Characterization of organic matter in the fine-grained siliciclastic sediments of the Shemshak Group (Upper Triassic–Middle Jurassic) in the Alborz Range, Northern Iran

2009 ◽  
Vol 312 (1) ◽  
pp. 161-174 ◽  
Author(s):  
Ali Shekarifard ◽  
François Baudin ◽  
Johann Schnyder ◽  
Kazem Seyed-Emami
Keyword(s):  
Organic Matter ◽  
Middle Jurassic ◽  
Upper Triassic ◽  
Northern Iran ◽  
Fine Grained ◽  
Alborz Range ◽  
Siliciclastic Sediments

scholarly journals Thermal maturity of the Upper Triassic–Middle Jurassic Shemshak Group (Alborz Range, Northern Iran) based on organic petrography, geochemistry and basin modelling: implications for source rock evaluation and petroleum exploration

2011 ◽  
Vol 149 (1) ◽  
pp. 19-38 ◽  
Author(s):  
ALI SHEKARIFARD ◽  
FRANÇOIS BAUDIN ◽  
KAZEM SEYED-EMAMI ◽  
JOHANN SCHNYDER ◽  
FATIMA LAGGOUN-DEFARGE ◽  
...  
Keyword(s):  
Middle Jurassic ◽  
Vitrinite Reflectance ◽  
Upper Triassic ◽  
Petroleum Exploration ◽  
Thermal Maturity ◽  
Northern Iran ◽  
Carbonaceous Shales ◽  
Petroleum Generation ◽  
Central Eastern ◽  
Alborz Range

AbstractOrganic petrography and geochemical analyses have been carried out on shales, carbonaceous shales and coals of the Shemshak Group (Upper Triassic–Middle Jurassic) from 15 localities along the Alborz Range of Northern Iran. Thermal maturity of organic matter (OM) has been investigated using vitrinite reflectance, Rock-Eval pyrolysis and elemental analysis of kerogen. Reflectance of autochthonous vitrinite varies from 0.6 to 2.2% indicating thermally early-mature to over-mature OM in the Shemshak Group, in agreement with other maturity parameters used. The shales of the Shemshak Group are characterized by poor to high residual organic carbon contents (0.13 to 5.84%) and the presence of hydrogen-depleted OM, predominantly as a consequence of oxidation of OM at the time of deposition and the hydrogen loss during petroleum generation. According to light-reflected microscopy results, vitrinite/vitrinite-like macerals are dominant in the kerogen concentrates from the shaly facies. The coals and carbonaceous shales of the Shemshak Group show a wide range in organic carbon concentration (3.5 to 88.6%) and composition (inertinite- and vitrinite-rich types), and thereby different petroleum potentials. Thermal modelling results suggest that low to moderate palaeo-heat flow, ranging from 47 to 79 mW m−2 (57 mW m−2 on average), affected the Central-Eastern Alborz basin during Tertiary time, the time of maximum burial of the Shemshak Group. The maximum temperature that induced OM maturation of the Shemshak Group seems to be related to its deep burial rather than to a very strong heat flow related to an uppermost Triassic–Liassic rifting. The interval of petroleum generation in the most deeply buried part of the Shemshak Group (i.e. Tazareh section) corresponds to Middle Jurassic–Early Cretaceous times. Exhumation of the Alborz Range during Late Neogene time, especially along the axis of the Central-Eastern Alborz, where maximum vitrinite reflectance values are recorded, probably destroyed possible petroleum accumulations. However, on the northern flank of the Central-Eastern Alborz, preservation of petroleum accumulations may be expected. The northern part of the basin therefore seems the best target for petroleum exploration.

scholarly journals The use of spectral natural gamma-ray analysis in reservoir evaluation of siliciclastic sediments: a case study from the Middle Jurassic of the Harald Field, Danish Central Graben

2003 ◽  
Vol 1 ◽  
pp. 349-366 ◽  
Author(s):  
Ida L. Fabricius ◽  
Louise Dahlerup Fazladic ◽  
Armgard Steinholm ◽  
Uffe Korsbech
Keyword(s):  
Middle Jurassic ◽  
Gamma Ray ◽  
Clay Content ◽  
Heavy Minerals ◽  
Reservoir Evaluation ◽  
Fine Grained ◽  
Natural Gamma ◽  
The Difference ◽  
Siliciclastic Sediments ◽  
Quartz Grains

Danish Central GrabenA cored sandstone interval from the Middle Jurassic Harald Field of the Danish North Sea was chosen for an investigation of the mineralogical sources for the gamma-ray activity, and with the purpose of determining how the Spectral Natural Gamma (SNG) log could be used as an indicator of reservoir quality. Core intervals of quartz arenites and quartz wackes were selected. Although no linear relationship was found between clay content and potassium (K), thorium (Th), or uranium (U), the K content characterises three discrete lithofacies. Lithofacies I has a grain-supported texture, with a predominance of quartz grains; only minor fine-grained matrix is present. Sandstones of lithofacies I have a low K content and most of the K is hosted in feldspar. Porosity varies between 23% and 28% and permeability is in the range 200–2000 mD. Lithofacies II sandstones have a grain-supported texture, with a predominance of quartz grains; fine-grained matrix fills the intergranular volume. Sandstones of lithofacies II have an intermediate K content, with K-feldspar, mica, and illite as the main sources. Porosity varies between 11% and 17% and permeability is in the range 0.4–25 mD. Lithofacies III has a matrix-supported texture with quartz grains floating in a clay-rich matrix. Samples from lithofacies III have the highest K signal. Illite and illitised kaolinite are roughly equal in importance as sources of K. Porosity is up to 11% and permeability up to 0.5 mD. The Th and U content of all lithofacies is governed primarily by the presence of heavy minerals; no apparent general relationship between U and Total Organic Carbon (TOC) was found. Comparisons between the core measurements of K, Th, and U, and the SNG log disclosed a discrepancy between the calibrations of laboratory and borehole measurements. For U the discrepancy contains an erratic element, whereas the difference for K and Th can be eliminated by correction factors. Thus, the conclusions based on laboratory measurements appear to be applicable to the log data, and, using corrected K values, the facies subdivision can be extended throughout the reservoir section based on the SNG log.

scholarly journals Characterization of organic matter in bottom sediments of Ivashkina Lagoon, Laptev Sea

2019 ◽  
Vol 98 ◽  
pp. 06006
Author(s):  
Elena Gershelis ◽  
Ivan Goncharov ◽  
Oleg Dudarev ◽  
Alexey Ruban ◽  
Igor Semiletov
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Bottom Sediments ◽  
Laptev Sea ◽  
Terrestrial Vegetation ◽  
Fine Grained ◽  
The Core ◽  
Volatile Organic ◽  
The Laptev Sea

Here we present lithological and geochemical characteristics of the core drilled in coastal part of the Laptev Sea (Ivashkina Lagoon, Bykovsky Peninsula). It is shown that for sediments accumulated in specific lagoon conditions the increased content of organic carbon is confined to fine-grained lacustrine and lagoonal sediments in the uppermost layers. Pyrolytic analysis results indicate a sharp variability in the content of total organic carbon and volatile organic compounds across the studied horizons. The distribution of n-alkanes is characterized by the dominance of high molecular weight homologues, which indicates the ubiquitous contribution of higher terrestrial vegetation discharged with river and coastal thermo abrasion fluxes to the organic matter of bottom sediments.

scholarly journals Characterization of organic matter in the Oligocene (Chattian) turbiditic fine grained deposits, offshore Angola

2010 ◽  
Vol 41 (2) ◽  
pp. 135-145 ◽  
Author(s):  
Isabelle Deniau ◽  
Jean-Robert Disnar ◽  
François Baudin ◽  
Jean-Pierre Houzay
Keyword(s):  
Organic Matter ◽  
Fine Grained

scholarly journals Depositional environments of coal and associated siliciclastic sediments in the Lower and Middle Jurassic of Denmark. The Øresund -5, -7, -13, -15 and -18 wells

1994 ◽  
Vol 33 ◽  
pp. 1-55
Author(s):  
Henrik Ingermann Petersen
Keyword(s):  
Organic Matter ◽  
Middle Jurassic ◽  
Saline Water ◽  
Open Water ◽  
Depositional Environments ◽  
Border Zone ◽  
Coal Seams ◽  
Raised Bog ◽  
Type 3 ◽  
Siliciclastic Sediments

Five cored wells located in the Fennoscandian Border Zone in the Øresund area, Denmark, encountered Lower or Middle Jurassic coal-bearing strata; the coal seams are Lignite to Sub-bituminous A/High Vol. Bituminous C in rank. A number of shallowing-upward units are recognized in the five wells. Each unit is capped by a coal seam. Correlation of these shallowing-upward units between wells is difficult on the basis of available biostratigraphy and log data. Seven of the coal seams result from establishment of peatforming conditions due to infilling of freshwater lakes, whereas the last two of the coal seams result from peat accumulation on top of restricted brackish lagoon or bay sediments. However, only one of the latter two seams accumulated in an environment influenced by saline water. Hence, the investigated coals represent almost entirely freshwater peat-forming environments. Three main types of environments are defined: 1) Type 1 is a sparsely vegetated open water swamp; it is represented by a limnic facies. The deposit is typically a carbonaceous claystone with a high content of allochthonous organic matter; 2) Type 2 is a densely vegetated rheotrophic, nutrient-rich and anoxic swamp; it is represented by a limnotelmatic to telmatic facies. The coal has a very high content of humified organic matter; 3) Type 3, subdivided into the types 3a and 3b, is the driest environment of the three types. Type 3a is a desiccated ombrotrophic raised bog represented by a terrestrial facies. It is strongly influenced by a fluctuating watertable. The coals contain a high content of inertinite that generally shows a low reflectance. Type 3b is a mesotrophic to ombrotrophic domed bog; the environment alternates between dry oxidizing conditions and wet conditions. It is represented by a telmatic to terrestrial facies. In general, the three types of environments form ecosystems characterized by the groundwater influence, nutrient supply, and vegetation. Successions representing the hydrological evolution towards drier conditions due to vertical peat accretion are recognized in some of the seams. The vegetation was small-statured and consisted of a prominent herbaceous type of flora, shrub-like plants, smaller arboreous plants and, to a lesser extent, larger plants.

Lithostratigraphy of the Upper Triassic–Middle Jurassic Shemshak Group of Northern Iran

2009 ◽  
Vol 312 (1) ◽  
pp. 129-160 ◽  
Author(s):  
Franz Theodor Fürsich ◽  
Markus Wilmsen ◽  
Kazem Seyed-Emami ◽  
Mahmoud Reza Majidifard
Keyword(s):  
Middle Jurassic ◽  
Upper Triassic ◽  
Northern Iran

Characterization of dissolved organic matter (DOM) extracted from soils by hot water percolation (HWP)

2010 ◽  
Vol 59 (1) ◽  
pp. 99-108 ◽  
Author(s):  
M. Takács ◽  
Gy. Füleky
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Natural Organic Matter ◽  
Extraction Methods ◽  
Soil Samples ◽  
Hot Water ◽  
Soil Extracts ◽  
Water Percolation ◽  
Soil Humic Acid

The Hot Water Percolation (HWP) technique for preparing soil extracts has several advantages: it is easily carried out, fast, and several parameters can be measured from the same solution. The object of this study was to examine the possible use of HWP extracts for the characterization of soil organic matter. The HPLC-SEC chromatograms, UV-VIS and fluorescence properties of the HWP extracts were studied and the results were compared with those of the International Humic Substances Society (IHSS) Soil Humic Acid (HA), IHSS Soil Fulvic Acid (FA) and IHSS Suwannee Natural Organic Matter (NOM) standards as well as their HA counterparts isolated by traditional extraction methods from the original soil samples. The DOM of the HWP solution is probably a mixture of organic materials, which have some characteristics similar to the Soil FA fractions and NOM. The HWP extracted organic material can be studied and characterized using simple techniques, like UV-VIS and fluorescence spectroscopy.

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