2008 Vol. 26, No. 1
Display Method:
2008, 26(1): 1-10.
Abstract:
The concentrations of rare earth elements(REE) and trace elements were analysed from MioceneOligocene lacustrine carbonates collected in the Tongtianhe section of Tuotuohe Basin of Tibetan Plateau. The total REE contents(∑REE) of lacustrine limestone and dolostones covers a wide range:36.23×10-6～189.64×10-6 and its average value of 28 samples is 78.58×10-6. The shalenormalized REE patterns display middle REE enrichments and strong positive Eu anomalies. The relatively high Eu/Eu* ratios occur across the Oligocene and Miocene boundary layers. This is the first report of positive Eu anomalies observed in REE patterns in terrestrial sediment records. Based on REE distributions and covariance between Eu and Ba, this paper presents Eu anomaly in lacustrine carbonate samples of the study area implies hydrothermal venting occurrence in paleolake systems.
The concentrations of rare earth elements(REE) and trace elements were analysed from MioceneOligocene lacustrine carbonates collected in the Tongtianhe section of Tuotuohe Basin of Tibetan Plateau. The total REE contents(∑REE) of lacustrine limestone and dolostones covers a wide range:36.23×10-6～189.64×10-6 and its average value of 28 samples is 78.58×10-6. The shalenormalized REE patterns display middle REE enrichments and strong positive Eu anomalies. The relatively high Eu/Eu* ratios occur across the Oligocene and Miocene boundary layers. This is the first report of positive Eu anomalies observed in REE patterns in terrestrial sediment records. Based on REE distributions and covariance between Eu and Ba, this paper presents Eu anomaly in lacustrine carbonate samples of the study area implies hydrothermal venting occurrence in paleolake systems.
2008, 26(1): 11-20.
Abstract:
The major element geochemical analysis of sandstone and siltstones samples were performed for tectonic setting discrimination and discussion the nature and evolution of northern Qiangtang basin in ZhidoiZadoi area, southern Qinghai. The result of study indicates that the tectonic settings of provenances are passive continental margin in the Early Carboniferous, passive continental margin, active continental margin and continental island arc in the Early and Middle Permian, passive continental margin, active continental margin and continental island arc in the Late Triassic. Along with the stratigraphy, sedimentology and petrology, the nature of basin evolved from craton basin in the Early Carboniferous to riftbasin in the Early and Middle Permian and passive continental margin basin in the Early and Middle Triassic to backarc basin in the Late Triassic, and this is sedimentation responding to evolvement of Jinshajiang suture belt and GarzeLitang suture belt in study area.
The major element geochemical analysis of sandstone and siltstones samples were performed for tectonic setting discrimination and discussion the nature and evolution of northern Qiangtang basin in ZhidoiZadoi area, southern Qinghai. The result of study indicates that the tectonic settings of provenances are passive continental margin in the Early Carboniferous, passive continental margin, active continental margin and continental island arc in the Early and Middle Permian, passive continental margin, active continental margin and continental island arc in the Late Triassic. Along with the stratigraphy, sedimentology and petrology, the nature of basin evolved from craton basin in the Early Carboniferous to riftbasin in the Early and Middle Permian and passive continental margin basin in the Early and Middle Triassic to backarc basin in the Late Triassic, and this is sedimentation responding to evolvement of Jinshajiang suture belt and GarzeLitang suture belt in study area.
2008, 26(1): 28-38.
Abstract:
Based on systematic analysis of lithological composition, microstructure and sedimentary facies, in this paper many discusses have been conducted for the REE characteristics of LongeniAngdanrco paleooil dolomite in southern part of the central uplift zone of Qiangtang basin. The amount of ∑REE in dolomite and concomitant calcite is lower in comparison with other carbonates in China, and is still under the control of sedimentary facies and process. The HREE of dolomite is even more impoverished than LREE compared to concomitant calcite in this area. In distributed patterns, all the carbonates show a complicate model, and the dolomite is even more flat compared to concomitant calcite. For the two typical indexes, the δEu of calcite is higher, and the δCe of dolomite is higher. All these show that REE have been undergoing an impoverished process in dolomitization, and the calcite has been formed in deep water deoxidized environment, the dolomite being formed in shallow water oxidized environment. The dolomite in this area should be the result of mixed water replacement to calcite.
Based on systematic analysis of lithological composition, microstructure and sedimentary facies, in this paper many discusses have been conducted for the REE characteristics of LongeniAngdanrco paleooil dolomite in southern part of the central uplift zone of Qiangtang basin. The amount of ∑REE in dolomite and concomitant calcite is lower in comparison with other carbonates in China, and is still under the control of sedimentary facies and process. The HREE of dolomite is even more impoverished than LREE compared to concomitant calcite in this area. In distributed patterns, all the carbonates show a complicate model, and the dolomite is even more flat compared to concomitant calcite. For the two typical indexes, the δEu of calcite is higher, and the δCe of dolomite is higher. All these show that REE have been undergoing an impoverished process in dolomitization, and the calcite has been formed in deep water deoxidized environment, the dolomite being formed in shallow water oxidized environment. The dolomite in this area should be the result of mixed water replacement to calcite.
2008, 26(1): 61-69.
Abstract:
Seep carbonate were collected in an area actively seeping methane in the Green Canyon Block 338 of Gulf of Mexico, which is composed of microcrystalline calcite, cement and pyrite framboid. The cement is composed of speroidal, oval, and rodshaped particles ~0.1 to 0.5 μm in diameter that filled the pores between the calcite crystals. The underside of the carbonate crusts occurs a microlayer consisted of ball, worm, rodshaped calcite particles. The larger ball (~5μm) in the microlayer has a distinct cores surrounded by an outer shell which both consists of smaller calcite particles. Pyrite framboids are also arranged in an inner core surrounded by an outer layer. These layeredstructure characteristics of the carbonate balls and the pyrite framboids are similar with living colonies of methane oxidizing archea (MOA) and sulfate reducing bacteria (SRB). The speroidal, oval, and rodshaped particles and layeredstructure in the carbonate crusts suggest that these could be fossilized MOA and SRB bacteria.
Seep carbonate were collected in an area actively seeping methane in the Green Canyon Block 338 of Gulf of Mexico, which is composed of microcrystalline calcite, cement and pyrite framboid. The cement is composed of speroidal, oval, and rodshaped particles ~0.1 to 0.5 μm in diameter that filled the pores between the calcite crystals. The underside of the carbonate crusts occurs a microlayer consisted of ball, worm, rodshaped calcite particles. The larger ball (~5μm) in the microlayer has a distinct cores surrounded by an outer shell which both consists of smaller calcite particles. Pyrite framboids are also arranged in an inner core surrounded by an outer layer. These layeredstructure characteristics of the carbonate balls and the pyrite framboids are similar with living colonies of methane oxidizing archea (MOA) and sulfate reducing bacteria (SRB). The speroidal, oval, and rodshaped particles and layeredstructure in the carbonate crusts suggest that these could be fossilized MOA and SRB bacteria.
2008, 26(1): 70-76.
Abstract:
SinoKeorea plate was in tensile period of Yanliao aulacogen in the Mesoproterzoic, which likely to trigger big storm. It was well developed the stromatolite and coagulum stone bioherm, and which mainly consists of dolomite interbeded with siliceous rock. Research shows that there developed storm siliceous rock in this area. Storm siliceous rock with surface of scour, siliceous gravel arranged as daisy, which was formed in storm surge, and destroyed in the late period of the diagenetic stage before they got consolidated or compacted, which resulted the siliceous fragments straight on the under layers, and formed typical storm deposit. Stromatolithic dolomite interbeded with siliceous strip was normal weather deposit. The paper concluded through the micro photo and field work that the typical storm depositional series of siliceous rock in Wumishan formation, Jixian. The scourlike structure and buninoid structure were developed in the storm siliceous rock, which were the fast and proximal sedimentary deposit. And the origin of the siliceous rock mostly could be seemed as the thermal water activities offering the SiO2. Deposit environment could be the slope of the carbonate platform.
SinoKeorea plate was in tensile period of Yanliao aulacogen in the Mesoproterzoic, which likely to trigger big storm. It was well developed the stromatolite and coagulum stone bioherm, and which mainly consists of dolomite interbeded with siliceous rock. Research shows that there developed storm siliceous rock in this area. Storm siliceous rock with surface of scour, siliceous gravel arranged as daisy, which was formed in storm surge, and destroyed in the late period of the diagenetic stage before they got consolidated or compacted, which resulted the siliceous fragments straight on the under layers, and formed typical storm deposit. Stromatolithic dolomite interbeded with siliceous strip was normal weather deposit. The paper concluded through the micro photo and field work that the typical storm depositional series of siliceous rock in Wumishan formation, Jixian. The scourlike structure and buninoid structure were developed in the storm siliceous rock, which were the fast and proximal sedimentary deposit. And the origin of the siliceous rock mostly could be seemed as the thermal water activities offering the SiO2. Deposit environment could be the slope of the carbonate platform.
2008, 26(1): 86-91.
Abstract:
It is the key factor for establishment of scientific sequence stratigraphy framework to conduct sequence stratigraphic unit classification and correlation of deepwater fine sedimentary series. In addition, it is one important basic research for exploration and development of lithologic oil and gas reservoirs in deepwater areas. Its classification marker, which is usually indistinct, handicaps sequence stratigraphic unit correlation of deepwater fine sedimentary series and acts as one difficult point for sequence stratigraphy research. On the basis of high resolution sequence stratigraphy theory, this paper starts with origin and presence of sedimentary sequence and carries out sequence stratigraphic unit classification and correlation for semideep lake to deep lake marl deposit in lower Es3 of Jizhong depression in Shulu sag, Bohai Bay Basin by using periodical variation rules in vertical of organic geochemical parameters that present sedimentary environment or sediment characteristics. And consequently, cycle grade4 and grade5 are distinguished in a better way, which provides basis to establish highresolution sequence stratigraphy framework.
It is the key factor for establishment of scientific sequence stratigraphy framework to conduct sequence stratigraphic unit classification and correlation of deepwater fine sedimentary series. In addition, it is one important basic research for exploration and development of lithologic oil and gas reservoirs in deepwater areas. Its classification marker, which is usually indistinct, handicaps sequence stratigraphic unit correlation of deepwater fine sedimentary series and acts as one difficult point for sequence stratigraphy research. On the basis of high resolution sequence stratigraphy theory, this paper starts with origin and presence of sedimentary sequence and carries out sequence stratigraphic unit classification and correlation for semideep lake to deep lake marl deposit in lower Es3 of Jizhong depression in Shulu sag, Bohai Bay Basin by using periodical variation rules in vertical of organic geochemical parameters that present sedimentary environment or sediment characteristics. And consequently, cycle grade4 and grade5 are distinguished in a better way, which provides basis to establish highresolution sequence stratigraphy framework.
2008, 26(1): 100-104.
Abstract:
Triaromatic dinosteroid hydrocarbons and dinosteranes are two important molecular fossils derived from dinosterols, compounds known in modern organisms to be the nearly exclusive widely occurring natural products of dinoflagellates. Now they have been identified from a Paleogene lacustrine basin, Jiyang superdepression located at East China, by GCMS and GCMSMS. The results show that different genera of dinoflagellates including the Deflandrea living in salinebrackish lacustrine (Es4u), the SentusidiniumRhombodella in brackish lacustrine (Es1) and the BohaidinaParabohaidina in fresh lacustrine (Es3) all could offer these two molecular fossils. However, it is observed that there are not linear pertinences between the triaromatic dinosteroid hydrocarbons and dinosteranes. The abundance of triaromatic dinosteroid hydrocarbons is consisted with the distribution of dinocysts in the Shahejie Formation. In saline and nearshore deposition, the TAI (triaromatic dinosteroid i
Triaromatic dinosteroid hydrocarbons and dinosteranes are two important molecular fossils derived from dinosterols, compounds known in modern organisms to be the nearly exclusive widely occurring natural products of dinoflagellates. Now they have been identified from a Paleogene lacustrine basin, Jiyang superdepression located at East China, by GCMS and GCMSMS. The results show that different genera of dinoflagellates including the Deflandrea living in salinebrackish lacustrine (Es4u), the SentusidiniumRhombodella in brackish lacustrine (Es1) and the BohaidinaParabohaidina in fresh lacustrine (Es3) all could offer these two molecular fossils. However, it is observed that there are not linear pertinences between the triaromatic dinosteroid hydrocarbons and dinosteranes. The abundance of triaromatic dinosteroid hydrocarbons is consisted with the distribution of dinocysts in the Shahejie Formation. In saline and nearshore deposition, the TAI (triaromatic dinosteroid i
2008, 26(1): 111-119.
Abstract:
In these years, new discovery of petroleum exploration has often been in connection with the palaeotectonics active regions, such as the finding of Qianmiqiao condensate pool at Dagang Oilfield in Bohaiwan Basin, the exploration of Jingbian Gas Field in Ordos Basin and the finding of Hetianhe Gas Field & Tahe Oilfield in Tarim Basin, etc. According to years of exploration experiences, good palaeouplift had bad vital function for the migration, accumulation and reservoiring of oil and gas. Our studies showed that tectonic movements controlled the development of many a types of reservoir: the karstingfracturecaved reservoir from prior weathered crusts and fractured reservoir. We appointed the concept and classing system; pointed out that the petrotectonic facies are material showings of tectonic movements in rocks solidified, and fingered they can classified by rockstratigraphic unit, tectonic movement stage and style. Beyond the analysis on the Mumishan Formation oil pool from buried carbonate hill of Renqiu Oilfield in Bohaiwan Basin and the Xujiahe gas pool of Chishui gas field in Sichuan Baisn, the reservoir characters was discussed for upliftkarsted petrotectonic facies and joint petrotectonic facies. The forward facies is found mostly in carbonate stones, whose reservoir space are all kinds of pore, cave and fracture lined to karst; the following facies can be found in different rocks, whose reservoir space are tectoclase and correlated pores; reservoir physical properties of the two facies are both relative complex. We advice to strengthen the research of reservoir petrotectonic facies; we meanwhile hope to carry out the development of associated recognition technique for petrotectonic facies of reservoirs.
In these years, new discovery of petroleum exploration has often been in connection with the palaeotectonics active regions, such as the finding of Qianmiqiao condensate pool at Dagang Oilfield in Bohaiwan Basin, the exploration of Jingbian Gas Field in Ordos Basin and the finding of Hetianhe Gas Field & Tahe Oilfield in Tarim Basin, etc. According to years of exploration experiences, good palaeouplift had bad vital function for the migration, accumulation and reservoiring of oil and gas. Our studies showed that tectonic movements controlled the development of many a types of reservoir: the karstingfracturecaved reservoir from prior weathered crusts and fractured reservoir. We appointed the concept and classing system; pointed out that the petrotectonic facies are material showings of tectonic movements in rocks solidified, and fingered they can classified by rockstratigraphic unit, tectonic movement stage and style. Beyond the analysis on the Mumishan Formation oil pool from buried carbonate hill of Renqiu Oilfield in Bohaiwan Basin and the Xujiahe gas pool of Chishui gas field in Sichuan Baisn, the reservoir characters was discussed for upliftkarsted petrotectonic facies and joint petrotectonic facies. The forward facies is found mostly in carbonate stones, whose reservoir space are all kinds of pore, cave and fracture lined to karst; the following facies can be found in different rocks, whose reservoir space are tectoclase and correlated pores; reservoir physical properties of the two facies are both relative complex. We advice to strengthen the research of reservoir petrotectonic facies; we meanwhile hope to carry out the development of associated recognition technique for petrotectonic facies of reservoirs.
2008, 26(1): 120-127.
Abstract:
To provide a reasonable means for the flow units division and verification in lithologic oil and gas reservoir. Considering the characteristics of Chang 3 lithologic oil reservoir of Huachi oilfield in Ordos Basin, the main parameters that controlling fluid flowing has been taken to divide flow units after formation division and facies differentiation, and mathematical method, microflow experiments, and dynamic analysis in macro has been adopt to verify the reasonableness of the flow units division in the research. The study results show: 1) three kinds of flow units are divided, they are called as A, B and C. The A flow unit is always located in the main face tract of underwater distributary river course, and its physical property is better. The C flow unit is always located in the edge of underwater distributary river course, and its physical property is not so good. The B flow unit is always in the middle of A flow unit and C flow unit no matter the face position or its physical property; 2) The methods of discrimination analysis, microflow experiments, and dynamic analysis in macro are effective to verify the reasonableness of the flow units division. The correct rate of 100 data points that be selected randomly have been over 95%; the same flow units have similar microflow characteristics, and different flow units are obvious disparate, which reflect in the order of fluid entry, the fluid displacement mode, and the remaining oil types; the product dynamic characters are related with the classification of flow units, reflecting in initial production, the hygroscopic state of water wells, and response and breakthrough of oil wells; 3) C flow units and the joint areas of different flow units between injection well and production well will be the main oilrich of residual oil. And an injection well had better be opened the same flow units at the same time for reducing the water level of interference, and as while the same flow units should be opened to reducing the injected water finger advance, and so the oil recovery will be enhanced.
To provide a reasonable means for the flow units division and verification in lithologic oil and gas reservoir. Considering the characteristics of Chang 3 lithologic oil reservoir of Huachi oilfield in Ordos Basin, the main parameters that controlling fluid flowing has been taken to divide flow units after formation division and facies differentiation, and mathematical method, microflow experiments, and dynamic analysis in macro has been adopt to verify the reasonableness of the flow units division in the research. The study results show: 1) three kinds of flow units are divided, they are called as A, B and C. The A flow unit is always located in the main face tract of underwater distributary river course, and its physical property is better. The C flow unit is always located in the edge of underwater distributary river course, and its physical property is not so good. The B flow unit is always in the middle of A flow unit and C flow unit no matter the face position or its physical property; 2) The methods of discrimination analysis, microflow experiments, and dynamic analysis in macro are effective to verify the reasonableness of the flow units division. The correct rate of 100 data points that be selected randomly have been over 95%; the same flow units have similar microflow characteristics, and different flow units are obvious disparate, which reflect in the order of fluid entry, the fluid displacement mode, and the remaining oil types; the product dynamic characters are related with the classification of flow units, reflecting in initial production, the hygroscopic state of water wells, and response and breakthrough of oil wells; 3) C flow units and the joint areas of different flow units between injection well and production well will be the main oilrich of residual oil. And an injection well had better be opened the same flow units at the same time for reducing the water level of interference, and as while the same flow units should be opened to reducing the injected water finger advance, and so the oil recovery will be enhanced.
2008, 26(1): 139-143.
Abstract:
Speleothem studies have the potential to considerably improve our knowledge of climate changes of the past 500 000 a. Above all, this is due to the independent and reliable calendar year chronology provided by uraniumseries dating techniques and to the multitude of paleoclimate proxy records preserved in speleothems. Here we present an absolutedated and highresolution stable oxygen record from a stalagmite（No.YX21）in Yongxing Cave, Shennongjia natural reservation, central China, giving the details on climatic fluctuations during the Last Interglacial periods. Based on 4 230Th dates and 303 oxygen isotope data, an averaged 8 a East Asian Monsoon precipitation series was established through 127.32 to 124.95 thousand years before present (ka BP). This detailed record uncovered that the δ18O have the highfrequency variability characteristic, indicating the instability of the East Asian Monsoon during the Last Interglacial. During this interval, the YX21 record has 4 Asian Monsoon weak events, possibly related to the interglacial icerafting events in the North Atlantic. Power spectral analysis of the record shows statistically significant periodicities centered on 661 a，127 a，118 a，19~22 a. These periodicities are close to significant periods of the δ14C record, indicates that solar changes are also responsible for changes of Asian Monsoon intensity.
Speleothem studies have the potential to considerably improve our knowledge of climate changes of the past 500 000 a. Above all, this is due to the independent and reliable calendar year chronology provided by uraniumseries dating techniques and to the multitude of paleoclimate proxy records preserved in speleothems. Here we present an absolutedated and highresolution stable oxygen record from a stalagmite（No.YX21）in Yongxing Cave, Shennongjia natural reservation, central China, giving the details on climatic fluctuations during the Last Interglacial periods. Based on 4 230Th dates and 303 oxygen isotope data, an averaged 8 a East Asian Monsoon precipitation series was established through 127.32 to 124.95 thousand years before present (ka BP). This detailed record uncovered that the δ18O have the highfrequency variability characteristic, indicating the instability of the East Asian Monsoon during the Last Interglacial. During this interval, the YX21 record has 4 Asian Monsoon weak events, possibly related to the interglacial icerafting events in the North Atlantic. Power spectral analysis of the record shows statistically significant periodicities centered on 661 a，127 a，118 a，19~22 a. These periodicities are close to significant periods of the δ14C record, indicates that solar changes are also responsible for changes of Asian Monsoon intensity.
2008, 26(1): 151-157.
Abstract:
This article describes the changes of environment and vegetation of the Pearl River (Zhujiang) drainage basin by 13C/12C ratios (δ13C value) of particulate organic carbon (POC) and the content of POC, which can be used as effective indicators of the changes of vegetation, and also provides a new way for studying the environmental changes in shorttime scale. The organic carbon isotopes composition of suspended matter from the Pearl River identifies the vegetation cover and soil erosion of their watershed. Suspended matter from Beijiang River, the tributary of Pearl River, emphasizes the sole influence of organic matter derived from C3rich plants. Suspended matter from the Xijiang River and Dongjiang River emphasizes the influence of organic matter derived from C3 and C4 plants. In normal seasons, it shows that the influence of organic matter derived from C3 plants in Xijiang and Dongjiang River. The δ13C value of POC gradually went up in Dongjiang River suspended matter from 1990 to 1999, and it varied from 17.8‰ to 26.1‰. Some suspended matter from the Dongjiang River has extremely high δ13C values in flood season (up to 17.6 ). These high values may be the result of severe erosion in the densely populated and intensively farmed region of the middle and lower reaches of Dongjiang River drainage basin. The erosion degree of the Dongjiang River drainage basin was greater than that of the Xijiang River.
This article describes the changes of environment and vegetation of the Pearl River (Zhujiang) drainage basin by 13C/12C ratios (δ13C value) of particulate organic carbon (POC) and the content of POC, which can be used as effective indicators of the changes of vegetation, and also provides a new way for studying the environmental changes in shorttime scale. The organic carbon isotopes composition of suspended matter from the Pearl River identifies the vegetation cover and soil erosion of their watershed. Suspended matter from Beijiang River, the tributary of Pearl River, emphasizes the sole influence of organic matter derived from C3rich plants. Suspended matter from the Xijiang River and Dongjiang River emphasizes the influence of organic matter derived from C3 and C4 plants. In normal seasons, it shows that the influence of organic matter derived from C3 plants in Xijiang and Dongjiang River. The δ13C value of POC gradually went up in Dongjiang River suspended matter from 1990 to 1999, and it varied from 17.8‰ to 26.1‰. Some suspended matter from the Dongjiang River has extremely high δ13C values in flood season (up to 17.6 ). These high values may be the result of severe erosion in the densely populated and intensively farmed region of the middle and lower reaches of Dongjiang River drainage basin. The erosion degree of the Dongjiang River drainage basin was greater than that of the Xijiang River.
2008, 26(1): 163-167.
Abstract:
The dark mudstone in the Shuinan Section, Laiyang Formation of the Cretaceous age from the Laiyang Depression belongs to a type of fine source rock with dominant source matter of aglinite and amorphinite. With high magnification of microscopy, a lot of petroleum inclusions were found, which occur in the fissures of sand grains and authigenic minerals in the source rock. The petroleum inclusions have a narrow range of homogenization temperature of 78～82 ℃. Combined use of the geothermal evolution history of the Shuinan Section in the borehole LK2 and the trapping temperature of the petroleum inclusions, its formation time was deduced to be 74～77 Ma. According to the PVT simulation calculation, the trapping pressure of the petroleum inclusions was in the range of 305～307 bar. The occurrence of the petroleum inclusions has shown that the source rock underwent a deep burial and petroleum generation and expulsion before the uplifting of the Laiyang Depression in Tertiary, and the Shuinan section is the important source rock in this depression. This result has provided important information for further evaluation and exploration of this depression.
The dark mudstone in the Shuinan Section, Laiyang Formation of the Cretaceous age from the Laiyang Depression belongs to a type of fine source rock with dominant source matter of aglinite and amorphinite. With high magnification of microscopy, a lot of petroleum inclusions were found, which occur in the fissures of sand grains and authigenic minerals in the source rock. The petroleum inclusions have a narrow range of homogenization temperature of 78～82 ℃. Combined use of the geothermal evolution history of the Shuinan Section in the borehole LK2 and the trapping temperature of the petroleum inclusions, its formation time was deduced to be 74～77 Ma. According to the PVT simulation calculation, the trapping pressure of the petroleum inclusions was in the range of 305～307 bar. The occurrence of the petroleum inclusions has shown that the source rock underwent a deep burial and petroleum generation and expulsion before the uplifting of the Laiyang Depression in Tertiary, and the Shuinan section is the important source rock in this depression. This result has provided important information for further evaluation and exploration of this depression.
2008, 26(1): 21-27.
Abstract:
REE is a good geological indicator. In order to understand REE role in stratigraphic subdivision and correlation, REE in Late Permian coal measure from Bijie City, western Guizhou Province, China have been studied. The results show that the contents of both individual LREE and ∑REE in the boundary between Longtan Formation and Changxing Formation are sharply increased. This phenomenon is related to the REEs sources (gyration and discontinuity eruption Emeishan basalt) and the transgressionregression frequently. So we can subdivide and correlate the strata, even understand the sealevel change by studying REE of coal measure with same sources.
REE is a good geological indicator. In order to understand REE role in stratigraphic subdivision and correlation, REE in Late Permian coal measure from Bijie City, western Guizhou Province, China have been studied. The results show that the contents of both individual LREE and ∑REE in the boundary between Longtan Formation and Changxing Formation are sharply increased. This phenomenon is related to the REEs sources (gyration and discontinuity eruption Emeishan basalt) and the transgressionregression frequently. So we can subdivide and correlate the strata, even understand the sealevel change by studying REE of coal measure with same sources.
2008, 26(1): 39-45.
Abstract:
A spectacular sediment wave field which situated at water depth of 2 600～4 100m cover area of approximately 35 000 km2 in Manila Trench, the northeast South China Sea. The sediment field can be judged the turbidity current’s origin based on its related characters, regional distribution and material composition, which initiated at 1.2 Ma and build the sediment body exhibiting the wave seismic reflection and thus is different from the underlying parallel seismic reflection distinctly. A surface of initiation can be distinguished between the two different sediment bodies. The development of the sediment wave is totally controlled by the characteristic development of Taiwan Orogenesis. Luzon Arc be part of the Philippine Sea Plate which move towards NWW direction collide with Eurasian Continent Margin at approximately 6.5 Ma obliquely and the focus of collision propagated southward consistently because of the inherent oblique collision. In 1.2 Ma the focus of collision arrived at the present south part of Taiwan Island and so significantly enhanced the physical denudation rate of related region, thus the rapidly increased the supply of material to deepwater environment, and result in quite enhancement of the strength and the frequency of turbidity current, and resultantly significantly modified the sediment dynamics status of deepwater environment. Just under such setting the development of sediment wave can be initiated and developed. The Taiwan Orogenesis and development of sediment wave constitute a perfect pair of tectonic activity and response of sedimentation.
A spectacular sediment wave field which situated at water depth of 2 600～4 100m cover area of approximately 35 000 km2 in Manila Trench, the northeast South China Sea. The sediment field can be judged the turbidity current’s origin based on its related characters, regional distribution and material composition, which initiated at 1.2 Ma and build the sediment body exhibiting the wave seismic reflection and thus is different from the underlying parallel seismic reflection distinctly. A surface of initiation can be distinguished between the two different sediment bodies. The development of the sediment wave is totally controlled by the characteristic development of Taiwan Orogenesis. Luzon Arc be part of the Philippine Sea Plate which move towards NWW direction collide with Eurasian Continent Margin at approximately 6.5 Ma obliquely and the focus of collision propagated southward consistently because of the inherent oblique collision. In 1.2 Ma the focus of collision arrived at the present south part of Taiwan Island and so significantly enhanced the physical denudation rate of related region, thus the rapidly increased the supply of material to deepwater environment, and result in quite enhancement of the strength and the frequency of turbidity current, and resultantly significantly modified the sediment dynamics status of deepwater environment. Just under such setting the development of sediment wave can be initiated and developed. The Taiwan Orogenesis and development of sediment wave constitute a perfect pair of tectonic activity and response of sedimentation.
2008, 26(1): 77-85.
Abstract:
Talaha region in Songliao Basin is the gentle slope which was covered with water in long term during the depositional periods of the Fourth Member of Quantou Formation to Third Member of Nenjinag Formation. On the basis of sequence stratigraphy studies, it is found that there are 7 types of sequence boundaries manifestation in the drilling well data, such as: (1)boundary between uppercoarsing cycle and upperfining cycle within the sandrich part of well profile; (2) boundary between uppercoarsing sandrich cycle and upperfining mudrich cycle of well profile; (3) boundary between uppercoarsing mudrich cycle and upperfining sandrich cycle of well profile; (4) boundary between uppercoarsing cycle and upperfining cycle within carbonaterich part of well profile; (5) boundary between uppercoarsing carbonaterich cycle and upperfining mudrich cycle of well profile; (6) boundary between uppercoarsing mudrich cycle and upperfining carbonaterich cycle of well profile; (7) boundary between uppercoarsing cycle and upperfining cycle within mudrich part of well profile. The secondorder and thirdorder sequence boundaries dominated by the boundary between uppercoarsing cycle and upperfining cycle within the sandrich part of well profile, respectively is 92% and 39%. The fourthorder sequence boundaries are provided with diversity, there are near equal probability of 7 types of sequence boundaries. The characteristics of sequence boundaries are controlled by fluctuation of lake level, supply of source and intensity of evaporation.
Talaha region in Songliao Basin is the gentle slope which was covered with water in long term during the depositional periods of the Fourth Member of Quantou Formation to Third Member of Nenjinag Formation. On the basis of sequence stratigraphy studies, it is found that there are 7 types of sequence boundaries manifestation in the drilling well data, such as: (1)boundary between uppercoarsing cycle and upperfining cycle within the sandrich part of well profile; (2) boundary between uppercoarsing sandrich cycle and upperfining mudrich cycle of well profile; (3) boundary between uppercoarsing mudrich cycle and upperfining sandrich cycle of well profile; (4) boundary between uppercoarsing cycle and upperfining cycle within carbonaterich part of well profile; (5) boundary between uppercoarsing carbonaterich cycle and upperfining mudrich cycle of well profile; (6) boundary between uppercoarsing mudrich cycle and upperfining carbonaterich cycle of well profile; (7) boundary between uppercoarsing cycle and upperfining cycle within mudrich part of well profile. The secondorder and thirdorder sequence boundaries dominated by the boundary between uppercoarsing cycle and upperfining cycle within the sandrich part of well profile, respectively is 92% and 39%. The fourthorder sequence boundaries are provided with diversity, there are near equal probability of 7 types of sequence boundaries. The characteristics of sequence boundaries are controlled by fluctuation of lake level, supply of source and intensity of evaporation.
2008, 26(1): 92-99.
Abstract:
Based on the knowledge of the sedimentary setting of the Jialingjiang Formation in Luzhou Paleohigh, with
Based on the knowledge of the sedimentary setting of the Jialingjiang Formation in Luzhou Paleohigh, with
2008, 26(1): 105-110.
Abstract:
Based on observation in the field, this paper documents the sedimentary features and variations of Jiufotang Formation in the Luanping basin. A special kind of rock, namely, peperite, was identified and described in detail. Taking the geological setting of the basin into account, the author believes that the Luanping basin is a volcanic sedimentary basin. The intensive synsedimentary tectonic activity has resulted in the peperite in the Jiufotang Formation.
Based on observation in the field, this paper documents the sedimentary features and variations of Jiufotang Formation in the Luanping basin. A special kind of rock, namely, peperite, was identified and described in detail. Taking the geological setting of the basin into account, the author believes that the Luanping basin is a volcanic sedimentary basin. The intensive synsedimentary tectonic activity has resulted in the peperite in the Jiufotang Formation.
2008, 26(1): 46-53.
Abstract:
The wide application of the laser particle size analyzer results in a problem in the comparison between the new and old, historical data sets; it is necessary to establish the relationships between the two. In this study, based on the grain size analysis using the laser technique and pipettesieve method for tidal flat sediment samples from the Jiangsu coast, eastern China, the two sets of grain size parameters are compared and the differences between the two methods are analyzed. The results show that: for the Jiangsu coast sediment samples there is a significant linear relationship between the mean grain sizes; compared with the laser analysis, the percentages of coarsegrained materials are relatively small in the sieving analysis, whereas the percentages of finegrained materials are relatively large in the settling analysis; and the linear correlation is enhanced after the sediment samples are classified according to their grain size compositions and regression analysis are carried out for different groups, indicating the influence of the composition factor. The relationship between the two types of analysis not only depends upon the region in consideration, it is but also related to the grain size composition patterns.
The wide application of the laser particle size analyzer results in a problem in the comparison between the new and old, historical data sets; it is necessary to establish the relationships between the two. In this study, based on the grain size analysis using the laser technique and pipettesieve method for tidal flat sediment samples from the Jiangsu coast, eastern China, the two sets of grain size parameters are compared and the differences between the two methods are analyzed. The results show that: for the Jiangsu coast sediment samples there is a significant linear relationship between the mean grain sizes; compared with the laser analysis, the percentages of coarsegrained materials are relatively small in the sieving analysis, whereas the percentages of finegrained materials are relatively large in the settling analysis; and the linear correlation is enhanced after the sediment samples are classified according to their grain size compositions and regression analysis are carried out for different groups, indicating the influence of the composition factor. The relationship between the two types of analysis not only depends upon the region in consideration, it is but also related to the grain size composition patterns.
2008, 26(1): 61-69.
Abstract:
It is typically developed Dalazi Formation stratigraphy of Early Cretaceous in Songjiang Basin of Yanbian region of Jilin Province. According to lithologic series, from bottom to top, the stratigraphy of Dalazi Formation is divided into sandstoneconglomerate sector and oilbearing shale sector. On the basis of the analyses of rock types of field sections and outcrops, grain features, primary sedimentary structure, paleontology fossil combination of Dalazi Formation, 4 sedimentary facies are recognized: luvial fan facies, fan delta facies, lake facies and lake subaqueous fan, with 9 sedimentary subfacies. Plan view, fluvial fan is mainly formed in the south of Toudaogou, southeast of Basin, the belt zone along Yangcaogou to Dongnancha and northeast of Basin; Fan delta chiefly occurs at the circum of Basin, the east of ShajingouYangcaogou and the south of YangcaogouXiaoshahe, and of which is much rich in northwest of Xiaoshahe; Lake facies mostly emergent at the center of Basin and the zone along Laopianpo, Dongshan, Shajingou, Songjiangtun; Lake subaqueous fan nearly concentrated in the zone north of SongjiangzhenShajingou, and some formed in the south of Dongnancha. The sedimentation and evolution of Dalazi Formation in Songliao Basin is obviously influenced and controlled by local tectonic activities, paleotopography, paleoclimate and baselevel change. Early of Dalazi Formation, the Basin developed fluvial fan and fan delta, but lake facies is confided .The deposit center located in the belt of XiaoshaheXinfeng and the sediments maily came from the northeast of the basin. After that, the basin expanded southwards, with deposit center moving to the zone of YangmutunShenglitun. The basin developed lake facies, with some lake subaqueous fans distributed in somewhere of moderate deep lake and deep lake.
It is typically developed Dalazi Formation stratigraphy of Early Cretaceous in Songjiang Basin of Yanbian region of Jilin Province. According to lithologic series, from bottom to top, the stratigraphy of Dalazi Formation is divided into sandstoneconglomerate sector and oilbearing shale sector. On the basis of the analyses of rock types of field sections and outcrops, grain features, primary sedimentary structure, paleontology fossil combination of Dalazi Formation, 4 sedimentary facies are recognized: luvial fan facies, fan delta facies, lake facies and lake subaqueous fan, with 9 sedimentary subfacies. Plan view, fluvial fan is mainly formed in the south of Toudaogou, southeast of Basin, the belt zone along Yangcaogou to Dongnancha and northeast of Basin; Fan delta chiefly occurs at the circum of Basin, the east of ShajingouYangcaogou and the south of YangcaogouXiaoshahe, and of which is much rich in northwest of Xiaoshahe; Lake facies mostly emergent at the center of Basin and the zone along Laopianpo, Dongshan, Shajingou, Songjiangtun; Lake subaqueous fan nearly concentrated in the zone north of SongjiangzhenShajingou, and some formed in the south of Dongnancha. The sedimentation and evolution of Dalazi Formation in Songliao Basin is obviously influenced and controlled by local tectonic activities, paleotopography, paleoclimate and baselevel change. Early of Dalazi Formation, the Basin developed fluvial fan and fan delta, but lake facies is confided .The deposit center located in the belt of XiaoshaheXinfeng and the sediments maily came from the northeast of the basin. After that, the basin expanded southwards, with deposit center moving to the zone of YangmutunShenglitun. The basin developed lake facies, with some lake subaqueous fans distributed in somewhere of moderate deep lake and deep lake.
2008, 26(1): 128-138.
Abstract:
The grain size and contents of heavy metals, As, P and N of sediments have been analyzed for the environmental and sedimentological survey along the coast of Bohai Gulf. The contents of heavy metals and As in the surficial sediments less than ＜62.5μm are varied greatly. Average value of Hg,Cd,Cu,Ni,Pb,Zn,Cr,Mn and As (μg/g) along the coast of Tianjin is 0.15,0.19,31.6,46.5,29,112,82,1008 and 16.2, respectively. They are 0.08,0.44,24.2,34.1,29,96,64.4,976 and 13.1 along the coast of Liaoning Province, and 0.03,0.13,20.3,28.7,22.7,58,63,888 and 8.5 along the coast of Hebei Province. The high values of Hg,Cr and As (μg/g) along the coast of Tianjin are 0.26～0.35，83.4～94.9 and 23.3. It is found that the contents of Hg, Cd and Zn in the sediment of a local site of Hebei Province are high up to 3.12, 2.01 and 602 (μg/g), respectively. The results described above reflect that the sediments along the coast of Bohai Gulf have been contaminated by heavy metals and As in a different degree. Contents of TN and TP (mg/g) in the sediment of the Hg,Cd,Znheavy contaminated site of Hebei Province are high up to 6.6 and 1.5, so that it is need further to study the toxic effect on benthic organisms.
The grain size and contents of heavy metals, As, P and N of sediments have been analyzed for the environmental and sedimentological survey along the coast of Bohai Gulf. The contents of heavy metals and As in the surficial sediments less than ＜62.5μm are varied greatly. Average value of Hg,Cd,Cu,Ni,Pb,Zn,Cr,Mn and As (μg/g) along the coast of Tianjin is 0.15,0.19,31.6,46.5,29,112,82,1008 and 16.2, respectively. They are 0.08,0.44,24.2,34.1,29,96,64.4,976 and 13.1 along the coast of Liaoning Province, and 0.03,0.13,20.3,28.7,22.7,58,63,888 and 8.5 along the coast of Hebei Province. The high values of Hg,Cr and As (μg/g) along the coast of Tianjin are 0.26～0.35，83.4～94.9 and 23.3. It is found that the contents of Hg, Cd and Zn in the sediment of a local site of Hebei Province are high up to 3.12, 2.01 and 602 (μg/g), respectively. The results described above reflect that the sediments along the coast of Bohai Gulf have been contaminated by heavy metals and As in a different degree. Contents of TN and TP (mg/g) in the sediment of the Hg,Cd,Znheavy contaminated site of Hebei Province are high up to 6.6 and 1.5, so that it is need further to study the toxic effect on benthic organisms.
2008, 26(1): 144-150.
Abstract:
A Holocene loesssoil profile is studied on the river terraces, hills and plateaus of the east piedmont of the Songshan Mountain in the upper reaches of the Yinghe River as a tributary of the Huihe River. Higher resolution proxy data of magnetic susceptibility, particle size distribution and >0.063 mm% were obtained from the profile. Chronology framework of the data series was decided by a stratigraphic correlation. Based on analysis of characteristic of magnetic susceptibility and grainsize of the loesssoil profile, the paper discussed the relation of the grainsize distribution of loesssoil sequences in the upper reaches of the Yinghe River and the sandstorm activity in the Yellow River floodplain, then probed into the characteristic of the sandstorm activity during the Holocene climatic various stages in the Yellow River floodplain. During the late Holocene (3100～0 a B.P.) while the climate was tended to become arid, the flooding frequency in the lower riches of the Yellow River was increasing, the area of dust activity extending, the sandstorm activity intensity was more strong.
A Holocene loesssoil profile is studied on the river terraces, hills and plateaus of the east piedmont of the Songshan Mountain in the upper reaches of the Yinghe River as a tributary of the Huihe River. Higher resolution proxy data of magnetic susceptibility, particle size distribution and >0.063 mm% were obtained from the profile. Chronology framework of the data series was decided by a stratigraphic correlation. Based on analysis of characteristic of magnetic susceptibility and grainsize of the loesssoil profile, the paper discussed the relation of the grainsize distribution of loesssoil sequences in the upper reaches of the Yinghe River and the sandstorm activity in the Yellow River floodplain, then probed into the characteristic of the sandstorm activity during the Holocene climatic various stages in the Yellow River floodplain. During the late Holocene (3100～0 a B.P.) while the climate was tended to become arid, the flooding frequency in the lower riches of the Yellow River was increasing, the area of dust activity extending, the sandstorm activity intensity was more strong.
2008, 26(1): 158-162.
Abstract:
He and Ar isotopic compositions of fourteen natural gas samples from the north margin of Qaidam Basin were analyzed. The relation of gas and source was also correlated using 40Ar/36Ar ratio. It is found that the 40Ar/36Ar values of natural gases in the area distribute in the range from 951 to 1 712, averaging 1098, with most values higher than 40Ar/36Ar values of the Jurassic natural gases from other Chinese basins. The research shows that there were not mantle derived fluid with high 40Ar/36Ar values in the region, and an aging effect of reservoirs could not result in the phenomena. Therefore, the higher 40Ar/36Ar values are mainly caused by the aging effect of source rocks. By calculation, the age of gas source rocks distributes between 164.7 and 460.8 Ma, averaging 345.1 Ma, showing that the most might be from Carboniferous. This conclusion is in agreement with the fact that there are widely distributed Carboniferous source rocks and crude oils derived from the Carboniferous. The discovery of the Carboniferous gases in the area indicates that Carboniferous is a new exploration target, developing a new exploring area in the north margin of Qaidam Basin.
He and Ar isotopic compositions of fourteen natural gas samples from the north margin of Qaidam Basin were analyzed. The relation of gas and source was also correlated using 40Ar/36Ar ratio. It is found that the 40Ar/36Ar values of natural gases in the area distribute in the range from 951 to 1 712, averaging 1098, with most values higher than 40Ar/36Ar values of the Jurassic natural gases from other Chinese basins. The research shows that there were not mantle derived fluid with high 40Ar/36Ar values in the region, and an aging effect of reservoirs could not result in the phenomena. Therefore, the higher 40Ar/36Ar values are mainly caused by the aging effect of source rocks. By calculation, the age of gas source rocks distributes between 164.7 and 460.8 Ma, averaging 345.1 Ma, showing that the most might be from Carboniferous. This conclusion is in agreement with the fact that there are widely distributed Carboniferous source rocks and crude oils derived from the Carboniferous. The discovery of the Carboniferous gases in the area indicates that Carboniferous is a new exploration target, developing a new exploring area in the north margin of Qaidam Basin.
2008, 26(1): 168-177.
Abstract:
Based on vitrinite reflectivity analysis, paleogeotemperature inversion and X ray diffraction series of the smallest granule illite crystallinity, this paper has analyzed thermal evolution of source rock since CarboniferousPermian. The result indicates that 1:CarboniferousPermian source rock was in high maturity, entered threshold of oil generation after the lower Jurassic deposition. After the upper Jurassic, paleogeotemperature was up to 245℃. 2: Fanghushan Formation of the lower Jurassic was also in higher maturity, entered threshold of oil generation after the middle Jurassic, maximal paleogeotemperature up to 260℃ after the middle Cretaceous. 3: Middleupper Jurassic enter threshold of oil generation at lower Cretaceous. Its maximal paleogeotemperature up to 225℃ and 230℃ after Zhuxiang Formation.4: Maximal paleogeotemperature of Zhuxiang Formation up to 110120℃ at the end of the early Cretaceous 5:. Dingyuan Formation of paleogene is immature, maximal paleogeotemperature less than 50℃ after Dingyuan Formation deposition.
Based on vitrinite reflectivity analysis, paleogeotemperature inversion and X ray diffraction series of the smallest granule illite crystallinity, this paper has analyzed thermal evolution of source rock since CarboniferousPermian. The result indicates that 1:CarboniferousPermian source rock was in high maturity, entered threshold of oil generation after the lower Jurassic deposition. After the upper Jurassic, paleogeotemperature was up to 245℃. 2: Fanghushan Formation of the lower Jurassic was also in higher maturity, entered threshold of oil generation after the middle Jurassic, maximal paleogeotemperature up to 260℃ after the middle Cretaceous. 3: Middleupper Jurassic enter threshold of oil generation at lower Cretaceous. Its maximal paleogeotemperature up to 225℃ and 230℃ after Zhuxiang Formation.4: Maximal paleogeotemperature of Zhuxiang Formation up to 110120℃ at the end of the early Cretaceous 5:. Dingyuan Formation of paleogene is immature, maximal paleogeotemperature less than 50℃ after Dingyuan Formation deposition.
