Organic Geochemistry Research Papers

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- by Rudolf Bertrand
- •
- 13
  Earth Sciences, Organic Geochemistry, Statistical Analysis, Carbon

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- by Paul Farrimond
- •
- 13
  Earth Sciences, Organic Geochemistry, Carbon, Biomarkers

The interaction of organic compounds with the mineral phase is considered as one stabilization mechanism for organic carbon (OC) in soils. The objective of this study is to assess the role of mineral surfaces for the long-term... more

The interaction of organic compounds with the mineral phase is considered as one stabilization mechanism for organic carbon (OC) in soils. The objective of this study is to assess the role of mineral surfaces for the long-term stabilization of OC in arable soils, with special emphasis on iron oxides. Soil samples were taken from two contrasting treatment types, i.e. fertilized plots and C-depleted plots, in long-term agroecosystem experiments. The soil organic carbon pool of the C-depleted plots is considered to show a lower contribution of labile compounds and consequently to be relatively enriched in refractory compounds compared with the fertilized counterparts. In fractions <6 μm, OC was studied in relation to total mineral surface area, surface area contributed by oxides and silicates, and the content and type of iron oxides (dithionite and oxalate extractable iron, Fed and Feo). In two sandy soils, OC contents were linearly related to total mineral surface area and the content of the two iron oxide fractions (Fed and Feo). The surface area developed by the silicates was low and thus the surface area contribution from oxides was dominant in fractions <6 μm. In contrast to the sandy soils, in a loamy soil OC was not correlated with surface area or the iron oxide content. However, the different soils agreed with respect to the behavior of C in density fractions: losses of OC occurred mainly from the light fraction (⩽2 g cm−3), whereas C in the heavy fraction (>2 g cm−3) proved to be stable. For the sandy soils, mineral surface area appears to control the storage of OC in fine fractions. Given the dominant surface area contribution from oxides, OC storage here primarily depends on the oxides. The C-depleted plots in particular show that surface area controls the accumulation of refractory C. The interaction of organic compounds with the mineral phase, mainly with the surface of oxides, seems to be a major mechanism for the long-term stabilization of OC in these sandy soils. An interaction with minerals seems to be important for stabilizing OC also in the loamy soil, although this is not reflected by a proportional relation between OC and surface area across the fractions.

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- by Rita carbone
- •
- 14
  Earth Sciences, Organic Geochemistry, Environmental Sciences, Nitrogen

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- by Stephen Opsahl and +1
  Ronald Benner
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- 10
  Earth Sciences, Organic Geochemistry, Decomposition, Environmental Sciences

Fossil leaves which show excellent preservation of lipids and other organic compounds are preserved in abundance at the Miocene Clarkia lake deposit in northwestern Idaho, USA. Eighty three fossils from nine genera which are commonly... more

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- by Juhn Liou
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- 20
  Earth Sciences, Geology, Geochemistry, Geophysics

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- by Bruno Glaser and +1
  Eugene Balashov
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- 13
  Earth Sciences, Organic Geochemistry, Scanning Electron Microscopy, Environmental Sciences

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- by Tar Adam
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- 10
  Geology, Geochemistry, Organic Geochemistry, Biodegradation

Book on Seabed pockmark craters and seepage of fluids through the seafloor and lake floors

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- by Martin Hovland and +1
  Alan Judd
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- 13
  Marine Biology, Geology, Marine Ecology, Organic Geochemistry

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- by samuel akande
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- 20
  Earth Sciences, Organic Geochemistry, Pyrolysis, Oil and gas

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- by Geoffrey Eglinton and +1
  Simon Brassell
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- 5
  Earth Sciences, Organic Geochemistry, Environmental Sciences, CHEMICAL SCIENCES

Sub-basins within the New York/New Jersey (NY/NJ) Harbor host variable amounts and sources of polycyclic aromatic hydrocarbons (PAHs). Analyses of radionuclides 137Cs and 7Be were used to assign approximate dates to individual sections of... more

Sub-basins within the New York/New Jersey (NY/NJ) Harbor host variable amounts and sources of polycyclic aromatic hydrocarbons (PAHs). Analyses of radionuclides 137Cs and 7Be were used to assign approximate dates to individual sections of sediment cores collected from four major sub-basins of the harbor complex. Sampling sites range from heavily contaminated Newark Bay and Passaic River to less contaminated Raritan Bay and Jamaica Bay. PAHs were identified with GC–MS and quantified by GC respectively. Gas chromatography–isotope ratio mass spectrometry (GC/IRMS) was applied to determine δ13C values of pyrene (δ13CPy), a principal 4 ring parent PAH. Two end-member PAH source components, petroleum-related PAHs (PRPAH) and combustion-related PAHs (CRPAH), were calculated from a carbon isotopic mass balance equation based on assumptions that petroleum-related δ13CPy is −29‰, and that combustion-derived δ13CPy is −24‰. Temporal trends of PRPAH in these cores are similar to those of the petroleum-derived unresolved complex mixture (UCM), whereas CRPAH resembled trends of “Total” PAH (TPAH). Three molecular ratios, fluoranthene to fluoranthene plus pyrene (Fl/(Fl + Py)), high molecular weight 4–6 ring PAH to total PAH (Ring456/TPAH) and parent to total (Par/(Par + Alkyl)), correlate strongly with each other, and show a moderate to strong positive correlation with δ13CPy. In contrast, the ratios of anthracene to phenanthrene plus anthracene (A/(Pa + A)), benzo[a]anthracene to benzo[a]anthracene plus chrysene (BaA/(BaA+Chy)), and indeno[1,2,3-cd]pyrene to indeno[1,2,3-cd]pyrene plus benzo[ghi]perylene (IP/(IP + Bghi)) show no, weak, or even negative correlation with the four well correlated ratios (δ13CPy, Par/(Par + Alkyl), Fl/(Fl + Py), and Ring456/TPAH). Combined application of the four well correlated molecular indicators suggests that PAH contribution from combustion became more important in most areas of the NY/NJ Harbor during the last three decades of the 20th century.

The Hammerfest Basin (HB) is an important area for petroleum exploration in the southwestern Nor-wegian Barents Sea. This contribution is aimed to characterize oils and condensates hosted in Triassic and Jurassic reservoirs, establish... more

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- by Wendy A . Murillo
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- 5
  Organic Geochemistry, Biomarkers, Stable Isotopes, Petroleum geology

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- by Edgar Muñoz
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- 8
  Earth Sciences, Organic Geochemistry, FTIR, Environmental Sciences

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- by Paul Farrimond
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- 10
  Earth Sciences, Organic Geochemistry, Environmental Sciences, Bacteria

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- by Łukasz Karwowski
- •
- 3
  Geology, Geophysics, Organic Geochemistry

Diamondoid distributions in solvent extracts from marine siliciclastic shales, marine carbonates, and coals of a wide variety of maturities were determined by GC–MSD. For this sample set, published diamondoid maturity parameters did not... more

Sedimentary basins are significant deposits for both fossil energy sources and metallic ore deposits. It has been reported in numerous studies that a close relationship exists between oil and gas reservoirs and metallic ore deposits.... more

Sedimentary basins are significant deposits for both fossil energy sources and metallic ore deposits. It has been reported in numerous studies that a close relationship exists between oil and gas reservoirs and metallic ore deposits. Besides, in many studies, it has been determined that both source rocks and petroleum resources have a high amount of metal concentrations. In ore deposits, for hand specimens and on a microscopic scale, metallic ores are spatially associated with hydrocarbons. Organic matter in sediments can occur in different forms such as kerogen, bitumen, solid carbon, hydrocarbon gas, and more, in fractures and inclusions in significant amounts of free oil. On a regional scale, both metallic ore deposits and hydrocarbon reservoirs or seeps are generally bounded by the same tectonic units of the basin and controlled by the similar structures (especially regional anticlines, domes or paleo-highs). The results of the study show that hydrocarbons and metals derived from sediment pores during diagenesis are deposited by the co-transportation process by the same hydrothermal fluid and so, ore and organic matter in host rocks have a common source. In other words, organic- and metal-rich sediments in a sedimentary basin are used as a source for both metallic ore deposits and hydrocarbon reservoirs. Metal- and hydrocarbon-rich fluids derived from sediments consolidated as a result of topographic uplift and the compression of the basin laterally migrate along aquifers and head towards the boundaries of the basin and paleo-highs through the faults in the main- and sub-basin. Thus, they constitute metallic ore deposits and hydrocarbon reservoirs characterized by different deposition and trapping mechanisms in different compartments. Metallic ores are deposited in faults, fracture zones, and unconformity surfaces in areas where ore fluids encounter appropriate geochemical barriers. Hydrocarbons accumulate in stratigraphic, lithological, and structural traps. Within the scope of the study, the usage of metallic ore deposits as an indicator in hydrocarbon exploration are investigated in the regions where there are no surface hydrocarbon shows (outcrop of source rocks, oil or gas seeps, oil or gas fields), but there are the metallic ore deposits in operable scales. For this purpose, the results of the studies performed in four different regions of Turkey where there are the metallic ore deposits in operable-sizes have been presented. As a result of the study, it has been inferred that, in the regions where especially economic metallic ore deposits are located, they can be utilized as a shallow and reliable indicator for oil and gas exploration.

Keywords: Oil and gas exploration, Ore deposit, Mineral, Mineralization, Geochemical indicator, Geothermal resources

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- by Dr.Adil Ozdemir and +1
  Yildiray Palabiyik
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- 20
  Geochemistry, Organic Geochemistry, Petroleum geology, Gold Mineralization

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- by Arie Nissenbaum and +1
  Joan Grimalt
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- 9
  Earth Sciences, Organic Geochemistry, Quaternary, Environmental Sciences

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- by Clifford Walters
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- 15
  Earth Sciences, Organic Geochemistry, Biomarkers, Stable Isotopes

Hopanoic acids were found in all but the two most mature of a suite of 30 Triassic to Cretaceous sedimentary rocks. Their carbon number distributions generally maximise at C 32 , consistent with hopanoic acids found in modern sediments.... more

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- by Roxanne Vingarzan and +1
  Robie Macdonald
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- 9
  Earth Sciences, Organic Geochemistry, Environmental Sciences, Fossil Fuels

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- by Manzur Ahmed and +1
  Herbert Volk
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- 4
  Earth Sciences, Organic Geochemistry, Environmental Sciences, CHEMICAL SCIENCES

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- by Arthur de L. Scofield
- •
- 10
  Earth Sciences, Organic Geochemistry, Kinetics, Oil Spill

Four representative oil samples have been collected from productive wells, namely: Gharib-164, Gharib-163, Gharib-106, and Gharib-116, scattered within the Ras Gharib oilfield located in the central Gulf of Suez. Their chemical... more

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- by Matthias Witt and +1
  Boris Koch
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- 8
  Earth Sciences, Organic Geochemistry, Mass Spectrometry, Environmental Sciences

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- by Andrew Gize
- •
- 5
  Earth Sciences, Geology, Organic Geochemistry, Environmental Sciences

The factors affecting the amounts and types of organic matter in lacustrine sediments are summarized in this review, and synthesis, of published studies. Biota living in the lake and in its watershed are the sources of the organic... more

Organic Geochemistry

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