scholarly journals Organic and Isotopic Geochemistry of Evaporites and Shales of the Santana Group (Araripe Basin, Brazil): Clues on the Evolution of Depositional Systems and Global Correlation during the Lower Cretaceous

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 795
Author(s):  
Naedja Vasconcelos Pontes ◽  
Daniel Bezerra das Chagas ◽  
Ana Clara Braga de Souza ◽  
Daniel Rodrigues do Nascimento Junior ◽  
Wellington Ferreira da Silva Filho ◽  
...  
Keyword(s):  
Lower Cretaceous ◽  
Organic Geochemistry ◽  
Organic Content ◽  
Type I ◽  
Oceanic Anoxic Event ◽  
Global Correlation ◽  
Depositional Systems ◽  
Gaseous Hydrocarbons ◽  
Rock Eval ◽  
High Organic Content

Even being the more studied of the interior basins of Northeast Brazil, the Araripe Basin still lacks research in organic geochemistry designed to support interpretations of depositional systems and conditions of formation. This work aims to investigate the organic behavior of evaporites and shales from the Santana Group (Lower Cretaceous), as well as discuss their role in the evolution of its depositional systems. A total of 23 samples, 17 shales and six evaporites, were collected in outcrops and quarries. Analyses of Total Organic Carbon (TOC), Total Sulfur (TS), Rock Eval pyrolysis, and the δ34S isotope ratio were performed. The TOC results revealed high organic content for seven intervals, of which only five had high TS content. From the Rock Eval pyrolysis, dominance of the Type I kerogen was verified, thus corresponding to the best type of organic matter (mainly algal) for the generation of liquid and gaseous hydrocarbons. The Lower Cretaceous (probably Aptian) response to the progressive evolution in redox conditions is linked to a remarked Oceanic Anoxic Event (OAE-1a). The TOC/TS ratio suggests variable palaeosalinity, indicating most of the shales were formed under brackish waters with saline influence, yet tending to increase the salinity upwards where hypersaline conditions dominate in the Ipubi Formation. The isotope data also suggest the occurrence of marine ingressions in the depositional systems even prior to the well-documented event of the Romualdo Formation.

Programmed pyrolysis (Rock-Eval) data and shale paleoenvironmental analyses: A review

2015 ◽  
Vol 3 (1) ◽  
pp. SH41-SH58 ◽  
Author(s):  
B. S. Hart ◽  
A. S. Steen
Keyword(s):  
Organic Matter ◽  
Petroleum Industry ◽  
Organic Content ◽  
Type I ◽  
Type Iv ◽  
Marine Organic Matter ◽  
Depositional Settings ◽  
Organic Matter Type ◽  
Rock Eval ◽  
Original Organic Matter

We use public-domain data from programmed pyrolysis, collected using Rock-Eval or similar apparatuses, to illustrate the utility and challenges of using this method for paleoenvironmental analyses. These data are widely available and commonly collected and analyzed for a variety of purposes in the petroleum industry in the fields of paleo-oceanography and paleoclimate research and elsewhere. We show how factors such as sample condition, mineralogy, organic content, and others can influence the results, leading to potential interpretational complications. We also evaluate ways that the data can be plotted to maximize their utility for interpretation purposes. Four types of organic matter are commonly identified based on programmed pyrolysis results. Type I organic matter has a high (e.g., [Formula: see text]) hydrogen index (HI), is oil-prone and is commonly assumed to represent lacustrine depositional settings. Type II organic matter is also oil-prone (i.e., having an HI between 350 and 700) but is commonly assumed to represent marine organic matter. Type III organic matter has a lower HI ([Formula: see text]), will tend to generate gas, and is commonly assumed to represent terrigenous (e.g., land plants) organic matter. Type IV organic matter has very low HI values and is associated with nongenerative (i.e., inert) organic matter. We show that these simple associations between organic matter type and paleoenvironment were not always valid. Preburial degradation of the organic matter and mixing of different organic matter types are two possibilities that can lead to erroneous paleoenvironmental interpretations. Furthermore, the programmed pyrolysis results characterize the present composition of the organic matter which, especially at high thermal maturities (e.g., dry gas window), can be significantly different to that of the original organic matter. Other types of advanced geochemical and sedimentologic analyses should be integrated with the programmed pyrolysis results during their interpretation.

Boosted microbial productivity during the Toarcian Oceanic Anoxic Event in the Paris Basin, France: new evidence from organic geochemistry and petrographic analysis

2021 ◽  
pp. SP514-2020-167
Author(s):  
Carolina Fonseca ◽  
João Graciano Mendonça Filho ◽  
Carine Lézin ◽  
François Baudin ◽  
António Donizeti de Oliveira ◽  
...  
Keyword(s):  
Marine Environment ◽  
Organic Geochemistry ◽  
Bacterial Biomass ◽  
Integrated Approach ◽  
Organic Content ◽  
Marine Phytoplankton ◽  
Petrographic Analysis ◽  
Paris Basin ◽  
Oceanic Anoxic Event ◽  
Anoxic Event

AbstractThe Toarcian Oceanic Anoxic Event (T-OAE) is marked by major paleoenvironmental and paleoceanographical changes at a global scale, associated to a severe disturbance of the global carbon cycle, and organic-rich facies deposition. Here, a multi-proxy approach (petrographic and geochemical techniques) was applied to the study of the organic content of the T-OAE of the Paris Basin, whose phytoplanktonic origin has been previously inferred by its geochemical signature.The top of tenuicostatum Zone is characterized by palynomorphs and marine phytoplankton-derived amorphous organic matter (AOM), representing a proximal marine environment with emplacement of euxinic conditions to the top (total organic carbon/sulfur content and increase in AOM). At the base of the serpentinum Zone the proliferation of bacterial biomass begins, with phytoplankton playing a secondary role. This indicates the development of stagnant and restrictive conditions in a proximal environment, with water column stratification (neohop-13(18)-ene). The majority of the serpentinum Zone is dominated by bacterial biomass, suggesting a marine environment with bottom waters stagnation, possibly related to basin paleogeomorphology and circulation patterns, with episodic euxinia.This therefore suggests that the T-OAE organic fraction is dominated by bacterial biomass, not phytoplankton, showing the importance of an integrated approach to the determination of the organic facies.

scholarly journals Geochemical Considerations from the Carboniferous Unconventional Petroleum System of SW Iberia

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 811
Author(s):  
Gabriel A. Barberes ◽  
Rui Pena dos Reis ◽  
Nuno L. Pimentel ◽  
André L. D. Spigolon ◽  
Paulo E. Fonseca ◽  
...  
Keyword(s):  
Random Distribution ◽  
Thermal Evolution ◽  
Organic Geochemistry ◽  
Black Shales ◽  
Petroleum System ◽  
Point Of View ◽  
Gas Reservoir ◽  
Thermal Maturation ◽  
Petrographic Analyses ◽  
Rock Eval

The Baixo Alentejo Flysch Group (BAFG) is an important stratigraphic unit that covers over half of the South Portuguese Zone (SPZ) depositional area, and it is composed by three main tectono-stratigraphic units: the Mértola, Mira, and Brejeira formations. All of these formations contain significant thicknesses of black shales and have several wide areas with 0.81 wt.%, 0.91 wt.%, and 0.72 wt.% average total organic carbon (TOC) (respectively) and thermal maturation values within gas zones (overmature). This paper is considering new data from classical methods of organic geochemistry characterization, such as TOC, Rock–Eval pyrolysis, and organic petrography, to evaluate the unconventional petroleum system from the SPZ. A total of 53 samples were collected. From the stratigraphical point of view, TOC values seem to have a random distribution. The Rock–Eval parameters point out high thermal maturation compatible with gas window (overmature zone). The samples are dominated by gas-prone extremely hydrogen-depleted type III/IV kerogen, which no longer has the potential to generate and expel hydrocarbons. The petrographic analyses positioned the thermal evolution of these samples into the end of catagenesis to metagenesis (wet to dry gas zone), with values predominantly higher than 2 %Ro (dry gas zone). The presence of thermogenic hydrocarbon fluids characterized by previous papers indicate that the BAFG from SPZ represents a senile unconventional petroleum system, working nowadays basically as a gas reservoir.

scholarly journals Age and paleoenvironment of the Nukhul Formation, Gulf of Suez, Egypt: Insights from palynology, palynofacies and organic geochemistry

GeoArabia ◽  
2013 ◽  
Vol 18 (4) ◽  
pp. 137-174
Author(s):  
Haytham El Atfy ◽  
Rainer Brocke ◽  
Dieter Uhl
Keyword(s):  
Nile Delta ◽  
Organic Geochemistry ◽  
Regional Scale ◽  
Tectonic Activity ◽  
Gulf Of Suez ◽  
Spores And Pollen ◽  
Shallow Marine ◽  
History Of ◽  
Geochemical Analyses ◽  
Rock Eval

ABSTRACT Palynological results of a detailed study carried out on 56 samples retrieved from two selected wells (GH 404-2A and SA-E6A) of the Hilal and Shoab Ali fields within the southern part of the Gulf of Suez, Egypt, are presented. This study is mainly focused on the poorly dated Nukhul Formation, for which very little information from palynology is available despite its importance from a petroleum viewpoint. The assemblages discovered in our study are moderately preserved and reveal a sparse but significant record of spores and pollen and dinoflagellates together with highly diverse fungi and algal taxa, e.g. Botryococcus and Pediastrum. A latest Oligocene–Early Miocene (Chattian–Aquitanian) age has been suggested for the Nukhul Formation, based on compiling palynostratigraphic and ecologic data obtained from palynomorphs that have previously been assumed to be representatives for this period on a regional scale. In addition, the Oligocene/Miocene Boundary (OMB) could be lithostratigraphically defined within the studied formation, most likely at the boundary between the lower Shoab Ali Member and upper Ghara Member. A fungal/algal ‘event’ within the interval from 11,370–11,430 ft in the GH 404-2A Well may be associated with a strong regressive phase. Such a regression was previously observed in the Nile Delta and other locations around the Red Sea province, and may be assigned to the global Mi-1 glaciation event at the OMB. However, not only glacial-driven eustacy but also tectonic activity related to the Gulf of Suez rifting may have contributed in forming such an event. Palynofacies investigations were carried out under both transmitted and fluorescence microscopy and the results were partly supplemented by existing organic geochemical analyses (GH 404-2A Well) involving Rock-Eval pyrolysis and total organic carbon (TOC) measurements. The analysis was used to interpret the depositional regime, paleoenvironment and thermal maturation history of the studied succession. These results support the temporary existence of shallow, pond- or lake-like aquatic habitats during deposition of the lower Shoab Ali Member that evolved into a shallow-marine environment with the onset of the deposition of upper Ghara Member of the Nukhul Formation.

scholarly journals Uranium-series isotopes from Eemian lake deposits, Hollerup, Denmark

1998 ◽  
Vol 44 ◽  
pp. 173-179
Author(s):  
C. Israelson ◽  
S. Bjorck ◽  
N. Noe Nygaard ◽  
C. J. Hawkesworth
Keyword(s):  
Ground Water ◽  
Lake Sediments ◽  
Sedimentary Facies ◽  
Organic Content ◽  
Time Interval ◽  
Decay Products ◽  
Large Spread ◽  
Isotope Study ◽  
Lake Deposits ◽  
High Organic Content

We report the results of a U-series isotope study on Eemian lake sediments from Hollerup, western Denmark. The purpose is to examine the possibility of dating these, and similar, sediments with the 238U-23"h method. Two sedimentary facies were studied; carbonate-present, and virtually carbonate-free but organic-rich sediments. All carbonate-present sediments (5-95%) have (230ThP38U) values higher than unity and relatively radiogenic (23"W232Th) values between 2 and 6.5, indicating postdeposition removal of U, probably by percolation of ground water. Carbonate-free sediments, but with high organic content (40-60%) had (230Th/238U) values lower than 1 and 'model ages' between 89 and 199 ky. The large spread in ages and variation in U content for these sediment samples that were deposited over a much shorter time interval, indicate a complex postdepositional migration pattern of U, probably involving several episodes of leaching and absorption of U from ground water. Our results suggest that lake sediments, such as those found in Hollerup, are vulnerable to mobilization of U and its decay products and care should be taken when interpreting U-series disequilibrium data from such sediments. Future studies will concentrate on sediments that have been more deeply buried andor are less compacted and sealed from percolation of oxidized groundwater.

scholarly journals Sosialisasi Pengelolaan Limbah Dapur Serta Program 3R (Reuse, Reduce, Recycle) Bagi Pemilik Rumah Makan dan Jasa Boga di Wilayah Kota Tasikmalaya

2018 ◽  
Vol 1 (2) ◽  
pp. 53-62
Author(s):  
Melly Mellyanawaty ◽  
Estin Nofiyanti ◽  
A Ibrahim ◽  
N Salman ◽  
N Nurjanah ◽  
...  
Keyword(s):  
Solid Waste ◽  
Energy Requirement ◽  
Organic Content ◽  
Limited Area ◽  
Solid Waste Disposal ◽  
Kitchen Waste ◽  
Egg Shells ◽  
Cooked Food ◽  
Pre Treatment ◽  
High Organic Content

Society services activity in kitchen waste management system has been implemented to the owner of restaurant and catering work in Tasikmalaya City area. This activity has colaborated with Indonesian Catering Associations (APJI). The rapid growth of restaurant and catering activities has created serious problems of energy requirement, water, and solid waste disposal. Less information and limited area become the problems in handling of kitchen waste. A simple technique is needed to overcome the environmental problem which is caused by kitchen waste. The components of kitchen waste include vegetables, peelings, fruit skins, spoilt fruit, cooked and uncooked meat, bones, fats, egg-shells, bread and pastries, cooked food waste, etc. Due to a high organic content, bioconversion technologies such as anaerobic digestion are more suitable to handle the waste convert to biogas. It would be reducing the LPG usage. For the kitchen wastewater, grease trap as pre-treatment followed by a physical and biological process is one of a simple process which can produce the effluent in accordance with government standard. The activities were continued by the socialization of 3R program (reuse, reduce, recycle) by doing demo utilization of kitchen solid waste such as packing material, mineral water bottle is made a handicraft. Knowledge transfer run well and the enthusiasm of the participants in following the activity were very good.

Erosion resistance and behaviour of highly organic in-sewer sediment

2013 ◽  
Vol 69 (3) ◽  
pp. 672-679 ◽  
Author(s):  
I. Seco ◽  
M. Gómez Valentín ◽  
A. Schellart ◽  
S. Tait
Keyword(s):  
Organic Content ◽  
Natural Environments ◽  
Time Varying ◽  
Storm Events ◽  
Dry Period ◽  
Sewer Systems ◽  
Organic Sediment ◽  
Combined Sewer ◽  
Tank Design ◽  
High Organic Content

Reliable prediction of time-varying pollutant loads in combined sewer systems during storm periods can aid better management of the release of pollution into natural environments as well as enhancing storage tank design. Better understanding of the behaviour of sewer sediments is crucial for the development of models that adequately describe the transport of in-sewer solids and accurately predict the changes in pollutant concentration within combined sewers during storm events. This paper reports on the results of a test programme to examine the erosion of highly organic sewer sediment under the application of time-varying shear stress. The tests were carried out with and without supplying oxygen, and varying simulated dry-weather periods. The aim was to investigate the behaviour of real in-sewer sediment with a high organic content (around 80%) in an attempt to improve prediction of the transport rates under the particular Mediterranean conditions of long dry-period/build-up and intense rainfall/wash-off, and understand how this environment affects the erosional resistance and subsequent sediment release. Results have been compared with previous work on lower organic content sewer sediments and artificial organic sediment.

Recurrent global carbon cycle disturbances during the Aalenian: Evidence from France and Chile

2021 ◽  
Author(s):  
Alicia Fantasia ◽  
Thierry Adatte ◽  
Jorge E. Spangenberg ◽  
Emanuela Mattioli ◽  
Enrique Bernárdez ◽  
...  
Keyword(s):  
High Resolution ◽  
Carbon Cycle ◽  
Middle Jurassic ◽  
Environmental Changes ◽  
Global Carbon Cycle ◽  
Oceanic Anoxic Event ◽  
Carbon Substrates ◽  
Rock Eval ◽  
Resolution Dataset ◽  
Global Carbon

<p>The Jurassic was punctuated by several episodes of abrupt environmental changes associated with climatic instabilities, severe biotic crisis, and perturbations of the global carbon cycle. Over the last decades, the Toarcian Oceanic Anoxic Event (Early Jurassic, ~183 Ma) and the early Bajocian Event (Middle Jurassic, ~170–168 Ma) have attracted much attention because they represent such episodes of global and severe environmental change. Bracketed in between the Toarcian and the Bajocian, the Aalenian stage (Middle Jurassic, ~174-170 Ma) has received less attention, although there is some evidence from Tethyan and Boreal records that it was a time of environmental changes marked by marine biotic turnovers. The lack of knowledge about the Aalenian palaeoenvironments leaves a gap in our understanding of the wider context of the Toarcian and Bajocian events and hence of environmental feedback mechanisms surrounding Mesozoic carbon cycle perturbations. In this study, we provide a high-resolution, biostratigraphically well-defined carbon isotope records (<em>δ</em><sup>13</sup>C<sub>org </sub>and <em>δ</em><sup>13</sup>C<sub>carb</sub>) combined to Rock-Eval data for the upper Toarcian–lower Bajocian interval from two expanded marl/limestone alternation successions from France (French Subalpine Basin) and Chile (Andean Basin). The comparison with available records from the Tethyan and Boreal domains highlights that medium-term <em>δ</em><sup>13</sup>C fluctuations are reproducible across different palaeoceanographic settings from both hemispheres and between different carbon substrates. The new high-resolution dataset highlights the complexity of the Aalenian <em>δ</em><sup>13</sup>C record, including previously identified <em>δ</em><sup>13</sup>C shifts and hitherto undescribed fluctuations. This study provides one of the most expanded high-resolution chemostratigraphic reference records for the entire Aalenian stage, and shows compelling evidence from both hemispheres that it was a time marked by recurrent perturbations to the global carbon cycle and environmental changes.</p><p> </p>

scholarly journals Glycan-specific precipitation of glycopeptides in high organic content sample solvents used in HILIC

2020 ◽  
Vol 1150 ◽  
pp. 122196
Author(s):  
Petr Kozlik ◽  
Katarina Molnarova ◽  
Tomas Jecmen ◽  
Tomas Krizek ◽  
Radoslav Goldman
Keyword(s):  
Organic Content ◽  
High Organic Content
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