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151.
Muhammad Rustam Khan Shahid Saleem Bilali Fahad Hameed Awais Rabnawaz Sohail Mustafa Naveed Azad Muhammad Basharat Abrar Niaz 《Arabian Journal of Geosciences》2018,11(6):131
The present geophysical study deals with the ores and crustal demonstration of southeastern Hazara and its adjoining areas of Azad Jammu and Kashmir, Pakistan, on the basis of terrestrial gravity and magnetic data. Tectonically, the study area lies in the Lesser Himalayas as well as to an extent in the sub-Himalaya, more specifically in the western limb of Hazara Kashmir Syntaxis. In this study, 567 gravity and 508 magnetic stations have been measured with CG-5 gravimeter and proton precession magnetometer, respectively. The collected data have been processed by applying standard corrections and then different types of maps were prepared. The ores in the area have been delineated by the qualitative interpretation of residual Bouguer anomaly and reduction to pole total magnetic intensity maps, whereas regional structures are demarcated by the Bouguer anomaly and regional Bouguer anomaly maps. The positive contour closures on the residual Bouguer anomaly map indicate the iron ore and phosphate, whereas negative contour closures are the effects of low-density material which consists of gypsum and soapstone. The pole-reduced total intensity map also shows the negative and positive contour closures almost in the same localities and confirms the residual Bouguer anomaly map. The geological model computed on the basis of Bouguer anomaly demarcated a series of faults between different rock units in the study area. The Kashmir Boundary Thrust cuts the western limb of Hazara Kashmir Syntaxis near the apex in the north of Muzaffarabad and marks the boundary between Murree Formation and carbonates of Abbottabad Formation. The gravity model also suggests that the thickness of the crust increases towards the northeast. 相似文献
152.
Natural Hazards - Slope stability is one of the most important issues of geotechnical engineering. Significant slope failures (landslides), which result from earthquakes, can cause considerable... 相似文献
153.
Natural Hazards - An earthquake of magnitude 6.9 hit the city of Izmir (Turkey) on 30 October 2020, resulting in 117 deaths (in Turkey) and considerable economic losses. The earthquake also... 相似文献
154.
Mustafa Kuscu Oya Cengiz Asuman Kahya 《Journal of the Geological Society of India》2018,91(4):496-504
The sediment-hosted huntite-magnesite deposits are located in the Egirdir-Hoyran lake basin in the Isparta Angle (southern Turkey). The deposits occur at two different localities in the region: (1) Kemersirti huntite deposit, (2) Köytepe huntite-magnesite deposit. The huntite-magnesite occurrences are found in shallow lacustrine rocks of the Miocene-Pliocene Kizilcik Formation and formed as a result of Neogene tectonic activity. Based on X-ray diffraction and scanning electron microscopic studies, the mineral assemblage of huntite deposits contains mostly huntite, less magnesite, dolomite, very little calcite, illite, simectite, brucite, and quartz in the Kemersirti area but contain huntite, magnesite, dolomite, and calcite in the Köytepe area.In the huntite and magnesite-bearing huntite samples, MgO varies from 32.70 to 37.95 wt. %, CaO from 7.83 to 15.10 w.t. %, and SiO2 from 0.99 to 10.60 w.t. %. Ba and Sr are dominant minor elements in the deposits. Ba and Sr for huntite and magnesite bearing huntite in the study area vary from 11 to 233 ppm and from 325 to 765 ppm, respectively. As, U, Zr, V and Ce contents ranged from 11.5-146 ppm, 0.5-3.7 ppm, 1.4-13.2 ppm, 7-34 ppm, and 0.9-2.7 ppm respectively. The huntite-magnesite is characterized by relatively lower Ni (0.5-2.4 ppm) and Co (0.5-1.1 ppm) contents. The huntite and magnesite-bearing huntite occurrences have higher Ba, Sr, As, Zr, V, and U contents than those of the other elements. The d13C isotope values vary between 7.8‰ to 8.8‰ PDB for huntite+magnesite, 8.2‰ PDB for huntite, 1.4‰ PDB for magnesite+dolomite, and 4.0‰ PDB for limestone from deposits in the study area. The δ18O isotope values of the huntite deposits ranged from 30.4 to 35.5‰ SMOW for huntite+magnesite, 32.4‰ SMOW for huntite, 29.8‰ SMOW for magnesite+ dolomite, and 26.9‰ SMOW for limestone.The presence of nodular huntite and the abundance of gastropod, ostracoda and Chura shells in the carbonate units indicate that the huntite occurrences are precipitated at shallow, alkaline (8.5-9.5 pH) and lower temperature (approximately 25°C) lake conditions. The Mg++, Ca++ and Si++ ions for the huntite formation were derived from the surrounding rocks such as ultrabasic rocks, dolomite, dolomitic limestone, and limestone in the Egirdir-Hoyran lake basin. Also, the C isotope ratios indicate that the CO2 source for the huntite formations results to sedimentary basin from metamorphic CO2, carbonate rocks, fresh water carbonates, and ground water. The source of oxygen for the huntite formation may come from marine limestone, fresh water carbonates and meteoric water. 相似文献
155.
156.
An empirical attenuation relationship for Northwestern Turkey ground motion using a random effects approach 总被引:2,自引:0,他引:2
Cem
zbey Ali Sari Lance Manuel Mustafa Erdik Yasin Fahjan 《Soil Dynamics and Earthquake Engineering》2004,24(2):115-125
Using a random effects model that takes into consideration the correlation of data recorded by a single seismic event, a database consisting of 195 recordings from 17 recent events is employed to develop empirical attenuation relationships for the geometric mean of horizontal peak ground acceleration and 5-percent damped spectral acceleration (Sa). The recordings employed are obtained from strong motion stations operating in Northwestern Turkey and resulted from events that include the Kocaeli (Mw=7.4) and the Düzce (Mw=7.1) earthquakes and their aftershocks as well as other events. By studying differences in standard errors, the random effects model is compared with a fixed effects model that does not account for distinctions between intra- and inter-event variability. Effects of local site conditions are included in the empirical relationships developed. The dependence on frequency of the various model parameters is also studied. Frequency-dependent attenuation coefficients for the proposed random effects models developed are summarized in tables to facilitate their use. 相似文献
157.
Paleostress analysis of the Cretaceous rocks in the eastern margin of the Dead Sea transform, Jordan
Abdullah A. Diabat Mohammad Atallah Mustafa R. Salih 《Journal of African Earth Sciences》2004,38(5):155
This paper presents the first paleostress results from fault-slip data on Cretaceous limestone at the eastern rim of the Dead Sea transform (DST) in Jordan. Stress inversion of fault-slip data is performed using an improved right dieder method, followed by rotational optimization (Delvaux, TENSOR Program). The orientation of the principal stress axes (σ1, σ2 and σ3) and the ratio of the principal stress differences (
) show two main paleostress fields marking two main stress regimes, strike-slip and extensional. The first is characterized by NNW–SSE compression and ENE–WSW extension and related to Middle Miocene-Recent sinistral movement along the Dead Sea transform and the opening of the Red Sea. The second paleostress field is a WNW–ESE compression and NNE–SSW extension restricted to the northern part of the investigated area. This stress field could be associated with the development of the Syrian Arc fold belt which started during the Turonian, or it may be due to an anticlockwise rotation of the first stress field. 相似文献
158.
Mustafa Ergin eref Keskin A. Umran Doan Yusuf Kaan Kadolu Zehra Karaka 《Marine Geology》2007,240(1-4):185-196
Backshore sediment samples from 22 beaches along the Antalya and Finike Gulfs have been studied for their grain size, chemical and heavy mineral composition. Data presented here suggest that well- to moderately-sorted (0.41 Φ–0.92 Φ) medium sand (1 Φ–2 Φ) represents dominant mean grain size in most beaches. In contrast, some beaches from the western part of the Gulf of Antalya (Göynük, Kemer-Kiriş and Beldibi) are composed of pebble- to boulder-size grained beaches which are located close to mouths of short and steep-gradient ephemeral rivers entering the sea from the Western Taurus Mountains. The heavy mineral assemblages are dominated by detrital opaque minerals (14–58% magnetite, chromite, and hematite), pyroxene (8–65% augite), amphibole (3–15% tremolite and actinolite), epidote (3–25%), garnet (2–9% pyrope and almandine) and micas (3–20 biotite, muscovite and chlorite). The very high concentrations of heavy minerals (up to 86% of bulk sediment) together with the significant concentrations of some elements found in beach sediments from the Gulf of Finike and western Gulf of Antalya (Fe: 18.40%; Cr: 10.00%; and Ti: 1.32%) are indicative of ultramafic origin, mainly derived from the ophiolitic rocks of the Antalya–Tekirova nappe on coastal hinterland. 相似文献
159.
Fusun Balik Sanli Saygin Abdikan Mustafa Tolga Esetlili Filiz Sunar 《Journal of the Indian Society of Remote Sensing》2017,45(4):591-601
This research aimed to explore the fusion of multispectral optical SPOT data with microwave L-band ALOS PALSAR and C-band RADARSAT-1 data for a detailed land use/cover mapping to find out the individual contributions of different wavelengths. Many fusion approaches have been implemented and analyzed for various applications using different remote sensing images. However, the fusion methods have conflict in the context of land use/cover (LULC) mapping using optical and synthetic aperture radar (SAR) images together. In this research two SAR images ALOS PALSAR and RADARSAT-1 were fused with SPOT data. Although, both SAR data were gathered in same polarization, and had same ground resolution, they differ in wavelengths. As different data fusion methods, intensity hue saturation (IHS), principal component analysis, discrete wavelet transformation, high pass frequency (HPF), and Ehlers, were performed and compared. For the quality analyses, visual interpretation was applied as a qualitative analysis, and spectral quality metrics of the fused images, such as correlation coefficient (CC) and universal image quality index (UIQI) were applied as a quantitative analysis. Furthermore, multispectral SPOT image and SAR fused images were classified with Maximum Likelihood Classification (MLC) method for the evaluation of their efficiencies. Ehlers gave the best score in the quality analysis and for the accuracy of LULC on LULC mapping of PALSAR and RADARSAT images. The results showed that the HPF method is in the second place with an increased thematic mapping accuracy. IHS had the worse results in all analyses. Overall, it is indicated that Ehlers method is a powerful technique to improve the LULC classification. 相似文献
160.
Hayrettin Acar Fevzi Karsli Mustafa Dihkan 《Journal of the Indian Society of Remote Sensing》2017,45(2):209-216
Image matching has been widely used in various fields such as digital photogrammetry, remote sensing, image processing and computer vision. In this study, the speeded up robust feature extraction algorithm for automatic point extraction was applied to a pair of high resolution digital aerial stereo images. In contrast to other studies, the universal transverse mercator coordinates of randomly selected test points were computed automatically with the proposed approach and compared with the same points that were manually measured. As a result, the mean square differences for the UTM coordinates’ in the X, Y and Z axes were calculated as ±0.043, 0.030 and 0.153 m, respectively. It is proved that the proposed algorithm is successful in matching remotely sensed high-resolution images acquired with digital cameras. Moreover, the automatization of the basic tasks in image matching and the 3D coordinate acquisition were also achieved by the algorithm. 相似文献