Petrogenesis of the Az Zabirah south zone bauxite ore deposits,central northern Saudi Arabia     

Al-Mutairi  Abdulaziz N.  Galmed  Mahmoud A.  Aldamegh  Khaled S. 《Arabian Journal of Geosciences》2015,8(4):2327-2339

Arabian Journal of Geosciences - The bauxite ore deposits are mainly found around the Az Zabirah area in the central northern part of Saudi Arabia. The age of the Az Zabirah bauxites was suggested...  相似文献   

Taphonomic and diagenetic aspects of the Late Cretaceous Libycoceras ismaeli (Zittel) from Northern Jordan     

Mahmoud A. Galmed  Mohamed F. Aly  Ahmed Smadi  G. Hassan Abu Azzam 《Arabian Journal of Geosciences》2013,6(2):573-583

Taphonomy and diagenesis of the ammonoid Libycoceras ismaeli (Zittel) have been approached in order to interpret the post-mortem depositional history during the Late Cretaceous of Jordan based on the comparative analysis of composition and taphonomy. The Campanian–Maastrichtian Al-Hisa Phosphorite Formation is exposed in northwestern and central Jordan is rich in cephalopods. It consists of alternating thin-bedded limestone, more or less silicified or calcified phosphorite layers, thick- and cross-bedded oyster lumachells, and lenses and layers of minable phosphate. The sphenodiscid ammonite L. ismaeli (Zittel) predominantly occurs in the middle part of this formation. L. ismaeli is associated with different nautiloid and baculitid species. The mode of occurrence of the studied ammonoids suggesting that they are best interpreted to been nektobenthic, not nektoplanktic. Taphonomic and diagenetic studies of transversely sliced specimens were carried out by means of polarizing and scanning electron microscope.  相似文献   

Mapping Oolitic Iron Ore Deposits in the Ashumaysi Formation,Western Saudi Arabia,Using Different Remote Sensing Techniques Applied to Landsat 7 Enhanced Thematic Mapper Plus Data (ETM+)     

Habes A. Ghrefat  Abdullah A. Al Zahrani  Mahmoud A. Galmed 《Journal of the Indian Society of Remote Sensing》2018,46(9):1399-1411

Mapping the surficial extent of oolitic iron ore deposits hosted in the Oligo–Miocene sedimentary rocks of the Ashumaysi Formation, western Saudi Arabia, was carried out using Landsat 7 Enhanced Thematic Mapper Plus (ETM+) data. Ore samples were collected from four various locations in the study area, and were studied in the laboratory using the GER 3700 Spectroradiometer (0.4–2.5 µm) and X-ray diffraction (XRD). Principal component analysis (PCA), minimum noise fraction (MNF), and minimum distance classification were used and assessed to map mineralization zones in the study area. Good correspondences were observed between the results obtained from the above mentioned techniques, spectral reflectance analyses, and XRD. The confusion matrix results revealed that mapping of iron ores using MNF is better and more accurate than using PCA. Good matching was also observed between the spectral reflectance curves of the collected samples and the corresponding pixels from Landsat 7 ETM+. The results demonstrated the usefulness of the image processing and interpretation of Landsat 7 ETM+ data for the detection and delineation iron ore deposits in arid and semi-arid areas.  相似文献   

Uranium and rare earth elements in Hazm El-Jalamid phosphate,Saudi Arabia: concentrations and geochemical patterns comparison     

Ashraf E. M. Khater  Mahmoud A. Galmed  Mahmoud M. Nasr  Atef El-Taher 《Environmental Earth Sciences》2016,75(18):1261

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