Discovery of antler from a new site in the Pinjor Formation (Pleistocene) of Pakistan     

Abdul Ghaffar  Muhammad Akhtar  Muhammad Akbar Khan  Abdul Majid Khan  Khizar Samiullah  Mehboob Iqbal 《Journal of the Geological Society of India》2012,80(1):119-122

Partially complete right antler from the Pinjor Formation (Pleistocene) of the Upper Siwalik Subgroup is identified, described and its phylogenetic relationship is discussed. The fossil antler is compared with other known fossil records of family Cervidae as well as with the extant species, on the basis of which it can be attributed to Axis punjabiensis. This species has not been reported previously from this fossil site.  相似文献   

Assessment of flood hazard,vulnerability and risk of mid-eastern Dhaka using DEM and 1D hydrodynamic model   总被引：1，自引：0，他引：1  

Masood  Muhammad  Takeuchi  Kuniyoshi 《Natural Hazards》2012,61(2):757-770

Floods are regular feature in rapidly urbanizing Dhaka, the capital city of Bangladesh. It is observed that about 60% of the eastern Dhaka regularly goes under water every year in monsoon due to lack of flood protection. Experience gathered from past devastating floods shows that, besides structural approach, non-structural approach such as flood hazard map and risk map is effective tools for reducing flood damages. In this paper, assessment of flood hazard by developing a flood hazard map for mid-eastern Dhaka (37.16 km²) was carried out by 1D hydrodynamic simulation on the basis of digital elevation model (DEM) data from Shuttle Radar Topography Mission and the hydrologic field-observed data for 32 years (1972–2004). As the topography of the area has been considerably changed due to rapid land-filling by land developers which was observed in recent satellite image (DigitalGlobe image; Date of imagery: 7th March 2007), the acquired DEM data were modified to represent the current topography. The inundation simulation was conducted using hydrodynamic program HEC-RAS for flood of 100-year return period. The simulation has revealed that the maximum depth is 7.55 m at the southeastern part of that area and affected area is more than 50%. A flood hazard map was prepared according to the simulation result using the software ArcGIS. Finally, to assess the flood risk of that area, a risk map was prepared where risk was defined as the product of hazard (i.e., depth of inundation) and vulnerability (i.e., the exposure of people or assets to flood). These two maps should be helpful in raising awareness of inhabitants and in assigning priority for land development and for emergency preparedness including aid and relief operations in high-risk areas in the future.  相似文献   

Collinear Equilibrium Solutions of Four-body Problem     

Muhammad Shoaib  Ibrahima Faye 《Journal of Astrophysics and Astronomy》2011,32(3):411-423

We discuss the equilibrium solutions of four different types of collinear four-body problems having two pairs of equal masses. Two of these four-body models are symmetric about the center-of-mass while the other two are non-symmetric. We define two mass ratios as μ ₁ = m ₁/M _T and μ ₂ = m ₂/M _T, where m ₁ and m ₂ are the two unequal masses and M _T is the total mass of the system. We discuss the existence of continuous family of equilibrium solutions for all the four types of four-body problems.  相似文献   

Instabilities in a nonstationary model of self-gravitating disks. III. The phenomenon of lopsidedness and a comparison of perturbation modes     

K. T. Mirtadjieva  S. N. Nuritdinov  J. K. Ruzibaev  Muhammad Khalid 《Astrophysics》2011,54(2):184-202

This is an examination of the gravitational instability of the major large-scale perturbation modes for a fixed value of the azimuthal wave number m = 1 in nonlinearly nonstationary disk models with isotropic and anisotropic velocity diagrams for the purpose of explaining the displacement of the nucleus away from the geometric center (lopsidedness) in spiral galaxies. Nonstationary analogs of the dispersion relations for these perturbation modes are obtained. Critical diagrams of the initial virial ratio are constructed from the rotation parameters for the models in each case. A comparative analysis is made of the instability growth rates for the major horizontal perturbation modes in terms of two models, and it is found that, on the average, the instability growth rate for the m = 1 mode with a radial wave number N = 3 almost always has a clear advantage relative to the other modes. An analysis of these results shows that if the initial total kinetic energy in an isotropic model is no more than 12.4% of the initial potential energy, then, regardless of the value of the rotation parameter Ω, an instability of the radial motions always occurs and causes the nucleus to shift away from the geometrical center. This instability is aperiodic when Ω = 0 and is oscillatory when Ω ≠ 0 . For the anisotropic model, this kind of structure involving the nucleus develops when the initial total kinetic energy in the model is no more than 30.6% of the initial potential energy.  相似文献   

Cervid remains from the middle Siwaliks of Hasnot (Late Miocene), Pakistan     

Muhammad Akbar Khan  Muhammad Akhtar  George Iliopoulos 《Journal of the Geological Society of India》2014,84(3):352-360

The late Miocene-early Pliocene fossil deposits of Hasnot in northern Pakistan have yielded a very rich vertebrate fauna. In this paper we describe the remains of Cervidae from six of these localities. By dental remains, at least four species of cervids are documented. These remains significantly widen the time distribution of the cervids and draw back the first appearance of cervids in the Dhok Pathan Formation of the Siwaliks. The data indicate a diverse set of coexisting ungulates in the area, subsisting within a mosaic of habitats.  相似文献   

Effect of soil hydraulic properties model on slope stability analysis based on strength reduction method   总被引：2，自引：0，他引：2  

Muhammad Mukhlisin  Marlin Ramadhan Baidillah  Aniza Ibrahim  Mohd. Raihan Taha 《Journal of the Geological Society of India》2014,83(5):586-594

Soil hydraulic properties models which have been proposed were derived based on the empirical fitting curve such as Brooks-Corey model (BC) and Van Genuchten model (VG), or based on soil pore radius distribution such as Lognormal model (LN). Each model has different accuracy for predicting soil moisture distribution. In the analysis of rainfall-induced slope failure, the soil hydraulic properties model was needed to describe the physical phenomena of behavior characteristic of water in unsaturated soil. As moisture content has an effect on soil strength, it is vital to select the suitable soil hydraulic properties model for predicting Factor of Safety (FOS) especially in forecasting landslide hazard. In this study, a numerical model of seepage finite element analysis using BC, VG, and LN model were used and compared in order to analyze the soil moisture distribution, water movement phenomenon, and slope stability characteristic in unsaturated soil slope based on the strength reduction method (SRM). The results showed that the variations of the parameters predicting the moisture content of soil leads to differences of FOS in some cases. The parametric study showed that for the unsaturated soil condition, BC model has the greatest FOS value than the other model, while VG model has the lowest. On the other hand, the FOS of all models have the same result for the saturated condition. Other than that, it was found that the increasing of ESP value in the surface layer has significant effect in the sub-surface layer.  相似文献   

Determinants of farmers’ choice of coping and adaptation measures to the drought hazard in northwest Balochistan,Pakistan   总被引：2，自引：0，他引：2  

Muhammad Ashraf  Jayant K. Routray  Muhammad Saeed 《Natural Hazards》2014,73(3):1451-1473

This study identifies the coping and adaptation behavior of the farm households and also examines the factors that influence farmers’ choice for drought-induced adaptation strategies. The study employs a multivariate probit model on 215 farm households’ survey data from northwest Balochistan, Pakistan. The findings reveal that the farmers have shown considerable fortitude in coping with the impacts of drought on their agro-based practices and employed several adaptation initiatives both at on-farm and off-farm levels. These include crop management, water management, adjustment in agricultural inputs, income diversification, economization of expenditure and consumption smoothing, migrating to other places to seek alternative sources of income, assets depletion, and borrowing. Empirically, it is depicted that landholding, annual income, livestock ownership, credit access, farmer-to-farmer extension, GOs/NGOs support increase the probability of farmers’ decision to cope and adapt better with drought hazard. This study implies for specific policy and practice-oriented solutions in order to cope with and adapt in drought situation.  相似文献   

Facies analysis and geochemistry of the Euphrates Formation in Central Iraq     

Moutaz A. Al-Dabbas  Salih Muhammad Awadh  Ayad Abed Zaid 《Arabian Journal of Geosciences》2014,7(5):1799-1810

The Euphrates Formation (Lower Miocene) in the Central Iraq consists mainly of shallow marine carbonates. Two hundred ten samples were collected from 21 wells (1E to 21ED) at Bahar Najaf area, and 18 samples were collected at Wadi Asadi in Baghdadi area, from Euphrates Formation. Four microfacies are identified, namely mudstone, wackestone, packstone, and rare grainstone with ten submicrofacies. The allochems in the Euphrates Formation are dominated by bioclasts. Peloids, ooids, and intraclasts are less abundant. The common fossils in the Euphrates Formation are miliolids, algae, ostracods, Miogypsina, and abundant shells of pelecypods and gastropods. Calcite and dolomite are the predominant mineral components of the Euphrates Formation. The carbonates of the Euphrates Formation have been affected by a variety of diagenetic processes such as micritization, dissolution, neomorphism, cementation, stylolitization, dolomitization, dedolomitization, and silicification. The Euphrates Formation was deposited in open to restricted platforms which indicated lagoonal environment with warm and restricted open circulation. In fact, prevalence and abundance of micrite provide an evidence of a shallow marine of low-energy environment and, in some places, may be approaching to be stagnant environment. The average of CaO in Najaf area (51.5 %) is slightly lower than that in Baghdadi area (53.3 %), which was reflected in calcite content found being 91 % in Najaf and 94 % in Baghdadi. Dolomite and gypsum appeared as minor minerals beside calcite, so low concentration of MgO (0.83 % in Najaf; 0.63 in Baghdadi) and SO₃ (0.55 % in Najaf; 0.53 % in Baghdadi) was reflected information of small amounts of dolomite (2 % in Najaf; 1.6 % in Baghdadi) and gypsum (0.7 % in Najaf and 0.6 in Baghdadi) in the Euphrates Formation. The insoluble residue in Najaf area (4.37 %) is relatively higher than that in Baghdadi area (1.9 %), indicating that the Euphrates Formation in Najaf Area has deposited in an environment closer to the shoreline. Concentrations of the trace elements Sr, Mn, and Fe which support the conclusion that reminds the Euphrates Formation had been deposited in a shallow marine environment of quiet energy, with the likelihood that the shoreline was the nearest to Najaf rather than to Baghdadi.  相似文献   

The inner ramp facies of the Thanetian Lockhart Formation,western Salt Range,Indus Basin,Pakistan   总被引：1，自引：1，他引：0  

Muhammad Hanif  Muhammad Imraz  Fahad Ali  Muhammad Haneef  Abdus Saboor  Shahid Iqbal  Sajjad Ahmad Jr 《Arabian Journal of Geosciences》2014,7(11):4911-4926

The Lockhart Formation from a major carbonate unit of the Paleocene Charrat Group in Upper Indus Basin, Pakistan represents a larger foraminiferal–algal build up deposited in a cyclic sequence of the carbonate ramp. The foraminiferal–algal assemblages of the Lockhart Formation are correlated here to larger foraminiferal biostratigraphic zone, i.e. Shallow Benthic Zone (SBZ3) of the Thanetian Age. Inner ramp lagoon, shoal and fore shoal open marine are three main facies associations represented by wackstone and packstone foraminiferal–algal deposits. These facies are present in a cyclic order and displayed a retrograding carbonate ramp indicating the Thanetian transgressive deposits associated with eustatic sea level rise. The correlation of the microfacies of the Lockhart Formation (Upper Indus Basin) and facies of the Dungan Formation (Lower Indus Basin) provide detailed configuration of the depositional setting of the Indus Basin during the time interval represented by the Thanetian Zone SBZ3.  相似文献   

Origin of Quartz Cement in the Paleogene Sandstone Reservoir of Shahejie Formation, Bohai Bay Basin, China     

Muhammad KASHIF  CAO Yingchang  Nizam Ud DIN  Uzair SIDDIQUE  XI Kelai  Faisal REHMAN  Noor AHMED  GU Xihao  Mohammad Saleh GAGHMAN 《《地质学报》英文版》2022,96(1):248-260

The precipitation of authigenic quartz plays a significant role to reduce the reservoir characteristics and enhance the stiffness of the rock.The Es₁ sandstone of Shahejie Formation is acting as a significant hydrocarbon producing rock in the Nanpu Sag.Various methods like thin section petrography,cathodoluminescence(CL),scanning electron microscope(SEM,with EDS),and electron microprobe analysis has been used to reveal the origin of quartz cement as well as to evaluate the effect of quartz cement on reservoir quality.The studied sandstone is classified as immature to mature feldspathic litharenite and lithic arkose and consists of quartz,feldspar,rock fragments and micas.Petrographic studies and SEM analysis shows that the authigenic quartz is acting a significant cement that reduces the reservoir quality.Whereas clay minerals(kaolinite and mixed layer illite to smectite)are dominant in the Es₁ sandstone,that can reduce the reservoir quality.SEM,CL and thin section analysis reveal that there are two stages of quartz cement in the studied samples;that are pore filling authigenic cement and quartz overgrowth cement.Fluid inclusion homogenization temperatures shows that stages of quartz cement were developed with continuous process from 70℃ to 130℃.Quartz cements were generally originated from I/S reaction,feldspar dissolution,conversion of rock fragments and pressure solution.Feldspar dissolution(K-feldspar)and kaolinite to illite reaction is an insignificant silica source for the silica cement which is internally precipitated in a close system with diffusion transporting mechanism.Overall,quartz cement significantly enhance the rock strengthen and brittleness effectively as well as it reduce the overall reservoir quality.  相似文献