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1.
Previous studies have shown that the oxidizing brines from the Early Permian Rotliegende sequence have influences on the organic matter of Kupferschiefer. However, inside the Rotliegende sequence there are two other black shales: the Lower and Upper Antracosia shales, which have not been studied as much in detail as in Kupferschiefer. In the present study 12 samples from the Lower and Upper Antracosia shales were analyzed by organic geochemical methods in order to clarify the influences of the oxidizing brines on organic matter. The results indicate that the organic matter of the samples from the Upper Antracosia shale and the bottom of the Lower Antracosia shale was oxidized under the influences of the oxidizing brines. The oxidation resulted in a depletion of saturated hydrocarbons and the alky Is of the aromatic compounds.  相似文献   

2.
Previous studies have shown that the ascending, oxidizing brines play a very important role in Kupferschiefer mineralization. Fractures could be the pathway of the brines. In order to clarify the influences of the brines on bulk organic matter, aromatic hydrocarbons and Kupferschiefer mineralization, one veinlet Kupferschiefer profile from the Lubin mine, southwestern Poland was studied with the microscopic, geochemical and Rock-Eval methods. The microscopic results indicate that organic matter of the veinlet sample consists dominantly of bitumen. Its extract content is higher than in other samples. The dominant aromatic compounds are naphthalene and alkylated naphthalenes (Na-PAH), which have migrated into the veinlet sample from other sediments. The content of phenanthrene and its methylated derivatives (Ph-PAH) is much lower than in other samples. The reason may be due to their heavier mass than Na-PAH. It is more difficult for Ph-PAH to migrate. The Na-PAH was probably removed from the shale by dist  相似文献   

3.
The bulk composition of organic matter and saturated and aromatic hydrocarbons extracted from 16 samples collected from two Kuperschiefer profiles in the Rudna mine,Southwest Poland has been analyzed to study the role of organic matter during base metal enrichment in the Kupferschiefer shale.The results indicated that the extract yields and saturated hydrocarbon yields decreased with increasing base metal contents.GC and GC/MS analyses indicated that n -alkanes and alkylated aromatic compounds were depleted and may have served as hydrogen donators for thermochemical sulfate reduction.The enrichment of base metal is closely connected with the destruction of hydrocarbons.  相似文献   

4.
max vs the present depth of the Kupferschiefer, soluble organic matter (SOM) yields, and relative proportions of saturated and aromatic hydrocarbons of the SOM provide evidence for an oxidative alteration of organic matter in highly mineralized Kupferschiefer samples near the Rote F?ule zones. This is confirmed by differences in the composition of the saturated and aromatic hydrocarbon fractions of the soluble organic matter: Saturated hydrocarbons from Rote F?ule samples are dominated by short-chain n-alkanes and higher abundances of pristane and phytane relative to heptadecane (n-C17) and octadecane (n-C18), respectively, compared with samples more distant to the Rote F?ule zone. Compositional changes of the aromatic hydrocarbon fractions with decreasing distance to that zone are characterized by the occurrence of polycyclic aromatic hydrocarbons and elevated ratios of phenanthrene to methylphenanthrenes that are attributed to demethylation reactions and resulted in a decrease of the methylphenanthrene index (MPI 1). Kupferschiefer samples from the barren zone of the Polish Basin do not show these alteration patterns. The observed variations in organic matter composition with burial depth are consistent with changes due to increasing thermal maturation. Maturity assessment is achieved from MPI 1 and the methyldibenzothiophene ratio (MDR). From the relationship between the maturity of organic matter in terms of vitrinite reflectance values and depth of the Kupferschiefer strata, a continuous increase in reflectance of vitrinite is obtained within the Polish Basin. The alteration pattern of organic matter related to base metal mineralization of the Kupferschiefer corresponds to changes in the isotopic composition of organic carbon and calcite. Kerogen within, or close to, Rote F?ule zone is enriched in 13C caused by the preferential release of isotopically light organic compounds through progressive degradation of organic matter. The opposite tendency towards lower δ 13C and δ 18O values of calcite provides evidence for isotopic exchange between carbonate and the oxidizing, ore-bearing solutions and for organic matter remineralization. In contrast, organic matter and calcite from the Kupferschiefer do not show regular trends in δ 13C with increasing thermal maturation. Received: 25 June 1999 / Accepted: 1 December 1999  相似文献   

5.
1INTRODUCTION ORGANICALLY BOUNDSULFURCOMPOUNDSWEREPREVI OUSLYDETECTEDINTHEKUPFERSCHIEFER(P櫣TTMANNAND GO EL,1990;ROSPONDEKETAL.,1994).P櫣TTMANN ANDGO EL(1990)INVESTIGATEDTHEEXTRACTABLEORGANIC MATTERINTHEKUPFERSCHIEFERFROMTHENORTH SUDETIC SYNCLINEANDPROPOS…  相似文献   

6.
The paper reviews data (acquired in 2007–2016) on aliphatic and polycyclic aromatic hydrocarbons in comparison with data on concentrations of lipids, Corg, and chlorophyll a in the water and bottom sediments the river–sea geochemical barrier (for the Northern Dvina, Ob, Yenisei, and Lena rivers). It was established that the concentrations of anthropogenic hydrocarbons decrease and these compounds precipitate like other organic compounds and particulate matter, where riverine and marine waters mix. Relatively pure water flows in the pelagic zones of seas. In spite of low temperatures in the Arctic, anthropogenic hydrocarbons transform so rapidly that natural compounds dominate in the water and bottom sediments: autochthonous in the seawater and allochthonous in the bottom sediments.  相似文献   

7.
Within the Central European Zechstein Basin the Permian Kupferschiefer has been deposited under anoxic conditions. In most parts of the basin, the metal content does not exceed values commonly observed in black shales. However, in areas near to the Zechstein sea-shore which are simultaneously related to rift zones a significant base metal enrichment is observed. Organic geochemical analyses of the copper-mineralized sections in the Kupferschiefer from Southwest Poland show that significant changes in the composition of organic matter are associated with the metal enrichment processes. Porphyrins, commonly abundant constituents of the shale, have been decomposed by oxidizing fluids. Additionally, aliphatic hydrocarbons have been largely removed from the bitumen and alkylated aromatic systems were affected by side-chain degradation. This particular type of alteration is explained by ascending oxidizing solutions which transported high amounts of base metals from Lower Permian red beds into the Kupferschiefer horizon acting as a geochemical trap. The metal precipitation is suggested to be a result of thermochemical sulphide production with organic matter acting as hydrogen source. In areas such as the Lower Rhine Basin in the bottom section of the Kupferschiefer the base metals lead and zinc as well as barium have been accumulated from basinal Carboniferous formation waters. Copper enrichment is not observed because potential source rocks are missing in this area. However, the observed compositional changes of the organic matter do not point towards thermochemical redox processes.  相似文献   

8.
Benzene extractable aliphatic hydrocarbons from the New Albany Shale in the Illinois Basin were characterized by gas chromatography and mass spectrometry, and the total organic matter of the shale was characterized by solid state carbon-13 cross polarization magic angle spinning nuclear magnetic resonance. Core samples from a northwest-trending cross-section of the Illinois Basin were studied. Gas chromatography (GC) and gas chromatography-mass spectrometric analysis (GC/MS) data indicate a regional variation of the aliphatic composition of the shale extracts. A positive, linear relationship between the two ratios, pristane/n-C17 and phytane/n-C18, is indicated. The NMR results indicated that organic matter deposited in northwestern Illinois shale is relatively high in aliphatic hydrocarbon content while, in contrast, organic matter found in southeastern Illinois shale is relatively low in aliphatic hydrocarbon content. Our findings suggest that the organic variation of the shale is mainly due to the differences in thermal maturity of the shale organic matter and the use of pristane/n-C17 ratio as a thermal parameter in the study of oil may be extended to the study of the ancient sediments.  相似文献   

9.
《Applied Geochemistry》2001,16(3):375-386
The concentrations of the lanthanide rare earth elements (REE) and Pt group elements (PGE) were measured in the Kupferschiefer from the Polish Zechstein Basin at, and in proximity to, the Rote Fäule near the Lubin Mining District. The Rote Fäule is a zone of post-depositional oxidation characterized by the presence of extensive amounts of Fe(III) oxides replacing syn-sedimentary framboidal pyrite. Outward from the Rote Fäule, the remainder of the Kupferschiefer is composed of Cu- and Pb/Zn-mineralized shale surrounding the Rote Fäule and a non-mineralized pyritic black shale in the central basin.The leading hypothesis explaining the high concentrations of PGE, and REE in the Kupferschiefer states that PGE, REE and the associated base metals were mobilized by oxidizing Cl− brines which migrated outward from the Rote Fäule into the reduced Kupferschiefer. According to available thermodynamic data, PGE were in all likelihood present as chloro-complexes in these oxidizing brines, as geologically realistic concentrations of Pt, Pd and Au could be transported as chloro-complexes. The Eh of these brines decreased as they migrated further from the Rote Fäule and into the Kupferschiefer. Base metals and PGE were precipitated in the order of their decreased solubility in these brines. As a result, the concentrations of least soluble PGE (Pt) are highest in the Rote Fäule and in the transition zone adjacent to the Rote Fäule (e.g. [Pt]=202–537 ppb) while the concentrations of the more soluble metals in these brines (Ag, Cu, Pb, and Re) are highest in the reduced-mineralized Kupferschiefer. The sources of the PGE and REE are enigmatic. It is likely that the metals were derived either from the underlying Rotliegendes sandstones and volcanics, the Variscan basement rocks, or the Kupferschiefer shale whose metals were mobilized by saline, oxidizing fluids released during intra-continental rifting in the Triassic period.  相似文献   

10.
《Applied Geochemistry》1997,12(5):577-592
A densely sampled profile (58 cm in thickness) composed of 13 samples of the Kupferschiefer and overlying Zechstein carbonates from the Sangerhausen Basin, Germany has been analysed by various geochemical and microscopic methods in order to clarify the mechanism of base metal accumulation. In this location, the Kupferschiefer is only slightly influenced by the hematite-bearing, oxidized fluids calledRote Fäule.The determination of facies-dependent parameters along the profile indicates that Kupferschiefer from the Sangerhausen Basin was largely deposited in a marine environment; only at the beginning of Kupferschiefer sedimentation did euxinic conditions prevail. The bottom part of the profile is significantly enriched in trace elements such as Cu, Ph, Zn, As, Co, Ag and U. The Cu concentration amounts to 19.88 wt.%. Post-depositional oxidation of the organic matter is observed only in the transition zone between the Kupferschiefer and the Zechstein conglomerate indicating the influence of ascending, oxidizing brines. Microscopic analyses show that only Fe sulfides form framboidal textures; Cu minerals are present along the total profile preferentially in fractures and as patchy structures composed of chalcocite, chalcopyrite and bornite. In the highly mineralized bottom section, Cu sulfides are associated with pyrobitumen, sparry calcite and arsenopyrite. Results from maturation studies of organic matter suggest that the maximum temperature affecting the Kupferschiefer was approximately 130°C.A 3-step-process of metal accumulation is proposed. During deposition of the sediment, framboidal pyrite and pyrite precursors were precipitated by bacterial SO42− reduction (BSR). During diagenesis the pyrite and pyrite precursors were largely replaced by mixed Cu/Fe minerals and by chalcocite (PR). In the section with very high Cu contents (> 8%) reduced sulfur from Fe-sulfides was not sufficient for precipitation of Cu and other trace metals from ascending solutions. In this part of the profile, thermochemical SO42− reduction (TSR) occurred after pyrite replacement as indicated by the presence of pyrobitumen and sparry calcite.  相似文献   

11.
This paper reports data on the concentrations of organic compounds (organic carbon, Corg; lipids; aliphatic hydrocarbons, AHCs; and polycyclic 0aromatic hydrocarbons, PAHs) in snow, ice, and subice waters from the mouth of the Severnaya Dvina River (2005–2007) and Kandalaksha Gulf (Chupa Bay, 2004) at the end of winter. It was established that organic compounds are accumulated in the snow and upper ice layer near the town of Archangelsk. The distribution of molecular markers indicates that pollution was mainly caused by local fallouts. In Chupa Bay, organic compounds are concentrated in the lower ice layers, which is typical of the Arctic snow-ice cover. The high contents of organic compounds in the snow-ice cover of the White Sea are caused by the pollution of its air and water during the winter season.  相似文献   

12.

On the basis of GC–MS analysis, a suite of nine coal-measure source rocks (Ro 0.51%–0.63%) from the southern margin of Junggar basin was found to contain many biomarkers for bacterially-generated hydrocarbons: hopane, sesquiterpene, C23+ monomethyl alkanes (even carbon predominance), and C24+ alkyl cyclohexane. Rock–eval and microscope analysis indicate that vitrinite (especially desmocollinite and homocollinite) plays a significant role in the generation of hydrocarbons in coal-measure source rocks. Vitrinite performs this role by absorbing ultramicroscopic organic matter, generally in the form of resins or bacterial plastids. C23+ monomethyl alkanes (even carbon predominance) and C24+ alkyl cyclohexane series compounds are derived from bacterial metabolites of higher plants. The ultramicro organic matter adsorbed by vitrinite source rocks in the study area is probably ultramicro bacterial plastids. Because the organic matter of higher plants with low hydrogen content has been transformed into organic matter rich in hydrogen by bacteria, the hydrocarbon generation capacity of source rocks is greatly improved. In other words, in coal-measure source rocks, bacteria play an important role in hydrocarbon generation.

  相似文献   

13.
Samples around a coal gangue dump of the Gequan Coal Mine were collected in April 2009. GC (gas chromatography) and GC/MS (gas chromatography/mass spectrometry) were employed to analyze the composition of organic matter in the samples. ICP-MS (inductively coupled plasma mass spectrometry) was used to determine the concentrations of heavy metals. The contents of organic extracts are within the range of 140-750 mg/kg. Alkand aro-ratios are relatively high. Compared to those of the background sample (GQ13 ), the contents of saturated hydrocarbon compounds in all the samples are relatively high. The contents of polycyclic aromatic hydrocarbons (PAHs) are relatively high with the distance getting closer to the coal gangue dump. These indicate that organic matter in the samples is from coal particles of the coal gangue dump. The distributions of heavy metals are very similar: the contents decrease with distance from the dump, which indicates that the harmful heavy metals from the coal gangue dump have polluted as thick as at least 500 m.  相似文献   

14.
Currently, the presence of free n-alkanes and isoprenoid alkanes in carbonaceous meteorites is usually explained either by microbial contamination during the period between the meteorite fall and collection or by contamination from the environment of analytical laboratories and museums. The goal of this research was to repeat analysis of hydrocarbon components in meteorites and to investigate possible meteorite contamination routes discussed in the literature. Experimental analysis of free organic constituents in five carbonaceous meteorites by infrared spectroscopy (IR) and gas chromatographic (GC) methods confirmed the presence of extractable aliphatic components, n-alkanes in the C15H32-C27H56 range and isoprenoid alkanes (phytane, pristane, and norpristane), in some of these meteorites. The contents of these compounds vary depending on the source. Insoluble organic components of two meteorites (meteorite kerogens) were isolated, and their composition was analyzed by IR and cracking/GC methods. Comparison with the data on several terrestrial contamination sources proposed in the literature shows that the presence of free saturated hydrocarbons in meteorites and the composition of the meteorite kerogen could not be explained either by microbial contamination or by contamination from the laboratory environment. The types of the hydrocarbons in meteorites resemble those typical of ancient terrestrial deposits of organic-rich sediments, except for the absence of lighter hydrocarbons, which apparently slowly evaporated in space, and multi-ring naphthenic compounds of the biologic origin, steranes, terpanes, etc. The prevailing current explanation for the presence of free linear saturated hydrocarbons in carbonaceous meteorites, apart from contamination, is the abiotic route from hydrogen and carbon monoxide. However, the data on the structure of meteorite kerogens require a search for different routes that initially produce complex polymeric structures containing n-alkyl and isoprenoid chains which are attached, via polar links (esters, salts, etc.), to a cross-linked polymer matrix. Later, the polymer slowly decomposes with the liberation of free aliphatic hydrocarbons.  相似文献   

15.
As geochemical appraisals of mineral regions of commercial prospectivity evolve, the organic matter associated with metal rich ores has attracted greater attention. Petroleum basin and modern seafloor hydrothermal vent studies have suggested that organic matter can have a significant influence on the behaviour of mineralising fluids. There have been many isolated reports of certain organic compositional or morphological (e.g. pyrobitumen) features showing an apparent relationships with hydrothermal fluids or minerals, raising expectations that organic based parameters might be useful to mineral exploration. However, the understanding of organic–inorganic relationships in Earth systems is far from complete. For example, the detailed mechanics of the interaction of organics with hydrothermal fluids over geological time remain largely undefined. Organic geochemistry studies have traditionally involved the measurement and interpretation of the hydrocarbon composition of sedimentary rocks. Here we review the types of aliphatic hydrocarbons, aromatic hydrocarbons and metalloporphyrins often detected from organic geochemical investigations in mineral-rich regions. Such molecular data can be particularly diagnostic of biochemical sources and the palaeo-environments at the time mineral associated organic matter was deposited. Sub-surface trends of hydrocarbon alteration may also reflect major biogeochemical processes such as thermal maturity and biodegradation. Organic geochemistry data can also occasionally provide information about the nature (e.g., origin, composition, temperatures) and migration pathways of hydrothermal fluids and can make a contribution to holistic ore genesis models. The well preserved organic matter associated with the economic “Here's Your Chance” Pb–Zn–Ag Mine (Paleoproterozoic Barney Creek Formation, McArthur Basin, Australia) and the transition metal-rich Early Permian Kupferschiefer Formation (Germany–Poland) have attracted significant attention. A more detailed summary of the organic character of these deposits is provided to highlight the contribution organic geochemistry can make to understanding mineralisation processes. Most organic geochemical studies of highly mineralised regions, however, have not adequately addressed the significance of organic matter to mineralisation. A slightly different analytical focus than traditionally used for exploration appraisal of petroleum hydrocarbons may be required to properly evaluate the significance of organic species to the mobilisation, transport and deposition of ore metals. The characterisation and subsequent thermodynamic modeling of organic substances and complexes within metalliferous hydrothermal systems will contribute to a better understanding of the nature and role of organic–inorganic fluids or other affiliated organics in ore systems.  相似文献   

16.
These Kupferschiefer deposits were probably formed as a result of a mixing of two brines. The upper cold brine (UCB) is an unmineralized brine rich in Na, Ca, Cl and SO4, with a pH>7 and originating from evaporites overlying the metal-bearing Zechstein rocks. The lower hot brine (LHB) rich in Mg, K, Cl, SO4 and CO3 with a pH<=7 formed in sediments in the central part of the Zechstein basin at a depth of 7,000 m. This brine was subjected to heating and upward convection toward the Fore-Sudetic monocline along the bottom of the Z1 carbonates. During its migration, it caused albitization, serpentinization and leaching of the primary metal deposits in rocks underlying the Zechstein becoming enriched in heavy metals. The mineralization process, being a result of the mixing of the two brines (UCB and LHB), and catalytic oxidation of the organic matter of the black shale were initiated at shallow depths in the area of the Fore-Sudetic monocline. The boundary of the two brines generally overlapped the strike of the black shale.Parts of the deposit with shale-free host rock suggest that the action of two brines alone was capable of producing economic concentrations of Cu, Pb and Zn. Where the boundary of the two brines overlaps the autooxidation zone (the black shale bottom) and also coincides with radiation of thucholite, concentrations of noble metals result.The characteristic vertical distribution of the triplet CuPbZn from the bottom upward is universal in the Kupferschiefer environment.  相似文献   

17.
Water samples from Narragansett Bay and the Providence River, and fulvic acid/ saline water solutions were examined for their ability to solubilize n-alkane (n-C16 and n-C20), isoprenoid (pristane) and aromatic (phenanthrene and anthracene) hydrocarbons and dibutyl phthalate. Removal of the dissolved organic matter (D.O.M.) from the natural samples by activated charcoal and by ultra-violet oxidation resulted in a 50–99 per cent decrease in the amounts of n-alkanes and isoprenoid hydrocarbons solubilized. This decrease was directly related to the amount of D.O.M. removed. The solubilities of the aromatic hydrocarbons were unaffected by the D.O.M. Fulvic acid from a marine sediment, surface active organic material isolated at a chloroform/sea water interface, organic material extracted from a marine sediment by sea water, and organic matter contributed by a municipal sewage effluent, promote n-alkane solubility when added to NaCl solutions and re-enhance solubility when added to organic depleted sea water. The solubility of No. 2 fuel oil increased 2.5 times in the presence of fulvic acid (3.7 mg C/l.) with most of the increase seen in the alkane and isoprenoid components.N-Alkane solubility increases in fulvic acid/saline water solutions with increasing pH and reaches a maximum with respect to ionic strength at I = 0.3. There is evidence to suggest that the mode of solubilization of the hydrocarbons is by incorporation into micelles formed by intermolecular association of the surface active humic-type monomers. The presence of ionic species is a prerequisite for micelle formation.  相似文献   

18.
To study the detailed structural and isotopic heterogeneity of the insoluble organic matter (IOM) of the Murchison meteorite, we performed two types of pyrolytic experiments: gradual pyrolysis and stepwise pyrolysis. The pyrolysates from the IOM contained 5 specific organic groups: aliphatic hydrocarbons, aromatic hydrocarbons, sulfur-bearing compounds, nitrogen-bearing compounds, and oxygen-bearing compounds. The release temperatures and the compositions of these pyrolysates demonstrated that the IOM is composed of a thermally unstable part and a thermally stable part. The thermally unstable part mainly served as the linkage and substituent portion that bound the thermally stable part, which was dispersed throughout the IOM. The linkage and substituent portion consisted of aliphatic hydrocarbons from C4 to C8, aromatic hydrocarbons with up to 6 rings, sulfo and thiol groups (the main reservoirs of sulfur in the IOM), and carboxyl and hydroxyl groups (the main reservoirs of oxygen). However, the thermally stable part was composed of polycyclic aromatic hydrocarbons (PAHs) containing nitrogen heterocycles in the IOM. Isotopic data showed that the aliphatic and aromatic hydrocarbons in the linkage and substituent portion were rich in D and 13C, while the thermally stable part was deficient in D and 13C. The structural and isotopic features suggested that the IOM was formed by mixing sulfur- and oxygen-bearing compounds rich in D and 13C (e.g., polar compounds in the interstellar medium (ISM)) and nitrogen-bearing PAHs deficient in D and 13C (e.g., polymerized compounds in the ISM).  相似文献   

19.
1 Introduction China’s widespread marine carbonate rock series are mostly characterized by intensive thermal evolution and low abundance of organic matter, especially the Lower Paleozoic carbonate rocks have experienced multi-episodes of tectonics and ap…  相似文献   

20.
Solid bituminous matter (SBM) typically occurs in the late hydrothermal assemblages of pegmatites of the Khibiny and Lovozero massifs, being confined to a microporous framework Ti-, Nb-, and Zr-silicates, which are sorbents of small molecules and efficient catalysts of the polymerization, reforming, and selective oxidation of organic matter. Bituminous matter from the pegmatites of the Lovozero Massif typically have elevated contents of aliphatic hydrocarbons, sulfur, and sodium, but are depleted in oxygen and trace elements. SBM from the pegmatites of the Khibiny Massif are depleted in sulfur and enriched in oxygen-bearing derivatives of polycyclic aromatic hydrocarbons. Being complexing agents for Th, REE, Ba, Sr, and Ca, they play a key role in the transfer and accumulation of Th and in the accumulation of alkali earth and rare earth elements during the hydrothermal stage of mineral formation. Oxidized SBM bearing rare and alkali earth elements are complex microheterogenous systems, which contain mineral (Th silicates, calcite, etc.), metalorganic (with REE, Ca, Sr, Ba), and predominantly organic phases formed by the exsolution of initial metalorganic material with decreasing temperature.  相似文献   

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