A palynostratigraphic approach to the SW Anatolian molasse basin: Kale-Tavas molasse and Denizli molasse     

Funda Akgiin  Hasan Sözbilir 《Geodinamica Acta》2013,26(1-3):71-93

Abstract

The study, explains stratigraphy of the Oligo-Miocene molasse around the Denizli province (SW Anatolia), based on the palynology which is also supported by the detailed mapping and correlation of the measured sections from the coal-bearing sequences of the molasse deposits. For this purpose, two huge depressions named as the Kale-Tavas molasse and Denizli molasse basins were examined. The Kale-Tavas molasse deposits has a basal unconformity with the underlying pre-Oligocene basement and begins with the Chattian Karadere and Mortuma formations which are covered unconformably by the Aquitanian Yenidere formation. An angular unconformity between the Chattian and the Burdigalian is only observed in the middle part of the basin, around Kale, In the Tavas section, the Aquitanian and the Burdigalian are absent. The Denizli molasse is characterized by Chattian-Aquitanian sequence consisting of distinctive sedimentary facies, alluvial fan and deltaic-shallow marine deposits with carbonate patch reefs. Palynostratigraphic studies, which have given the Chattian age, have been carried out from the coal lenses of alluvial fan and delta plain deposits. In addition to the palynological determinations, coral and foraminiferal content of the carbonate patch reefs which rest conformably on the coal-bearing sequences have yielded the Chattian- Aquitanian age. Two different palynomorph associations have been determined from the molasse deposits. The first palynomorph association which is established in the samples from the Sa?dere and Mortuma formations, corresponds to the Chattian age, whilst the second is of the Aquitanian age. The Late Oligocene-Early Miocene which is claimed as the time of N-S-extensional tectonics in western Turkey, is related to the depositional time of the molasse sequences in the study area. Thus, the molasse is older than the basal deposits of the Gediz and Büyük Menderes grabens. © 2001 Éditions scientifiques et médicales Elsevier SAS  相似文献   

Evidence for two episodes of volcanism in the Bigadiç borate basin and tectonic implications for western Turkey     

Fuat Erkül  Cahi&#x;t Helvaci  Hasan Szbi&#x;li&#x;r 《Geological Journal》2005,40(5):545-570

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Fatigue reliability analysis of deep water rigid marine risers associated with Morison-type wave loading   总被引：1，自引：0，他引：1  

Muddassir Nazir  Faisal Khan  Paul Amyotte 《Stochastic Environmental Research and Risk Assessment (SERRA)》2008,22(3):379-390

This work presents a simple and efficient framework for the fatigue reliability assessment of a vertical top-tensioned rigid riser. The fatigue damage response is considered as a narrow-band Gaussian stationary random process with a zero mean for the short-term behavior of a riser. Non-linearity in a response associated with Morison-type wave loading is accounted for by using a factor, which is the ratio of expected damage according to a non-linear probability distribution to the expected damage according to a linear method of analysis. Long-term non-stationary response is obtained by summing up a large number of short-term stationary responses. Uncertainties associated with both the strength and stress parts of the limit state function are quantified by a lognormal distribution. A closed form reliability analysis is carried out, which is based on the limit state function formulated in terms of Miner’s cumulative damage rule. The results thus obtained are compared with the well-documented lognormal format of reliability analysis based on time to fatigue failure. The validity of using the lognormal hazard rate function in predicting the fatigue life is discussed. A Monte Carlo simulation technique is also used as a reliability assessment method. A simple algorithm is used to reduce the uncertainty associated with direct sampling at small probability of failure values and a small number of simulations. Simulation results are compared with closed form solutions. A worked example is included to show the practical riser design problem based on reliability analysis.  相似文献   

Active fault database of Turkey     

Ömer Emre  Tamer Y. Duman  Selim Özalp  Fuat Şaroğlu  Şeyda Olgun  Hasan Elmacı  Tolga Çan 《Bulletin of Earthquake Engineering》2018,16(8):3229-3275

We have updated the active fault map of Turkey and built its database within GIS environment. In the study, four distinct active fault types, classified according to geochronological criteria and character, were delineated on the 1:25,000 base map of Turkey. 176 fault segments not included in the former active fault map of Turkey, have been identified and documented. We infer that there are 485 single fault segments which are substantially potential seismic sources. In total 1964 active-fault base-maps were transferred into the GIS environment. Each fault was attributed with key parameters such as class, activity, type, length, trend, and attitude of fault plane. The fault parameters are also supported by slip-rate and seismogenic depth inferred from available GPS, seismological and paleoseismological data. Additionally, expected maximum magnitude for each fault segment was estimated by empirical equations. We present the database in a parametric catalogue of fault segments to be of interest in earthquake engineering and seismotectonics. The study provides essential geological and seismological inputs for regional seismic hazard analysis of all over Turkey and its vicinity.  相似文献   

Artificial neural network simulation for prediction of suspended sediment concentration in the River Ramganga,Ganges Basin,India     

Mohd Yawar Ali Khan  Fuqiang Tian  Faisal Hasan  Govind Joseph Chakrapani 《国际泥沙研究》2019,34(2):95-107

The relation between the water discharge (Q) and suspended sediment concentration (SSC) of the River Ramganga at Bareilly, Uttar Pradesh, in the Himalayas, has been modeled using Artificial Neural Networks (ANNs). The current study validates the practical capability and usefulness of this tool for simulating complex nonlinear, real world, river system processes in the Himalayan scenario. The modeling approach is based on the time series data collected from January to December (2008-2010) for Q and SSC. Three ANNs (T1-T3) with different network configurations have been developed and trained using the Levenberg Marquardt Back Propagation Algorithm in the Matlab routines. Networks were optimized using the enumeration technique, and, finally, the best network is used to predict the SSC values for the year 2011. The values thus obtained through the ANN model are compared with the observed values of SSC. The coefficient of determination (R2), for the optimal network was found to be 0.99. The study not only provides insight into ANN modeling in the Himalayan river scenario, but it also focuses on the importance of understanding a river basin and the factors that affect the SSC, before attempting to model it. Despite the temporal variations in the study area, it is possible to model and successfully predict the SSC values with very simplistic ANN models.  相似文献   

An improved input energy spectrum verified by the shake table tests     

Ahmet Güllü  Ercan Yüksel  Cem Yalçın  A. Anıl Dindar  Hasan Özkaynak  Oral Büyüköztürk 《地震工程与结构动力学》2019,48(1):27-45

Input energy is the principal component of the energy balance equation. It is beneficial to determine, through its components, how the recoverable and irrecoverable energies are distributed within the structural elements. Several equations and attenuation relations to define mass-normalized input energy spectra exist in the literature. They are mainly proposed for elastic systems subjected to far-fault EQs. There is a lack of experimental verification of these proposed spectra. In this paper, experimental assessment was performed to the existing spectra, and further improvements were accomplished. For this purpose, steel cantilever columns were tested on the shake table for two specific historical EQs coincidently having similar spectral acceleration values. Based on the experimental results, a three-part mass-normalized relative input energy spectrum was formulated including soil type, EQ (corner period, intensity, duration, spectral acceleration, and velocity), and structural behavioral characteristics (period and structural damping). The proposed input energy spectrum was experimentally calibrated and numerically validated for various EQs featuring near- and far-field types. Analytical and experimental comparisons were made between the previously developed spectrum and the newly proposed one. The validation studies and the statistical evaluations exposed that the proposed spectrum yielded better agreement with the experimental and numerical results.  相似文献   

Magnetohydrodynamic equilibrium and stability of pre-flare loops     

S. S. Hasan 《Solar physics》1980,67(2):267-283

The equilibrium and stability of a loop in which energy storage occurs prior to a solar flare is discussed. Working on the hypothesis, that the onset of the flare begins only after sufficient magnetic energy has been stored in the loop typical values of parameters which describe the equilibrium are found for a magnetic field with a constant twist. The stability of this configuration is examined next and it is shown that for the force-free case, the structure is always unstable to kinking for any degree of twist. However, a slight deviation from the force-free configuration, through the presence of a small positive transverse pressure gradient, can stabilize the loops for moderate degrees of twist. The range of wave-numbers for which instability occurs and the maximum growth rates are also presented. Lastly, it is shown that the pressure gradients required to stabilize a pre-flare loop do not lead to conflict with observations.  相似文献   

Dynamic linkages among energy consumption,air pollution,greenhouse gas emissions and agricultural production in Pakistan: sustainable agriculture key to policy success     

Muhammad Imran Qureshi  Usama Awan  Zeeshan Arshad  Amran Md. Rasli  Khalid Zaman  Faisal Khan 《Natural Hazards》2016,80(1):367-388

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Integrated geo-microbial and trace metal anomalies for detection of hydrocarbon microseepage in Ahmedabad block of Cambay basin,India     

M. A. Rasheed  P. L. Srinivasa Rao  Annapurna Boruah  Syed Zaheer Hasan  Bougi Mohamoud Mohamed Seddik  Disha Pandey  T. Harinarayana 《Journal of the Geological Society of India》2016,88(4):433-439

The aim of the present work is to define the geo-microbial signatures along with trace metals, and to investigate whether the geo-microbial anomalies have correlation with trace metal anomalies in Ahmedabad block of Cambay basin. The surface geochemical techniques are based on seepage of light hydrocarbon gases from the oil and gas pools to the shallow surface and can bring up near-surface oxidation reduction zones that favor the development of a diverse array of chemical and mineralogical changes. The paper reports the role of hydrocarbon microseepage in surface alterations of trace metal concentrations and hydrocarbon oxidizing bacteria and its interrelationship. For the purpose a total of 90 soil samples are collected in grid pattern of 2 x 2 km interval. The paper reports the chemical alterations associated with trace metals in soils that are related to hydrocarbon microseepages above some of the major oil and gas fields of this petroliferous region. The concentrations of V (0 to149 ppm), Cr (2 to 192 ppm), Cu (4 to 171 ppm), Se (98 to 440 ppm), Zn (56 to 1215 ppm) are obtained. It is observed that the concentrations of trace elements are tremendously increased when they are compared with their normal concentrations in soils. In this study the hydrocarbon oxidizing bacterial counts ranged between 1.0 x 10³ and 1.59 x 10⁶ cfu/g of soil sample respectively. The attempt has made for the first time, which revealed good correlation as both these anomalies are found as apical in relation. Integrated studies between trace elements and hydrocarbon oxidizing bacterial anomalies showed positive correlation with existing oil and gas wells in the study area.  相似文献   

Assessment of backbreak due to blasting operation in open pit mines: a case study     

Ebrahim Ghasemi  Hasan Bakhshandeh Amnieh  Raheb Bagherpour 《Environmental Earth Sciences》2016,75(7):552

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