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The character of convergence along the Arabian–Iranian plate boundary changes radically eastward from the Zagros ranges to
the Makran region. This appears to be due to collision of continental crust in the west, in contrast to subduction of oceanic
crust in the east. The Makran subduction zone with a length of about 900 km display progressively older and highly deformed
sedimentary units northward from the coast, together with an increase in elevation of the ranges. North of the Makran ranges
are large subsiding basins, flanked to the north by active volcanoes. Based on 2D seismic reflection data obtained in this
study, the main structural provinces and elements in the Gulf of Oman include: (i) the structural elements on the northeastern
part of the Arabian Plate and, (ii) the Offshore Makran Accretionary Complex. Based on detailed analysis of these data on
the northeastern part of the Arabian Plate five structural provinces and elements—the Musendam High, the Musendam Peneplain,
the Musendam Slope, the Dibba Zone, and the Abyssal Plain have been identified. Further, the Offshore Makran Accretionary
Complex shown is to consist Accretionary Prism and the For-Arc Basin, while the Accretionary Prism has been subdivided into
the Accretionary Wedge and the Accreted/Colored Mélange. Lastly, it is important to note that the Makran subduction zone lacks
the trench. The identification of these structural elements should help in better understanding the seismicity of the Makran
region in general and the subduction zone in particular. The 1945 magnitude 8.1 tsunamigenic earthquake of the Makran and
some other historical events are illustrative of the coastal region’s vulnerability to future tsunami in the area, and such
data should be of value to the developing Indian Ocean Tsunami Warning System. 相似文献
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An integrated geological-petrophysical analysis of the rudist-bearing sequence of the Cretaceous Sarvak Formation is given one giant oilfield, and provides an improved understanding of this main reservoir in the Abadan Plain, in the Zagros Basin, SW Iran. The main objective of this study is to evaluate reservoir potential of the Sarvak Formation, and then to utilize the calibrated well log signature to correlate reservoir potential in un-cored wells. Eight main facies are recognized and categori... 相似文献
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Mohammad Hadi Moeini Amir Etemad-Shahidi Vahid Chegini Iraj Rahmani 《Ocean Dynamics》2012,62(5):785-797
The main goal of this study is to develop an efficient approach for the assimilation of the hindcasted wave parameters in
the Persian Gulf. Hence, the third generation SWAN model was employed for wave modeling forced by the 6-h ECMWF wind data
with a resolution of 0.5°. In situ wave measurements at two stations were utilized to evaluate the assimilation approaches.
It was found that since the model errors are not the same for wave height and period, adaptation of model parameter does not
result in simultaneous and comprehensive improvement of them. Therefore, an approach based on the error prediction and updating
of output variables was employed to modify wave height and period. In this approach, artificial neural networks (ANNs) were
used to estimate the deviations between the simulated and measured wave parameters. The results showed that updating of output
variables leads to significant improvement in a wide range of the predicted wave characteristics. It was revealed that the
best input parameters for error prediction networks are mean wind speed, mean wind direction, wind duration, and the wave
parameters. In addition, combination of the ANN estimated error with numerically modeled wave parameters leads to further
improvement in the predicted wave parameters in contrast to direct estimation of the parameters by ANN. 相似文献
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Ehsan BARZGAR Iraj ABDOLLAHIE FARD Rasoul HAMIDZADEH MOGHADAM Emadoddin ABDOLLAHIE KHALILI Aboozar GARAVAND 《《地质学报》英文版》2015,89(1):105-120
A structural cross-section constructed across the Zagros Fold-Thrust Belt covering the Abadan Plain, Dezful Embayment, and Izeh Zone applied 2D and 3D seismic data, well data, surface and subsurface geological maps, satellite images and field reconnaissance. Besides validation and modification of the cross-section, restoration allows better understanding of the geology, structural style and stratigraphy of the Zagros basin. In the area of interest, the Hormuz basal decollement and the Gachsaran detachment play the most significant roles in the structural style and deformation of the Zagros belt. More complexity is associated with interval decollements such as Triassic evaporites, Albian shales and Eocene marls. A variety of lithotectonic units and detachment surfaces confound any estimation of shortening, which generally decreases with increasing depth. Deformation completely differs in the Abadan Plain, Dezful Embayment and Izeh Zone because of different sedimentation histories and tectonic evolution; gentle and young structures can be interpreted as pre-collisional structures of the Dezful Embayment before the Late Cretaceous. After the Late Cretaceous, the Mountain Front Fault is the main control of sedimentation and deformation in the Zagros Basin, and this completely characterizes fold style and geometry within the Dezful Embayment and the Izeh Zone. 相似文献
7.
Douglas Mackay Charles Paradis Timothy Buscheck Eric Daniels Emily Hathaway Nicholas de Sieyes Ehsan Rasa Radomir Schmidt Juan Peng 《Ground Water Monitoring & Remediation》2018,38(1):26-41
We compare two methods for estimating the natural source zone depletion (NSZD) rate at fuel release sites that occurs by groundwater flow through the source zone due to dissolution and transport of biodegradation products. Dissolution is addressed identically in both methods. The “mass budget method”, previously proposed and applied by others, estimates the petroleum hydrocarbon biodegradation rate based on dissolved electron acceptor delivery and dissolved biodegradation product removal by groundwater flow. The mass budget method relies on assumed stoichiometry for the degradation reactions and differences in concentrations of dissolved species (oxygen, nitrate, sulfate, reduced iron, reduced manganese, nonvolatile dissolved organic carbon, methane) at monitoring locations upgradient and downgradient of the source zone. We illustrate a refinement to account for degradation reactions associated with loss of reduced iron from solution. The “carbon budget method,” a simplification of approaches applied by others, addresses carbon‐containing species in solution or lost from solution (precipitated) and does not require assumptions about stoichiometry or information about electron acceptors. We apply both methods to a fuel release site with unusually detailed monitoring data and discuss applicability to more typical and less thoroughly monitored sites. The methods, as would typically be applied, yield similar results but have different constraints and uncertainties. Overall, we conclude that the carbon budget method has greater practical utility as it is simpler, requires fewer assumptions, accounts for most iron‐reducing reactions, and does not include CO2 that escapes from the saturated to the unsaturated zone. 相似文献
8.
Jannat Forouzandeh Khorasani-Zavareh Davoud Mir-Aghazadeh-Attari Javad Allahbakhshi Kiyoumars Mohebbi Iraj 《Natural Hazards》2020,103(2):1807-1821
Natural Hazards - Organization of volunteer personnel and proper management of these enormous and valuable human resources to make that most of their scientific, experiential, physical, and... 相似文献
9.
Soil is a dynamic natural body and fundamental resource. Human activities influence intensively the natural processes in soils.
They modify and accelerate the development of soils. In this investigation, the deposition of colluvial sediments (colluviation)
and soil formation are proposed as geoindicators for a better understanding of long-term environmental changes and environmental
impact assessment. Deposition of colluvial sediments during several time periods and subsequent soil formation under different
land-use systems reflect important aspects on the long-term human interference in the environment. In this study, we hypothesize
that intensive human activities and environmental changes during middle and late Holocene are responsible for a strong modification
of soils in an investigation area in Schleswig–Holstein (Germany). Soil age information together with geomorphological data,
physical, chemical and biological soil properties provide the database which is necessary to study the types and rates of
colluviation and soil formation. After the investigation with a high resolution in time and space, results show that middle
and late Holocene land-use changes and land management are responsible for soil formation in colluvial layers. Properties
of soils and sediments vary intensively from Mesolithic until Modern times. Intensive soil formation took place during periods
of geomorphodynamic stability in dense woodland. Evidence in our investigations shows that colluviation has a strong relation
with decision-making and environmental degradation in the past. This confirms, too, that a geoindicator concept is needed
to understand and to monitor long-term environmental changes and degradation. 相似文献
10.
Conservative tracer experiments can provide information useful for characterizing various subsurface transport properties. This study examines the effectiveness of three different types of transport observations for sensitivity analysis and parameter estimation of a three-dimensional site-specific groundwater flow and transport model: conservative tracer breakthrough curves (BTCs), first temporal moments of BTCs (m 1), and tracer cumulative mass discharge (M d) through control planes combined with hydraulic head observations (h). High-resolution data obtained from a 410-day controlled field experiment at Vandenberg Air Force Base, California (USA), have been used. In this experiment, bromide was injected to create two adjacent plumes monitored at six different transects (perpendicular to groundwater flow) with a total of 162 monitoring wells. A total of 133 different observations of transient hydraulic head, 1,158 of BTC concentration, 23 of first moment, and 36 of mass discharge were used for sensitivity analysis and parameter estimation of nine flow and transport parameters. The importance of each group of transport observations in estimating these parameters was evaluated using sensitivity analysis, and five out of nine parameters were calibrated against these data. Results showed the advantages of using temporal moment of conservative tracer BTCs and mass discharge as observations for inverse modeling. 相似文献