Upper Cretaceous and Eocene litho- and biostratigraphy of the Istria Basin (NW Black Sea)

2020 ◽  
Author(s):  
Madalina Eliza Anton ◽  
Ioan Munteanu ◽  
Corneliu Dinu ◽  
Mihaela C. Melinte-Dobrinescu
Keyword(s):  
Black Sea ◽  
Large Scale ◽  
Upper Cretaceous ◽  
Middle Eocene ◽  
Structural Characteristics ◽  
Normal Fault ◽  
Hydrocarbon Exploration ◽  
Thickness Variation ◽  
Foot Wall ◽  
Early Eocene

<p>The Istria basin, situated in the NW Black Sea, is composed of Mesozoic to Cenozoic successions. The opening of the Western Black Sea, including the Istria basin, initiated in the late Early Cretaceous. Rifting and expansion continued in the Late Cretaceous, while in the Late Paleogene a compressional regime settled. In the Middle Eocene, the Western Black Sea basin margin inverted, due to the collision of Pontides and Taurides belts (Okay and Tüysüz, 1999; Dinu et al., 2005). The continuing compression shaped this basin until the Middle Miocene (Ionescu et al., 2002).</p><p> </p><p>Tens of wells for hydrocarbon exploration were drilled in the Istria basin (Romanian offshore) since the 70’s. In this study, we have interpreted the acquired core reports containing litho- and biostratigraphic data. Based on identified calcareous nannofossil biozones, a continuous deposition was found in the Cenomanian-Maastrichtian interval. Lithologically, the Upper Cretaceous is composed of carbonatic rocks, such as limestones and marlstones, with intercalations of calcareous sandstones. The Eocene deposits are unconformably lying on Upper Cretaceous ones. Lithologically, the Eocene is characterized by alternating calcareous and siliciclastic sandstones. Biostratigraphy on planktonic and benthic foraminifers, as well as calcareous nannofossils, indicate a late Early Eocene to Middle Eocene age (i.e., late Ypresian to Bartonian).</p><p> </p><p>The observed large thickness variation, from W towards E in the Istria Basin, is a consequence of various tectonic settings. The western part (i.e., the Sinoe area) is situated in the hanging-wall of an inverted normal fault filled with Early Eocene deposits and was inverted by high angle thrust fault during the Late Eocene-Oligocene interval. In the E (i.e., the Lebǎda area), there is an uplifted normal fault foot-wall, showing a reduced thickness in comparison with the W (Munteanu et al., 2011). The erosion level increased eastward, removing the entire Upper Eocene and the top of the Middle Eocene. This feature may be linked to a large sea level drop towards the Eocene top, with subaerial erosion and development of large-scale canyons system at the self to slope transition, like the Plio-Quaternary Viteaz Canyon of the NW Black Sea.</p><p> </p><p>The financial support for this paper was provided by the Romanian Ministry of Research and Innovation, through the Programme Development of the National System of Research – Institutional Performance, Project of Excellence for Rivers-Deltas-Sea Systems No. 8PFE/2018.</p><p> </p><p>References</p><p>Dinu, C., Wong, H.K., Țambrea, D., Mațenco, L., 2005. Stratigraphic and structural characteristics of the Romanian Black Sea shelf. Tectonophysics, 410, 417-435.</p><p>Ionescu, G., Sisman, M., Cataraiani, R., 2002. Source and reservoir rocks and trapping mechanism on the Romanian Black Sea shelf. In: Dinu, C., Mocanu, V. (Eds.) Geology and Tectonics of the Romanian Black Sea Shelf and its Hydrocarbon Potential. BGF Special Volume, 2, 67–83.</p><p>Munteanu, I., Maţenco, L., Dinu, C., Cloetingh, S., 2011. Kinematics of back-arc inversion of the western Black Sea basin. Tectonics, 30, TC5004.</p><p>Okay, A.I., Tüysüz, O., 1999. Tethyan sutures of northern Turkey. Geological Society, London, Special Publications, 156, 475-515.</p>

The Grobogan Mud Volcano Complex: An Identification to Reveal the Opportunity of Hydrocarbon Exploration

2020 ◽  
Author(s):  
C. Jatu
Keyword(s):  
Water Analysis ◽  
Middle Eocene ◽  
Research Result ◽  
Hydrocarbon Exploration ◽  
System Model ◽  
Mud Volcano ◽  
Hydrocarbon Potential ◽  
Mud Volcanoes ◽  
Central Java ◽  
Surface Data

Mud volcanoes in Grobogan are referred as the Grobogan Mud Volcanoes Complex in Central Java where there is evidence of oil seepages. This comprehensive research is to determine the characteristics and hydrocarbon potential of the mud volcanoes in the Central Java region as a new opportunity for hydrocarbon exploration. The Grobogan Mud Volcano Complex consists of eight mud volcanoes that have its characteristics based on the study used the geological surface data and seismic literature as supporting data on eight mud volcanoes. The determination of geological surface characteristics is based on geomorphological analysis, laboratory analysis such as petrography, natural gas geochemistry, water analysis, mud geochemical analysis and biostratigraphy. Surface data and subsurface data are correlated, interpreted, and validated to make mud volcano system model. The purpose of making the mud volcanoes system model is to identify the hydrocarbon potential in Grobogan. This research proved that each of the Grobogan Mud Volcanoes has different morphological forms. Grobogan Mud Volcanoes materials are including muds, rock fragments, gas, and water content with different elemental values. Based on this research result, there are four mud volcano systems models in Central Java, they are Bledug Kuwu, Maesan, Cungkrik, and Crewek type. The source of the mud is from Ngimbang and Tawun Formation (Middle Eocene to Early Miocene) from biostratigraphy data and it been correlated with seismic data. Grobogan Mud Volcanoes have potential hydrocarbons with type III kerogen of organic matter (gas) and immature to early mature level based on TOC vs HI cross plot. The main product are thermogenic gas and some oil in relatively small quantities. Water analysis shows that it has mature sodium chloride water. This analysis also shows the location was formed within formations that are deposited in a marine environment with high salinity. Research of mud volcanos is rarely done in general. However, this comprehensive research shows the mud volcano has promising hydrocarbon potential and is a new perspective on hydrocarbon exploration.

scholarly journals Late oligocene–early miocene shortening in the Thrace Basin, northern Aegean

2021 ◽  
Author(s):  
Ümitcan Erbil ◽  
Aral I. Okay ◽  
Aynur Hakyemez
Keyword(s):  
Large Scale ◽  
Middle Eocene ◽  
Early Miocene ◽  
Fold Axis ◽  
Late Oligocene ◽  
The Balkans ◽  
Sedimentary Sequences ◽  
The North ◽  
Early Oligocene ◽  
Thrace Basin

AbstractLate Cenozoic was a period of large-scale extension in the Aegean. The extension is mainly recorded in the metamorphic core complexes with little data from the sedimentary sequences. The exception is the Thrace Basin in the northern Aegean, which has a continuous record of Middle Eocene to Oligocene marine sedimentation. In the Thrace Basin, the Late Oligocene–Early Miocene was characterized by north-northwest (N25°W) shortening leading to the termination of sedimentation and formation of large-scale folds. We studied the stratigraphy and structure of one of these folds, the Korudağ anticline. The Korudağ anticline has formed in the uppermost Eocene–Lower Oligocene siliciclastic turbidites with Early Oligocene (31.6 Ma zircon U–Pb age) acidic tuff beds. The turbidites are underlain by a thin sequence of Upper Eocene pelagic limestone. The Korudağ anticline is an east-northeast (N65°E) trending fault-propagation fold, 9 km wide and 22 km long and with a subhorizontal fold axis. It is asymmetric with shallowly-dipping northern and steeply-dipping southern limbs. Its geometry indicates about 1 km of shortening in a N25°W direction. The folded strata are unconformably overlain by Middle Miocene continental sandstones, which constrain the age of folding. The Korudağ anticline and other large folds in the Thrace Basin predate the inception of the North Anatolian Fault (NAF) by at least 12 myr. The Late Oligocene–Early Miocene (28–17 Ma) shortening in the Thrace Basin and elsewhere in the Balkans forms an interlude between two extensional periods, and is probably linked to changes in the subduction dynamics along the Hellenic trench.

Mineral exploration with 3-D controlled-source electromagnetic method: a synthetic study of Sukhoi Log gold deposit

2019 ◽  
Vol 219 (3) ◽  
pp. 1698-1716 ◽  
Author(s):  
M Malovichko ◽  
A V Tarasov ◽  
N Yavich ◽  
M S Zhdanov
Keyword(s):  
Finite Difference ◽  
Gold Deposit ◽  
Large Scale ◽  
Mineral Exploration ◽  
Mineral Deposit ◽  
Hydrocarbon Exploration ◽  
Contraction Operator ◽  
Inversion Algorithm ◽  
Controlled Source ◽  
Regularized Inversion

SUMMARY This paper presents a feasibility study of using the controlled-source frequency-domain electromagnetic (CSEM) method in mineral exploration. The method has been widely applied for offshore hydrocarbon exploration; however, nowadays this method is rarely used on land. In order to conduct this study, we have developed a fully parallelized forward modelling finite-difference (FD) code based on the iterative solver with contraction-operator preconditioner. The regularized inversion algorithm uses the Gauss–Newton method to minimize the Tikhonov parametric functional with the Laplacian-type stabilizer. A 3-D parallel inversion code, based on the iterative finite-difference solver with the contraction-operator preconditioner, has been evaluated for the solution of the large-scale inverse problems. Using the computer simulation for a synthetic model of Sukhoi Log gold deposit, we have compared the CSEM method with the conventional direct current sounding and the CSEM survey with a single remote transmitter. Our results suggest that, a properly designed electromagnetic survey together with modern 3-D inversion could provide detailed information about the geoelectrical structure of the mineral deposit.

scholarly journals Fabrication of Ultrathin MoS2 Nanosheets and Application on Adsorption of Organic Pollutants and Heavy Metals

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 504 ◽  
Author(s):  
Siyi Huang ◽  
Ziyun You ◽  
Yanting Jiang ◽  
Fuxiang Zhang ◽  
Kaiyang Liu ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Electrostatic Interactions ◽  
Large Scale ◽  
Layer Structure ◽  
Structural Characteristics ◽  
Hexagonal Phase ◽  
Two Dimensional ◽  
Mos2 Nanosheets ◽  
Hybrid Strategy ◽  
Ultrathin Mos2 Nanosheets

Owing to their peculiar structural characteristics and potential applications in various fields, the ultrathin MoS2 nanosheets, a typical two-dimensional material, have attracted numerous attentions. In this paper, a hybrid strategy with combination of quenching process and liquid-based exfoliation was employed to fabricate the ultrathin MoS2 nanosheets (MoS2 NS). The obtained MoS2 NS still maintained hexagonal phase (2H-MoS2) and exhibited evident thin layer-structure (1–2 layers) with inconspicuous wrinkle. Besides, the MoS2 NS dispersion showed excellent stability (over 60 days) and high concentration (0.65 ± 0.04 mg mL−1). The MoS2 NS dispersion also displayed evident optical properties, with two characteristic peaks at 615 and 670 nm, and could be quantitatively analyzed with the absorbance at 615 nm in the range of 0.01–0.5 mg mL−1. The adsorption experiments showed that the as-prepared MoS2 NS also exhibited remarkable adsorption performance on the dyes (344.8 and 123.5 mg g−1 of qm for methylene blue and methyl orange, respectively) and heavy metals (185.2, 169.5, and 70.4 mg g−1 of qm for Cd2+, Cu2+, and Ag+). During the adsorption, the main adsorption mechanisms involved the synergism of physical hole-filling effects and electrostatic interactions. This work provided an effective way for the large-scale fabrication of the two-dimensional nanosheets of transition metal dichalcogenides (TMDs) by liquid exfoliation.

Drivers of (non-)linear Eocene surface warming in the DeepMIP ensemble

2021 ◽  
Author(s):  
Sebastian Steinig ◽  
Jiang Zhu ◽  
Ran Feng ◽  
Keyword(s):  
Temperature Gradient ◽  
Heat Transport ◽  
Climate Sensitivity ◽  
Radiative Forcing ◽  
Large Scale ◽  
Surface Albedo ◽  
Early Eocene ◽  
Meridional Heat Transport ◽  
Surface Warming ◽  
Global Mean

<p>The early Eocene greenhouse represents the warmest interval of the Cenozoic and therefore provides a unique opportunity to understand how the climate system operates under elevated atmospheric CO<sub>2</sub> levels similar to those projected for the end of the 21st century. Early Eocene geological records indicate a large increase in global mean surface temperatures compared to present day (by ~14°C) and a greatly reduced meridional temperature gradient (by ~30% in SST). However, reproducing these large-scale climate features at reasonable CO<sub>2</sub> levels still poses a challenge for current climate models. Recent modelling studies indicate an important role for shortwave (SW) cloud feedbacks to drive increases in climate sensitivity with global warming, which helps to close the gap between simulated and reconstructed Eocene global warmth and temperature gradient. Nevertheless, the presence of such state-dependent feedbacks and their relative strengths in other models remain unclear.</p><p>In this study, we perform a systematic investigation of the simulated surface warming and the underlying mechanisms in the recently published DeepMIP ensemble. The DeepMIP early Eocene simulations use identical paleogeographic boundary conditions and include six models with suitable output: CESM1.2_CAM5, GFDL_CM2.1, HadCM3B_M2.1aN, IPSLCM5A2, MIROC4m and NorESM1_F. We advance previous energy balance analysis by applying the approximate partial radiative perturbation (APRP) technique to quantify the individual contributions of surface albedo, cloud and non-cloud atmospheric changes to the simulated Eocene top-of-the-atmosphere SW flux anomalies. We further compare the strength of these planetary albedo feedbacks to changes in the longwave atmospheric emissivity and meridional heat transport in the warm Eocene climate. Particular focus lies in the sensitivity of the feedback strengths to increasing global mean temperatures in experiments at a range of atmospheric CO<sub>2</sub> concentrations between x1 to x9 preindustrial levels.</p><p>Preliminary results indicate that all models that provide data for at least 3 different CO<sub>2</sub> levels show an increase of the equilibrium climate sensitivity at higher global mean temperatures. This is associated with an increase of the overall strength of the positive SW cloud feedback with warming in those models. This nonlinear behavior seems to be related to both a reduction and optical thinning of low-level clouds, albeit with intermodel differences in the relative importance of the two mechanisms. We further show that our new APRP results can differ significantly from previous estimates based on cloud radiative forcing alone, especially in high-latitude areas with large surface albedo changes. We also find large intermodel variability and state-dependence in meridional heat transport modulated by changes in the atmospheric latent heat transport. Ongoing work focuses on the spatial patterns of the climate feedbacks and the implications for the simulated meridional temperature gradients.</p>

Early Tertiary thermotectonic history of the northern Yukon and adjacent Northwest Territories, Arctic Canada

1997 ◽  
Vol 34 (10) ◽  
pp. 1366-1378 ◽  
Author(s):  
Paul B. O'Sullivan ◽  
Larry S. Lane
Keyword(s):  
Northwest Territories ◽  
Fission Track ◽  
Middle Eocene ◽  
Geothermal Gradient ◽  
Crystalline Rock ◽  
Early Eocene ◽  
Channel Formation ◽  
Rapid Cooling ◽  
Early Tertiary ◽  
History Of

Apatite fission-track data from 16 sedimentary and crystalline rock samples indicate rapid regional Early Eocene denudation within the onshore Beaufort–Mackenzie region of northwestern Canada. Rocks exposed in the area of the Big Fish River, Northwest Territories, cooled rapidly from paleotemperatures of >80–110 °C to <6 0°C at ca. 56 ± 2 Ma, probably in response to kilometre-scale denudation associated with regional structuring. The data suggest the region experienced a geothermal gradient of ~28 °C/km prior to rapid cooling, with ~2.7 km of section having been removed from the top of the exposed section in the Moose Channel Formation and ~3.8 km from the top of the exposed Cuesta Creek Member. Farther to the west, rocks exposed in the headwaters of the Blow River in the Barn Mountains, Yukon Territories, were exposed to paleotemperatures above 110 °C in the Late Paleocene prior to rapid cooling from these elevated paleotemperatures due to kilometre-scale denudation at ca. 56 ± 2 Ma. Exposure of these samples at the surface today requires that a minimum of ~3.8 km of denudation occurred since they began cooling below ~110 °C. The apatite analyses indicate that rocks exposed in the northern Yukon and Northwest Territories experienced rapid cooling during the Early Eocene in response to kilometre-scale denudation, associated with early Tertiary folding and thrusting in the northern Cordillera. Early Eocene cooling–uplift ages for onshore sections are slightly older than the Middle Eocene ages previously documented for the adjacent offshore foldbelt and suggest that the deformation progressed toward the foreland of the foldbelt through time.

Structural characteristics of a developing turbulent planar jet

1986 ◽  
Vol 163 ◽  
pp. 227-256 ◽  
Author(s):  
F. O. Thomas ◽  
V. W. Goldschmidt
Keyword(s):  
Large Scale ◽  
Structural Characteristics ◽  
Energy Spectra ◽  
Two Dimensional ◽  
Structural Pattern ◽  
Potential Core ◽  
Planar Jet ◽  
Fluctuation Phase ◽  
Oriented Parallel ◽  
Phase Angles

An experimental study of the developing structural characteristics of a two-dimensional jet in an extremely quiet environment was performed. The jet, at an exit Reynolds number of 6000 and with fluctuation intensity under 0.2% at the mouth, was operated within a large anechoic room. Measurements of energy spectra, fluctuation phase angles and two-dimensionality led to the inference of structural patterns in the flow. These patterns are initially characterized by relatively strong symmetric modes exhibiting limited two-dimensionality and oriented parallel to the mouth of the jet. Subsequent downstream evolution led to the formation of an antisymmetric pattern beyond the jet potential core and the associated development of extended structures possessing a definite large lateral inclination. The results of this work suggest a developing large-scale structural pattern more complicated than previously supposed.

scholarly journals Seismic-Scale Evidence of Thrust-Perpendicular Normal Faulting in the Western Outer Carpathians, Poland

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1252
Author(s):  
Jan Barmuta ◽  
Krzysztof Starzec ◽  
Wojciech Schnabel
Keyword(s):  
Large Scale ◽  
Fault Plane ◽  
Normal Fault ◽  
Normal Faulting ◽  
Seismic Profiles ◽  
Horizontal Movement ◽  
Outer Carpathians ◽  
Differential Uplift ◽  
Seismic Scale ◽  
Detachment Surface

Based on the interpretation of 2D seismic profiles integrated with surface geological investigations, a mechanism responsible for the formation of a large scale normal fault zone has been proposed. The fault, here referred to as the Rycerka Fault, has a predominantly normal dip-slip component with the detachment surface located at the base of Carpathian units. The fault developed due to the formation of an anticlinal stack within the Dukla Unit overlain by the Magura Units. Stacking of a relatively narrow duplex led to the growth of a dome-like culmination in the lower unit, i.e., the Dukla Unit, and, as a consequence of differential uplift of the unit above and outside the duplex, the upper unit (the Magura Unit) was subjected to stretching. This process invoked normal faulting along the lateral culmination wall and was facilitated by the regional, syn-thrusting arc–parallel extension. Horizontal movement along the fault plane is a result of tear faulting accommodating a varied rate of advancement of Carpathian units. The time of the fault formation is not well constrained; however, based on superposition criterion, the syn -thrusting origin is anticipated.

scholarly journals Maastrichtian–Rupelian paleoclimates in the southwest Pacific – a critical re-evaluation of biomarker paleothermometry and dinoflagellate cyst paleoecology at Ocean Drilling Program Site 1172

2021 ◽  
Vol 17 (6) ◽  
pp. 2393-2425
Author(s):  
Peter K. Bijl ◽  
Joost Frieling ◽  
Margot J. Cramwinckel ◽  
Christine Boschman ◽  
Appy Sluijs ◽  
...  
Keyword(s):  
Marine Sediments ◽  
State Of The Art ◽  
Middle Eocene ◽  
Potential Temperature ◽  
Critical Evaluation ◽  
Marine Biodiversity ◽  
Early Eocene ◽  
Ocean Drilling Program ◽  
Ocean Drilling ◽  
Sw Pacific

Abstract. Sea surface temperature (SST) reconstructions based on isoprenoid glycerol dialkyl glycerol tetraether (isoGDGT) distributions from the Eocene southwest (SW) Pacific Ocean are unequivocally warmer than can be reconciled with state-of-the-art fully coupled climate models. However, the SST signal preserved in sedimentary archives can be affected by contributions of additional isoGDGT sources. Methods now exist to identify and possibly correct for overprinting effects on the isoGDGT distribution in marine sediments. Here, we use the current proxy insights to (re-)assess the reliability of the isoGDGT-based SST signal in 69 newly analyzed and 242 reanalyzed sediments at Ocean Drilling Program (ODP) Site 1172 (East Tasman Plateau, Australia) following state-of-the-art chromatographic techniques. We compare our results with paleoenvironmental and paleoclimatologic reconstructions based on dinoflagellate cysts. The resulting ∼ 130 kyr resolution Maastrichtian–Oligocene SST record based on the TetraEther indeX of tetraethers with 86 carbon atoms (TEX86) confirms previous conclusions of anomalous warmth in the early Eocene SW Pacific and remarkably cool conditions during the mid-Paleocene. Dinocyst diversity and assemblages show a strong response to the local SST evolution, supporting the robustness of the TEX86 record. Soil-derived branched GDGTs stored in the same sediments are used to reconstruct mean annual air temperature (MAAT) of the nearby land using the Methylation index of Branched Tetraethers with 5-methyl bonds (MBT'5me) proxy. MAAT is consistently lower than SST during the early Eocene, independent of the calibration chosen. General trends in SST and MAAT are similar, except for (1) an enigmatic absence of MAAT rise during the Paleocene–Eocene Thermal Maximum and Middle Eocene Climatic Optimum, and (2) a subdued middle–late Eocene MAAT cooling relative to SST. Both dinocysts and GDGT signals suggest a mid-shelf depositional environment with strong river runoff during the Paleocene–early Eocene progressively becoming more marine thereafter. This trend reflects gradual subsidence and more pronounced wet/dry seasons in the northward-drifting Australian hinterland, which may also explain the subdued middle Eocene MAAT cooling relative to that of SST. The overall correlation between dinocyst assemblages, marine biodiversity and SST changes suggests that temperature exerted a strong influence on the surface-water ecosystem. Finally, we find support for a potential temperature control on compositional changes of branched glycerol monoalkyl glycerol tetraethers (brGMGTs) in marine sediments. It is encouraging that a critical evaluation of the GDGT signals confirms that most of the generated data are reliable. However, this also implies that the high TEX86-based SSTs for the Eocene SW Pacific and the systematic offset between absolute TEX86-based SST and MBT'5me-based MAAT estimates remain without definitive explanation.

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