黄河口及近海表层沉积物中烃类化合物的组成和分布

为探讨黄河口近海表层沉积物有机质中烃类化合物的分布特征及输运过程,2003年9月采集了南北两个断面表层沉积物样品,对沉积物中正构烷烃和多环芳烃进行了分析,结果表明,黄河口表层沉积物中正构烷烃和多环芳烃的含量分别为0.38~2.55和0.371~0.650μg/g。在南北断面两种烃类化合物的分布明显不同:北断面受石油平台影响,烃类化合物在口门含量较高;南断面受黄河输入影响,由于大颗粒易于沉降,而吸附烃类化合物的能力较强的小颗粒易长距离输运,使这两种烃类化合物的含量从河口到近海整体呈上升的趋势。与北断面相比,南断面受水生源影响相对较弱,而且水生源的贡献随着离岸距离的增加而加强,在最大浑浊带后水生源急剧增强;在南断面多环芳烃主要来源为热解源,北断面多环芳烃受热解源和石油污染的共同影响。     

南海现代表层沉积物中有机物的分布研究

应用GC,GC/MS分析法,系统剖析了南海现代沉积物中有机质的分子地球化学特征,对其生物标志物组成、成熟度和成因进行了研究.研究认为,南海现代沉积物中有机质族组成具有现代有机质特征,但部分生物标志物参数特征表明烃类具有低成熟度,可能有外源有机质的加入.O-2,O-6,O-10和O-13样品中的烃类组成特点说明,这4个样品中的烃类是在海相贡献略高于其他样品环境中的条件下形成的.甾烷的组成特点说明了南海现代沉积物中有机质生源的特殊性.     

西太平洋WP02-1柱状样品有机地球化学特征及其与Fe、Mn成岩成矿作用

在较系统地定量分析了西太平洋WP02-1柱状样品中的有机碳、可溶有机质(氯仿沥青“A”)及其族组成(总烃、饱和烃、芳烃、非烃、沥青质)、正构烷烃分子组合指数(nC^-₂₃/nC⁺₂₄、CPI)、类异戊二烯烃(Pr/Ph、Pr/nC₁₇、Ph/nC₁₈)的基础上,研究了它们的组成来源、正构烷烃生物标志化合物的地球化学特征,同时结合成矿元素Fe、Mn含量进行相关性分析。研究发现,有机烃类组分与成岩成矿元素有密切的成因联系,这一区域在Fe、Mn成岩成矿过程中,有机质起到重要作用。     

Sources and hydrothermal alteration of organic matter in Quaternary sediments: A synthesis of studies from the Central Gulf of California

Deep sea drilling in the Central Gulf of California, a young and active spreading centre, shows that the high heat flow typical of these regions causes extensive alteration of sediment organic matter, especially near sills and above magma chambers where hydrothermal activity is concentrated. Even on the nearby passive margin, where there are no sills, heat flow is moderately high and hydrocarbon generation has begun in immature sequences. Migrating light hydrocarbons are detected especially where hydrothermal activity is concentrated. Thermogenic methane is more widespread, though not in the passive margin bordering the spreading centre. Despite the incidence of hydrocarbon generation and migration, the amounts of hydrocarbons involved are relatively small and apparently do not lead to commercially significant accumulations of petroleum.The organic matter in these sediments is mostly marine because the Gulf of California generally has low runoff from land and highly productive surface waters. Turbidites rich in terrigenous organic material are locally abundant in the mainly pelagic section in the Guaymas Basin. The highest concentrations of organic matter are found in laminated diatomites deposited on the Guaymas passive margin within the oxygen minimum zone.     

Organic geochemical study of the Upper Kimmeridge Clay of the Dorset type area

Results are presented from an organic geochemical investigation of a suite of rock samples taken from the Upper Kimmeridge Clay near Kimmeridge, Dorset. All samples contain immature organic matter of marine origin, although one horizon, the Whitestone Band, contains an additional secondary input of partially biodegraded mature hydrocarbons, due to an oil seepage of unknown origin. With the exception of increased relative abundances of 4-methylsteroidal hydrocarbons in the more organic-rich samples, the immature molecular distributions are very similar, suggesting a consistent source of organic matter. The results are in agreement with the palaeoenvironmental model proposed by Tyson et al. (1979) for the deposition of the Kimmeridge Clay, where the different lithologies are controlled by a fluctuating oxic/anoxic boundary, with only the organic-poor mudstones being deposited in relatively oxygenated waters.     

南黄海北部海底沉积物饱和烃地球化学特征及物源判识

对南黄海北部48个海底表层沉积物样品进行了常规的有机地球化学分析测试,对沉积有机质中的饱和烃组分进行了色谱定量、色谱—质谱分析。测试结果显示沉积有机质受微生物的降解作用在饱和烃色谱图中出现不同程度的UCM鼓包,峰型为双峰型,奇偶碳优势明显,且长链烃奇数碳优势更加显著;石油烃参数Pr/nC17和Ph/nC18比值较高;甾、萜烷成熟度生物标志物参数均显示了有机质进入生烃的热成熟阶段。综合分析认为,南黄海北部海底沉积物受双源控制,以陆源输入为主,有机质保存条件好,成熟度较高,推测可能有外源烃的污染。     

Particulate matter and components of the organic substance in the surface waters of the Southern and Atlantic Oceans

The integrated studies of the particulate matter and organic compounds in the surface waters and the snow-ice cover by means of geochemical (the concentrations of the particulate matter, the Corg, the hydrocarbons, the lipids, and the chlorophyll a) and optical techniques were performed in the Southern Ocean and in the east of the Atlantic Ocean along the vessel’s route: Africa-Antarctica-Africa-St. Petersburg. The correlations between the treated compounds were found. It was shown that the supply of pollutants affects not only the concentrations but also the proportions of the considered compounds. New data were obtained on the processes of the accumulation of particulate matter and organic compounds under the ice formation.     

Petroleum hydrocarbons and particulate organic matter in the Sea of Azov waters

The paper discusses the results of investigations on contamination of the Sea of Azov by petroleum hydrocarbons and particulate organic matter. After cessation of open sea observations in 1992, the contamination of the sea by petroleum hydrocarbons is predicted for the period from 1993 to 1997. Translated by Vladimir A. Puchkin.     

Recognizing and compensating for interference from the sediment’s background organic matter and biodegradation during interpretation of biomarker data from seafloor hydrocarbon seeps: An example from the Marco Polo area seeps,Gulf of Mexico,USA

A suite of seep samples from the vicinity of the Marco Polo field in the Green Canyon area of the Gulf of Mexico provides an exceptional opportunity to study the impact of interference from sediment background organic matter and alteration by biodegradation on thermogenic hydrocarbons from seafloor seeps. These seep samples contain a range in both the concentration of seeped hydrocarbons present and level of biodegradation experienced. In addition, the subsurface oil that sources the seepage was available for comparison.     

Biomineralization of organic matter in cobalt-rich crusts from the Marcus–Wake Seamounts of the western Pacific Ocean

Organic matter in cobalt-rich crust(CRC) from the Marcus–Wake Seamounts of the western Pacific Ocean, Sample CM1D03, has been analyzed to understand the source, geochemistry and mineralization of organic matter, and the mineralization environment. Biomarkers, including n-alkanes, isoprenoids, terpanes and sterols, have been detected in various layers of the CRC sample, using gas chromatography(GC) and gas chromatography–mass spectrometry(GC–MS). The content of organic carbon(OC) and its stable isotope(δ13C), and the combined features of the biomarkers show that the mineralized organic matter in CM1D03 CRC was mainly derived from microorganisms and lower plankton(e.g., bacteria and algae, respectively) from marine surface water, with some terrestrial higher plant components. The ratio of chloroform bitumen "A": OC was high in the CRC, between 10.51 and 20.66, showing significant migration characteristics of n-alkanes. Four mineralization categories of organic matter were recognized based on GC chromatograms of n-alkane molecules:(1) primitive type(bacteria and algae), which is characterized by moderately mature of n-alkanes preserving the original characteristics of the organic matter from microorganisms and lower plankton;(2) microbial degradation type, which is characterized by low contents of n-alkanes and rising baseline in the chromatogram, with the "bulge" being the products of organic matter by biodegradation;(3) organic matter migration type, which is characterized by low carbon number of n-alkanes with n C18 as the main peak carbon, without odd even predominance, and low concentrations of isoprenoids and hydrocarbons with high carbon number; and(4) organic matter hydrothermal type, which is characterized by relatively low concentration of small molecular weight n-alkanes, pristane, and phytane, accompanied by higher concentration of n-alkanes with carbon number greater than n C18. This study shows that biomarkers can record controlling factors of mineralization and their variation.     

Assessment of the oil source-rock potential of the Pedregoso Formation (Early Miocene) in the Falcón Basin of northwestern Venezuela

The early Miocene Pedregoso Formation is one of the numerous formations rich in organic matter within the stratigraphic record of the Urumaco Trough, in the central area of the Falcón Basin. Due to its lithological characteristics and stratigraphic position, this formation is of great interest regarding the basin's petroliferous systems. The evaluation of various inorganic and organic geochemical parameters indicates that the organic matter is primarily of marine origin, deposited in a marine carbonate environment typical of reefal systems, under oxic-to-dysoxic conditions. The low variability in the TOC concentrations and in the distributions of the biomarkers extracted from the samples suggests that the paleoenvironmental conditions and the organic-matter supply remained approximately constant throughout the sedimentation of this unit. The Pedregoso type-II organic matter (marine origin) and initial organic richness value (∼1.8%) suggest that this unit has probably generated hydrocarbons within the Urumaco Trough. However, present-day thermal maturity parameters reveal that the Pedregoso organic matter is overmature (dry gas window), indicating that this unit is only capable to generate gas. In addition, the geothermal gradient, maturity parameters, and the maximum paleotemperature estimated in this study suggest that the Pedregoso Formation reached a maximum burial depth the ∼6.5 km, consistent with the value obtained from data of stratigraphic thickness in the Urumaco Trough. This implies that the thermal anomaly that affected the basin during the Late Eocene–Early Miocene did not reach the central part of the basin, and therefore, the organic matter maturation in this unit is due to the sedimentary burial.     

Basic regularities of the process of sedimentation of suspended organic matter in the shallow-water zones of the seas at middle latitudes

On the basis of analysis of literature data, we consider the regularities of sedimentation of suspended organic matter in shallow waters. The seasonal variability in sedimentation is demonstrated, and its scheme is constructed involving such classes of organic compounds as suspended amino acids, fatty acids, and hydrocarbons. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

Seasonal variation of particulate hydrocarbons in relation to biological parameters

Particulate matter was sampled for hydrocarbon analyses at three anchor stations in Kiel Bight during different seasons (autumn, winter and spring). Additionally, the following parameters were measured: salinity, temperature, nutrients, chlorophyll, dissolved organic carbon and phytoplankton composition. From these concomitant measurements showing normal hydrographic or meteorologic situations, it was concluded that no intrusions of water masses occurred during the sampling periods; all collected material was produced at or near the sampling location under biological conditions which are encountered normally in this region at these times. During every season the concentration of biogenic hydrocarbons exceeded that of the petrogenic ones. Among the biogenic hydrocarbons the concentration of heneicosahexaene (HEH) was predominant, but in highly variable concentrations, depending on phytoplankton activity. No direct correlation between individual hydrocarbons and plankton species could be established, but a quantitative relationship between the biogenic hydrocarbons and the biological summation parameter was obvious.     

中太平洋富钴结壳中生物标志物、有机碳同位素地球化学及其古海洋环境意义

利用2003年大洋DY105-12,14航次在中太平洋海山获取的KXD28富钴结壳样品,采用气相色谱(GC)内标法对该结壳样品的分层样进行了可溶有机质(氯仿沥青“A”)及其族组成(饱和烃、芳烃、非烃)、正构烷烃、类异戊二烯烃的定量分析,并结合总有机碳(TOC)及有机碳同位素(δ¹³C)分析,探讨了结壳样品有机质来源及富钴结壳组成与生长环境之间的关系。结果表明:(1)富钴结壳中有机质生物母源主要为海洋生物和菌藻类,并混有少量陆源物质;有机碳同位素同样也指示了海洋水生生物碳同位素特征;(2)KXD28结壳从底层到最外层有机碳同位素发生了很大变化,结壳中有机碳同位素组成变化与结壳生长过程中的海洋环境气候相符合:富钴结壳生长前期δ¹³C组成由正变负,对应全球气候变冷,南极底层流向太平洋挺进;而富钴结壳生长后期δ¹³C逐渐偏正,与全球气候变暖和南极底层流萎缩相关联。     

High resolution characterization of a core from the Lower Jurassic Gordondale Member,Western Canada Sedimentary Basin

The Gordondale Member is a hydrocarbon source rock and potential unconventional reservoir that extends across northeastern British Columbia and central-northwestern Alberta. It is an organic-rich, calcareous, fossiliferous mudstone with a median total organic carbon value of 6.0 wt%. A total of 230 samples were collected from approximately 25 m of Gordondale Member core for organic matter analysis using Rock-Eval 6 analysis and organic petrology. Detailed core logging provides sedimentological context for organic matter characterization. The predominant organic material in the samples is solid bitumen and liptinite with lesser zooclast and inertinite. Most kerogen is Type II, autochthonous marine biomass, with minimal dilution by inert organic carbon. Rock-Eval T_max values and random reflectance measurements of solid bitumen indicate the samples are within the oil generation window. Solid bitumen contributes a substantial amount of hydrocarbon potential to the interval. A micro-reservoir structure within the core is produced by thin intervals of impermeable displacive calcite that act as barriers to the upward migration of free hydrocarbons. These free hydrocarbon accumulations could make excellent targets for horizontal wells within the Gordondale Member.     

塔里木盆地寒武－奥陶系生油岩成油期─－兼谈喜山晚期“二次生油”

寒武－奥陶系生油岩是塔里木盆地主力油源，尤以满加尔坳陷发育最佳。本文以基础数据为依据，主要论述该套烃源岩的成油期问题，认为寒武系生油岩主成油期为古生代，并在中新生代具二次生油特点；奥陶系生油岩主成油期为海西晚期（满加尔坳陷）和中新生代。塔北、塔中诸多高产油气田中的油气主要为中新生代所形成。     

Generation,migration and accumulation of oil of El-Ayun Field,Gulf of Suez,Egypt

This study is an attempt to solve the problem of oil generation, migration and accumulation of oil in El-Ayun Field, Gulf of Suez. The organic carbon, hydrogen and organic matter contents in addition to the composition of kerogen are determined. The degree of transformation of organic matter to hydrocarbon and the level of thermal maturity of these sediments to yield hydrocarbons are deduced. The geothermal gradient mnd level of organic metamorphism (LOM) are determined by using the bottom hole temperature. The vitrinite reflectance values are used in this respect. The determined trace element contents for both crude oils and sediments clarifies the process of oil migration from possible source rocks to oil reservoirs.Recommendations, concerning exploratory testing of favourable sites for oil accumulation, laterally and vertically, are postulated on the basis of the achieved results.     

Organic geochemistry of sediments from the continental margin off southern New England,U.S.A. — Part II. Lipids

Organic geochemical measurements of the lipid fraction, comprising saturated and aromatic hydrocarbons, fatty acids, alcohols and sterols, have been carried out on six sediment cores collected from the Atlantic shelf, slope and the rise areas to evaluate the cross-shelf transport of the organic carbon.The concentration of most of the organic compound classes studied is correlated with the total organic carbon, which decreases from the shelf through slope to the rise. Terrigenous carbon is recognizable even in the slope and rise sediments, but terrestrial influx decreases relative to marine generated lipids in the slope and rise organic matter. We estimate that ∼50% of the shelf organic matter is exported to the slope.Data of sediment trap material collected at 1200 m from 1250 m water depth are discussed and compared with that of surface sediment from 1280 m water depth (slope). Fluxes for specific organic compound classes have been computed. The fluxes are of the same magnitude as for equatorial North Atlantic trap particulates at comparable water depth, studied by other investigators.     

南海沉积物中的正构烷烃和多环芳烃的分布及来源(英文)

重点研究南海沉积物中烃类化合物的有机地球化学特征,讨论了南海沉积物中有机物质的分布和来源。其中正构烷烃分布在Ｃ１６－Ｃ３３奇偶优势不明显,结合其轻重比值,显示有机质的输入在大部分站位以海洋源为主,在一些站位陆源输入的贡献也比较明显,海源输入中又以藻类等有机碎屑的贡献最大。在南海沉积物中共检出６０余种环芳烃,高环化合物（四环和五环）的总含量明显高于其他组分。一些陆源特征标志物如惹烯、烷基屈等化合物被检出,在大多数样品中都发现有的存在,推测其可能来源应是燃烧产物,而非陆源输入。     

Hydrocarbon alteration in the bituminous salt of the Kłodawa Salt Dome (Central Poland)

The so called bituminous salts occurring in the Kłodawa dome, located in Central Poland, differ from the surrounding salts by their colour change from light to dark brown. This colour is associated with an extremely large amount of hydrocarbon, mainly located in the inclusions. The presence of numerous fluid inclusions has been documented in previous petrologic studies, distinguishing seven main types of fluid inclusion assemblages (FIA) in terms of size, shape as well as the ratio of filling material. However, four types of inclusions were selected in the current investigations according to their unusual optical behaviour. Raman micro-spectroscopy a modern, non-destructive method was used for investigating a single inclusion being a part of FIA. Presented in this paper Raman spectra revealed a unique pattern of bands characterizing the content of the inclusions. The hydrocarbons show a very complex character reflected in the appearance of a strong fluorescence background. A well-marked heterogeneity characterized the inclusions, by diversity in the intensity of the background and in the pattern of the bands characterizing the presence of certain components. One can distinguish the presence of carbonaceous matter showing the different degrees of order. The depth profile and the analysis of the various points of the inclusions indicate that the carbonaceous matter is not evenly distributed in the inclusions but forms a thin, disorganized film on their walls. This film was also found in sites where the inclusions are filled with brine. The certain characteristics associated with the presence of the incipient phase transformation of the organic matter, or slightly transformed organic matter and the lack of light hydrocarbons as well as a number of petrologic features of inclusions indicate that these salt rocks have been subdivided into thermal transformations, accompanied by the recrystallization of the halite and the escape of the more volatile compounds such as methane, ethane, etc.