2018 Vol. 43, No. S1
Display Method:
2018, (S1): 1-9.
doi: 10.3799/dqkx.2018.524
PDF 10198KB
Abstract:
Functional genes could be qualitatively analyzed by real{{{\hyphen{}}}}time fluorescence PCR, but there is still much to learn from the qualitative data to qualitative reservoir prediction, especially great significance to the exploration of subtle reservoirs. Suganhu basin was studied in this work, which has the features of low exploration degree. 191 samples was collected with the interval of 1{{\hyphen{}}}4 km and the depth of 50 cm. Then the numbers of methane, propane oxidation bacteria functional genes ({\it pmoA}, {\it prmA}) in the samples were measured. Furthermore, based on the cumulative probability distribution and regression analysis, the anomaly grade classification system has been built, combing the anomaly zone with the strata interpreted by geophysical exploration, the favorable exploration areas of oil and gas in Suganhu basin were delineated. The results indicated that: the cumulative probability of {\it pmoA}, {\it prmA} nearly conform the 4\textsuperscript{{\it X}} $\times$ 10\textsuperscript{4}, 2\textsuperscript{{\it X}} $\times$ 10\textsuperscript{4} copies/g index distribution respectively, The natural numbers as 1, 2, 3, 4 were assigned to these two equations, thus obtained 4, 16, 64, 256 and (2, 4, 8, 16) $\times$ 10\textsuperscript{4} copies/g to divide the anomaly grades to four: low, medium, high and super. Anomaly zones above the medium level distribute in the east, west and central of basin, the medium anomaly zones in the east and west distribute slightly north of Permian and Jurassic strata, the medium anomaly zone in the central distribute between the two strata, these three medium anomaly zones above were delineated as the favorable exploration area of the~basin.
Functional genes could be qualitatively analyzed by real{{{\hyphen{}}}}time fluorescence PCR, but there is still much to learn from the qualitative data to qualitative reservoir prediction, especially great significance to the exploration of subtle reservoirs. Suganhu basin was studied in this work, which has the features of low exploration degree. 191 samples was collected with the interval of 1{{\hyphen{}}}4 km and the depth of 50 cm. Then the numbers of methane, propane oxidation bacteria functional genes ({\it pmoA}, {\it prmA}) in the samples were measured. Furthermore, based on the cumulative probability distribution and regression analysis, the anomaly grade classification system has been built, combing the anomaly zone with the strata interpreted by geophysical exploration, the favorable exploration areas of oil and gas in Suganhu basin were delineated. The results indicated that: the cumulative probability of {\it pmoA}, {\it prmA} nearly conform the 4\textsuperscript{{\it X}} $\times$ 10\textsuperscript{4}, 2\textsuperscript{{\it X}} $\times$ 10\textsuperscript{4} copies/g index distribution respectively, The natural numbers as 1, 2, 3, 4 were assigned to these two equations, thus obtained 4, 16, 64, 256 and (2, 4, 8, 16) $\times$ 10\textsuperscript{4} copies/g to divide the anomaly grades to four: low, medium, high and super. Anomaly zones above the medium level distribute in the east, west and central of basin, the medium anomaly zones in the east and west distribute slightly north of Permian and Jurassic strata, the medium anomaly zone in the central distribute between the two strata, these three medium anomaly zones above were delineated as the favorable exploration area of the~basin.
2018, (S1): 10-18.
doi: 10.3799/dqkx.2018.911
Abstract:
To investigate the composition and diversity of nitrogen-fixing bacteria community and their responses to temperature gradients along two hot spring channels in Tengchong, Yunnan Province, China. Five sampling locations in the Hmzfj channel and four sampling locations in the Srbz channel were selected along outflows of each corresponding channel. The temperature and pH of the sampled waters were measured. The diversity of nitrogen-fixing bacteria community was studied through phylogenetic analyses of {\it nifH} genes. Temperatures of the nine sampling sites in the two hot spring channels in Tengchong range from 40.7 $^\circ$\hspace{-0.8pt}C to 86.8 $^\circ$\hspace{-0.8pt}C with a pH gradient of 6.5-8.7. Seven {\it nifH} gene clone libraries were constructed, and a total of 255 clones were randomly picked and subjected to phylogenetic analysis. The obtained {\it nifH} gene clones were grouped into 25~OTUs (operational taxonomic unit) at the cutoff of 97\% similarity. The nitrogen-fixing bacteria are mainly composed of {\it Chloroflexi}, {\it Cyanobacteria} and {\it Proteobacteria} in the two studied geothermal channels. Diversity indices of nitrogen-fixing bacteria community show no distinct differences among the studied sites. The PCoA (principal coordinates analysis) and cluster analyses illustrate that temperature played an important role in shaping the community structures of nitrogen-fixing bacteria in the studied samples. Temperature was the major factor influencing the composition of nitrogen-fixing bacteria community in Tengchong hot~springs
To investigate the composition and diversity of nitrogen-fixing bacteria community and their responses to temperature gradients along two hot spring channels in Tengchong, Yunnan Province, China. Five sampling locations in the Hmzfj channel and four sampling locations in the Srbz channel were selected along outflows of each corresponding channel. The temperature and pH of the sampled waters were measured. The diversity of nitrogen-fixing bacteria community was studied through phylogenetic analyses of {\it nifH} genes. Temperatures of the nine sampling sites in the two hot spring channels in Tengchong range from 40.7 $^\circ$\hspace{-0.8pt}C to 86.8 $^\circ$\hspace{-0.8pt}C with a pH gradient of 6.5-8.7. Seven {\it nifH} gene clone libraries were constructed, and a total of 255 clones were randomly picked and subjected to phylogenetic analysis. The obtained {\it nifH} gene clones were grouped into 25~OTUs (operational taxonomic unit) at the cutoff of 97\% similarity. The nitrogen-fixing bacteria are mainly composed of {\it Chloroflexi}, {\it Cyanobacteria} and {\it Proteobacteria} in the two studied geothermal channels. Diversity indices of nitrogen-fixing bacteria community show no distinct differences among the studied sites. The PCoA (principal coordinates analysis) and cluster analyses illustrate that temperature played an important role in shaping the community structures of nitrogen-fixing bacteria in the studied samples. Temperature was the major factor influencing the composition of nitrogen-fixing bacteria community in Tengchong hot~springs
2018, (S1): 31-41.
doi: 10.3799/dqkx.2018.276
Abstract:
Microbially mediated carbon cycles are the core component of biogeochemical element cyclingin hot spring ecosystem. Thus, the study of microbes and their metabolic mechamisms involved in carbon cycling in hot springs avails to reveal the origin and evolution of early life on Earth and to explore extraterrestrial life, and has great significance in bioengineering applications. Focus was given on the phylogenetic distribution of functional microorganisms involved in geothermal carbon cycling and their functional gene abundance, activity and composition in response to environmental factors (e.g., temperature, pH).This review aimsto understand the current situation of microbes driving carbon cycles in hot springs and provide theoretical basis for~futureresearch
Microbially mediated carbon cycles are the core component of biogeochemical element cyclingin hot spring ecosystem. Thus, the study of microbes and their metabolic mechamisms involved in carbon cycling in hot springs avails to reveal the origin and evolution of early life on Earth and to explore extraterrestrial life, and has great significance in bioengineering applications. Focus was given on the phylogenetic distribution of functional microorganisms involved in geothermal carbon cycling and their functional gene abundance, activity and composition in response to environmental factors (e.g., temperature, pH).This review aimsto understand the current situation of microbes driving carbon cycles in hot springs and provide theoretical basis for~futureresearch
2018, (S1): 31-41.
doi: 10.3799/dqkx.2018.511
Abstract:
To study the gene diversity involved in the Kalvin pathway of carbon fixation and its response to environmental variables in the lake surface sediments on the northern Qinghai- Tibetan plateau. In this study, we collected surface sediments from six typical lakes (Erhai Lake, Qinghai Lake, Tuosu Lake, Gahai Lake, Xiaochaidan Lake, Chaka Lake) on the Qinghai- Tibetan plateau. The carbon- fixing bacteria diversity in the collected samples was investigated by using the rbcL gene- based phylogenetic analysis. Correlation analysis was performed between the rbcL gene diversity and environmental parameters of the studied lakes. The phylogenetic analyses show that the rbcL gene population in the studied samples are classified into three phyla, i.e. Proteobacteria , Cyanobacteria , and Chlorophyta , and into eight classes, i.e. Acidithiobacillia , $\alpha$- Proteobacteria , $\beta$- Proteobacteria , $\gamma$- Proteobacteria , Chroococcidiopsidales , Oscillatoriophycideae , Synechococcales , and Chlorophyceae . In the freshwater lakes (Erhai Lake), the Synechococcales - related clones are dominant (the relative abundance is 71.32%); In the saline lakes (Qinghai Lake, Tuosu Lake), $\beta$- Proteobacteria , Synechococcale , and Oscillatoriophycideae are dominant classes (the relative abundances are 36.20%, 23.47%, and 22.02%, respectively); In the hypersaline lakes (Gahai Lake, Xiaochaidan Lake, Chaka lake), Acidithiobacillia and Chlorophyceae ~are dominant classes (the relative abundances are 53.33% and 30.40%, respectively). The rbcL gene population composition show significant ( p 0.05) correlations with salinity, dissolved organic carbon (DOC), TP, TN, dissolved inorganic carbon (DIC), pH and chlorophyll- a. Aggregated boosted tree (ABT) analyses show that TP and salinity are the two factors contributing the most (accounting for 20.04% and 16.81% of the microbial variation) to shaping carbon fixing microbial communities in the studied lakes. The majority of the rbcL gene population is affiliated with the Proteobacteria (mainly Acidithiobacillia ) and Synechococcale in the studied lake surface sediments. The rbcL gene population composition varies significantly among the studied lakes of different salinities, and the lacustrine habitats with similar salinities possess similar rbcL gene population. In summary, TP and salinity is an important factor affecting the distribution of carbon- fixing bacterial~population.
To study the gene diversity involved in the Kalvin pathway of carbon fixation and its response to environmental variables in the lake surface sediments on the northern Qinghai- Tibetan plateau. In this study, we collected surface sediments from six typical lakes (Erhai Lake, Qinghai Lake, Tuosu Lake, Gahai Lake, Xiaochaidan Lake, Chaka Lake) on the Qinghai- Tibetan plateau. The carbon- fixing bacteria diversity in the collected samples was investigated by using the rbcL gene- based phylogenetic analysis. Correlation analysis was performed between the rbcL gene diversity and environmental parameters of the studied lakes. The phylogenetic analyses show that the rbcL gene population in the studied samples are classified into three phyla, i.e. Proteobacteria , Cyanobacteria , and Chlorophyta , and into eight classes, i.e. Acidithiobacillia , $\alpha$- Proteobacteria , $\beta$- Proteobacteria , $\gamma$- Proteobacteria , Chroococcidiopsidales , Oscillatoriophycideae , Synechococcales , and Chlorophyceae . In the freshwater lakes (Erhai Lake), the Synechococcales - related clones are dominant (the relative abundance is 71.32%); In the saline lakes (Qinghai Lake, Tuosu Lake), $\beta$- Proteobacteria , Synechococcale , and Oscillatoriophycideae are dominant classes (the relative abundances are 36.20%, 23.47%, and 22.02%, respectively); In the hypersaline lakes (Gahai Lake, Xiaochaidan Lake, Chaka lake), Acidithiobacillia and Chlorophyceae ~are dominant classes (the relative abundances are 53.33% and 30.40%, respectively). The rbcL gene population composition show significant ( p 0.05) correlations with salinity, dissolved organic carbon (DOC), TP, TN, dissolved inorganic carbon (DIC), pH and chlorophyll- a. Aggregated boosted tree (ABT) analyses show that TP and salinity are the two factors contributing the most (accounting for 20.04% and 16.81% of the microbial variation) to shaping carbon fixing microbial communities in the studied lakes. The majority of the rbcL gene population is affiliated with the Proteobacteria (mainly Acidithiobacillia ) and Synechococcale in the studied lake surface sediments. The rbcL gene population composition varies significantly among the studied lakes of different salinities, and the lacustrine habitats with similar salinities possess similar rbcL gene population. In summary, TP and salinity is an important factor affecting the distribution of carbon- fixing bacterial~population.
2018, (S1): 42-52.
doi: 10.3799/dqkx.2018.912
Abstract:
MODIS and meteorological data were used to analyze the change of climate and vegetation in Three Gorges Reservoir Area (TGRA). The methods used in this study include kriging interpolation, sliding average, linear regression analysis, M{\hyphen{}}K test and geostatistical method. It was found that the annual mean air temperature increased significantly at the rate of 0.015 $^\circ$C/a for the period 1961—2014. Seasonally, the spring, autumn and winter mean air temperature increased significantly. Annual and seasonal precipitation changed insignificantly. In addition, the EVI and NDVI increased significantly and insignificantly, respectively, for the period 2001—2014. Seasonally, the NDVI increased significantly in autumn, and the EVI increased significantly in spring, autumn and winter. Spatially, the annual mean NDVI and EVI increased significantly in 29.74\% and 45.19\% of the study area, respectively. The NDVI and EVI decreased significantly in Chongqing city. The NDVI and EVI in spring were significantly and positively correlated with annual and spring mean air temperature. The EVI in autumn was significantly and negatively correlated with autumn mean air temperature. This study highlights that the mean air temperature has stronger effects on vegetation than precipitation and the effects of global warming on ecological environment at the local scale. The relevant policies in the TGRA have~worked.
MODIS and meteorological data were used to analyze the change of climate and vegetation in Three Gorges Reservoir Area (TGRA). The methods used in this study include kriging interpolation, sliding average, linear regression analysis, M{\hyphen{}}K test and geostatistical method. It was found that the annual mean air temperature increased significantly at the rate of 0.015 $^\circ$C/a for the period 1961—2014. Seasonally, the spring, autumn and winter mean air temperature increased significantly. Annual and seasonal precipitation changed insignificantly. In addition, the EVI and NDVI increased significantly and insignificantly, respectively, for the period 2001—2014. Seasonally, the NDVI increased significantly in autumn, and the EVI increased significantly in spring, autumn and winter. Spatially, the annual mean NDVI and EVI increased significantly in 29.74\% and 45.19\% of the study area, respectively. The NDVI and EVI decreased significantly in Chongqing city. The NDVI and EVI in spring were significantly and positively correlated with annual and spring mean air temperature. The EVI in autumn was significantly and negatively correlated with autumn mean air temperature. This study highlights that the mean air temperature has stronger effects on vegetation than precipitation and the effects of global warming on ecological environment at the local scale. The relevant policies in the TGRA have~worked.
Catalytic Role of Anaerobic Bacteria in Dolomite Formation in Lake~Jibuhulangtu Nuur, Inner~Mongolia
2018, (S1): 53-62.
doi: 10.3799/dqkx.2018.543
Abstract:
Much attention has been attracted to understand the formation mechanism of dolomite, a long-standing problem in earth sciences. A~microbial dolomite model, proposed by geomicrobiologists, has been considered to provide new insights into this old enigma. Although authigenic dolomite is rare in modern marine sediments, the occurrence of dolomite can be found in some hypersaline environments (e.g., tidal flats and saline lakes). Therefore, these highly-evaporating environments are believed as nature laboratory for probing the role of microbe in dolomite formation. In this study, it reports a new discovery of modern dolomite in Lake Jibuhulangtu Nuur, a saline lake in Inner Mongolia. In order to address whether anaerobic microbes are involved in dolomite precipitation in this lake and whether sulfate ion has an impact on this reaction, precipitation experiments using microbial enrichment and pure culture were performed in lab. Our results show that both microbial consortium and strain JN-1 were capable of inducing dolomite precipitation. There were no ordering reflections in X-ray diffraction patterns, thus indicating that these biogenic dolomites were highly disordered. The observations by using scanning electron microscopy further show that the crystal morphology of biogenic dolomite developed during incubation period. In the early incubation stage, dolomite particles were sub-micron sized spherulites, however, they transformed into larger spheroids and dumbbell-shaped crystals. Furthermore, it seemed that sulfate had little effect on microbial dolomite formation. Our findings would be of significance for providing the basic data for the interaction between sulfate ions and dolomite formation, and improving our understanding of the formation mechanism of~dolomite
Much attention has been attracted to understand the formation mechanism of dolomite, a long-standing problem in earth sciences. A~microbial dolomite model, proposed by geomicrobiologists, has been considered to provide new insights into this old enigma. Although authigenic dolomite is rare in modern marine sediments, the occurrence of dolomite can be found in some hypersaline environments (e.g., tidal flats and saline lakes). Therefore, these highly-evaporating environments are believed as nature laboratory for probing the role of microbe in dolomite formation. In this study, it reports a new discovery of modern dolomite in Lake Jibuhulangtu Nuur, a saline lake in Inner Mongolia. In order to address whether anaerobic microbes are involved in dolomite precipitation in this lake and whether sulfate ion has an impact on this reaction, precipitation experiments using microbial enrichment and pure culture were performed in lab. Our results show that both microbial consortium and strain JN-1 were capable of inducing dolomite precipitation. There were no ordering reflections in X-ray diffraction patterns, thus indicating that these biogenic dolomites were highly disordered. The observations by using scanning electron microscopy further show that the crystal morphology of biogenic dolomite developed during incubation period. In the early incubation stage, dolomite particles were sub-micron sized spherulites, however, they transformed into larger spheroids and dumbbell-shaped crystals. Furthermore, it seemed that sulfate had little effect on microbial dolomite formation. Our findings would be of significance for providing the basic data for the interaction between sulfate ions and dolomite formation, and improving our understanding of the formation mechanism of~dolomite
2018, (S1): 63-70.
doi: 10.3799/dqkx.2018.513
Abstract:
The origin of dolomite has remained an enigmatic issue of earth sciences. Dolomite mineral is generally considered as a replacement phase of pre-exsisting carbonate. However, a microbial/organogenic dolomite model has been recently proposed, suggesting that dolomite can also be directly precipitated from solutions with the aid of microorganisms or organic matters, thus providing new insight into the old enigma. This paper reviews the latest progress on the microbial/organogenic dolomite model and discusses how to improve such model. Microbes facilitate low-temperature dolomite formation primarily by enhancing the saturation state with respect to dolomite. Furthermore, the negatively-charged microbial cell walls can be functioned as template for dolomite nucleation. Microbial dolomite normally displays spherical, dumbbell and cauliflower-like morphologies. Microbially-induced dolomite formation can be facilitated by elevated salinity. The role of sulfate on microbial dolomite formation still awaits resolution. The recent studies have also demonstrated that microbial exopolymeric substances (EPS) play an important role in the dewatering of Mg-H2O complexes. In the similar manner with microbial EPS, natural organic matters can also catalyze dolomite precipitation. However, growing evidence shows that microbes could only precipitate proto-dolomite rather than ordered-dolomite. More studies are required to improve our understanding of the alteration of microbial/organogenic dolomite during burial~diagenesis
The origin of dolomite has remained an enigmatic issue of earth sciences. Dolomite mineral is generally considered as a replacement phase of pre-exsisting carbonate. However, a microbial/organogenic dolomite model has been recently proposed, suggesting that dolomite can also be directly precipitated from solutions with the aid of microorganisms or organic matters, thus providing new insight into the old enigma. This paper reviews the latest progress on the microbial/organogenic dolomite model and discusses how to improve such model. Microbes facilitate low-temperature dolomite formation primarily by enhancing the saturation state with respect to dolomite. Furthermore, the negatively-charged microbial cell walls can be functioned as template for dolomite nucleation. Microbial dolomite normally displays spherical, dumbbell and cauliflower-like morphologies. Microbially-induced dolomite formation can be facilitated by elevated salinity. The role of sulfate on microbial dolomite formation still awaits resolution. The recent studies have also demonstrated that microbial exopolymeric substances (EPS) play an important role in the dewatering of Mg-H2O complexes. In the similar manner with microbial EPS, natural organic matters can also catalyze dolomite precipitation. However, growing evidence shows that microbes could only precipitate proto-dolomite rather than ordered-dolomite. More studies are required to improve our understanding of the alteration of microbial/organogenic dolomite during burial~diagenesis
2018, (S1): 71-83.
doi: 10.3799/dqkx.2018.950
Abstract:
To better understand the seasonal variation of bGDGTs in soils, we collected samples time{\hyphen{}}serially from several Chinese alkaline soils over 1 year. On the seasonal scale, the composition of bGDGTs is the result of a long{\hyphen{}}time adaption to temperature variation rather than a short{\hyphen{}}time adjustment. bGDGTs{\hyphen{}}derived temperatures in soils from cold and high altitude of Tibet Plateau are likely to reflect the temperature of spring/summer transition period. However, in other sites, the distribution and proxies of bGDGTs don’t show significant seasonal variation or bias. Furthermore, soil pH appears to be the main reason for discrepancy in slopes of different calibrations, which can result in distinct calibration formulas in soils. Combining with the previously published datasets, our results demonstrate that the responses of MBT index to temperature are different in alkaline and acidic soils. Here, we propose an MBT{\hyphen{}}MAAT calibration in neutral to alkaline soils: MAAT = 20.78 $\times$ MBT + 5.92 ({\it R}\textsuperscript{2} = 0.88, {\it p} \textless{} 0.001) (5$\sim$25 $^\circ$C). This calibration partially amends the impact of soil pH on MBT{\hyphen{}}MAAT relationship, which provides more accurate calibration for paleotemperature reconstruction in specific regions of~China.
To better understand the seasonal variation of bGDGTs in soils, we collected samples time{\hyphen{}}serially from several Chinese alkaline soils over 1 year. On the seasonal scale, the composition of bGDGTs is the result of a long{\hyphen{}}time adaption to temperature variation rather than a short{\hyphen{}}time adjustment. bGDGTs{\hyphen{}}derived temperatures in soils from cold and high altitude of Tibet Plateau are likely to reflect the temperature of spring/summer transition period. However, in other sites, the distribution and proxies of bGDGTs don’t show significant seasonal variation or bias. Furthermore, soil pH appears to be the main reason for discrepancy in slopes of different calibrations, which can result in distinct calibration formulas in soils. Combining with the previously published datasets, our results demonstrate that the responses of MBT index to temperature are different in alkaline and acidic soils. Here, we propose an MBT{\hyphen{}}MAAT calibration in neutral to alkaline soils: MAAT = 20.78 $\times$ MBT + 5.92 ({\it R}\textsuperscript{2} = 0.88, {\it p} \textless{} 0.001) (5$\sim$25 $^\circ$C). This calibration partially amends the impact of soil pH on MBT{\hyphen{}}MAAT relationship, which provides more accurate calibration for paleotemperature reconstruction in specific regions of~China.
2018, (S1): 84-96.
doi: 10.3799/dqkx.2018.580
Abstract:
Vanadium is a typical redox-sensitive element that is abundant in the crust and is a superior catalyst in modern industry. Due to the geological weathering and intensive human activities such as mining, smelting and applications, vanadium pollution in soil and groundwater is becoming more and more serious, arousing widespread concern of researchers. This article reviews the latest research progress of remediation of vanadium contamination in soil and groundwater from three aspects: physical methods, chemical methods and biological methods. Physical methods include soil replacement and electrolysis. Chemical methods include chemical leaching, chemical adsorption and chemical reduction immobilization. Biological methods include phytoremediation and microbial remediation. Meanwhile, the trend of the development in remediation technology of vanadium contaminated soil and groundwater is also forecasted, which will provide reference for subsequent researches.
Vanadium is a typical redox-sensitive element that is abundant in the crust and is a superior catalyst in modern industry. Due to the geological weathering and intensive human activities such as mining, smelting and applications, vanadium pollution in soil and groundwater is becoming more and more serious, arousing widespread concern of researchers. This article reviews the latest research progress of remediation of vanadium contamination in soil and groundwater from three aspects: physical methods, chemical methods and biological methods. Physical methods include soil replacement and electrolysis. Chemical methods include chemical leaching, chemical adsorption and chemical reduction immobilization. Biological methods include phytoremediation and microbial remediation. Meanwhile, the trend of the development in remediation technology of vanadium contaminated soil and groundwater is also forecasted, which will provide reference for subsequent researches.
2018, (S1): 97-105.
doi: 10.3799/dqkx.2018.561
Abstract:
In our research we probed the microbial community composition in near wellbore zone of injection wells and the influence that the different nutrition systems-stimulations have on the oil reservoir microbial metabolism and the displacement process. We investigated the microbial community construction and succession in flowback fluid samples from different stages by high-throughput sequencing and real-time PCR at first, and then we used laboratory shaking culture to detect the influence on indigenous microorganisms stimulation effect which made by flowback fluid samples of different stages, different nutrient types and oxygen supplements. Our results indicated that the composition of initial microbial community from the flowback fluid samples of different stages have significantly difference, and its dominant microbial community have similarity after the stimulation of same nutrition system. The stimulation level of hydrocarbon degrading bacteria such as Dietzia, Actinomycetes is closely related with oil emulsification effect. In the zone near injection wells, timely oxygen supplement is beneficial to emulsification, which is necessary to activate indigenous microorganisms and enhanced oil recovery. Compared with the amount of 16S rRNA、rhlAB、alkB genes, the amount of cyp153 gene and pH of stimulated samples are more suitable index to measure emulsifying effect in MEOR progess.
In our research we probed the microbial community composition in near wellbore zone of injection wells and the influence that the different nutrition systems-stimulations have on the oil reservoir microbial metabolism and the displacement process. We investigated the microbial community construction and succession in flowback fluid samples from different stages by high-throughput sequencing and real-time PCR at first, and then we used laboratory shaking culture to detect the influence on indigenous microorganisms stimulation effect which made by flowback fluid samples of different stages, different nutrient types and oxygen supplements. Our results indicated that the composition of initial microbial community from the flowback fluid samples of different stages have significantly difference, and its dominant microbial community have similarity after the stimulation of same nutrition system. The stimulation level of hydrocarbon degrading bacteria such as Dietzia, Actinomycetes is closely related with oil emulsification effect. In the zone near injection wells, timely oxygen supplement is beneficial to emulsification, which is necessary to activate indigenous microorganisms and enhanced oil recovery. Compared with the amount of 16S rRNA、rhlAB、alkB genes, the amount of cyp153 gene and pH of stimulated samples are more suitable index to measure emulsifying effect in MEOR progess.
2018, (S1): 106-114.
doi: 10.3799/dqkx.2018.560
Abstract:
Magnetotactic bacteria (MTB) biomineralize intracellular magnetite (Fe3O4) and/or greigite (Fe3S4) magnetosomes. They are widely distributed in aquatic environments and play important roles in the biogeochemical cycles of Fe, S, C, N and P. Due to their difficulty of cultivation our knowledge on the diversity and environmental function of MTB remains very limited. Here, we have characterized a group of uncultivated MTB from Pond Lianhua in Beijing, China. Light and scanning electron microscopy shows coccoid and vibrioid in cell morphologies. Transmission electron microscopy and energy dispersive spectroscopy indicate that the mineral phase of magnetosomes is magnetite and that some cells of MTB contain large amount of intracellular sulfur and magnesium. 16S rRNA gene-based cultivation-independent analysis has identified seven operational taxonomic units (OTUs) belonging to the Alphaproteobacteria and Gammaproteobacteria in the Proteobacteria phylum. Taken together, our results highlight a high diversity of MTB in environment that may contribute to the geochemical cycling of iron and other~elements.
Magnetotactic bacteria (MTB) biomineralize intracellular magnetite (Fe3O4) and/or greigite (Fe3S4) magnetosomes. They are widely distributed in aquatic environments and play important roles in the biogeochemical cycles of Fe, S, C, N and P. Due to their difficulty of cultivation our knowledge on the diversity and environmental function of MTB remains very limited. Here, we have characterized a group of uncultivated MTB from Pond Lianhua in Beijing, China. Light and scanning electron microscopy shows coccoid and vibrioid in cell morphologies. Transmission electron microscopy and energy dispersive spectroscopy indicate that the mineral phase of magnetosomes is magnetite and that some cells of MTB contain large amount of intracellular sulfur and magnesium. 16S rRNA gene-based cultivation-independent analysis has identified seven operational taxonomic units (OTUs) belonging to the Alphaproteobacteria and Gammaproteobacteria in the Proteobacteria phylum. Taken together, our results highlight a high diversity of MTB in environment that may contribute to the geochemical cycling of iron and other~elements.
2018, (S1): 115-126.
doi: 10.3799/dqkx.2018.535
Abstract:
Many organisms, including microbes, insects, fish, birds and mammals, sense and use Earth’s magnetic field for orientation and navigation, a physiological trait known as magnetoreception or magnetotaxis. Magnetotactic bacteria (MTB) biomineralize intracellular chain(s) of membrane-bounded, nano-sized magnetosome crystals of either magnetite (Fe3O4) or greigite (Fe3S4) for magnetotaxis. So far, magnetosomes in MTB are the only magnetoreceptor that have been characterized and are therefore the model system with which the origin and evolution of magnetotaxis as well as microbial biomineralization can be explored. MTB also play important roles in the geochemical cycling of iron, sulfur, nitrogen and carbon. Here we review recent contributions to the fields of diversity, biogeography, origin, magnetotaxis, biomineralization mechanisms and environmental function of MTB. Novel technologies including metagenomics, single-cell genomics and nanoscale secondary ion mass spectrometry (NanoSIMS) that have recently been successfully applied to the research of MTB are also~summarized.
Many organisms, including microbes, insects, fish, birds and mammals, sense and use Earth’s magnetic field for orientation and navigation, a physiological trait known as magnetoreception or magnetotaxis. Magnetotactic bacteria (MTB) biomineralize intracellular chain(s) of membrane-bounded, nano-sized magnetosome crystals of either magnetite (Fe3O4) or greigite (Fe3S4) for magnetotaxis. So far, magnetosomes in MTB are the only magnetoreceptor that have been characterized and are therefore the model system with which the origin and evolution of magnetotaxis as well as microbial biomineralization can be explored. MTB also play important roles in the geochemical cycling of iron, sulfur, nitrogen and carbon. Here we review recent contributions to the fields of diversity, biogeography, origin, magnetotaxis, biomineralization mechanisms and environmental function of MTB. Novel technologies including metagenomics, single-cell genomics and nanoscale secondary ion mass spectrometry (NanoSIMS) that have recently been successfully applied to the research of MTB are also~summarized.
2018, (S1): 127-135.
doi: 10.3799/dqkx.2018.584
Abstract:
In recent years,the development and utilization of underground space has gained increasing interests and the construction of underground ecological livable cities and deep underground laboratories of science and engineering has become realities and achievable goals. However, abundant and diverse groups of underground microorganisms, such asarchaea, bacteria and fungi, will impact substantially on human development and utilization of underground space, of which one issue is how microorganisms affect the management of underground waste disposal. The results demonstrate that the activity of sulfate-reducing bacteria leads to the corrosion of underground engineering facilities and gas produced by the underground microorganism has a negative impact on the performance of nuclear waste disposal chambers and nuclear waste containers since it changes the underground space pressure during the long-term management of nuclear waste. This paper outlines the current understandings of the underground microorganisms and the implications for the long-term management of nuclear~waste.
In recent years,the development and utilization of underground space has gained increasing interests and the construction of underground ecological livable cities and deep underground laboratories of science and engineering has become realities and achievable goals. However, abundant and diverse groups of underground microorganisms, such asarchaea, bacteria and fungi, will impact substantially on human development and utilization of underground space, of which one issue is how microorganisms affect the management of underground waste disposal. The results demonstrate that the activity of sulfate-reducing bacteria leads to the corrosion of underground engineering facilities and gas produced by the underground microorganism has a negative impact on the performance of nuclear waste disposal chambers and nuclear waste containers since it changes the underground space pressure during the long-term management of nuclear waste. This paper outlines the current understandings of the underground microorganisms and the implications for the long-term management of nuclear~waste.
2018, (S1): 136-144.
doi: 10.3799/dqkx.2018.545
Abstract:
Methane is one of the most important greenhouse gases from nature and the renewable energy sources that human beings have explored extensively. Iron oxides, abundant mineral sources on earth, its interaction with anaerobic microorganism can exert significant influences on the methanogenic process. This review summarizes and discusses the different influences of iron oxides-anaerobic microorganism on the process of methanogenesis, including the change of iron oxides and microbial community, and the action mechanisms of iron oxides. Iron oxide could be dissolved and reduced by the microbe and novel mineral phase is generated under certain conditions. Microbial community and the function are influenced by the iron oxides which result in the change of methanogenic process. The influence could be mainly summarized as follows: (1) Fe3+/Fe2+generated from the dissolution and reduction of iron oxides influenced the microbial activity and redox potential of the surrounding environments; (2) iron reducing bacteria competed with methanogens for substrate; (3) direct toxicity of iron oxides on methanogens; (4) conductive iron oxides worked as electron conduits and promoted direct interspecies electron transfer between iron reducing bacteria syntrophic bacteria and methanogens. Finally, the research trends and main problems are proposed, which are expected to promote the studies on interaction between iron oxides and anaerobic microorganism and their environment effects
Methane is one of the most important greenhouse gases from nature and the renewable energy sources that human beings have explored extensively. Iron oxides, abundant mineral sources on earth, its interaction with anaerobic microorganism can exert significant influences on the methanogenic process. This review summarizes and discusses the different influences of iron oxides-anaerobic microorganism on the process of methanogenesis, including the change of iron oxides and microbial community, and the action mechanisms of iron oxides. Iron oxide could be dissolved and reduced by the microbe and novel mineral phase is generated under certain conditions. Microbial community and the function are influenced by the iron oxides which result in the change of methanogenic process. The influence could be mainly summarized as follows: (1) Fe3+/Fe2+generated from the dissolution and reduction of iron oxides influenced the microbial activity and redox potential of the surrounding environments; (2) iron reducing bacteria competed with methanogens for substrate; (3) direct toxicity of iron oxides on methanogens; (4) conductive iron oxides worked as electron conduits and promoted direct interspecies electron transfer between iron reducing bacteria syntrophic bacteria and methanogens. Finally, the research trends and main problems are proposed, which are expected to promote the studies on interaction between iron oxides and anaerobic microorganism and their environment effects
2018, (S1): 145-156.
doi: 10.3799/dqkx.2018.914
Abstract:
In order to simulate bio-reduction of manganese oxides and coupled carbonate precipitation induced by microbes in shallow sea environments, we took one of the most common manganese oxides-birnessite (K0.33Mn7O14~7H2O) as an example and carried out experiments under different Mg2+ and SO42- concentrations, where dissimilatory manganese-reducing bacteria Dietzia cercidiphylli 45-1b reduced birnessite under aerobic conditions. By analyzing variations of the concentrations of protein, Mn2+, etc., alongside X-ray powder diffraction (XRD) and X-ray absorption spectroscopy (XAS) for mineralogical transformations analyses, we discussed the impact on birnessite reduction and carbonate precipitation by Strain 45-1b under different initial concentrations of Mg2+ and SO42-. Results show that the pH in our experimental systems quickly increased from 7.0 to 9.3 during the course of four days, and Mn2+ concentrations increased to 166 mol/L in two days and rapidly decreased to 8 mol/L on the fourth day with rhodochrosite (MnCO3) as reduction products under aerobic conditions.The production of rhodochrosite decreased with increasing Mg2+ concentrations and increased with rising SO42- concentrations. These results indicate that Strain 45-1b can utilize acetate as the electron donor and birnessite as the electron acceptor under aerobic conditions, causing birnessite reduction and Mn2+ releasing and ultimately conversing organic carbon into inorganic carbonate minerals as rhodochrosite. Mg2+ inhibited microbial growth and the presence of rhodochrosite nucleation sites to affect birnessite reduction and rhodochrosite precipitation, and SO42- mitigated Mg2+ inhibition and promoted birnessite reduction and rhodochrosite~precipitation.
In order to simulate bio-reduction of manganese oxides and coupled carbonate precipitation induced by microbes in shallow sea environments, we took one of the most common manganese oxides-birnessite (K0.33Mn7O14~7H2O) as an example and carried out experiments under different Mg2+ and SO42- concentrations, where dissimilatory manganese-reducing bacteria Dietzia cercidiphylli 45-1b reduced birnessite under aerobic conditions. By analyzing variations of the concentrations of protein, Mn2+, etc., alongside X-ray powder diffraction (XRD) and X-ray absorption spectroscopy (XAS) for mineralogical transformations analyses, we discussed the impact on birnessite reduction and carbonate precipitation by Strain 45-1b under different initial concentrations of Mg2+ and SO42-. Results show that the pH in our experimental systems quickly increased from 7.0 to 9.3 during the course of four days, and Mn2+ concentrations increased to 166 mol/L in two days and rapidly decreased to 8 mol/L on the fourth day with rhodochrosite (MnCO3) as reduction products under aerobic conditions.The production of rhodochrosite decreased with increasing Mg2+ concentrations and increased with rising SO42- concentrations. These results indicate that Strain 45-1b can utilize acetate as the electron donor and birnessite as the electron acceptor under aerobic conditions, causing birnessite reduction and Mn2+ releasing and ultimately conversing organic carbon into inorganic carbonate minerals as rhodochrosite. Mg2+ inhibited microbial growth and the presence of rhodochrosite nucleation sites to affect birnessite reduction and rhodochrosite precipitation, and SO42- mitigated Mg2+ inhibition and promoted birnessite reduction and rhodochrosite~precipitation.
2018, (S1): 157-170.
doi: 10.3799/dqkx.2018.590
Abstract:
Microbial reduction of iron oxides minerals is an essential component of the biogeochemical cycle of iron. The use of redox active electron shuttles to mediate the transfer of biogenic electrons to minerals and accelerate Fe(III) reduction is an important pathway for iron bioreduction. Based on sorting the outcomes in related fields at home and abroad, the impacts of different electron shuttles (humic substances, quinones, sulfur species, cell-secreted compounds and solid carbon materials, etc.) on microbial reduction of iron oxides and their respective mechanisms are reviewed systematically in this paper. And key issues regarding electron shuttles in environmental geology to be solved are~suggested.
Microbial reduction of iron oxides minerals is an essential component of the biogeochemical cycle of iron. The use of redox active electron shuttles to mediate the transfer of biogenic electrons to minerals and accelerate Fe(III) reduction is an important pathway for iron bioreduction. Based on sorting the outcomes in related fields at home and abroad, the impacts of different electron shuttles (humic substances, quinones, sulfur species, cell-secreted compounds and solid carbon materials, etc.) on microbial reduction of iron oxides and their respective mechanisms are reviewed systematically in this paper. And key issues regarding electron shuttles in environmental geology to be solved are~suggested.
2018, (S1): 171-180.
doi: 10.3799/dqkx.2018.915
Abstract:
River-bed clogging caused by biological agent is a common phenomenon and affected by many environment factors. But bioclogging was rarely considered when studying the nitrogen cycle in hyporheic zone. It establishes a numerical model by simultaneously coupling water flow, reactive transport of solutes and microbial growth, to simulate the hyporheic exchange driven by an undulate river bed and explore the effect of bioclogging. The~present study showed that bioclogging promotes the development of a low permeability layer and high biomass in superficial zone of dunes. Bioclogging limits the spatial distribution of NO3- and results in NH4+ contamination in hyporheic zone. The abundance of organic carbon in river enhances bioclogging extent, which improves the rates of denitrification to remove NO3-. The more fluctuated river bed surface and the larger surface water flow would increase pressure gradient along bed-dunes, bioclogging range and bacterial biomass, then the reaction rates of nitrification and denitrification. It is helpful for the removal of NO3- and NH4+. The bioclogging is beneficial to remove nitrogen pollutants in hyporheic zone and is affected at pressure gradient along bed-dunes, as well as biomass of heterotrophic~bacteria.
River-bed clogging caused by biological agent is a common phenomenon and affected by many environment factors. But bioclogging was rarely considered when studying the nitrogen cycle in hyporheic zone. It establishes a numerical model by simultaneously coupling water flow, reactive transport of solutes and microbial growth, to simulate the hyporheic exchange driven by an undulate river bed and explore the effect of bioclogging. The~present study showed that bioclogging promotes the development of a low permeability layer and high biomass in superficial zone of dunes. Bioclogging limits the spatial distribution of NO3- and results in NH4+ contamination in hyporheic zone. The abundance of organic carbon in river enhances bioclogging extent, which improves the rates of denitrification to remove NO3-. The more fluctuated river bed surface and the larger surface water flow would increase pressure gradient along bed-dunes, bioclogging range and bacterial biomass, then the reaction rates of nitrification and denitrification. It is helpful for the removal of NO3- and NH4+. The bioclogging is beneficial to remove nitrogen pollutants in hyporheic zone and is affected at pressure gradient along bed-dunes, as well as biomass of heterotrophic~bacteria.
2018, (S1): 181-191.
doi: 10.3799/dqkx.2018.536
Abstract:
Anaerobic hydrocarbon degradation in oil reservoirs has gained considerable attention owing to its extreme environment and significant affect on oil recovery. Despite the fact that anaerobic hydrocarbon degradation has been extensively studied under various environments, the in-situ degradation mechanism in oil reservoirs remains poorly known. With the development of sequencing technology, omic-based analysis will be increasingly applied in oil reservoir samples, providing a new methodology for revealing the hydrocarbon degradation process in this specific geological environment. This review summarized recent advances in in-situ hydrocarbon degradation researches in oil reservoirs and metagenome-based analysis of oil reservoir samples, providing new insights for further~studies.
Anaerobic hydrocarbon degradation in oil reservoirs has gained considerable attention owing to its extreme environment and significant affect on oil recovery. Despite the fact that anaerobic hydrocarbon degradation has been extensively studied under various environments, the in-situ degradation mechanism in oil reservoirs remains poorly known. With the development of sequencing technology, omic-based analysis will be increasingly applied in oil reservoir samples, providing a new methodology for revealing the hydrocarbon degradation process in this specific geological environment. This review summarized recent advances in in-situ hydrocarbon degradation researches in oil reservoirs and metagenome-based analysis of oil reservoir samples, providing new insights for further~studies.
2018, (S1): 192-208.
doi: 10.3799/dqkx.2018.254
Abstract:
To understand the genesis of uranium deposits in different ore hosting rocks and discuss the relationship between deposits and tectonic geological setting of Xinlu volcanic basin in Quzhou city, Zhejiang province, we have focused on Jiuhuashan granitic volcanic-intrusive complex by zircon U-Pb geochronology，major and trace element analysis, and Sr-Nd isotopic analysis. SHRIMP U-Pb dating of zircon grains from the volcanic and intrusive rocks yield ages of 134.9~137.8 Ma, and both of them have similar geochemical characteristic with high Al (11.96 %~14.59 %), Na 2 O+K 2 O (7.35 %~9.30 %), Zr+Nb+Ce+Y (>350), FeO*/MgO (>10) and Ga/Al ratio (>2.6×10 -4 ), indicating that they are products of a synchronous magmatism with a typical characteristic of aluminous A-type granite. While those more acidic rocks have lower Zr and P contents, more enrichment in some LILEs，and more depletion in Ba、Ta、Nb、Ti and Eu, which announces a varying degree fractional crystallization in magma source. The isotope geochemical characteristics display young and dispersed Nd model age, high $\upvarepsilon$ Nd (t ) values in the range of -6.16 to 2.26, suggesting an input of mantle materials. We conclude the volcanic and intrusive rock formed in the same magmatic event which occurred at a tectonic setting of extension and upwelling of asthenosphere in Xinlu basin in early Cretaceous, and it provides a favourite ore-controlling structure, material source and heat for uranium mineralization. This also means those uranium deposits in different ore hosting rocks have similar genetic~mechanism.
To understand the genesis of uranium deposits in different ore hosting rocks and discuss the relationship between deposits and tectonic geological setting of Xinlu volcanic basin in Quzhou city, Zhejiang province, we have focused on Jiuhuashan granitic volcanic-intrusive complex by zircon U-Pb geochronology，major and trace element analysis, and Sr-Nd isotopic analysis. SHRIMP U-Pb dating of zircon grains from the volcanic and intrusive rocks yield ages of 134.9~137.8 Ma, and both of them have similar geochemical characteristic with high Al (11.96 %~14.59 %), Na 2 O+K 2 O (7.35 %~9.30 %), Zr+Nb+Ce+Y (>350), FeO*/MgO (>10) and Ga/Al ratio (>2.6×10 -4 ), indicating that they are products of a synchronous magmatism with a typical characteristic of aluminous A-type granite. While those more acidic rocks have lower Zr and P contents, more enrichment in some LILEs，and more depletion in Ba、Ta、Nb、Ti and Eu, which announces a varying degree fractional crystallization in magma source. The isotope geochemical characteristics display young and dispersed Nd model age, high $\upvarepsilon$ Nd (t ) values in the range of -6.16 to 2.26, suggesting an input of mantle materials. We conclude the volcanic and intrusive rock formed in the same magmatic event which occurred at a tectonic setting of extension and upwelling of asthenosphere in Xinlu basin in early Cretaceous, and it provides a favourite ore-controlling structure, material source and heat for uranium mineralization. This also means those uranium deposits in different ore hosting rocks have similar genetic~mechanism.
2018, (S1): 209-224.
doi: 10.3799/dqkx.2018.251
Abstract:
This paper reports the geochronological data of detrital zircons from the clastic rocks of Lishan Formation of Early Jurassic in southwestern Fujian, and the aim is ascertaining the composition and source of sediments in Early Jurassic strata revealing the natures of Mesozoic basins South China. The preponderant age compositions reflected by the upper section samples（GMC12）and the lower section samples（GMC22）of Lishan formation are similar, both having one main peak of 1 860 Ma and the other subsidiary peak of 230 Ma. But the age distribution of the lower section samples（GMC22）is relatively simple and the age peaks of 1 860 Ma and 230 Ma are get. The upper section samples（GMC12）show the multi-peak feature and there are multiple subsidiary peaks of about 230 Ma, about 280 Ma, about 410 Ma, about 490 Ma, about 770 Ma and 2 540 Ma except the main peak of 1 860 Ma. The composition of the detrital zircon ages changes from simple to complex from the lower section to the upper section. The upper section has older and complex age compositions than the lower section, suggesting that the provenances might be changed. The Early Jurassic sediment provenances in southwestern Fujian are mainly the Paleoproterozoic and Late Paleozic-early Mesozoic igneous rocks. Based on comparing these detrital zircon ages with those from late Paleozoic and early Mesozoic sediments from different basins around southwestern Fujian, we conclude that Early Jurassic provenances in southwestern Fujian are mainly from north and northeast of the study area. The sediment age compositions within basins from the study area to inland or southern part of South China changed from relatively complex and older to simple and young. From the early to late of Indosinian orogeny, the magmation of South China from the south coastal region to the South China inland but the magmations of South China Eastern coastal, northeast area and northern area were~active.
This paper reports the geochronological data of detrital zircons from the clastic rocks of Lishan Formation of Early Jurassic in southwestern Fujian, and the aim is ascertaining the composition and source of sediments in Early Jurassic strata revealing the natures of Mesozoic basins South China. The preponderant age compositions reflected by the upper section samples（GMC12）and the lower section samples（GMC22）of Lishan formation are similar, both having one main peak of 1 860 Ma and the other subsidiary peak of 230 Ma. But the age distribution of the lower section samples（GMC22）is relatively simple and the age peaks of 1 860 Ma and 230 Ma are get. The upper section samples（GMC12）show the multi-peak feature and there are multiple subsidiary peaks of about 230 Ma, about 280 Ma, about 410 Ma, about 490 Ma, about 770 Ma and 2 540 Ma except the main peak of 1 860 Ma. The composition of the detrital zircon ages changes from simple to complex from the lower section to the upper section. The upper section has older and complex age compositions than the lower section, suggesting that the provenances might be changed. The Early Jurassic sediment provenances in southwestern Fujian are mainly the Paleoproterozoic and Late Paleozic-early Mesozoic igneous rocks. Based on comparing these detrital zircon ages with those from late Paleozoic and early Mesozoic sediments from different basins around southwestern Fujian, we conclude that Early Jurassic provenances in southwestern Fujian are mainly from north and northeast of the study area. The sediment age compositions within basins from the study area to inland or southern part of South China changed from relatively complex and older to simple and young. From the early to late of Indosinian orogeny, the magmation of South China from the south coastal region to the South China inland but the magmations of South China Eastern coastal, northeast area and northern area were~active.
2018, (S1): 225-242.
doi: 10.3799/dqkx.2018.190
Abstract:
The tectonic setting and petrogenesis mechanism of the Late Triassic magmatic activity in the Longmu Co-Shuanghu Suture zone in central Qiangtang are still controversial. As aimed, it is significance to research the later tectonic evolution of the suture zone though isotopic chronology and geochemistry for the Jiangaidarina granite mass (hereinafter referred to as Jiangai mass). Located in the south of Longmu Co-Shuanghu Suture zone, Jiangai mass consist of biotite granodiorite and granite porphyry, and obtain three zircon U-Pb LA-ICP-MS ages of 212.6 $\pm$ 4.9 Ma、215.4 $\pm$ 2.7 Ma and 210.4 $\pm$ 2.0 Ma. These ages indicat that the Jiangai mass are Late Triassic magmatic activity instead of the Early Jurassic. Geochemically, the rocks are high in SiO2 and Al2O3，and wide range of K2O (2.60%~4.99%) and Na2O + K2O (3.98%~7.31%), with the A/CNK values of 0.91~1.50. The rocks contain amphibole minerals and P2O5 is negatively correlated with SiO2. The above characteristics indicate a series of high K-potssium, aluminum- peralumnous, and I-type granite rocks.Furthermore, the Jiangai mass are also characterized by low REE, relatively heavy LREE, enrichment LILE(Rb, Ba, Th, U, K) and depletion of HFSE(Sr, P, Ti), with the slightly negative Eu anomaly (0.56~0.87). The Hf (t) (-10.3~-2.4 and 10.2) and tDM2 ages (average \mbox{1 663 Ma and 453 Ma) of Jiangai parent magma mixing with the partial melts from remelting of ancient lower crust and mantle-derived material. Taking the regional geological setting into consideration, we infer that, triggered by the break-off of the Longmu Co-Shuanghu oceanic slab subducted beneath the North Qiangtang plate, the potassium basalt of lower crust South Qiangtang Block partial remelting, and the mantle-derived material transform the sediments at the same time. Followed by the amphibole, plagioclase and other crystallization process, the Jiangai mass formed eventually. The mechanism of Jiangai mass is mainly related to the subduction slab break-off. Meanwhile, it is proved the Longmu Co-Shuanghu Suture zone has been completely closed before the Late Triassic, and the Late Triassic is the post-collision tectonic~stage.
The tectonic setting and petrogenesis mechanism of the Late Triassic magmatic activity in the Longmu Co-Shuanghu Suture zone in central Qiangtang are still controversial. As aimed, it is significance to research the later tectonic evolution of the suture zone though isotopic chronology and geochemistry for the Jiangaidarina granite mass (hereinafter referred to as Jiangai mass). Located in the south of Longmu Co-Shuanghu Suture zone, Jiangai mass consist of biotite granodiorite and granite porphyry, and obtain three zircon U-Pb LA-ICP-MS ages of 212.6 $\pm$ 4.9 Ma、215.4 $\pm$ 2.7 Ma and 210.4 $\pm$ 2.0 Ma. These ages indicat that the Jiangai mass are Late Triassic magmatic activity instead of the Early Jurassic. Geochemically, the rocks are high in SiO2 and Al2O3，and wide range of K2O (2.60%~4.99%) and Na2O + K2O (3.98%~7.31%), with the A/CNK values of 0.91~1.50. The rocks contain amphibole minerals and P2O5 is negatively correlated with SiO2. The above characteristics indicate a series of high K-potssium, aluminum- peralumnous, and I-type granite rocks.Furthermore, the Jiangai mass are also characterized by low REE, relatively heavy LREE, enrichment LILE(Rb, Ba, Th, U, K) and depletion of HFSE(Sr, P, Ti), with the slightly negative Eu anomaly (0.56~0.87). The Hf (t) (-10.3~-2.4 and 10.2) and tDM2 ages (average \mbox{1 663 Ma and 453 Ma) of Jiangai parent magma mixing with the partial melts from remelting of ancient lower crust and mantle-derived material. Taking the regional geological setting into consideration, we infer that, triggered by the break-off of the Longmu Co-Shuanghu oceanic slab subducted beneath the North Qiangtang plate, the potassium basalt of lower crust South Qiangtang Block partial remelting, and the mantle-derived material transform the sediments at the same time. Followed by the amphibole, plagioclase and other crystallization process, the Jiangai mass formed eventually. The mechanism of Jiangai mass is mainly related to the subduction slab break-off. Meanwhile, it is proved the Longmu Co-Shuanghu Suture zone has been completely closed before the Late Triassic, and the Late Triassic is the post-collision tectonic~stage.
2018, (S1): 243-263.
doi: 10.3799/dqkx.2018.523
Abstract:
The Dongping tungsten deposit，located in the eastern section of Jiangnan orogenic belt in Jiangxi Province, which is a newly discovered giant “five-story” quartz vein type wolframite ore deposit. In order to study the metallogenic magmatic rock of the age, source and tectonic background of the Dongping tungsten deposit, this paper has carried out detailed zircon U-Pb chronology, major-trace element geochemistry，and Sr-Nd isotope studies of the Dongping metallogenic biotite granite. LA-ICP-MS zircon U-Pb dating results demonstrate the age of Dongping biotite granite is 132.9~1.4 Ma...
The Dongping tungsten deposit，located in the eastern section of Jiangnan orogenic belt in Jiangxi Province, which is a newly discovered giant “five-story” quartz vein type wolframite ore deposit. In order to study the metallogenic magmatic rock of the age, source and tectonic background of the Dongping tungsten deposit, this paper has carried out detailed zircon U-Pb chronology, major-trace element geochemistry，and Sr-Nd isotope studies of the Dongping metallogenic biotite granite. LA-ICP-MS zircon U-Pb dating results demonstrate the age of Dongping biotite granite is 132.9~1.4 Ma...
2018, (S1): 264-276.
doi: 10.3799/dqkx.2018.525
Abstract:
Understanding sedimentary features and establishing accurate sedimentary models play an important role in deciphering sedimentary environments of ancient sedimentary rocks as well as establishing sedimentary architecture models of hydrocarbon reservoirs. This study reviews the theoretic development of dryland fluvial systems in arid endorheic basins and recent results of modern Bolivian R'o Colorado River meandering river terminus system.On the low-gradient coastal regions dryland river terminus systems are generally characterized by only one active meandering channel with a downstream reduction in cross-sectional area while other channels are abandoned and completely (or partially) filled. This study also points out controls on channel morphology in the dryland meandering river terminus systems. Infrequent but high magnitude thunderstorm-induced floods enhanceriver bank bleaches, whereby abundance of crevasse splays are triggered along the channel and amalgamations of crevasse splays lead to‘sheet sand’ on floodplain. Avulsions are generally initiated as crevasse channels andnew river channels cut through or superimpose on previous channels over time forming an apparently distributive pattern. In addition, this study proposes the sedimentary model of fine-grained dryland meandering river terminus systems, including channel deposits, overbank deposits and floodplain deposits. Crevasse splays deposits are the majorcomponent of overbank deposits in this meandering river terminus system. Distinctions in terms of sedimentary settings were also discussed between shallow-water deltas and dryland meandering river terminus systems, indicating significant differences in climate and slope for the two sedimentary systems. The proposed sedimentary model of dryland river terminus systems not only complements the current theory of sedimentary systems in endorheic basins, but also helps to accurately characterize hydrocarbon reservoirs as well as provides a new perspective on the exploration and developments of hydrocarbon~resources.
Understanding sedimentary features and establishing accurate sedimentary models play an important role in deciphering sedimentary environments of ancient sedimentary rocks as well as establishing sedimentary architecture models of hydrocarbon reservoirs. This study reviews the theoretic development of dryland fluvial systems in arid endorheic basins and recent results of modern Bolivian R'o Colorado River meandering river terminus system.On the low-gradient coastal regions dryland river terminus systems are generally characterized by only one active meandering channel with a downstream reduction in cross-sectional area while other channels are abandoned and completely (or partially) filled. This study also points out controls on channel morphology in the dryland meandering river terminus systems. Infrequent but high magnitude thunderstorm-induced floods enhanceriver bank bleaches, whereby abundance of crevasse splays are triggered along the channel and amalgamations of crevasse splays lead to‘sheet sand’ on floodplain. Avulsions are generally initiated as crevasse channels andnew river channels cut through or superimpose on previous channels over time forming an apparently distributive pattern. In addition, this study proposes the sedimentary model of fine-grained dryland meandering river terminus systems, including channel deposits, overbank deposits and floodplain deposits. Crevasse splays deposits are the majorcomponent of overbank deposits in this meandering river terminus system. Distinctions in terms of sedimentary settings were also discussed between shallow-water deltas and dryland meandering river terminus systems, indicating significant differences in climate and slope for the two sedimentary systems. The proposed sedimentary model of dryland river terminus systems not only complements the current theory of sedimentary systems in endorheic basins, but also helps to accurately characterize hydrocarbon reservoirs as well as provides a new perspective on the exploration and developments of hydrocarbon~resources.
2018, (S1): 277-286.
doi: 10.3799/dqkx.2018.197
Abstract:
The patterns of sandy meandering river and pebbly braided river had been well documented on their sedimentary characteristics, but the pattern of pebbly meandering river had been rarely previously reported. Based on modern sedimentary investigations on the Xiaobangshuiya-Shangzhuangtuo stretch of Dashihe River in Qinghuangdao Area taken as a typical example of pebbly meandering river, the geomorphology units and sedimentary characteristics are described, and then the depositional succession and model are summarized to insight into its geneses in this paper. The geomorphology units include a single highly-sinuous channel, convex and concave banks alternately locating at the two sides of the channel, launder and small-scale flood plains. Sourced by the nearby mountainous provenance, the sediments are identified as lags deposits, pebbly point-bar deposits, gravelly launder deposits and sandy flood plain deposits with imbricate structure, and large-scale tabular, wedge-shaped and trough cross-bedding from bottom to top, presenting a fining-upward succession called as an atypical dual-structure that is constructed by coarse sediments in the lower and fine sediments in the upper. Accordingly, the pebbly meandering river is featured with geomorphology units similar to a sandy meandering river, and with hydrodynamic conditions, lithologic compositions and depositional succession similar to a pebbly braided river, so are called as dual properties. Integrating with the pebbly meandering river widely occurring in modern mountainous regions, three-graded river terraces in the study area indicated that the river pattern of pebbly meandering river is attributed to regional tectonic uplifts and river’s intense erosional actions. The study in this paper brings a challenge on understanding the classification, distribution and control factors of river patterns. Identifications of geo-historical pebbly meandering rivers should be significant to determine orogenic movements due to their close response to regional tectonic~uplift.
The patterns of sandy meandering river and pebbly braided river had been well documented on their sedimentary characteristics, but the pattern of pebbly meandering river had been rarely previously reported. Based on modern sedimentary investigations on the Xiaobangshuiya-Shangzhuangtuo stretch of Dashihe River in Qinghuangdao Area taken as a typical example of pebbly meandering river, the geomorphology units and sedimentary characteristics are described, and then the depositional succession and model are summarized to insight into its geneses in this paper. The geomorphology units include a single highly-sinuous channel, convex and concave banks alternately locating at the two sides of the channel, launder and small-scale flood plains. Sourced by the nearby mountainous provenance, the sediments are identified as lags deposits, pebbly point-bar deposits, gravelly launder deposits and sandy flood plain deposits with imbricate structure, and large-scale tabular, wedge-shaped and trough cross-bedding from bottom to top, presenting a fining-upward succession called as an atypical dual-structure that is constructed by coarse sediments in the lower and fine sediments in the upper. Accordingly, the pebbly meandering river is featured with geomorphology units similar to a sandy meandering river, and with hydrodynamic conditions, lithologic compositions and depositional succession similar to a pebbly braided river, so are called as dual properties. Integrating with the pebbly meandering river widely occurring in modern mountainous regions, three-graded river terraces in the study area indicated that the river pattern of pebbly meandering river is attributed to regional tectonic uplifts and river’s intense erosional actions. The study in this paper brings a challenge on understanding the classification, distribution and control factors of river patterns. Identifications of geo-historical pebbly meandering rivers should be significant to determine orogenic movements due to their close response to regional tectonic~uplift.
2018, (S1): 287-300.
doi: 10.3799/dqkx.2018.137
Abstract:
In this study, the grain size, chromaticity and elemental geochemistry of sediments from a borehole reaching Pliocene of Bohai Bay have been analyzed, and the sedimentary features and weathering degree of the sediments from this borehole since 5.2~Ma have been expounded. The results showed that the ratios of CIA (chemical index of alteration), Al/Si, Al/Na, Al/K, Ba/Sr and (La/Sm)N、 (La/Yb）N were good indicators of weathering degree and material composition of sediments in North China. The grain size composition, chromaticity change and element ratio characteristics revealed that the chemical weathering degree of the sediments from 5.2~Ma to 1.6~Ma changed from medium to weak, which revealed the synchronous effect caused by Late Cenozoic global cooling and the East Asian Winter Monsoon. Since 1.6~Ma, the (La/Sm）N、 (La/Yb）N from G4 hole have suddenly increased, and the trends of other indicators are not consistent with the slow decreasing characteristics of the deep ocean oxygen isotope ratio, the CIA and 87Sr/86Sr of loess, indicating the change of sediment source. Considering the regional tectonic and climatic conditions, we assume that the change of sediment source from G4 since 1.6~Ma is related to the entry of Yellow River into the North China Plain at 1.6~Ma, and the Yellow River eventually cut through the Sanmen Gorge and enter the North China Plain with the dynamic of intensive headward erosion caused by globe climate changes in the early Pleistocene. The combined section of boreholes from Bohai Bay revealed that the Huanghua depression was basically filled, and the peneplanation process of the North China Plain mainly completed from 1.6~Ma to 0.78~Ma, which indicated that the great mass of sediments from Yellow River made a huge contribution in the forming of the North China~Plain.
In this study, the grain size, chromaticity and elemental geochemistry of sediments from a borehole reaching Pliocene of Bohai Bay have been analyzed, and the sedimentary features and weathering degree of the sediments from this borehole since 5.2~Ma have been expounded. The results showed that the ratios of CIA (chemical index of alteration), Al/Si, Al/Na, Al/K, Ba/Sr and (La/Sm)N、 (La/Yb）N were good indicators of weathering degree and material composition of sediments in North China. The grain size composition, chromaticity change and element ratio characteristics revealed that the chemical weathering degree of the sediments from 5.2~Ma to 1.6~Ma changed from medium to weak, which revealed the synchronous effect caused by Late Cenozoic global cooling and the East Asian Winter Monsoon. Since 1.6~Ma, the (La/Sm）N、 (La/Yb）N from G4 hole have suddenly increased, and the trends of other indicators are not consistent with the slow decreasing characteristics of the deep ocean oxygen isotope ratio, the CIA and 87Sr/86Sr of loess, indicating the change of sediment source. Considering the regional tectonic and climatic conditions, we assume that the change of sediment source from G4 since 1.6~Ma is related to the entry of Yellow River into the North China Plain at 1.6~Ma, and the Yellow River eventually cut through the Sanmen Gorge and enter the North China Plain with the dynamic of intensive headward erosion caused by globe climate changes in the early Pleistocene. The combined section of boreholes from Bohai Bay revealed that the Huanghua depression was basically filled, and the peneplanation process of the North China Plain mainly completed from 1.6~Ma to 0.78~Ma, which indicated that the great mass of sediments from Yellow River made a huge contribution in the forming of the North China~Plain.
2018, (S1): 301-312.
doi: 10.3799/dqkx.2018.544
Abstract:
Zhangwu basin is an early Cretaceous fault depression basin in northeast China, underwent dextral transtension and shows obvious responses on sequence development for its appropriate area. With comprehensive utilization of seismic data, logging and drilling, research was conducted on tectonic evolution and sequence stratigraphic models of lower Cretaceous in Zhangwu basin. Jiufotang formation and lower Shahai formation could be divided into 13 three-order sequences, 4 two-order sequences and 2 one-order sequences. 8 types of stratigraphic models are developed, steep slope type with normal sediment supply, steep slope type with abundant sediment supply, gentle slope type with normal sediment supply, gentle slope type with abundant sediment supply, deep water type with normal sediment supply, deep water type with abundant sediment supply, deep groove type and platform type,~respectively.
Zhangwu basin is an early Cretaceous fault depression basin in northeast China, underwent dextral transtension and shows obvious responses on sequence development for its appropriate area. With comprehensive utilization of seismic data, logging and drilling, research was conducted on tectonic evolution and sequence stratigraphic models of lower Cretaceous in Zhangwu basin. Jiufotang formation and lower Shahai formation could be divided into 13 three-order sequences, 4 two-order sequences and 2 one-order sequences. 8 types of stratigraphic models are developed, steep slope type with normal sediment supply, steep slope type with abundant sediment supply, gentle slope type with normal sediment supply, gentle slope type with abundant sediment supply, deep water type with normal sediment supply, deep water type with abundant sediment supply, deep groove type and platform type,~respectively.
2018, (S1): 313-325.
doi: 10.3799/dqkx.2018.206
Abstract:
Study on the hydrochemical characteristics and formation mechanism of geothermal water can provide the hydrogeochemical basis for the exploitation and protection of geothermal resources. The insufficient research of hydrochemical formation mechanism is a limitation in the development of geothermal water in northern \mbox{Ji’nan}. Water samples were collected in southern Karst and geothermal wells in this paper. Methods including \mbox{Piper’s} triliner diagram, correlation analysis, ion ratio, mineral saturation index and the inverse geochemical modelling were employed to analyze the hydrochemical characteristics and formation mechanism. The results show that from south to north, the concentration of TDS and main ion content showed a rising trend, and the groundwater chemical types change from HCO\textsubscript{3}{\hyphen{}}Ca to HCO\textsubscript{3}{\hyphen{}}Ca$\cdotp $Mg, SO\textsubscript{4}{\hyphen{}}Ca, SO\textsubscript{4}{\hyphen{}}Ca$\cdotp $Na showing zoning characteristics. Carbonate, sulfate minerals and halite mineral dissolution{\hyphen{}}precipitation in this area were the dominant hydrogeochemical processes to control the groundwater chemical characteristics, accompanied by the dissolution of albite, K{\hyphen{}}feldspar and other silicate minerals. However, southern cold water is affected by a certain degree of human~activity.
Study on the hydrochemical characteristics and formation mechanism of geothermal water can provide the hydrogeochemical basis for the exploitation and protection of geothermal resources. The insufficient research of hydrochemical formation mechanism is a limitation in the development of geothermal water in northern \mbox{Ji’nan}. Water samples were collected in southern Karst and geothermal wells in this paper. Methods including \mbox{Piper’s} triliner diagram, correlation analysis, ion ratio, mineral saturation index and the inverse geochemical modelling were employed to analyze the hydrochemical characteristics and formation mechanism. The results show that from south to north, the concentration of TDS and main ion content showed a rising trend, and the groundwater chemical types change from HCO\textsubscript{3}{\hyphen{}}Ca to HCO\textsubscript{3}{\hyphen{}}Ca$\cdotp $Mg, SO\textsubscript{4}{\hyphen{}}Ca, SO\textsubscript{4}{\hyphen{}}Ca$\cdotp $Na showing zoning characteristics. Carbonate, sulfate minerals and halite mineral dissolution{\hyphen{}}precipitation in this area were the dominant hydrogeochemical processes to control the groundwater chemical characteristics, accompanied by the dissolution of albite, K{\hyphen{}}feldspar and other silicate minerals. However, southern cold water is affected by a certain degree of human~activity.
2018, (S1): 326-338.
doi: 10.3799/dqkx.2017.581
Abstract:
The strong spatial variability of the soil characteristics in the unsaturated zone has a significant impact on the distribution and transport process of the soil water. It should be particularly concerned in the Badain Jaran Desert, China, where the vadose zone has a huge thickness and is difficult to observe. Based on the collected data from soil water observations at different depths and measurements of the hydraulic parameters, the variability characteristics of the aeolian sands in the Badain Jaran Desert is analyzed with Monte-Carlo simulation by using the logarithmic normal distribution model and the cross-correlated model of the soil water retention characteristics. As indicated in the results, the volumetric content of movable water is less than 5\% in the downward infiltration zone. Accordingly, the vertical distribution of the soil water potential is reconstructed and the results indicate that the hydraulic gradient is approximately 1.0 in the downward infiltration zone, which basically satisfy the free infiltration condition under the force of gravity. Taking the residual water content as an independent random variable and using the Richards equation, the distributions of volumetric water content with respect to different infiltration rates are assessed with Monte-Carlo simulation. The reasonable variation range of the infiltration rate is determined from the comparison of statistical properties between simulated and observed data. Results show that the most possible range of the infiltration rate is 30-41 mm/a. The possibilities of infiltration rate values are very small for that are less than 10 mm/a or higher than 50 mm/a. Stochastic simulation of the vadose zone water provides a new perspective for the study of groundwater recharge in the Badain Jaran~Desert.
The strong spatial variability of the soil characteristics in the unsaturated zone has a significant impact on the distribution and transport process of the soil water. It should be particularly concerned in the Badain Jaran Desert, China, where the vadose zone has a huge thickness and is difficult to observe. Based on the collected data from soil water observations at different depths and measurements of the hydraulic parameters, the variability characteristics of the aeolian sands in the Badain Jaran Desert is analyzed with Monte-Carlo simulation by using the logarithmic normal distribution model and the cross-correlated model of the soil water retention characteristics. As indicated in the results, the volumetric content of movable water is less than 5\% in the downward infiltration zone. Accordingly, the vertical distribution of the soil water potential is reconstructed and the results indicate that the hydraulic gradient is approximately 1.0 in the downward infiltration zone, which basically satisfy the free infiltration condition under the force of gravity. Taking the residual water content as an independent random variable and using the Richards equation, the distributions of volumetric water content with respect to different infiltration rates are assessed with Monte-Carlo simulation. The reasonable variation range of the infiltration rate is determined from the comparison of statistical properties between simulated and observed data. Results show that the most possible range of the infiltration rate is 30-41 mm/a. The possibilities of infiltration rate values are very small for that are less than 10 mm/a or higher than 50 mm/a. Stochastic simulation of the vadose zone water provides a new perspective for the study of groundwater recharge in the Badain Jaran~Desert.
