Inorganic geochemical evidence for the depositional facies associations of the Upper Jurassic Chia Gara Formation in NE Iraq     

Ibrahim M. J. Mohialdeen  Sardar M. Raza 《Arabian Journal of Geosciences》2013,6(12):4755-4770

Four wells (K-109, Hr-1, Tk-3, and Bj-1) in NE Iraq (including parts of the Kurdistan Region) were selected to study the Tithonian–Berriasian Chia Gara Formation from the inorganic geochemical point of view. The intervals studied in each well occurred at present-day burial depths of Hr-1 3,075–3,310 m; K-109 2,780–3,090; Tk-1 2,770–2,890; and Bj-1 2,150–2,310 m. A total of 16 samples from the four studied wells were investigated geochemically using X-ray fluorescence in order to measure their major element oxides and their trace element contents. Among the major oxides, CaO has the highest weight percentages in all samples as expected in this limestone-dominated formation. SiO₂ and Al₂O₃ show higher concentrations only in well Bj-1 than the other sections, due to its shallower depth of deposition and its marginal location within the depositional basin. The general trace element distribution along all studied well successions showed good similarity. However, the ratios of V/Ni and V/Cr were of higher values in the lower part of the formation, which is considered as a good indicator to the deposition of this part of the formation within anoxic depositional environment. An exception was in well Bj-1, where the V/Ni ratio was lower in the this lower part of the formation than the upper part that may be due to the different lithology in this succession which is lacking distinct shale or calcareous shale beds. However, the V/Cr ratio can still indicate the prevailing of reducing condition because V/Cr ratios in all samples are >2. Also, Th/U ratio in the lower part of the studied successions was lower than the upper part, which is also coinciding with the domination of the reducing geochemical conditions in the depositional environment. It may be concluded from this study that the R-mode cluster analysis of the main oxides indicated to the main mineral constituent of the rock which is calcite. It is also confirmed that the SiO₂ and Al₂O₃ contents in the Chia Gara limestones are especially high in well Bj-1, particularly in the lower and upper parts of the succession. On the other hand, R-mode cluster analysis of the trace elements showed lower amounts of Zr and V in relation to silica and confirmed the random distribution of Sr and Ba in the studied samples. Q-mode cluster analysis indicated that the upper part of the studied formation is pure limestone in well H-1 and such purity of limestone beds also occurs in the lower part of the studied formation in well Tk-3. The elemental distribution within the sections as inferred from the studied samples indicates that the anoxic depositional conditions were prevailed during the Chia Gara Formation, especially during the accumulation of the lower part.  相似文献   

Groundwater resources assessment using integrated geophysical techniques in the southwestern region of Peninsular Malaysia   总被引：2，自引：0，他引：2  

Mohamed S. E. Juanah  Shaharin Ibrahim  Wan Nor Azmin Sulaiman  Puziah Abdul Latif 《Arabian Journal of Geosciences》2013,6(11):4129-4144

Combined geophysical techniques such as multi-electrode resistivity, induced polarization, and borehole geophysical techniques were carried out on volcano-sedimentary rocks in the north of Gemas as part of the groundwater resource’s investigations. The result identifies four resistivity units: the tuffaceous mudstone, tuffaceous sandstone, the tuff bed, and the shale layer. Two types of aquifer systems in terms of storage were identified within the area: one within a fracture system (tuff), which is the leaky area through which vertical flow of groundwater occurs, and an intergranular property of the sandy material of the aquifer which includes sandstone and tuffaceous sandstone. The result also reveals that the aquifer occupies a surface area of about 3,250,555 m² with a mean depth of 43.71 m and a net volume of 9.798?×?10⁷?m³. From the approximate volume of the porous zone (28 %) and the total aquifer volume, a usable capacity of (274.339?±?30.177)?×?10⁷?m³ of water in the study area can be deduced. This study provides useful information that can be used to develop a much broader understanding of the nature of groundwater potential in the area and their relationship with the local geology.  相似文献   

Stratigraphic architecture of the fluvio-lacustrine deposits, Bathan Formation, Al-Rehaili area, North Jeddah, Saudi Arabia     

Ibrahim M. Ghandour  Hamad A. Al-Washmi 《Arabian Journal of Geosciences》2013,6(4):995-1010

A siliciclastic-dominated succession (～11 m thick) underlying Harrat Rahat, belonging to the Miocene–Pliocene Bathan Formation is recently exposed at Al-Rehaili area, North Jeddah, Saudi Arabia. It covers a wide spectrum of grain sizes varying from clay-rich mudstones to cobble grade conglomerate and consists of a variety of facies vary from fluvial to marginal and open lacustrine deposited in a half-graben basin formed along the eastern margin of the extensional Red Sea Basin. Field-based sedimentologic investigation enables to identify ten facies grouped into three facies associations (A–C). The depositional history is subdivided into two stages. The first stage represents deposition in gravel to sand-dominated fluvial system sourced from a southern source and grade northward into lacustrine delta and open lacustrine setting. The second stage on the other hand includes deposition of fluvial channels running in E–W direction with attached bank sand bar. Sequence stratigraphic interpretations of the lacustrine deposits enable to identify three unconformity-bounded sequences (SQ_1–3). The basal sequence is incomplete, consisting of three aggradationally to progradationally stacked delta plain and delta front parasequences. The second sequence is sharply and erosively overlying a red paleosol bed that defines the upper boundary of the first sequence. It includes two system tracts; upward-fining and deepening lacustrine offshore mudstones of the transgressive system tracts unconformably overlain by red paleosol of the regressive systems tracts. The top of this sequence is delineated at the sharp transgressive surface of erosion at the base of delta mouth bar deposits of sequence 3. Changes in the accommodation and sedimentation rates by basin subsidence under the influence of tectonics and sediment compaction and loading as well as climatic oscillation between semi-arid to arid conditions were the major controls on the fluvio-lacustrine sedimentation and their facies distribution. Tectonic reorganization of the drainage system resulted in the formation of E–W flowing fluvial streams in the second stage.  相似文献   

Organisation hydrochimique,biologique et sédimentologique d’un lac intracontinental à peuplements lagunaires : la Birket Karoun (Fayoum,Egypte)     

Jean-Pierre Perthuisot  Olivier Guelorget  Ahmed Wahid et Sayed Ibrahim  Jean-Pierre Margerel  André Maurin  Maryvonne Piron-Frenet 《Geodinamica Acta》2013,26(2):73-89

Résumé

La Birket Karoun a été étudiée d’un point de vue biogéologique sur une période de 12 mois. Les données ainsi obtenues, ajoutées à celles de la littérature disponible, permettent de présenter les caractéristiques biogéologiques essentielles de ce bassin original.

Le lac n’est alimenté actuellement que par des eaux continentales issues du système nilotique ce qui entraîne des propriétés hydrochimiques assez différentes des corps d’eau paraliques influencés par la mer. Cependant, les caractéristiques hydrologiques, biologiques et sédimen-taires de la Birket Karoun la classent parmi les écosystèmes de type lagunaire. Il est même possible d’y reconnaître une organisation biogéologique zonale très semblable à celle des lagunes, la partie la plus « marine » (ou la moins confinée) se situant à l’opposé de la zone des apports d’eau douce. Une connexion entre le lac et la mer, actuelle ou passée, étant à peu près exclues, il faut admettre que les eaux continentales concentrées peuvent présenter, dans certains cas, des caractéristiques chimiques et biochimiques presque marines vis-à-vis des êtres vivants.

Dans cette optique, la Birket Karoun apparaît comme un modèle actuel susceptible de fournir une alternative à l’hypothèse d’une « Mer Saharienne » pour rendre compte de l’existence des lacs sahariens pleistocènes à faunes fossiles lagunaires.  相似文献   

Experimental Study Optimizing Hole Cleaning-Cuttings Transport in Oil Drilling Engineering     

IbrahimAA MusaTA 《中国地质大学学报(英文版)》2003,14(2):182-189

With a clear understanding of the drilling fluid techniques and the cutting-taking mechanism, a new advanced model is set up for analyzing field data and quantitative forecast of cutting-taking mechanism. Therefore, a number of values affecting the drilling rate and the hole cleaning are studied over a wide range of parameters. Drilling data obtained under high-borehole-pressure conditions are analyzed to determine the causes of the reduction in rate of penetration (ROP) as the borehole pressure increases, which in some cases is caused by the buildup of rock debris under the bit. The theoretical achievement and testing conclusions can be very instructional for horizontal well drilling. Much higher annular velocities are required for effective hole cleaning in directional wells than in vertical wells. Highviscosity muds are observed to provide better transport than low-viscosity muds.  相似文献   

The Ar Rayn Terrane: Geotectonic Implications of Unique Metallogeny in the Arabian Shield     

Jeff L. Doebrich  Timothy S. Hayes  Alim A. Siddiqui  Yasin Saleh  Peter R. Johnson  Fayek H. Kattan  Craig H. Mackay  Bandar Shaikan  Mabrouk Basahal  Hani Zahran 《Gondwana Research》2001,4(2)

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New variations of Mg II emission lines of Mira AB with HST     

M.R. Sanad  Alhassan I. Ibrahim 《New Astronomy》2009,14(1):65-70

This paper presents results from high resolution observations of the Mira AB binary system taken by the HST (Hubble Space Telescope) in the ultraviolet region through the period (1999–2004). By comparing the results using HST data with those obtained from the IUE (International Ultraviolet Explorer) observations through the period (1979–1995). we found new variations in the profiles, widths and fluxes of Mg II (k&h) emission lines. In addition to this it appears that there are another emission components at some phases in the red and blue sides of both Mg II (k&h) emission lines. These emission components may be of Mira A origin. There is a considerable shift of both Mg II (k&h) emission lines in observation taken on 2nd February 2004. The Mg II profiles extends up to more than 600 km/s, and redshifted as with IUE observations.  相似文献   

Separation of Vanillin from Oil Palm Empty Fruit Bunch Lignin     

Mohamad Nasir Mohamad Ibrahim  Mohamad Yusof Nor Nadiah  Mohd Salleh Norliyana  Coswald Stephen Sipaut  Sollehuddin Shuib 《洁净——土壤、空气、水》2008,36(3):287-291

The separation of vanillin from the lignin of empty fruit bunch oil palm is presented in this study. The lignin was extracted from soda black liquor derived from oil palm empty fruit bunches (EFB) using 20% sulfuric acid. Nitrobenzene oxidation was carried out by adding 50 mg of dry EFB lignin into a mixture of 7 mL of 2 M NaOH and 4 mL of nitrobenzene in a 15 mL steel autoclave. The autoclave was sealed tightly with a screw cap fitted with a Teflon gasket and heated to 165°C for 3 h in a preheated thermostatic oil bath. High performance liquid chromatography (HPLC) was used to determine the concentration of each compound present in the lignin. There were eight compounds detected in the HPLC chromatogram. The crystallization process was then used as a method to separate vanillin from other compounds. Based on the solubility of vanillin in acetone, 15 mL of acetone was added to the residue of the oxidized products and heated to 60°C for 10 min. A yield of 1.6% vanillin was isolated from a 50 mg lignin sample. The isolated compound was analyzed with HPLC, Fourier transform infrared spectrophotometry (FT‐IR) and nuclear magnetic resonance (¹³C‐NMR) for structural verification. The results of the characterization studies proved that the isolated compound is vanillin.  相似文献   

Epi- and endobiont faunal communities on an Egyptian Mediterranean rocky shore: species composition and their competition for space     

Magdy EL HEDENY  Mohamed RASHWAN  Sebastián RICHIANO  Saleh AL FARRAJ  Ghada AL BASHER 《海洋湖沼学报（英文）》2021,(1):198-207

The exposed calcareous rocky area of the Abu Qir Headland,east of Alexandria,Egypt which range from coarse grains,through pebbles,cobbles,and boulders to rocky platforms,was signifi cantly colonized by sclerobionts(epibionts and endobionts).The epibiont species diversity was comparatively higher than that of endobionts.Epibiont communities included bryozoans(the anascan-grade cheilostome Bifl ustra savartii),serpulid(Hydroides elegans,Spirobranchus cf.tetraceros,Vermiliopsis striaticeps and Protula or Apomatus)and spirorbid(Spirorbis)wormtubes,and balanoid barnacles(Amphibalanus amphitrite,Balanus trigonus,and Perforatus perforatus).The cheilostome bryozoan colonies,which developed extensive sheets,proliferated on the study rocky shore either encrusting the bioeroded basement directly,or encrusting other epilithic taxa,particularly balanoid barnacles and serpulid worms.Encrusters displayed a remarkable marginal competitive interaction(overgrowth and stand-off)for space on the study rocky shore.On the other hand,endobionts were not well represented on the studied rocky shore exposure.It was possible to identify three ichnotaxa:Gastrochaenolites,Maeandropolydora,and Finichnus.The fi ndings documented represent a signifi cant contribution to our knowledge of sclerobionts composition,sequence of their colonization and/or bioerosion,and their mutual relationships on the intertidal rocky shore of the Abu Qir Headland.  相似文献   

Molecular phylogeny and ultrastructure of a new population of Urostyla grandis(Ciliophora,Hypotrichida) from Harbin,China     

CAI Xinglong  CHEN Ying  ZHAO Xiaolu  GAO Jing  Saleh A. AL-FARRAJ  YU Lijie  PAN Xuming  QIU Zijian 《海洋湖沼学报（英文）》2019,(1):256-265

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