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1.
海洋极端环境微生物活动与油气资源关系 总被引:1,自引:0,他引:1
为了弄清海洋极端环境下微生物参与油气资源形成和演化的潜在机制, 进行了现代海洋热泉和冷泉等环境中微生物类型分析和生物量估算, 探讨了极端微生物活动和油气资源的潜在关系.认为海洋极端环境下微生物类型主要为细菌和古细菌, 热泉微生物群落主要为异养发酵菌、硫酸盐还原菌、产甲烷菌等; 冷泉微生物群落主要为ANME-2族的厌氧甲烷氧化古细菌、硫酸盐还原细菌和ANME-1族厌氧甲烷氧化古菌.这些极端微生物利用CH4和H2S等气体进行能量固定, 有较高的生物丰度和较低的分异度, 具有垂向和水平分带性, 并能营生一套独特的宏体生物.极端微生物活动直接和间接地参与了油气资源的形成和改造, 示踪海底油气资源的变迁.对于探索地球早期海洋微生物活动与油气资源形成, 寻找地史时期或华南地史早期烃源岩具有重要理论和实践指导意义. 相似文献
2.
The Late Permian Dalong Formation in Hubei, Hunan, Guizhou and Guangxi in South China could be subdivided into several sedimentary
types according to the lithology, indicative of the great spatial variations of both the lithology and sedimentary facies.
The Dalong Formation deposited during the highest transgression of Late Permian, in particular under the anaerobic and suboxic
conditions, which shows a strong linkage with the hydrocarbon source rocks. The Dalong Formation has some favorable properties
such as hydrocarbon source rocks, including the sediments deposited in highest transgression sea level, the deep slope sedimentary
environments and the low sedimentary rate, which raises the importance of the investigations on the sedimentary features,
the geochemical properties and their relationship with the oil potential.
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Translated from Earth Science—Journal of China University of Geosciences, 2007, 32(6): 774–780 [译自: 地球科学—中国地质大学学报] 相似文献
3.
On the geobiological evaluation of hydrocarbon source rocks 总被引:1,自引:0,他引:1
Xie Shucheng Yin Hongfu Xie Xinong Qin Jianzhong Hu Chaoyong Yan Jiaxin Huang Junhua Zhou Lian Yang Xianghua Wang Yongbiao Xu Sihuang 《Frontiers of Earth Science》2007,1(4):389-398
Hydrocarbon source rocks are characterized by the hydrocarbon discharge, and the alteration and variation in organic compositions
and organic content due to the enhanced thermal maturation. These variations throw constraints on the application of the conventional
inversion evaluation of hydrocarbon potential by assessing the residual organic matter left in source rocks. Geobiology, probing
the interaction between the life system and the earth system, provides new principles in deciphering the whole dynamic processes
related to the organic evolution history from living biomass to organic burial. Geobiological subdisciplines, including molecular
geobiology, geomicrobiology, geoecology and biogeochemistry, offer new methodology and techniques to estimate the paleoproductivity,
depositional organics and organic burial capacity and their components. Geobiofacies, newly proposed herein, is terminologized
to define the geobiological dynamic processes through the combination of biofacies with organic facies and sedimentary facies,
and expressed by the biohabitat types, paleoproductivity, depositional and preserved organics. Geobiofacies is identified
as a useful means to create the geobiological evaluation system, which in turn rectifies the conventional evaluation system
for the marine source rocks.
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Translated from Earth Science—Journal of China University of Geosciences, 2007, 32(6): 727–740 [译自: 地球科学—中国地质大学学报] 相似文献
4.
Wang Hongmei Ma Xiangru Liu Deng Yang Xiaofen Li Jihong 《Frontiers of Earth Science》2007,1(4):399-404
Understanding the dynamics of organic matter in modern marine water columns greatly favors the geobiological evaluation of
hydrocarbon source rocks. Biolipids could make great contribution to petroleum hydrocarbons due to their comparable chemical
components and the slightly refractory characteristics of biolipids during the microbial/thermal degradation. A variety of
environmental factors such as temperature, CO2 and salinity could affect the biochemical contents in microorganisms. As a result, microorganisms living in a changing environmental
condition might have a different contribution to the petroleum formation. Organic carbon flux is shown to bear a positive
correlation with the primary productivity only within a certain range of biomass volumes in a specific biohabitat. Furthermore,
organic matter is degraded much quickly in a water column with oxic conditions. Therefore, the anoxic condition, along with
the enhanced biological productivity, would be one of the significant factors in the formation of high-quality hydrocarbon
source rocks. The formation of biofilms and microbial mats favors the preservation of sedimentary organic matter by decreasing
the degradation rate of organic matter. Identification of biofilms and microbial mats in sedimentary rocks will thus greatly
help to understand the depositional processes of organic matter finally preserved in hydrocarbon source rocks.
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Translated from Earth Science—Journal of China University of Geosciences, 2007, 32(6): 748–754 [译自: 地球科学—中国地质大学学报 相似文献
5.
The calci-mircobialite is a special carbonate buildup, which is formed due to the activities of different kinds of microbes.
Abundant microfossils preserved in the microbialite show the high-level productivity during deposition, while characteristic
sedimentary minerals and geochemical compositions suggest an anoxic marine environment for organic burial. The high-level
productivity and anoxic sedimentary environment favor the efficient preservation of organic matter and thus the formation
of source rocks. On these points, microbialites could be one of the potential hydrocarbon source rocks, awaiting further geobiological
investigation and exploration. Precambrian and some of the great transitional stages in Phanerozoic are critical periods when
microbialites were well developed. Widespread microbialites have been found in North and South China. Bitumen observed in
many outcrops of Precambrian and late Devonian microbialites further raises the possibility of the calci-microbialite as a
potential hydrocarbon source rock.
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Translated from Earth Science-Journal of China University of Geosciences, 2007, 32(6): 797-802 [译自: 地球科学-中国地质大学学报] 相似文献
6.
To decipher the origin of oxygen-deficient shelfal deposits is significant for tracing the distribution of marine source rocks
and interpreting the evolution of depositional environment. The origin of the Middle Permian Chihsia Formation in South China
remains a puzzle for long with its evident oxygen-deficient features but diverse benthos. This paper shows a typical Chihsian
depositional rhythm composed of the massive and the laminated limestones with ecological and geochemical features. Massive
bioclastic limestone from the rhythm was aerobic in paleoxygenation condition indicated by both the ecological and geochemical
features. However, a contradictory oxygenation was inferred for the “laminated” counterpart from the rhythm, with the ecological
signal being aerobic and the geochemical one being anoxic. The difference in ecological and geochemical indications was interpreted
as the instability of paleoxygenation condition in shelf environments, caused by an enhanced paleoproductivity. Rhythmic occurrence
of the oxygen-deficient condition might have been stemmed from paleo-Tethyan paleocurrents flowing across South China.
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Translated from Earth Science—Journal of China University of Geosciences, 2007, 32(6): 789–796 [译自: 地球科学—中国地质大学学报] 相似文献
7.
On the basis of the results of hydropyrolysis simulations for about 90 different types of immature to mature source rocks
selected from about 5 000 marine source rocks in China, along with the natural thermal evolution profiles, the following conclusions
were obtained. (1) Total organic carbon (TOC) content of excellent marine source rocks does not change obviously when Ro < 0.8% or Ro > 1.3%, and the residual TOC content is decreasing gradually with the maturity increase at 0.8% < Ro < 1.3%. (2) At the high-post mature stage (Ro > 1.3%), the decreased maximums of residual TOC content for the kerogen of sapropel (I), II1, and II are usually 40%, 32% and 24%, respectively, and their TOC restitution coefficient is, respectively, 1.68, 1.48 and
1.32. (3) Both the TOC decreasing amplitude and the restitution coefficient decrease gradually with the decrease of TOC content
for the source rocks with low organic matter abundance (usually 0.3% < TOC < 1.0%). The TOC restitution coefficients are,
respectively, 1.20 and 1.0, when 0.3% < TOC < 0.5% and TOC < 0.3%. (4) TOCres of solid bitumen and shale with high organic matter abundance (TOC > 30%) also require no restitution at the high mature
stage. Such kind of TOC restitution is further supported by the coincidence of the decrease of residual TOC with the decreasing
of S1 + S2 and the increasing of hydrocarbon quantity during the experimental simulation of hydrocarbon generation and expulsion for
marine source rocks (0.3% < TOC < 30%) in natural thermal evolution profiles.
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Translated from Earth Science—Journal of China University of Geosciences, 2007, 32(6): 853–860 [译自: 地球科学—中国地质大学学报] 相似文献
8.
Zheng Jianping Yu Chunmei Yuan Xiaoping Yin Li Jiao Shujuan Tang Huayun Zhang Zhihai Lu Fengxiang 《Frontiers of Earth Science》2007,1(1):37-43
A petrochemical analysis was undertaken of peridotitic xenoliths in volcanic rocks that erupted from the Paleozoic to the
Cenozoic within the eastern part of the North China craton, and the peridotites as tectonic intrusion in the Early Mesozoic
from the Sulu orogen. The results show that the cratonic mantle, which was refractory and existed when the kimberlites intruded
in the Paleozoic, had almost been replaced by the newly accreted fertile lithospheric mantle during the Mesozoic-Cenozoic.
The erosion, metasomatism, and intermingling caused by the accreted asthenospheric material acting on the craton mantle along
the weak zone and deep fault (such as the Tanlu fault) in the existing lithosphere resulted in the lithospheric thinning at
a larger scale 100 Ma ago (but later than 178 Ma). The largest thinning would be in the Eogene. The upwelling asthenospheric
material transformed into accreted lithospheric mantle due to the asthenospheric temperature falling in the Neogene (leading
to relatively slight lithospheric incrassation), and finally accomplished mantle replacement. The peridotitic body in the
Sulu orogen represents the products spreading from the modified cratonic lithospheric mantle.
Translated from Earth Science—Journal of China University of Geosciences, 2006, 31(1): 49–56 [译自: 地球科学—中国地质大学学报] 相似文献
9.
Shi Wanzhong Chen Honghan Chen Changmin Pang Xiong Zhu Ming 《Frontiers of Earth Science》2007,1(2):241-250
The Pearl River Mouth basin is one of the most important offshore basins in China. Petroleum exploration in the deep-water
area is to start in the Baiyun sag in the basin. Due to the high cost of exploration in deep-water areas, the hydrocarbon
migration and pressure evolution needs to be thoroughly probed before any actual exploration is to be done. Drilling results
have indicated that the pore pressure is hydrostatic in shallow-water area. The mud diapirs found in the Baiyun sag indicate
that there may be overpressure in the deep-water area. At present, little is known about hydrocarbon migration and pressure
distribution in deep-water areas. On the basis of geological data from wells and basin modeling, the research comes to the
following conclusions. (1) At least three episodic accumulations and releases of pressure had happened in the Cenozoic, which
were closely related to the three regional tectonic movements: the Zhu-Qiong movement in the Late Eocene, the Nanhai movement
in the Middle Oligocene and the Dongsha movement between the latest Middle Miocene and Late Miocene. The pressure release
and associated hydrocarbon migration occurred primarily during the Dongsha movement, when most of the overpressure was released
to hydrostatic pressure except for some overpressure in the deep-water area. (2) Both the measured pressure and the modeling
results indicate that the pore pressure is hydrostatic pressure in the shallow-water area. Abnormally high pressure in the
deep-water area is noted to be present. The difference of pressure distribution is caused by the lithologies, facies and faults.
(3) The diapirs in the deep water cannot be driven by the overpressure because the maximum pressure is less than 9.0 MPa in
the course of pressure evolution. (4) The fluids migrated to the shallow-water area and deep-water area along faults. Some
faults connected the deep-water fans with the hydrocarbon source. Huge oil and gas fields may be formed in the deep-water
area more favourably than in the shallow-water area.
Translated from Earth Science-Journal of China University of Geosciences, 2006, 31(2): 229–236 [译自: 地球科学—中国地质大学学报] 相似文献
10.
Deep-sea is one of the most important extreme environments on the earth. Numerous and diverse extremophiles thrive in this extreme environment, presenting distinctive physiological structure, metabolic mechanism and symbiosis relations, which provide new methods to study the origin of life and extraterrestrial life. Despite extensive studies on deep-sea extremophiles from the point of view of biology, the impacts of deep-sea hydrothermal activity on the evolution of extremophiles remain largely unknown. On the basis of summarizing features of the deep-sea ziphysicochemical and geological environment, the distribution and formation mechanism of submarine hydrothermal vents were analyzed, respectively. Hydrothermal vents have great effect on the distribution and succession of communities. Our discussion focused on the extreme life forms of microorganisms surviving in the hydrothermal ecosystem and their important significance for the nutrient cycling and ecosystem evolution. However, the research of life processes in extreme environments is still in the primary stage and more work is needed on the in-situ detection technique, molecular biology and interdisciplinary research. 相似文献
11.
Su Wenbo Li Zhiming Ettensohn F. R. Johnson M. E. Huff W. D. Wang Wei Ma Chao Li Lu Zhang Lei Zhao Huijing 《Frontiers of Earth Science》2007,1(4):470-481
It is known that high-quality, black-shale source rocks occur in the uppermost Ordovician Wufeng Formation and in the lowermost
Silurian Longmaxi Formation in South China. Hence, it is important to understand their lithostratigraphy and the controls
on their deposition. A review of lithostratigraphic criteria for subdividing the two adjacent formations provides new regional
correlations between the formations and related stratigraphic successions and facies. Both the black shales and the related,
overlying flysch deposits at the Ordovician-Silurian transition in South China appear to have migrated northwestward in time
and space, reflecting probable flexural control in a foreland basin that developed in response to subduction-type orogeny
southeast of the Yangtze block. The black shales also contain K-bentonites from explosive, felsic-intermediate volcanism,
the distribution of which also supports orogeny to the southeast. Finally, the analysis of sequence stratigraphy, which shows
that the initiation of transgressive system tracts (TST) and condensed section (CS) in the related third-order sequences coincided
with the two black-shale horizons respectively, indicates that the main controlling factors for the deposition of the Ordovician-Silurian
black shales in South China are (1) northwestwardly migrating, foreland-basin subsidence caused by deformational loading related
to episodic accretion of the Cathaysia block to the Yangtze block during this period, and (2) the anoxic, sediment-starved
water column caused by rapid rise of the sea-level during the two successive phases of third-order global sea-level rise near
the Ordovician-Silurian transition in South China. In future exploration for hydrocarbon source rocks in the area, it is important
to consider likely flexural and eustatic causes for subsiding, deep, anoxic seas in recognizing other source rock intervals,
and our understanding of the Wufeng and Longmaxi formations may serve as models for future source rock exploration.
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Translated from Earth Science—Journal of China University of Geosciences, 2007, 32(6): 818–827 [译自: 地球科学—中国地质大学学报] 相似文献
12.
The paper presents the molybdenum isotope data, along with the trace element content, to investigate the geochemical behavior
of authigenic Mo during long-term burial in sediments in continental margin settings of the Yangtze block, as well as their
indication to the burial of original organic carbon. The burial rate of original organic carbon was estimated on the basis
of the amount of sedimentary sulfur (TS content), whilst the carbon loss by aerobic degradation was estimated according to
calculated Mn contents. On these points, the original organic carbon flux was calculated, exhibiting a large range of variation
(0.17–0.67 mmol/m2/day). The strong correlation between sedimentary Mo isotope values and organic carbon burial rates previously proposed on
the basis of the investigations on modern ocean sediments, was also used here to estimate the organic carbon burial rate.
The data gained through this model showed that organic carbon burial rates have large variations, ranging from 0.43–2.87 mmol/m2/day. Although the two sets of data gained through different geochemical records in the Yangtze block show a deviation of
one order of magnitude, they do display a strong correlation. It is thus tempting to speculate that the Mo isotope signature
of sediments may serve as a tracer for the accumulation rate of original organic carbon in the continental margin sediments.
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Translated from Earth Science—Journal of China University of Geosciences, 2007, 32(6) [译自: 地球科学—中国地质大学学报] 相似文献
13.
The study of oil geologic anomalies is a new area of petroleum geology. Using the evidence weight method, we selected tectonic,
hydrocarbon abundance of source rock, thickness of source rock, level of reservoir, complexity of reservoir, degree of mineralization
of formation water as the evidence layer to evaluate the favorable zones of pool forming in the Lower Paleozoic in the north
edge of the Middle and Lower Yangtze areas. Finally, we integrated our results with the petroleum geology of this area and
concluded that the North Sichuan basin, the western area of Hubei and the eastern area of Chongqing and parts of the Lower
Yangtze are the most profitable areas for exploration in the north edge of the Lower and Middle Yangtze areas.
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Translated from Journal of Jilin University (Earth Science Edition), 2007, 37(3): 458–462 [译自: 吉林大学学报(地球科学版)] 相似文献
14.
Northeast Sichuan basin is a Mesozoic-Cenozoic basin in the northern margin of the Yangtze plate which has a complex tectonic
background and hydrocarbon accumulation history. By means of the analysis method of wave processes, major cycles of sedimentary
wave process in this basin have been studied. The results show that there are five-order cycles corresponding to 760, 220,
100, 35 and 20 Ma respectively, two first-order sedimentary cycles (220 Ma) and four secondorder sedimentary cycles (100 Ma).
The authors find that the second-order sedimentary cycles are well matched with reservoir formation cycles through studying
the relationship between second-order sedimentary cycles and reservoir formation cycles, and divide three reservoir formation
cycles in this basin.
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Translated from Journal of Jilin University (Earth Science Edition), 2007, 37(3): 513–518 [译自: 吉林大学学报(地球科学版)] 相似文献
15.
By combining the carbon cycle model with the records of carbonate and organic (kerogen) carbon isotope, this paper presents
the calculation of the fraction of organic carbon burial (f
org) of beds 23–40 at the global boundary stratotype section and point (GSSP) of the Permian-Triassic boundary at Meishan, Zhejiang
Province. The resulting calculation produces two episodes of f
org maxima observed to occur at beds 23–24 and 27–29, which respectively corresponds to the two episodic anoxic events indicated
by the flourish of green sulfur bacteria. Two episodic f
org minima occurred at beds 25–26 and 32–34, generally coincident with the flourish of cyanobacteria (bed 26 and upper part of
beds 29 to 34) as shown by the high value of 2-melthyhopnoanes. It appears that the f
org is related to the redox conditions, with greater f
org values observed under the reductive condition. The relationship between f
org and the total organic carbon (TOC) content was complex. The f
org value was low at some beds with a high TOC content (such as bed 26), while high observed at some beds with a low TOC content
(e.g. bed 27). This association infers the important contribution of primary productivity to the TOC content. The original
organic burial could be thus calculated through the configuration of the function of the primary productivity and f
org, which can be used to correct the residual TOC measured today. This investigation indicates that compiling the organic-inorganic
carbon isotopes with the carbon cycle model favors to understand the fraction of organic carbon burial, providing information
for the reconstruction of the coupling among biota, environments and organic burial.
Journal of China University of Geosciences, 2007, 32(6): 767–773 [译自: 地球科学—中国地质大学学报] 相似文献
16.
Application of quantitative grain fluorescence techniques to study subtle oil migration pathway of lithological reservoir 总被引:1,自引:0,他引:1
This paper analyzes the quantitative grain fluorescence (QGF) and quantitative grain fluorescence on extract (QGF-E) properties
of 101 rock samples by using quantitative grain fluorescence techniques. The samples are collected from five wells in tight
sandstone and thin siltstone in the third sector of the Shahejie Formation in the Niuzhuang sag of the Dongying depression.
It was observed that both the tight sandstone and thin siltstone show relatively high fluorescence intensity of hydrocarbon,
which suggests that they are possibly good subtle oil-migration pathways in the present or geological time. These thin subtle
oil-migration pathways afford important clues for the researches on hydrocarbon accumulation in lithological reservoirs in
the middle and lower of Es
3 in deep sag zone, which has the hydrocarbon source from the upper of Es
4 when there is no apparent fault playing oil migration conduits to connect lithologic traps and deep source rocks. This study
shows good prospect of QGF techniques in discriminating oil migration pathways and paleo-oil zones. The results of this study
may be of great significance to the researches on hydrocarbon accumulation mechanism of subtle reservoirs in the Dongying
depression and other areas.
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Translated from Acta Geologica Sinica, 2007, 81(2): 250–254 [译自: 地质学报] 相似文献
17.
Wei Wenbo Jin Sheng Ye Gaofeng Deng Ming Tan Handong Martyn Unsworth John Booker Alan G. Jones Li Shenghui 《Frontiers of Earth Science》2007,1(1):121-128
The features of the faults in the central and northern Tibetan plateau are discussed, based on two super-wide band magnetotelluric
(MT) sounding profiles belonging to the INDEPTH (III)-MT project, which were finished between 1998 and 1999: one is from Deqing
to Longweicuo (named line 500), the other is from Naqu to Golmud (line 600). This work assists research on the collision and
subduction mode between the India and Asia plates. The MT results show that there is a series of deep faults, F1 to F10, in
the central and northern Tibetan plateau. Of these faults, F2 is an earlier main fault which leans to the north, and F1 is
a later main overriding fault. The Jiali deep fault zone, which has a very complex space structure, is composed of these two
faults. F3, F4 and F5 are super-deep faults. They are high-angle faults and lean a little to the south. The main fault zone
of the Bangong-Nujiang suture is composed of these three faults. Because of later activity in the structure, several shallow
faults formed in the upper crust within the Bangong-Nujiang suture. The Tanggula fault zone is composed of two main faults,
F6 and F7, and a series of sub-faults. The shallow segments of the main faults are in high angles and the deep segments of
main faults are in low angles. These two faults generally lean to the south and extend into the lower crust. The Jinshajiang
suture is composed of the Jinshajiang fault (F8) and the Kekexili fault (F9), and there is a series of sub-faults in the upper
crust between these two faults. The Jinshajiang suture is a very wide suture caused by continent-continent collision. The
Middle Kunlun fault (F10), which is the main structure of the Kunlun fault zone, is a high angle, super-deep fault. It is
the north boundary of the Songpan-Ganzi-Kekexili block. Based on the conductive structure of the profile, the southern part
of the Middle Kunlun fault belongs to the Tibetan plateau, but it is not certain whether the northern part of the Middle Kunlun
fault belongs to the Tibetan plateau. There are conductive bodies stretching from the crust into the upper mantle below the
Bangong-Nujiang suture and Jinshajiang suture. This may suggest heat exchange between the crust and mantle.
Translated from Earth Science—Journal of China University of Geosciences, 2006, 31(2): 257–265 [译自: 地球科学—中国地质大学学报] 相似文献
18.
Frequent flow cutoff has a serious effect on the eco-environment of the region along the Lower Yellow River. The authors study
the impact on lateral seepage quantity and groundwater cycling caused by cutoff of the Yellow River and compare it with that
of the year 1999 through the numerical simulation model of groundwater flow system of the affected zone. The lateral seepage
quantity decreased 53.8% on flow cutoff stage from Huayuankou to the river entrance and breaking time of 300 d. The lateral
seepage quantity will decrease 46.3% if flow cutoff is from Jiahetan to the river entrance and breaking time is 300 d, and
it will decrease 75.2% if flow cutoff occurs throughout the year. The lateral seepage quantity will decrease 19.8% if flow
cutoff is from Luokou to the river entrance and breaking time is 300 d, and it will decrease 25.1% if flow cutoff occurs throughout
the year. The lateral seepage quantity will decrease 4.7% if flow cutoff is from Lijin to the river entrance and flow cutoff
occurs throughout the year. Flow cutoff of the Yellow River has a minor effect on the shape of groundwater flow domain of
the affected zone. Thus, the boundary condition of the shallow groundwater system will not change. Although flow cutoff has
a major influence on the riverside source fields in the Lower Yellow River, it will not have a significant effect on groundwater
resources macroscopically in the affected zone of the Yellow River due to its large storage capacity.
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Translated from Journal of Jilin University (Earth Science Edition), 2007, 37(5): 937–942 [译自: 吉林大学学报(地球科学版)] 相似文献
19.
The anaerobic oxidation of methane (AOM) with sulphate is the most important sink for methane in marine environments. This process is mediated by a consortium of methanotrophic archaea and sulphate reducing bacteria. So far, three groups of anaerobic methane oxidisers (ANME-1, -2 and -3) related to the methanogenic Methanosarcinales and Methanomicrobiales were discovered. The sulphate reducing partner of ANME-1 and -2 are two different eco-types of SRB related to the Desulfosarcina/Desulfococcus cluster (Seep-SRB1), whereas ANME-3 is associated with Desulfobulbus spp. (DBB). In this article, we reviewed literature data to assign statistically significant lipid biomarker signatures for a chemotaxonomic identification of the three known AOM communities. The lipid signatures of ANME-2/Seep-SRB1 and ANME-3/DBB are intriguingly similar, whereas ANME-1/Seep-SRB1 shows substantial differences to these AOM communities. ANME-1 can be distinguished from ANME-2 and -3 by a low ratio of the isoprenoidal dialkyl glycerol diethers sn2-hydroxyarchaeol and archaeol combined with a comparably low stable carbon isotope difference of archaeol relative to the source methane. Furthermore, only ANME-1 contains substantial amounts of isoprenoidal glycerol dialkyl glycerol tetraethers (GDGTs), however, with the probable exception of the ANME-2c sub-cluster. In contrast to the ANME-1 archaea, the tail to tail linked hydrocarbon tetramethylhexadecane (crocetane) is unique to ANME-2, whereas pentamethylicosenes (PMIs) with 4 and 5 double bonds without any higher saturated homologues were only found in ANME-3. The sulphate reducing partner of ANME-1 can be discerned from those of ANME-2 and -3 by a low ratio of the fatty acids (FAs) C16:1ω5 relative to i-C15:0 and, although to a lesser degree, by a high abundance of ai-C15:0 relative to i-C15:0. Furthermore, substantial amounts of 13C depleted non-isoprenoidal monoalkyl glycerol ethers (MAGEs) were only found in the sulphate reducing partners of ANME-2 and -3. A differentiation of these SRB is possible based on the characteristic presence of the FAs cy-C17:0ω5,6 and C17:1ω6, respectively. Generally, the data analysed here show overlaps between the different AOM communities, which highlights the need to use multiple lipid signatures for a robust identification of the dominating microbes involved. 相似文献
20.
Ersi Kang Rensheng Chen Zhihui Zhang Xibin Ji Bowen Jin 《Frontiers of Earth Science》2008,2(4):384-392
The challenge is put forward to scientific hydrology by the advancement of water sciences; that is, how should we carry out
a multidisciplinary, integrated and cooperative research on hydrological processes in the basin, regional and global scales,
in order to better understand the role water plays in the changes of the natural resources and environment of the earth, and
to understand the hydrosphere and its interactions with the atmosphere, lithosphere and biosphere. How the changes and transformation
of the components of the water cycle and water balance occur in an inland river basin has yet to be understood. We also need
to understand what the interactions of water cycle, ecosystems and environment are, and what the responses and feedback of
the changes to global change and to human activities are. The water cycle in an inland river basin characterizes the runoff
generation region of the mountains upstream, the artificial oases region of water resources exploitation and utilization midstream
and the natural desert oases region of runoff dissipating downstream. The mountain hydrological processes are discussed from
water cycle, energy balance, water balance and ecological processes. The interactions of water and vegetation are discussed
in relation to ecohydrology, and the hydrological processes in the ground water-soil-vegetation layer are discussed from the
concept of the critical zone newly put forward abroad. The basic frame is put forward to carry out the field measurement,
experiment and studies of hydrological processes in a typical inland river basin.
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Translated from Advances in Earth Science, 2007, 22(9): 940–953 [译自: 地球科学进展] 相似文献