Yazar "Erik, Nazan Yalcin" seçeneğine göre listele

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    The biomarker properties and comparisons of Sahinali, Beypazari and Karapmar (Turkey) coaly Plio-Miocene depositions
    (ELSEVIER SCIENCE BV, 2014) Unal, Neslihan; Hokerek, Selin; Altunsoy, Mehmet; Ozcelik, Orhan; Erik, Nazan Yalcin; Bruckman, VJ; Hangx, S; Ask, M
    The distribution values of m/z 191 triterpane and m/z 217 sterane of coaly Plio Miocene units determined by GC-MS were used to compare biomarker properties of Sahinali, Beypazan and Karapmar areas located in Aydin, Ankara and Konya (Turkey) regions within this study. In the Sahinali region the Miocene units consist of conglomerate, coal, clayey coal, sandstone, siltstone, claystone, clayey limestone and silicified limestone. Middle Upper Miocene units of the Beypazan Basin are represented by conglomerate, agglomerate, sandstone, siltstone, claystone, coal, bituminous shale, limestone, and tuff. The Pliocene Karapmar area of interest, which is characterized by sandstone, siltstone, claystone, mudstone, lake and river bed coal deposits. When all the biomarker values are considered, it can be concluded that the organic matter is not mature. In two areas except Sahinali gammacerane is present indicating salinity. According to the C-27, C-28 and C-29 sterane distribution, it can be observed that the dominant organic matter is terrestrial based and accompanied by simple herbaceous and alg. The deposition conditions are seen to be anoxic even though some oxic depositions are found in areas. All the areas had oleananes indicating angiosperm presence. C-29/C-30 hophane ratio and decrease in C-31-C-35 peak height indicated detrial facies in all the areas. (C) 2015 The Authors. Published by Elsevier Ltd.
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    COAL-QUALITY PROPERTIES AND ENVIRONMENTAL INFLUENCES OF TERTIARY COALS OF THE ZILE (TOKAT) REGION IN CENTRAL ANATOLIA, TURKEY
    (VSB-TECH UNIV OSTRAVA, 2010) Erik, Nazan Yalcin; Fecko, P; Cablik, V
    This study has done related to the coal-quality and the environmental influences of the Zile coal field which developed in a limnotelmatic deposition environment in the west of the Tokat. Around Zile, two coal seams with a thickness of approximately 17 m are currently being exploited in open-cast mining and used in the nearby settletements. Coal-petrological studies along with proximate and ultimate analyses were undertaken to determine the organic-petrographic characteristics of the Zile coals. Huminite reflectances were found to be between 0.31 and 0.57%, values characteristic of low maturity. This parameter shows a good correlation with calorific values (507-5453 Kcal/kg). The studied coals and organic material underwent only 16w-grade transformation, a consequence of low lithostatic pressure. Therefore, the Zile coals are actually subbituminous in rank. The organic fraction of the coals is mostly comprised of humic group macerals, with small percentages derived from the inertinite and liptinite groups. In this study, organic-petrographic, and coal quality data were compared. The Zile deposit is a high-ash, high-sulfur coal. The mineral matter of the coals is comprised mainly of calcite and clay minerals. On the basis of proximate analytical data, there is no possibility that the Zile coals could be used for residential heating or industrial applications; when used, they cause significant of air pollution.
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    DEPOSITIONAL ENVIRONMENT CHARACTERISTICS OF UPPER CRETACEOUS SEDIMENTS IN HEKIMHAN BASIN (EASTERN ANATOLIA REGION, TURKEY): A BIOMARKER AND CARBON ISOTOPE APPROACH
    (GEOBALCANICA SOC, 2018) Erik, Nazan Yalcin
    Biomarker analysis of soluble organic matter in the sediments such as shale has contributed to our understanding of the characteristics of the depositional environment. In this study, depositional environment properties of Upper Cretaceous sediments in Hekimhan Basin are evaluated by biomarker data and stable carbon isotope (delta C-13) values. To ascertain the biomarker features of the aliphatic fractions, GC and GC-MS analyses were realized on the studied shale and limestone samples. Investigated shale samples have generally low (< 0.5%) the total organic carbon values, however, the amount (0.115.92%) of organic matter within limestone are slightly higher than shale levels. Hydrogen index values of limestone and shale samples vary between 0.0 and 629 mgHC/g TOC and between 0.0 and 42 mgHC/g TOC, respectively. The odd-numbered and even-numbered n-alkanes ranges between the C-15 and C-27, which are among the definable components, are close to each other in terms of abundance. There are n-alkanes, especially short-chain (< n-C-21) and medium-chain (n-C-21-n-C-25) as well as long-chain n-alkanes (> n-C-25) like C-26 and C-27, in clayey limestone. The diasterane/sterane ratio in the samples is between 0.19 and 0.60. Besides, the sterane/hopane ratio being high (> 2) and C-26/C-25 tricyclic terpane ratio (0.18-0.33) shows the marine precipitation conditions. The moretane/hopane, norhopane/hopane, C-24/C-23 tricyclic terpane and C-19/(C-19+ C-23 tricyclic terpane) ratios show the carbonate depositional conditions and, the 18 a(H)-oleanane has been determined and refer to Cretaceous or younger age. The existence of C-35 homohopanes, hopane index (< 1), high C-35/C-34 homohopanes (> 0.8) also supports this result. The Ts/Ts+ Tm ratios define the marine deposition conditions (suboxic), like the decrease in C31-35 homohopane distribution and the delta C-13 values (-25.18 % and -23.48 %).
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    Different types of learning algorithms of artificial neural network (ANN) models for prediction of gross calorific value (GCV) of coals
    (ACADEMIC JOURNALS, 2010) Yilmaz, Isik; Erik, Nazan Yalcin; Kaynar, Oguz
    Correlations are very significant from earliest days, in some cases, it is essential as it is difficult to measure the amount directly, and in other cases, it is desirable to ascertain the results with other tests through correlations. Soft computing techniques are now being used as alternative statistical tools, and new techniques such as; artificial neural networks, fuzzy inference systems, genetic algorithms, etc. and their hybrid forms have been employed for developing of the predictive models to estimate the needed parameters, in the recent years. Determination of gross calorific value (GCV) of coals is very important to characterize coal and organic shales; it is difficult, expensive, time consuming and is a destructive analysis. In this paper, use of different learning algorithms of artificial neural networks such as MLP, RBF (exact), RBF (k-means) and RBF (SOM) for prediction of GCV was described. As a result of this paper, all models exhibited high performance for predicting GCV. Although the four different algorithms of ANN have almost the same prediction capability, accuracy of MLP has relatively higher than other models. The use of soft computing techniques will provide new approaches and methodologies in prediction of some parameters in the investigations about the fuels.
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    Geophysical investigation and hydrocarbon potential of Cankiri-Corum Basin, Turkey
    (ELSEVIER SCIENCE BV, 2013) Aslan, Yasemin; Buyuksarac, Aydin; Erik, Nazan Yalcin; Aydemir, Attila; Ates, Abdullah
    The Cankiri-Corum Basin is one of the larger, onshore sedimentary basins in central Turkey. In this paper, the integration of geophysical data and geological findings in the Cankiri-Corum Basin was performed and they both present a complex basin structure. In the frame of geophysical study, two-dimensional (20) models were constructed using gravity and magnetic anomalies. Seismic sections were interpreted and correlated with the 2D models using the borehole data as control. Basement depth, basin geometry and sources for magnetic anomalies along the 20 model profiles were determined in integration of seismic, gravity, aeromagnetic and borehole data. Seismic section CC-L-1 is correlated with the Topuzsaray-1 well. Tuffs and volcanic units penetrated in this well might be correlated across a reverse fault close to the borehole. Seismic sections, CC-L-2 and CC-L-3, are consistent with the gravity models at the deeper parts of the sections. On the other hand, there are inconsistencies in the shallow sections with the gravity models due to unexpected velocity variations in both the horizontal and vertical directions. The average depth of basement was found to be about 5 km by means of gravity modelling, which was correlated with the seismic sections. Magnetic anomalies are represented by intense values in the NW portion of the study area, but they indicate very low intensities in the middle of the map. A reverse magnetised body to the north of the study area was modelled in 2D along a profile and it was interpreted that this body might be an ophiolitic remnant. Polarities of many anomalies to the south and northeast of the region indicate remanent magnetisation. Alignment of the polarities extends in the northwest direction, indicating that the region rotated in the anticlockwise direction. Because there is around a 5 km sedimentary basin fill in the study area, it may exhibit hydrocarbon potential and the Yesilcat oil seep evidences this potential. Surface samples were collected to examine source rock potential and to correlate with the Yesilcat seep by analysing the organic geochemical properties. In this study, 72 samples were collected from different formations and it was found that the Yoncali Formation displays better source rock potential than the other formations studied. (C) 2013 Elsevier B.V. All rights reserved.
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    GROUND PENETRATING RADAR (GPR) METHOD OF GEOLOGICAL PROPERTIES OF COAL SEAMS NEAR THE SURFACE
    (STEF92 TECHNOLOGY LTD, 2014) Kosaroglu, Sinan; Erik, Nazan Yalcin
    Requirement needed to energy increases as a result of the changes occured in today's technologic situations. The low-rank coals of Turkey represent the country's major energy source with their relatively large geological reserves. Fossil fuels, at the present time, are the most required fuels and being estimated that they would preserve this situation in the future, although studies devoted to development as alternative of the renewable energy sources such as wind, solar and biogas resume rapidly. Thus, many research methods are required to determine the situations of the coal seams underground. In the previous years, by prectising their different physical properties because of their formation in order to be determined the coal layers, researches with the different geophysical methods such as seismic, electrical resistivity and gravity were made. But, it is possible to be acquired the needed high-definition underground-sections with the development of the geophysical measuring sets and methods in today's technology. The depths including coal seams near the surface and thicknesses can be determined with the GPR method which can collect data quite rapid to the other geophysical methods relatively and providing with high-resolution underground section. It can be provided information quickly and reliably with the Ground Penetrating Radar (GPR) method about the structural elements such as faulting, translation and kinking by forming sterograms with the different measurement techniques that are used.
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    Hydrocarbon generation potential and Miocene-Pliocene paleoenvironments of the Kangal Basin (Central Anatolia, Turkey)
    (PERGAMON-ELSEVIER SCIENCE LTD, 2011) Erik, Nazan Yalcin
    This study deals with the organic geochemical characteristics, hydrocarbon generative potential and Miocene-Pliocene paleoenvironments of the Kangal coal district, which developed in a limnic depositional environment and contains the Hamal. Etyemez and Kalburcayiri coal fields in the southern part of the Sivas Basin (Central Anatolia). Around Kalburcayiri, the average thickness of each of the two coal seams approximately 10 m are currently being exploited based on open-cast methods, the coal from which is used by the nearby lignite-fired Kangal power station. An attempt was made to elucidate depositional conditions through proximate and ultimate analyses, coal petrography and the geochemical characteristics of the Kangal coals. These coals have a huminite reflectance value of R-max = 0.40%. Accordingly, from the standpoint of coal rank, this is a dull brown coal of the "subbituminous C" type. Huminite is the most widespread maceral type, while gelinites are the most often encountered macerals. Relative to liptinites, the proportion of inertinites is high. On the basis of maceral composition, the depositional environment of the Kangal coals was determined to be either a forest swamp or a lake bottom. The distributions of the C-27 and C-28-C-29 steranes for all these coal samples are very similar (C-29>C-27>C-28). Tricyclic terpanes have low concentrations in all samples of the Kangal coals, and are dominated by low molecular weight compounds (C-20-C-24) with a maximum at C-23. Total organic carbon (TOC, wt.%) values of the Kalburcayiri samples are 4.64-30.64 wt.%, in the Hamal samples 0.83-2.53 wt.%, and in the Etyemez samples 8.91-10.39 wt.%. On the basis of T-max values, the samples are in the immature-early mature stage. According to Rock-Eval pyrolysis data, the coals have hydrocarbon source-rock potential, but the coaly shales and other organic-matter-rich levels have no hydrocarbon source-rock potential. The high inertinite levels and high vitrinite/inertinite ratios suggest that the Kangal coals have more potential for gas generation than oil. (C) 2011 Elsevier Ltd. All rights reserved.
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    Investigation of the organic matter properties and hydrocarbon potential of the Sivas Basin, Central Eastern Anatolia, Turkey, using Rock-Eval data and organic petrography
    (ELSEVIER SCIENCE BV, 2015) Erik, Nazan Yalcin; Aydemir, Attila; Buyuksarac, Aydin
    The main goal of this study is to assess the organic geochemical properties and hydrocarbon generation potential of the Tertiary units in the Sivas Basin which is one of the largest sedimentary basins in the Central Anatolia, Turkey. In this investigation, 200 representative samples were collected from the Tertiary sedimentary rock outcrops. In addition, 15 scaled columnar sections were measured and 187 samples were also collected from these sections. Hydrocarbon generating potential and the maturity levels of the Tertiary units along with the geological history in this basin were determined by means of the total organic carbon (TOC) analysis, Rock-Eval pyrolysis, vitrinite reflectance (R-o) and the organic petrographical observations. Kerogen slides of 96 samples containing high TOCs were prepared to determine the organic matter types. Information about maturity degrees were also obtained using the spore fluorescence colours and the vitrinite reflection (R-o). According to the results of analyses, TOC values of the Hafik (0.05-0.17%), Kalekoy (0.01-0.12%), Yagmurluseki (0.01-0.54%) and Selimiye (0.01-017%) Formations are very low and other geochemical parameters are not encouraging to perform further investigations for these formations. Because of these reasons, they may not be accepted as source rocks. However, the Bozbel (0-1.43%) and Karayun (0.07-7.5%) Formations display high TOC values indicating poor to moderate source rock characteristics with S-1 + S-2 values up to 1.03 mg HC/g rock for the Bozbel and up to 23.45 mg HC/g rock for the Karayun Formation. Organic matter types of the Bozbel and Karayun Formations are mainly Type-Ill and Type-II/III in the HI-OI and HI-T, diagrams, respectively. Samples of the other formations include only Type-III kerogen, in general. The maturation degree of the Bozbel Formation varies in a broad range, from immature to mature levels in the majority of samples. The Karayun Formation is generally in the early mature interval. Consequently, both formations have a limited gas generation potential. However, the Sivas Basin is still worth to explore for hydrocarbons, because all samples were collected from outcrops and type sections close to the basin margins, not from boreholes or from the deeper parts of the basin. Thickness of the sedimentary units is found as 8-10 km in average in the previous studies. On the other hand, the deepest parts of the basin containing such a thick sedimentary deposits have not been drilled, yet. It is possible to find out more encouraging results in case of drilling deep exploration wells. (C) 2015 Elsevier B.V. All rights reserved.
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    On the Use of Conventional and Soft Computing Models for Prediction of Gross Calorific Value (GCV) of Coal
    (TAYLOR & FRANCIS INC, 2011) Erik, Nazan Yalcin; Yilmaz, Isik
    Gross calorific value (GCV) is an important characteristic of coal and organic shale; the determination of GCV, however, is difficult, time-consuming, and expensive and is also a destructive analysis. In this article, the use of some soft computing techniques such as ANNs (artificial neural networks) and ANFIS (adaptive neuro-fuzzy inference system) for predicting GCV (gross calorific value) of coals is described and compared with the traditional statistical model of MR (multiple regression). This article shows that the constructed ANFIS models exhibit high performance for predicting GCV. The use of soft computing techniques will provide new approaches and methodologies in prediction of some parameters in investigations about the fuel.
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    ORGANIC FACIES VARIATION FROM WELL DATA ON THE COALY PLIOCENE UNITS, THE CENTRAL PART OF TURKEY (KARAPINAR-KONYA)
    (INT SCIENTIFIC CONFERENCE SGEM, 2011) Ozcelik, Orhan; Tuze, Zeynep; Altunsoy, Mehmet; Hokerek, Selin; Erik, Nazan Yalcin; Taka, Mehmet; Acar, Ferhat
    Some 100 core samples of coal and coaly units from the Pliocene succession (Hotamis Formation) were collected from well KK-147, in the southern part of Central Turkey (Karapinar-Konya). 30 samples were screened for total organic carbon (TOC) content. Selected samples were then analyzed by Rock-Eval Pyrolysis. Visual kerogen analysis and vitrinite reflectance measurements were also undertaken. Detailed data from thick Pliocene sediments made it possible to construct an organic facies framework using different zonations. Organic facies type C, CD and D were identified in the investigated units. The main composition in the organic matter of the sediments are woody (80%), with minor portions of planty (8%), amorphous (6%) and coaly (6%) in the investigation well. Alteration colors of these materials are yellow and dark yellow. Spore colors of these samples are yellow and dark yellow (SCI: 3-4). Organic facies C is related to clayey-sandy coal and coal lithofacies. This facies is composed of organic matter with average values of HI around 144 (equivalent to Type II/III Kerogene), TOC around 15.94 and S2 between 11.98 and 30.10 mg HC/g sample. Organic facies C is the "gas-prone" facies. The organic matter is dominated by terrestrial debris in various stages of oxidization. Sediments of organic fades C were commonly deposited on Tertiary and Mesozoic shelves and slopes of the continantel margins. Most coals are organic facies C. The organic faces CD is related to the clayey coal, coal and claystone lithofacies. This facies is characterized by average values of HI around 89 (equivalent to Type III Kerogene), TOC around 15.7%, and an average of S2 of 15.18 mg HC/g of rock. The CD facies reflects a mixture of source materials including terrestrial plant detrius, reworked and fine grained amophous organic matter. An organic facies D, associated with the coal, claystone, clayey limestone lithofacies, displays values of H1 around 26 (equivalent to Type III Kerogene) and TOC around 1.17%. S2 varies between 0.03 and 1.87 mg HC/g of rock. The D facies consists of highly decomposed, reworked organic matter. These types of organic facies generally appear to be weakly sorted in marine and lake sediments.
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    Paleoenvironment characteristics and hydrocarbon potential of the Lower Miocene bituminous shales in Sivas Basin (Central Anatolia, Turkey)
    (SPRINGER HEIDELBERG, 2016) Erik, Nazan Yalcin
    This study is based around Karayun which is in the Sivas Tertiary Basin, one of the important sedimentary basins in Turkey. The units observed in the study area and nearby are Oligocene Hafik, Lower Miocene Karayun and Lower-Middle Miocene Karacaoren Formations and Quaternary alluvium. This study focused on samples from the Karayun Formation due to the presence of alternations of bituminous shale levels in the formation. The studied bituminous shales are characterized by relatively high total organic carbon values up to 10.44 % and S2 values ranging from 0.01 to 89.02 HC/g rock, indicating fair to excellent source rock. Most of the bituminous shales are at the immature to early mature stage for hydrocarbon generation. Generally, genetic potential values are over 2 mg HC/g rock. The hydrogen index value of samples are between 9 and 887 mg HC/g total organic carbon (TOC) (on average 333.62 mg HC/g TOC). Oxygen index values vary between 17 and 557 mg CO2/g TOC (on average 135.35 mg CO2/g TOC). On the basis of Rock-Eval pyrolysis analysis, kerogens are type I/II and type II/III mixed. Dominant organic matter observed in this formation is algal amorphous organic matter. Thermal alteration index (TAI), Spore colour index (SCI), vitrinite reflectance values (R-o) and T-max evaluations indicate that maturity of the unit is between diagenesis and the early mature zone, and at the beginning of the hydrocarbon-producing stage. As a result of a series of analyses, it was found that the Karayun Formation has organic facies of B, BC and C and limited hydrocarbon generation potential in the basin.
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    Petrographical properties and unusual features of Kangal coals, Sivas-Turkey
    (ELSEVIER SCIENCE BV, 2011) Toprak, Selami; Erik, Nazan Yalcin
    In Turkey, low-rank coal is used in three sectors: power generation industry, and household and commercial heating. Due to poor quality, coal is suitable for thermal power generation only. Kangal coal is of low-rank being mostly used in a thermal power station. Kangal coal basin, located in Eastern-central Turkey, formed in a Pliocene aged fresh-water lacustrine depositional environment and includes Kalburcayiri, Hamal and Etyemez Fields. Approximately 202.6 Mt of coal reserve, with calorific values between 1010 and 3420 kcal/kg are hosted in the area. Kalburcayiri Field is the only open pit production site in the basin. Fifty two channel samples were collected from different sites. The composite profile samples of the seams were taken into considerations. The content and depositional properties as well as some chemical and physical properties of the main coal seams are compared. Detailed organic petrographic and chemical analyses were applied for this study. All coal samples tend to have similar coal petrographic properties and were deposited in a lacustrine basin. Later, they were affected by faulting. As a result, there are variations in the properties and rank of the coal samples. The most abundant maceral group is huminite and the most abundant maceral is gelinite. Liptinite and inertinite contents of the coal are low and the maceral assemblage of the coals show extremely unusual. Broken and deformed maceral contents tend to be more abundant, considering the other Turkish coals. The maceral contents, textures and the unusual appearances imply that the coals were formed as in a hypautochtonous way. The reflectance measurements indicate the rank of the coals to be mostly as sub bituminous, although some chemical analyses exhibit inefficient results. (C) 2011 Elsevier B.V. All rights reserved.
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    The impact of an outdoor education project on middle school students' perceptions and awareness of the renewable energy
    (Pergamon-Elsevier Science Ltd, 2020) Buldur, Serkan; Bursal, Murat; Erik, Nazan Yalcin; Yucel, Eren
    This study investigated the effects of a nature education project on middle school students' perceptions on renewable energy by using a mixed method research design. The data was collected from 60 middle school students, who participated in a nature education project in 2017 and 2018. Using a mixed method research paradigm, the views of the participants on renewable energy were explored by collecting both qualitative and quantitative data. The qualitative data was collected from pre and post interviews, whereas the quantitative data was collected from the pretest and posttest applications of the Renewable Energy Perceptions (REP) scale, which was originally developed for university students and adapted to middle school students population in the first stage of this study. The findings from both qualitative and quantitative data agreed on that while the participants had already positive perceptions toward the renewable energy before the study, significant contributions have been made to increase their perceptions and awareness levels about renewable energy during the nature education project.
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    Use of petrological and organic geochemical data in determining hydrocarbon generation potential of coals: miocene coals of Malatya Basin (Eastern Anatolia-Turkey)
    (Springernature, 2021) Erik, Nazan Yalcin; Ay, Faruk
    With this study, the hydrocarbon generation potential of Miocene aged coals around Arguvan-Parcikan in the northern district of Malatya province was evaluated with the aid of petrological and organic geochemical data. According to organic petrography, coal quality data, and low thermal maturity, the Arguvan-Parcikan coals are of high-ash, high-sulfur subbituminous B/C rank. The organic fraction of the coals is mostly comprised of humic group macerals, with small percentages derived from the inertinite and liptinite groups. The mineral matter of the coals is comprised mainly of calcite and clay minerals. The total organic carbon (TOC, wt%) values of the shale and coal samples are between 2.61 wt% and 43.02 wt%, and the hydrogen index values are between 73 and 229 mg HC/g TOC. Pyrolysis (T-max, PI), huminite/vitrinite reflectance (R-o, %), and biomarker ratios (CPI, Pr/Ph ratio, Ts/(Ts + Tm) ratio, C-32 homohopane ratio (22S/22S + 22R) and C-29 beta beta/(beta beta + alpha alpha sterane ratio) indicate that the organic matter of the studied coals is thermally immature. When all these data are taken together, Miocene aged coals around Arguvan are suitable for hydrocarbon generation, especially gas, in terms of organic matter type (Type III and Type II/III mixed), organic matter amount (> 10 wt% TOC), however, low liptinitic macerals (< 15%-20%), low hydrogen index (< 200 mg HC/g TOC) and low thermal maturity values inhibit the hyrocarbon generation.