-DHVE disappears and 2S-DHVE is predominent along with the increase of burial depth and the raise of temperature。 In the depth section, there is the stable alignment of δ γ α type or the transformed rela tion of α→γ→δ type among DHVE homoegues in source rocks and oils., δ / α, δ / γ and δ/ (α+γ) ratios show gradually increase trend in general change with depth of burial which indi cates mature degree of organic matter. Up to now, DHVE reported in geological body is mainly identified in gypseous salt sedimentary environment which is formed underdry scotching climate condition. Enough sunsb ing is more favourable to bio-photosynthesis, and so, both 1 lower livings and higher plants can synthesis abundent VE.Most sampls contain DHVE. They are gypseous, plastery, calcific mudstone with visiable plant trace, that locate at the Qianjiang depression margin in Jianghan Basin. Therefore it may be indicated that higher concentration of DHVE may be partly due to the contribution of conlinenbtal sources and the strong reduction nature and climate condition of saline environment that are more favourable to occuration preservation and transformation of VE and DHVE. The identification in sedimentary organic matter of DHVE shows that it is important composition of oil- generating matters. As a biomolecular fossil, DHVE may indicate sedimentary environment, mature degree of organic matter, and be another precursor of pristane and other isopenoid compounds. The appearance of DHVE in oils furnish more relia-bled evidence for existance of immature or lower mature oil, which has important theoretical value to further approching mechanism for organic matter to generate hydrocarbon.
1990, 8(1): 79-90.
Abstract:
The late permian Strata, Sichuan, Which are a kind of sequence of mixed siliciclastic and carbonate sediments, were deposited during the period of relative tectonic quiescence on the Yang Zi Platform which was adjacent to lower relief tectonic highland of Kang Dian (Yunnan and the west part of Sichuan Provinces) .During the early period of the Late Permian, Sichuan and the west part in the central-west part of Sichuan, the carbonate ramp in the east part of Sichuan, the open marine basin in the west part of HuBei.The coal-bearing basin in the central-west part of Sichuan was developed into the coal-bearing siliciclastic sediments that contained continental and marine materials named Long Tan Fromation.The terrigenous materials were entered into the basin from the west part of lower relief tectonic highland o Kang Dian.The influx of the materials, however, was not great enough to shut out carbonate productior completely.Therefore, the carbonate ramp in the east part of Sichuan consisted of medium bedded and dark gray chert limestone with some silicious shales, which are called Wu Jiaping Formation.In the open marine basin of the west part of Hubei, there was a deposition of argillaceous limestong and silicious shale. By the late period of the Late Permian, transgressive rate was increasing and the sea was expanding from the carbonate ramp to the coal-bearing basin. Only minor siliciclastic materials poured into the basin.At he same time, the coal-bearing basin was begining to migrate toward the west pat of Sichuan ba sin in which sediments deposited are named Xin Wen Formation (P22) .The carbonate sediments called Changxing Formation (P22) overlain on the coal strata of Longtan Formation. At the north-east pan and east part of Sichuan basin, Changxing limeston are overlain by the Dalong Formation (P23) consisting of limeston and silicious shales which are a part of deep water facies. It can be concluded that transgression is a major geological event according to the correlation of the Upper Permian' s strata, the migration of coal-bearing scries, the distribution of clay minerals in the shales of the coal-bearing units and the climbing on the ramp for organic build-up from cast to west.The characteristic of dcpositional cycles in the coal-bearing series shows that there are some smaller events of transgression-regression during the large transgrcssive period.The upper- part of each cycle shows the small transgressivc scqcnces and its lower part contains the small regressive sequences. The transgressive and regressive sequences are quite clear in the coal series. However the eustatic sea-level changs caused by transgression and regression are hard to recognize in the limestone of Wujiaping Formation and Changing Formation. Perhaps the changes can be revealed by the crosional surfaces in organic build-up and the interbeddings between shales and limestones in the Wujiaping and Changxing Formations. With the increase of transgrcssive rate and the contract of coal-bearing basin, carbonate materials were rapidly produced.The processes of carbonate deposition effectively and rapidly turned a carbonate ramp in the Wu Jiaping period into a carbonate platform in the Changxing period. Consequently, the coal- bearing basin diminished toward the land ( the rate of the basin diminution is about 200m/ 1000yr.), and the open marine basin in the west part of Hubei displayed a feature of starved basin.Their dipositional rates in the various areas are different.The coai-bearing basin, for example, is about 0.6036cm/1000yr., the open marine basin in the west part of Hubci 0.5004cm/ 1000yr., the Wujiaping carbonate ramp 0. 888cm/ 1000yr., and the Changxing carbonate platcform 1.4728cm / 1000yr..The depositional rate of the Changxing carbonate plateform is 2.5 times as much as the rate of the coal-bearing basin, and 1 times as much as the rate of Hubei open marine basin. Therefore, it can be concluded that the Late Permian Lithofacics model of Sichuan basin and the west part of Hubei results from the changes of sea level and the
The late permian Strata, Sichuan, Which are a kind of sequence of mixed siliciclastic and carbonate sediments, were deposited during the period of relative tectonic quiescence on the Yang Zi Platform which was adjacent to lower relief tectonic highland of Kang Dian (Yunnan and the west part of Sichuan Provinces) .During the early period of the Late Permian, Sichuan and the west part in the central-west part of Sichuan, the carbonate ramp in the east part of Sichuan, the open marine basin in the west part of HuBei.The coal-bearing basin in the central-west part of Sichuan was developed into the coal-bearing siliciclastic sediments that contained continental and marine materials named Long Tan Fromation.The terrigenous materials were entered into the basin from the west part of lower relief tectonic highland o Kang Dian.The influx of the materials, however, was not great enough to shut out carbonate productior completely.Therefore, the carbonate ramp in the east part of Sichuan consisted of medium bedded and dark gray chert limestone with some silicious shales, which are called Wu Jiaping Formation.In the open marine basin of the west part of Hubei, there was a deposition of argillaceous limestong and silicious shale. By the late period of the Late Permian, transgressive rate was increasing and the sea was expanding from the carbonate ramp to the coal-bearing basin. Only minor siliciclastic materials poured into the basin.At he same time, the coal-bearing basin was begining to migrate toward the west pat of Sichuan ba sin in which sediments deposited are named Xin Wen Formation (P22) .The carbonate sediments called Changxing Formation (P22) overlain on the coal strata of Longtan Formation. At the north-east pan and east part of Sichuan basin, Changxing limeston are overlain by the Dalong Formation (P23) consisting of limeston and silicious shales which are a part of deep water facies. It can be concluded that transgression is a major geological event according to the correlation of the Upper Permian' s strata, the migration of coal-bearing scries, the distribution of clay minerals in the shales of the coal-bearing units and the climbing on the ramp for organic build-up from cast to west.The characteristic of dcpositional cycles in the coal-bearing series shows that there are some smaller events of transgression-regression during the large transgrcssive period.The upper- part of each cycle shows the small transgressivc scqcnces and its lower part contains the small regressive sequences. The transgressive and regressive sequences are quite clear in the coal series. However the eustatic sea-level changs caused by transgression and regression are hard to recognize in the limestone of Wujiaping Formation and Changing Formation. Perhaps the changes can be revealed by the crosional surfaces in organic build-up and the interbeddings between shales and limestones in the Wujiaping and Changxing Formations. With the increase of transgrcssive rate and the contract of coal-bearing basin, carbonate materials were rapidly produced.The processes of carbonate deposition effectively and rapidly turned a carbonate ramp in the Wu Jiaping period into a carbonate platform in the Changxing period. Consequently, the coal- bearing basin diminished toward the land ( the rate of the basin diminution is about 200m/ 1000yr.), and the open marine basin in the west part of Hubei displayed a feature of starved basin.Their dipositional rates in the various areas are different.The coai-bearing basin, for example, is about 0.6036cm/1000yr., the open marine basin in the west part of Hubci 0.5004cm/ 1000yr., the Wujiaping carbonate ramp 0. 888cm/ 1000yr., and the Changxing carbonate platcform 1.4728cm / 1000yr..The depositional rate of the Changxing carbonate plateform is 2.5 times as much as the rate of the coal-bearing basin, and 1 times as much as the rate of Hubei open marine basin. Therefore, it can be concluded that the Late Permian Lithofacics model of Sichuan basin and the west part of Hubei results from the changes of sea level and the
1990, 8(1): 98-105.
Abstract:
Cosmic spherules is a kind of the important material from the solar system. We found sedimentary cosmic spherules in the rocks of Late Palaeozoic coal- bearing series of the eastern Yellow River Coalfield, while studying the sedimentary of the coalfield with binocular and scanning electronic microscope. The surface features of micro-textures being found as follow: irregular holorystallines, miarlitre, resortive, warty, calaclastic spherulitic, hollow-prism and plicated structure, totalling 8 types According to the chemical compositions measured by electronic probing, there arc three kinds of cosmic spherules such as glassy, silicate and ferrous spherules in this district This is similar 10 the cosmic spherules which have been reported in the chemical compositions. And the content Ir (being called as "dactylotype element") is high, up to 1.09%, in the ferrous cosmic spherules. The fact that It is. found so much in the spherules has proved the spherules is really a kind of material from outer planet. Studying cosmic spherules contributes to knowing the originality and evolution of soiar system and the cause of extinct or degcnevalion of creatures. Meanwhile, its studying has widely been used in cosmography, astronautics, oceanography, physics, astronomic geology and geological exploration and so on.
Cosmic spherules is a kind of the important material from the solar system. We found sedimentary cosmic spherules in the rocks of Late Palaeozoic coal- bearing series of the eastern Yellow River Coalfield, while studying the sedimentary of the coalfield with binocular and scanning electronic microscope. The surface features of micro-textures being found as follow: irregular holorystallines, miarlitre, resortive, warty, calaclastic spherulitic, hollow-prism and plicated structure, totalling 8 types According to the chemical compositions measured by electronic probing, there arc three kinds of cosmic spherules such as glassy, silicate and ferrous spherules in this district This is similar 10 the cosmic spherules which have been reported in the chemical compositions. And the content Ir (being called as "dactylotype element") is high, up to 1.09%, in the ferrous cosmic spherules. The fact that It is. found so much in the spherules has proved the spherules is really a kind of material from outer planet. Studying cosmic spherules contributes to knowing the originality and evolution of soiar system and the cause of extinct or degcnevalion of creatures. Meanwhile, its studying has widely been used in cosmography, astronautics, oceanography, physics, astronomic geology and geological exploration and so on.
1990, 8(1): 122-128.
Abstract:
Many research items on the manganese nodules from ocean bottom have been earned ouu but the growth rales of manganese nodules as well as their movements on the ocean bottom still puzzles the scientists. Various methods have bee created to answer these question. The trustworthy and acceptable methods are -230Th excess; -230Th / -232Th; -231Pa; K / Ar and -10Be. Three manganese nodules have been analysed using -230Th excess and -230Th / -232Th methods in order to detect their growth rates. The procedures are as follows: Successive layers of specimens from top side and bottom side arc scraped; acid leaching; separation and purification of U and Th using Dowcsi-8 resin; TTA extraction and a counting. The growth rates of three nodules using two different methods a;e agreeable, ranging l-10mm / M.Yr. The last turnover of the noduics can be evaluated from the different activities of -230Th at the surface of top and bottom sides. The results range from 5 ×104to 2.5 × 105ycars, thereat -210Pb profiles indicates that the turnover of the noduics didn ' t take place in the last 150 years.
Many research items on the manganese nodules from ocean bottom have been earned ouu but the growth rales of manganese nodules as well as their movements on the ocean bottom still puzzles the scientists. Various methods have bee created to answer these question. The trustworthy and acceptable methods are -230Th excess; -230Th / -232Th; -231Pa; K / Ar and -10Be. Three manganese nodules have been analysed using -230Th excess and -230Th / -232Th methods in order to detect their growth rates. The procedures are as follows: Successive layers of specimens from top side and bottom side arc scraped; acid leaching; separation and purification of U and Th using Dowcsi-8 resin; TTA extraction and a counting. The growth rates of three nodules using two different methods a;e agreeable, ranging l-10mm / M.Yr. The last turnover of the noduics can be evaluated from the different activities of -230Th at the surface of top and bottom sides. The results range from 5 ×104to 2.5 × 105ycars, thereat -210Pb profiles indicates that the turnover of the noduics didn ' t take place in the last 150 years.
1990, 8(1): 133-142.
Abstract:
Probability of transition of semi-Markov process means that when point A of section just is located upper bound of ith lithic stratum probability Pij (1) of point B is in jth lithic stratum, point B is upper the point A and distance between point B with A is l.This probability can be decomposed as two events probability, the two events are in what follows: (1) In point A, the ith lithic stratum translats to the jth lithic stratum with only passing one step and thickness of the jth lithic stratum is lager than 1; (2) In point O that is between piont A and B, the ith lithic stratum translats to the jth lithic stratum with passing n steps (n = 2, 3, …0, this is that n-1 stuatum layering are contained between point A and O apart l1 it translats at once to jth lithic stratum in point O and the jth lithic stratum thickness is larger than 1- l1. For the 1th event, if only a stratum layering thickness distribution is gave, the event probability can be computed, if thicknees .distribution of n s tratum layerings can be gave, the Zth event probability can be easy computed. Thus the author supposes that n stratum layering thicknesses submit independently same parameter - distrbution: Among others x is the stochastic variable of stratum layering thickness, v, a are the distribu- tion parameters and v 0, a 0. As a result, probability density function of n stratum layerrings thickness sum can be derived from characteristic function of n independent stochastic variables sum distribution: Proceed to the next step, directly comput formula of probability of transition of semi- Markov process can be derived. The author has wrote specific computer program to calculat it by means of the disital integration. With the directly comut metheod the author has studied semi- Markov process appeared by A unite part in a detailed deposition section, the section presents deltaic sedimentary system effected by tide in a coal measures.A unite is oldest unite ofsystem.It separates B lithofacies constitutes (mudstone, divaricationg channel, tide way, tidal flat, distal bar, limestone, coal, tidal sand ridge) .Statistical analysis of 1 practice survey columns of A unite in this section shows state transition among the lithofacies constitutes having obvious Markov property and shows Γ-distribution is considerably perfect for fitting the stritum thicknees of lithofacies constitute. With the directly comput method the author calculates transition probability matrix or semi-Markov process among the lithofacies constitutes Q-mode factor analysis for the transition probabillity matrix obtains factors, the factors reflect effect factors of deposition environment.the preceding 3 factors effect main coal gather action of marginal deltaic basin, low deltaic plain, roof of deltaic plain below the water, distal bar building action, mutual action of river with tide. With facies unite of every column as sample, the author carries on step regression analysis of coal bed total thickness with deposition environment effect factors in the facies unite. F- testing and regression residual analysis show the regression epuation to be obvious statisticlly.This illustrates that espression of deposition environment control to coal thickness is in what follows: (1) To formation of thick-bedded coal fen plain of marginal deltaic is the fa vourablest; (2) Marginal deltaic basin deltaic plain below the water and low deltaic plain of riv er and tide development only form thin coal bed.
Probability of transition of semi-Markov process means that when point A of section just is located upper bound of ith lithic stratum probability Pij (1) of point B is in jth lithic stratum, point B is upper the point A and distance between point B with A is l.This probability can be decomposed as two events probability, the two events are in what follows: (1) In point A, the ith lithic stratum translats to the jth lithic stratum with only passing one step and thickness of the jth lithic stratum is lager than 1; (2) In point O that is between piont A and B, the ith lithic stratum translats to the jth lithic stratum with passing n steps (n = 2, 3, …0, this is that n-1 stuatum layering are contained between point A and O apart l1 it translats at once to jth lithic stratum in point O and the jth lithic stratum thickness is larger than 1- l1. For the 1th event, if only a stratum layering thickness distribution is gave, the event probability can be computed, if thicknees .distribution of n s tratum layerings can be gave, the Zth event probability can be easy computed. Thus the author supposes that n stratum layering thicknesses submit independently same parameter - distrbution: Among others x is the stochastic variable of stratum layering thickness, v, a are the distribu- tion parameters and v 0, a 0. As a result, probability density function of n stratum layerrings thickness sum can be derived from characteristic function of n independent stochastic variables sum distribution: Proceed to the next step, directly comput formula of probability of transition of semi- Markov process can be derived. The author has wrote specific computer program to calculat it by means of the disital integration. With the directly comut metheod the author has studied semi- Markov process appeared by A unite part in a detailed deposition section, the section presents deltaic sedimentary system effected by tide in a coal measures.A unite is oldest unite ofsystem.It separates B lithofacies constitutes (mudstone, divaricationg channel, tide way, tidal flat, distal bar, limestone, coal, tidal sand ridge) .Statistical analysis of 1 practice survey columns of A unite in this section shows state transition among the lithofacies constitutes having obvious Markov property and shows Γ-distribution is considerably perfect for fitting the stritum thicknees of lithofacies constitute. With the directly comput method the author calculates transition probability matrix or semi-Markov process among the lithofacies constitutes Q-mode factor analysis for the transition probabillity matrix obtains factors, the factors reflect effect factors of deposition environment.the preceding 3 factors effect main coal gather action of marginal deltaic basin, low deltaic plain, roof of deltaic plain below the water, distal bar building action, mutual action of river with tide. With facies unite of every column as sample, the author carries on step regression analysis of coal bed total thickness with deposition environment effect factors in the facies unite. F- testing and regression residual analysis show the regression epuation to be obvious statisticlly.This illustrates that espression of deposition environment control to coal thickness is in what follows: (1) To formation of thick-bedded coal fen plain of marginal deltaic is the fa vourablest; (2) Marginal deltaic basin deltaic plain below the water and low deltaic plain of riv er and tide development only form thin coal bed.
