PUBLICATIONS OF PROFESSOR DR AHMAD SHAHAB AL BANNA -DEPARTMENT OF GEOLOGY COLLEGE OF SCIENCE UNIVERSITY OF BAGHDAD
Proceedings of the Ninth International Conference on Basement tectonics, Canberra, Australia,
July 1990, pp191-196.
AN E-W TRANSECT SECTION THROUGH CENTRAL IRAQ
S. A. AL-SINAWI AND A. S. AL-BANNA
Department of Geology/ University of Baghdad/ Iraq
Geological and geophysical measurements give an idea about the crustal thickness beneath an E-W transect 620 km long through central Iraq. Because the basement of Iraq is hidden below younger rocks, several studies in neighboring countries have been compiled by Buday and Jassim (1987) who deduced that the basement is metamorphosed and of Precambrian age. The Basement depth was determined from an aeromagnetic survey and is used in this study to calculate a density contrast of 0.1 gm/ cc between the sedimentary cover and basement. A gravity model for the crust in central Iraq has been built to fit the smoothed anomaly. The crustal thickness along the transect range between 31 km and 37 km with an average of 34 km. The geological and tectonic data along the transect are compared with the available aeromagnetic and Bouguer anomalies and seismic reflection data. The resulting model is compared with published empirical relations for crustal thickness and a close correlation is noted.
Iraqi J. Sci., Vol. 32, No. 2, 1991, PP 373-386.
ISOSTATIC CONSIDERATION FOR CENTRAL AND SOUTH IRAQ
A. S. AL-BANNA
The elevation of 159 gravity basic station selected from the gravity basic station network of Iraq (Al-Khadimi et al 1985), in addition to the ideal proportionality factor between the elevation and Bouguer anomaly (0.11) were used to obtain an isostatic anomaly map of Iraq for the area between latitude 29 and 34 N. The zero isostatic isoline runs southward close to longitude 43 E from the north of the studied area until latitude 31 N, then trends SE toward the south. The regional isostatic anomaly values decrease toward the east and the lowest negative values appear at the Iraqi- Iranian border. The value increases westward reaching a maximum positive value at the Iraqi- Jordanian border.
The isostatic anomaly maps of the present study and those prepared by Colley 1955, are generally comparable. The present study provides for the first-time new information about the isostatic situation in the western area of Iraq, which was not covered by the IPC gravity survey.
Iraqi j. Sci., Vol.33, No. 1-2, 1992, PP 63-79
GRAVITY LINEAMENT, FAULT TRENDS AND DEPTH OF BASEMENT ROCKS IN WESTERN DESERT, IRAQ
A. S. Al-BANNA
The Bouguer anomaly map for the western desert of Iraq is considered to trace the trends of the gravity anomalies and the maximum horizontal gradient, that are related to the basement features. These trends are correlated with the major fracture direction created by Hejaz and Najd Orogeneses.
The calculated basement depth of the studied area range between 6-8.5 km, are similar to that suggested by the Compagnie Generale De Geophisque (C.G.G.) 1974.
The discontinuity of the gravity anomalies and the faults, or the change in their trends show undefined faults. These faults may have imposed certain effect on the development of the major valleys in the western desert of Iraq.
Iraqi J. Sci., Vol. 33, No. 3-4, 1992, PP507-523.
ANALYSIS OF GRAVITY AND MAGNETIC LINEAMENTS AND BASEMENT DEPTH ESTIMATION OF AL-JEZIRA AREA, NORTHWESTERN IRAQ.
AHMED S. AL-BANNA
Department of geology, College of Science, Baghdad University, Iraq
The gravity and vertical magnetic anomalies maps are used to outline the basement rocks lineaments for Al-Jezira area, northwestern Iraq.
These lineaments and faults, that represent the trace of maximum horizontal gradient, are generally grouped into three systems, each system includes two sets of perpendicular trends, these are N-S; E-W, N70W; N20E and N50E; N40W. These lineaments and faults may have been affected by Hejaz and Najd orogeneses.
The average depth of the basement rocks in the studied area was found to be about 6.5 Km, which is in agreement with that results obtained from other calculations using seismic, gravity and magnetic data.
The studied area is divided by several faults, which shows area as an uplifted and subsidence blocks. According to the thickness of about 6.5 Km of sedimentary rocks in the study area, the author believed that the thickness of Paleozoic rock that must penetrate to reach the basement rocks in Khleisia area is about 2.5-3 Km.
Iraqi Geological Journal, Vol. 26, No.1, 1993, PP42-55.
CORRELATATION BETWEEN BOUGUER ANOMALIES AND ELEVATION AND THEIR RELATION TO ISOSTASY IN CENTRAL AND SOUTH OF IRAQ.
AHMED S. AL-BANNA AND FITIAN R. AL-RAWI
The relation between the Bouguer anomaly and elevation for 79 gravity stations, covering most of the central and south of Iraq territory is presented. The above relation was compiled from Gravity Basic Stations distributed along six east-west narrow zones across Iraq.
On the basic of the correlation between Bouguer anomaly values and elevation one can divided the studied area into two regions. The eastern region is characterized by positive relation between Bouguer and elevation, while the western region shows a general negative relation. From these relationships it is possible to deduced that the western region is overcompensated and the eastern region is undercompensated. It is remarkable that these regions almost coincide with the stable and unstable tectonic zones defined on the tectonic map of Iraq.
Proceedings of First Scientific Conference for Soil Mechanic and foundation
Engineering, Baghdad 13-14 December 1993, National Center for Construction Laboratories (NCCL). PP. 212-225.
Microgravimetric Survey for Engineering Application- Case study
Fitian Al-Rawi and Ahmed S. Al-Banna
The application of microgravimetric survey to define area of low gravity anomalies prior to grouting for engineering purposes has been explore. Field measurements have been compared with the amount of grouting mix. Injected in the ground in an area characterized by fissures and cavernous limestone at various depths. The results indicate that the negative gravity anomalies are correlated with the amount of the injected mix, in certain parts of the profile.
On the other part of the profile poor correlation is found, However, these anomalies areas where grouting mix may flow through fissures to fill cavernous around boreholes which in turn explains the poor correlation directly beneath the drilling grouting boreholes. Certain procedures of interpretation are followed to explain this relationship and also to overcome the difficulty in defining the area of interest for engineers. The results show the successful application of the microgravimetric survey for grouting investigation.
Iraqi J. Sci., Vol. 35, No.3, 1994, pp. 749-764.
Crustal Thickness Map of Iraq Deduced from Gravity Data
Ahmed S. Al-Banna and Emad A. Al-Heety
The Bouguer anomaly data of Iraq has been used in order to construct a crustal thickness map. The depth to the Moho discontinuity is obtained along three gravity profiles by two- dimensional modeling. The correlation between the Bouguer anomaly values and the crustal thickness is found to correlation is found to correspond very well with Woollard’s equation (1959). The Moho depth map is performed using the obtained equation.
The resulted map shows that the Moho depths ranging between about 32 Km to 39 Km for the study area with gradual increase from the west toward the east and north.
Iraqi J. Sci., Vol. 37, No. 3, 1996, PP. 1049-1065.
A Preliminary Procedure to Seismic Sources Delineation Study in North and Northeast of Iraq.
Ahmed S. Al-Banna
Two methods are used to construct the seismic map of northern and northeastern parts of Iraq for the period 1905- 1987. One of them suggested for the first time to delineate the seismic strips sources. The second is based on determination of (A) value (intercept on log N axis). The suggested procedure is simple and reliable to depicts the seismic sources. It is concluded that the active seismic area source area is actually an area of intersection of many seismic strip sources.
Iraqi Geological Journal, Vol. 30, No.2, 1997, PP. 158-165.
Fitian R. Ai-Rawi and Ahmed S. Al-Banna
The Role of Smoothing Microgravity Data in Gradient Determination for Fault Delineation
Gradient technique has been used to define parameter of a concealed fault in site where microgravimetric survey has been conducted. Treating field data can directly give rise to fictitious in calculating gradient values which are difficult to interpret. Smoothing of data may provide good and easily -interpretable results. Comparison with models of various geologic structure helps in defining parameters that concern the source of gravity anomalies.
Iraqi Geological Journal, Vol 31, No. 1, 1998, PP. 1- 12
Contribution to the tectonic Evaluation of Hamrin – Samarra- Tikrit Area Using Gravity Data.
Ahmed S. Al-Banna
Gravity data of Hamrin-Samarra-Tikrit triangle area analyzed, in order to contribute to the tectonic framework of the area. The analysis is based on the regional and residual anomalies of gravity data related to deep and shallow structures respectively. It is found that the boundary between the Folded and Mesopotamian Zones can be defined on deep structures basis better than surface or shallow subsurface structures.
The predominate trend of shallow subsurface structures is N50W and N-S. Comparison between the axes position of the residual positive gravity anomalies and surface structures shows shift at southern part of southern Hamrin. This shift may be caused by the action of orthogonal stresses related to the Alpine Orogeny.
Many possible anticline trending North-South are located in the area between Al-Dour city and Shari Playa. These anticlines characterized by gravity anomalies of low amplitude of about 1 mGal. Some of these folds are accompanied with faults such that of Shari Playa anticline.
The longitude and transvers faults subdivided the area into many blocks. The former is parallel to the Zagros belt, While the latter is perpendicular to the longitudinal faults. The transverse faults may be related to stresses nature, along the arch line defining the collision between the Arabian, Iranian and Anatolian plates, and the differential movement of the different blocks.
Iraqi J. Sci. Vol. 40C, No. 4, 1999, PP. 8-22.
The Main Lithological Basement Regions Inferred from Geophysical Data in Western Desert of Iraq.
Ahmed S. Al-Banna
Gravity and magnetic information are used to delineate the main lithological basement rocks in western desert of Iraq. This delineation was based on the qualitative interpretation of aeromagnetic, gravity, isostatic anomalies and basement depth maps.
Mainly two types of basement rocks are defined in the studied area. First type is ultrabasic rocks in certain area called positive regions. These regions are characterized by positive gravity and magnetic anomalies. The second type is granitic rocks found in area called negative regions. These areas characterized by negative gravity and magnetic anomalies.
The lithologic basement delineation is important due to their usefulness to construct a suitable geological model which confirms the gravity and magnetic data. It is also helpful in recognizing different thermal conductivities, which may play a great role in maturing organic matters and generating hydrocarbons.
Faculty of Science Bulletin, Sana’a University, Vol. 13, 2000, PP. 121- 131.
Tower Measurements of Gravity Gradient and Their Applications- Case Studies
Ahmed S. Al-Banna and Fitian R. Al-Rawi
The significance of measured and calculated gravity vertical gradients (GVG) in defining the boundaries of an Irrigation Canal and Natural Cave are presented and discussed. Although the measured and calculated GVG have successfully defined the boundaries of the considered canal and cave, but a comparison between them shows: The boundary of the cave is well defined by measured vertical gradient than the calculated one. The measured anomaly has grater amplitude and smaller width relative to the calculated one.
First National Scientific Conference in Environmental Pollution and means
of protection, Baghdad, Iraq, 5-6 Nov. 2000, PP. 25-32.
Site Selection Based on Gravity Data Evaluation of Four Potential Sites for Industrial Construction (Case Study).
Mohammed J. Abbas and Ahmed S. Al-Banna
Gravity method considered as one of geophysical took that applied for studying the subsurface features. The local and regional horizontal gravity gradient in addition to isostatic condition techniques was applied to evaluate the subsurface situations of four proposed potential sites (A, B, C, and D). This technique is applied in order to select the best site from engineering point of view for construction an important industrial facility.
Gravity measurement along two perpendicular profiles one of them parallel to the main structural trend in the area, the other is across them were evaluated in each potential site. Length of each profile is 12 km with gravity station spacing of 100m along them. The polynomial technique and the ratio (maximum gravity/half width) of the gravity anomalies are used to determine the regional and local gravity horizontal gradients respectively. The isostatic conditions were evaluated depending on the state of the potential sites relative to ideal proportional factor between gravity and elevation value that obtained by woollard (1959, 1971) and Coron (1971). The site characteristics (local gravity gradient and the regional gradient in NE-SW and NW-SE direction, as well as the relative isostatic conditions) were evaluated using the ordinal scaling technique. Based on the results of this study the best suitable potential site from gravity point of view was selected.
Tikrit Journal for Pure Science, Vol. 7, No. 5, 2001, PP. 146-163.
A New Interpretation to the Tectonic Zones of the Southern Iraq
Ahmed S. Al-Banna, Hassan A. Hassan and Sabbar A. Al-Kasiy
The available geological and geophysical data are considered to evaluate the tectonic zones at the southern part of Iraq. Some of these data are used with simple modification, while others are subjected to a polynomial process in order to enhance the data. The southern part of Iraq is separated into definite zones as a result of the data processing related to the physical and chemical properties of the deformed rocks due to tectonic activities. The main tectonic zones obtained are A, B, C, and D. Zone A confirms the area, which are considered in previous studies as a stable shelf. Zone B considered as a transition zone between the other zones. This zone contains the steep change or the variation in rock properties and geological activities that are considered in the present study. This zone started at the northern part of the studied area, then separated into two branches west of Bussaya town. The eastern branch confirms the previous location of the boundary between stable and unstable shelves, but as strip and not as a line. The western branch separate zone D from A (stable shelf) and zone C may confirm the unstable shelf. The new suggested zone D located between the two branches of the transition zone. This zone has different properties from other zones. This difference may be caused by the presence of granitic basement uplift. The obtained result is considered as a very useful for the tectonic situation of the area and for petroleum traps evaluation.
Iraqi J. Sci. Vol. 42C, No.1, 2001, PP. 108-128
Application of Amplitude- Direction Matrix Technique- for Gravity Data of Anah and North – Nasiriyah regions, Iraq.
Ahmed S. Al-Banna
Department of Geology, College of science, University of Baghdad.
The amplitude -direction matrix technique is used in this study in order to obtain the predominant trends of Bouguer, regional and residual anomalies of Anah and north Nasiriyah regions. A computer program in basic language is constructed for this purpose. Rose diagram and frequency of occurrence profile in addition to the amplitude- direction matrix technique present results of the program. Trends of Bouguer, regional, and residual anomalies are compared with each other. It is obtained that the direction of residual and regional anomalies of Anah range between 75- 105 degree indicating that the area may be influenced by the margin of Nubio- Arabian shelf structures. The main trends of Bouguer, regional and residual anomalies of North Nasiriyah range between 125- 145 degree. Such trend may be influenced by structures that related to the recent sedimentary basin.
Scientific Jour. Tikrit Uni. Eng. Sci., Vol. 9, No. 1, 2002, PP. 62-80.
Groundwater Saturation Indices for Evaluation of Foundation Soil Problems Case Study at Baiji Sub-basin, Iraq.
Hassan A. Hassan, Ahmed S. Al-Banna, Sabbar A. Al-Kaisy.
The analysis of ground water system at Baiji Sub-Basin shows that the saturation indices reflect the under-saturation condition of the gypsum and anhydrite equilibrium matrix. Thus, the fluctuation of groundwater and /or leaks from industrial activities lead to dissolution of the two minerals. Accordingly, cavities or weak zones may be formed with time. So, there will be a possibility of instability of soil pressure upward against downward weight pressure. It is also found that there is a significant correlation between saturation indices with the direct salinity measure of the (EC) form. Accordingly, it is possible to explain 90% of the saturation indices variation by the EC variation with time. Thus, this model will provide information about the saturation indices type from the field measurement of salinity.
Faculty of Science Bulletin, Sana’a University, Vol. 15, 2002, PP. 85-93.
Enhancement of Gradient Analytical Signal by Smoothing Technique- Case Study.
Ahmed S. Al-Banna, Fitian R. Al-Rawi, Ahmed. S. Al-Gabery.
An attempt is carried out to enhance the gradient analytical signal used in gravity interpretation. The procedure is based on smoothing technique as a way to eliminate most of undesirable noise in the anomalies. The case shows the power and role of smoothing technique in calculating the gradient analytical signal to define the boundary of subsurface source representing here by a cave with known information about its dimensions and depths. The information provided by such technique is very useful in many geophysical applications particularly in engineering purposes.
Dirasat, Pure Sciences Journal, University of Jordan, Vol. 30, No. 2, 2003, PP. 212-229.
Microgravity Method for the Detection of Weak Zones under the foundation of a Building Site- Case Study in Iraq.
Ahmed S. Al-Banna, Hassan A. Hassan, Sabbar A. Al-Kaisy and Samir R. Hujab
Microgravity method is used in this study to detect the weak zones under the foundation of a building site. It is the first attempt, in Iraq, to carry out the microgravity survey inside a building of an operating unit in potential electrical station. The measurements of the micro gravimeter were corrected using the conventional corrections in order to obtain the Bouguer anomaly (Gb). The gravity effect of the geometrical structures (Gs) in the studied site, such as tanks, piles, wall and channels were calculated using the published gravity formula for the geometrical bodies. The calculated gravity effect of the geometrical bodies is added to the Bouguer anomaly data (Gb), in order to eliminate the gravity effect of the surface geometrical structure. The residual anomaly values (Gres) are obtained by subtract the regional values from the final gravity anomaly values (Gf). The residual gravity map shows many negative anomalies. It is concluded, from the comparison between the regional and residual anomaly map of Gb and Gf that the gravity effect determination of the geometrical structures is necessary for detecting the gravity effect of such cases.
Two-dimensional gravity is applied along two profiles crossing the main negative gravity anomaly. These models show that the weak zones in the studied site are detected within the three meters below the earth’s surface. The result of the present study is used to evaluate the previous grouting process and to plan the next grouting boreholes network, in which the amount of grouting materials is confirming the gravity survey results.
Rafidian Jour. Sci., Vol. 16, No. 1, Geology, Special Issue, 2005, PP. 32-44.
Determination of the Location of Ground Water Table Anomalies by the Ring and Central Point Method Study of Three Areas in Iraq.
Sabbar A. Salih, Ahmed S. Al-Banna and Hassan A. Hassan
The groundwater table is observed in three areas in Iraq. Many wells are used to construct the ground water table maps in these areas. These maps are reflecting the irregularity in the water table. The observed values of groundwater table are converted to a regular grid of water table points, with different spacing interval from area to another. The regional groundwater table is calculated, using the ring and central point method, in each observation point. The residual (local) anomalies in the ground water table values for the grid point are obtained by subtracting of the regional (average values) of ground water table from the observed values. The gridding of water table and calculations of regional and residual anomalies are done using QBASIC computer program build for this purpose. The regional ground water table and residual anomalies of groundwater table are mapped, regional maps show the main water table level in the studied areas. The residual maps show many positive and negative anomalies of ground table. These maps reflect that the positive anomalies related to the leakage of water from the subsurface pipelines and drainage channels in the studied areas, while the negative anomaly related to the high pumping or discharge rate. This method can be used to determine the locations of leakage from pipelines and drainage channels.
Tikrit J. of Pure Science, Vol. 11, No. 1, 2006, PP. 231-238
Using of Gradient Techniques for Depth estimation of Gravity Source
Ahmed S. Al-Banna and Sabbar A. Al-Kasiy
A new method, depends on the determination of the horizontal and vertical gradients of gravity data, is introduced for estimating the depth of gravity source. The distance of the nearest intersection point, of horizontal and vertical gradient, to the central axis of the gravity anomaly (x) is found to be related directly to depth of gravity source. Two relations were obtained to estimate the depth of the source that is approximated to spherical or horizontal cylinder bodies. The suggested method is applied on four groups of gravity data, where the depth to the sources are well known, and the result are generally confirming the actual depth. The introduced method is applied for two gravity anomalies in Iraq of which the depth is unknown and acceptable results are obtained.
Journal of Kerbala University, Vol. 4, No. 4, 2006, PP. 33- 42.
Seismic Refraction and Cross- Hole Techniques for investigate the top Soil and Water Table Beneath the High Pumping Station Hall of Al-Hussian Water Supply Station, Kerbala, Iraq.
Ahmed S. Al-Banna, Ammer J. Al-Khafaji and Esam S. Banno.
The present study aims to investigate the possible causes of cracks, in the wall of buildings and storage tanks, in Al-Hussian water project of Kerbala city. Eight seismic refraction profiles and seven cross section were made to investigate the pumping station at the studied site. Two refractors were obtained. The first one is at depth range 1-2.5m, which coincide with the depth of water table and base of foundation (two meters below the ground surface). The second refractor is obtained from cross-hole results of range 4-4.5m; which confirms the top of the dense sand layer.
It is believed that the water seepage from broken pipes and its infiltration through the soil play the role in washing the soil and changing the water table level from one point to others. The differential washing causes differentia settlement beneath the buildings which is causes the cracks in the walls.
Journal of King Abdulaziz University, Vol. 18, 2007, PP. 1- 28.
Interpretation of Two Regional Seismic Sections for Jurassic Sediments in Southern Iraq.
Ahmed S. Al-Banna, Hamid N. Al-Sadi, and Suhilla A. Mouhammad
This study included the construction of two regional seismic sections in southern Iraq; the first is 196 km in length and started from SA-1 well in southwestern Iraq, and ended at SA-3 well, passing through well SA-2 well at Basrah region. The second regional seismic section, about 167 km in length, started at SA-3 well near southern boundaries of Iraq, south of Basrah City, and passing by SA-3, SA-4 and SA-5 wells, then ended at SA-6well at Amara region. Twelve seismic reflection lines were used, in addition to some minor seismic lines to link the major lines. Many conventional processing tools were applied to construct the two regional sections. One of the results of the present study is the explanation of the general structural features along the regional sections. The results also show the detailed structural changes on the Jurassic Sediments considered in the present study, which included Gotnia, Najmah, Sargelu, and Alan formations. Gotnia Formation showed a decrease in thickness between 2390- 2470 CDP, which is thought to have resulted from salt and anhydrite beds motion. Generally, it is believed that the thickness of Jurassic sediments for the studied formations is reduced in southern Rumaila and Halfaya due to vertical movement which affected the structures of the southern and southeastern regions of Iraq. The boundary between the main tectonic units of Iraq (the stable and unstable shelf) has been defined on the first regional seismic section at 1500- 2000 CDP.
Proceedings of the First Geological Conference, University of Kirkuk, 25-26 Nov 2012, PP1-18.
Geotechnical Study in Shewasoor Dam Site, Northern Iraq.
Ahmed S. Al-Banna, Salman Z. Khorshid, and Dhahir K. Ali
A geotechnical study held on Shewasoor dam site which aim to collect seasonal stream water. It is a small dam located in northeast of Kirkuk City about 40. Fifty-three samples of rocks obtained from drilled boreholes in the field, that carried out by the dam administration, is subjected to compression and shear wave velocity test using (MATEST) ultrasonic instrument in addition to the measurement of density. Core rock samples from core boxes were checked for rock quality designation (RQD) calculation. The Dynamic module has been calculated. Using the velocity and density the characterization of the dam site has been achieved. According to the (RQD) classification the rock of the site is generally good. The shear velocity is used for seismic hazard site classification and to determine the bearing capacity of the rock foundation, which is found good.
Arab J. Geoscience, Vol. 6, 2013, PP. 187-191.
The Boundary Between Stable and Unstable shelf in Iraq as Inferred from Using Ideal Gravity to Elevation Ratio
Ahmed S. Al-Banna, Khedar E. Al-Sagri, Lika Z. Humide.
The line of complete compensation, the ideal value for the ratio of gravity to elevation (-0.11 mGal/m) in Iraq, is obtained using gravity data derived from 477 stations. This line is found to separate the stable shelf from unstable shelf. It is also confirmed with the western limit of the basin as shown on the structural map that is constructed at the base of Al-Fath (L-Fars) Formation (M. Miocene). The obtained line coincides with the thinnest crustal line shown on the crustal thickness map of Iraq. It is believed that this line may also define the thinnest sedimentary cover in Iraq. The obtained result can be useful template for tectonic view of Iraq.
International Journal of Civil Engineering and technology (IJCIET), Vol. 4, No. 6, 2013, PP. 252-260.
Characteristics of Some Geotechnical Properties of PilaSpi and Injana Sedimentary Formations, at Shaqlawa Area, Northern Iraq.
Ahmed S. Al-Banna, Dhahir K. Ali, and Hamed H. Abdulla
The geotechnical properties are an important aspect of civil engineering projects. So many construction and mining companies interest with such studies. In the present study, 18 limestone samples from PilaSpi formation and another 9 sandstone samples from Injana formation were collected from two limbs of syncline situated northeast Shaglawa City, northern Iraq. The Vp and Vs velocities with some geotechnical properties of these samples were investigated. It is concluded that the geotechnical properties of the samples are varied depending on many significant factors include water saturation, the relative location of the samples within the syncline limbs and the lithology as well. Each syncline limb has different geotechnical properties than the other due to the nature and degree of stresses influencing each limb.
Diyala Journal for Pure Sciences, Vol. 10, No. 2, 2014, PP. 1-12.
Geotechnical Evaluation to the Soil of Tikrit University Using Seismic Refraction method.
Salman Z. Khorshid, Mundhir Dh. Al-Awsi, Ahmed S. Al-Banna
Seismic refraction survey is conducted for geotechnical evaluation to the soil of Tikrit university at allocated site to construct a new building for housing the professors of the university. The measurements of compressional and shear waves velocities are conducted along six profiles at the study area. Four main layers were recognized from the results of the seismic data interpretation. Depending on the ( Vs/Vp) ratio, three geotechnical properties were calculated for geotechnical evaluation to the different layers, these are Poisson’s ratio, Material index, Plasticity index. The contour maps for different layers are plotted to show the distribution of geotechnical properties at the study area. These maps are divided into two zones, Zone A represent the area which has good geotechnical properties and Zone B represent the area which has weak geotechnical properties such as loose unconsolidated sediments or weak zones. The results of evaluation show that the first and third layers are fairly competent to intermediate competent layers because they have good geotechnical properties by comparing with second and fourth layers, which have poor geotechnical properties which represent incompetent layers. Depending on the values of plasticity index, the sediments of the study area ranges between low plasticity to intermediate plasticity sediments except some of the places characterized by high values of plasticity index representing high plasticity sediments.
Iraqi Journal of Science, Vol. 56, No. 1A, 2015, PP. 169-180.
Geoelectrical Study in Shewasoor dam Site in Kirkuk/ Northern Iraq
Salman Z. Khorshid, Ahmed S. Al-Banna, Dhahir K. Ali
A geotechnical investigation is carried out for a geological consideration in the Shewasoor dam site, which is situated 40 km northeast KriKuk City. Symmetrical Schlumberger array were applied for fifteen electrical sounding (VES) points, with a maximum spread distance 120- 200 meters. Seven vertical electrical sounding (VES)points were surveyed in the main valley. Two (VES) points taken at the area behind the dam, and two others points at the right side of the dam body. Additional four (VES) points measured at the left side within the spillway area. In order to achieve the qualitative and quantitative interpretations manual partial matching technique and (IPI2 WIN) (ID) software are used. The results show that the surface is comprise of recent Silt, Clay, Sand and Gravel sediments with trace of water. The subsurface within the valley nearby the dam body is dominated by Claystone underlined by pebbly sandstone with water table condition, while the spillway is characterized by silt and gravel sediments. The area behind the dam body subsurface is composed of silty sandstone underlined by sandy siltstone. It is concluded that the subsurface layer of the dam site is suffering from heterogeneity.
Iraqi Bulletin of Geology and Mining, Vol. 12, No. 1, 2016, PP. 31-39.
Using Vertical Electrical Sounding in Building Site investigation; A Case study in South of Baghdad, Iraq.
Jassim M. Thabit, Ahmed S. Al-Banna, and Mundher D. Al-Awsi.
Vertical Electrical Sounding was used for engineering purposes at Al-Jadiriya area, within Baghdad university site. Two different electrical resistivity techniques were applied using Schlumberger array. These are the vertical electrical sounding (VES) and cross vertical electrical sounding (CVES) technique. The measurements of VES were carried out at 38 points distributed as much as possible to cover the area. Three main layers were delineated, these are the top soil, unsaturated layer of clayey sand or silty sand, and saturated layer of sand to clayey sand and sand mixed with gravel at some places. The resistivity of the top soil varying from 11 – 600 Ωm, and thickness ranges from 0.7 - 2.8 m. The unsaturated layer has resistivity values varying from 46 – 320 Ωm, and thickness ranges from 2.0 - 7.2 m. The resistivity of the saturated layer varies from 11 – 60 Ωm, and thickness ranges from 4.6 - 13.8 m. There are also lenses in some places within the layers, which have high resistivity 800 -900 Ωm or low resistivity 9.6 – 29 Ωm that may represent fill material and clay lenses respectively, its thickness ranges from 1.2 - 2.45 m. The average depth of the ground water surface ranges between 5-8 m. The measurements of CVES were taken along two perpendicular directions around fixed central point, at 5 points. The results are presented as radial graphs to show the variation of resistivity with direction, these graphs show that the sediments are heterogeneous in vertical and horizontal distribution, especially for the top soil. Finally, it was concluded that three major causes of failures in the buildings prevail of Baghdad University. The first cause is the lateral inhomogeneity of the subsurface sediments. The second is the presence of lenses, and the third is the variation of ground water levels. These failures may cause many engineering problems at the study area such as cracks in foundation and walls of building.
Iraqi Journal of Science, 2017, Vol. 58, No.2B, pp: 884-890 DOI:10.24996. ijs. 2017.58.2B.13
The Theoretical Solving of Intersection Point of the Horizontal and Vertical Gravity Gradients in Order to Estimate the Depth of Causative Source of Gravity Anomaly
Ahmed, S. Al-Banna*, Kamal K. Ali Department of Geology, College of Science, University of Baghdad, Baghdad, Iraq.
The depth of causative source of gravity is one of the most important parameter of gravity investigation. Present study introduces the theoretical solve of the intersection point of the horizontal and vertical gradients of gravity anomaly. Two constants are obtained to estimate the depth of causative source of gravity anomaly, first one is 1.7807 for spherical body and the second is 2.4142 for the horizontal cylinder body. These constants are tested for estimating the depth of three actual cases and good results are obtained. It is believed that the constants derived on theoretical bases are better than those obtained by empirical experimental studies.
Iraqi Journal of Science, 2017, Vol. 58, No.3A, PP: 1235-1245
_______________________________ *Email: email@example.com
The Deep Faults in Kut-Hai and Surrounding Area Inferred from Gravity and Magnetic Data
Ahmed S .AL-Banna*1, Falih M. Daim2, Ali A.M.AL-Zubaidi1
1Department of Geology, College of Science, University of Baghdad, Baghdad, Iraq. 2Department of Interpretations, Ministry of Oil, Baghdad, Iraq.
Gravity and magnetic data are used to study the tectonic situation of Al-Kut- AlHai and surrounding areas in central Iraq. The study included application of many processing and interpretation programs. The window method with different spacing was used to separate the residual from regional anomalies for gravity and magnetic data. The Total Horizontal Derivative (THDR) techniques used to identify the fault trends in the basement and sedimentary cover rocks depending upon gravity and magnetic data. The identified faults in the study area show (NW-SE), (NE-SW) (NS) and (E-W) trends. It is believed that these faults extending from the basement to the upper most layer of the sedimentary cover rocks.
Iraqi Journal of Science, 2017, Vol. 58, No. 3B, pp: 1454-1463
DOI: 10.24996/ ijs.2017.58.3B.10
Interpretation of Potential Fields and Detection of Deep Faults of Kut-Dewania- Fajir Area, Central Iraq
Ahmed S. AL-Banna*1, Falih, M. Daim2, Ali A.M.AL-Zubaidi1
1Department of Geology, College of Science, University of Baghdad, Baghdad, Iraq. 2Department of Interpretations, Ministry of Oil, Baghdad, Iraq.
Gravity and magnetic data are used to study the tectonic situation of Kut- Dewania- Fajir and surrounding areas in central Iraq. The study includes the using of window method with different spacing to separate the residual from regional anomalies of gravity and magnetic data. The Total Horizontal Derivative (THD) techniques used to identify the fault trends in the basement and sedimentary rocks depending upon gravity and magnetic data. The obtained faults trends from gravity data are (N30W), (N60W) (N80E) and (N20E) and from magnetic data are (N30W), (N70E), (N20E),(N10W),(N40E). It is believed that these faults extend from the basement to the lower layers of the sedimentary rocks except the N60W trend that observed clearly in gravity interpretation. It is believed that this trend may be related to sedimentary cover only. Most residual gravity and magnetic anomalies coincide with each other concerning location and extension, which indicate that they may be created from common sources. There is a large positive gravity anomaly located at east of Hai-Fajir cities coincide with the relatively negative residual RTP magnetic anomaly. It is believed that this anomaly may represent an uplift structure within the sedimentary cover lying over deep basement rock.
Iraqi Journal of Science, 2017, Vol. 58, No. 4 A pp: 1910-1917 DOI: 10.24996/ ijs.2017.58.4A.13
The Oil Fields Relation to the Tectonic Boundaries that inferred from Seismic and Gravity Interpretation in Kut-Hai-Fajir and Surrounding Area, Central Iraq.
Ahmed S. AL-Banna1*, Ali A.M.AL-Zubaidi2, Falih M. Daim3
1Department of Geology, College of Science, University of Baghdad, Baghdad, Iraq. 2Department of Civil, College of Engineering, University of Wasit, Wasit, Iraq. 3Department of Interpretations, Ministry of Oil, Baghdad, Iraq.
The seismic reflection and gravity data were used to detect the tectonic boundaries in Kut-Hai-Fajir and surrounding areas, central Iraq. The depth maps of Dammam, Nhr Umr, and Sulaiy, formations were constructed and used to detect some boundaries in the study area. The residual gravity map and Total Horizontal derivative (THDR) also used to detected the tectonic boundaries. It is obtained that most boundaries or faults found in the deep formations; while some of them shown in the shallow formations. The faults or boundaries obtained from gravity interpretation mostly coincide with the deepest formation boundaries. Generally, the gravity anomalies conform the morphological feature locations within the depth maps of the formations. Many longitudinal and transverse faults were traced from the seismic and gravity interpretation. It is concluded that the oil fields in the study area lying within certain tectonic zones and coincide with the positive residual gravity anomalies of spacing window of 8 km; mostly near the zero-line values. It is believed that the integrated interpretation of residual gravity anomalies with the depth maps of some formations, that inferred from seismic data, gives good results for evaluation of an area for oil exploration.
Iraqi Journal of Science, 2018, Vol. 59, No.1A, pp: 156-172 DOI:10.24996/ijs.2018.59.1A.17
Inversion to Density and Velocity Model by Integrated with Wells Data at Regional Area (Central and Southwestern Iraq)
Ahmed S. AL-Banna, Salar S. Al- Karadaghi*
Department of Geology, College of Science, University of Baghdad, Baghdad, Iraq.
A new derivative applied to the old gravity Bouguer map (served in 1940s and 1950s), taking regional study area covered the mid and south of Iraq. The gravity anomaly reflects a density contrast variation; therefore, it is possible to use gravity inversion to the density and velocity model through layers (615m, 1100m, 1910m, 2750m and 5290m), the depth layers according to the power spectrum analysis of gravity Bouguer. The inversion is according to the integration of gravity anomalies of each depth layer with the same depth of wells data, considered to the estimations and analysis of density and velocity scatters of the oil wells distribution with depth at the regional area. Taking the relation curve of density and velocity by presenting the function of (8 logs), which obtained the main relation to Seismic velocity and density of the study area, which is confirm with (Nafe and Drake curve). The result of the gravity inversion is on the anomalies behavior in density and velocity domain, taking in seismic stack processing of seismic reflection records and time to depth conversion, as the geophysical integration data is addition to the well data distribution in the regional area of Iraq. Good results obtained on comparing the interpretation of the considered seismic section in the study area.
Iraqi Journal of Science, 2018, Vol. 59, No.1B, pp: 314-328
Integration Study of a New Gravity and Seismic Survey along NE- SW Profile in Al- Najaf Desert
Ahmed S. AL-Banna, Salar S. Al- Karadaghi* Department of Geology, College of Science, University of Baghdad, Baghdad, Iraq.
A new gravity and seismic survey along a profile length (70 Km) carried out at the area of exploration Block- 11 in Al- Najaf desert, southwest Iraq. The obtained gravity and seismic value compared with the previous available data that achieved by IPC and OEC for gravity and seismic data respectively. The difference between the new gravity profile and the old one is mainly in small anomaly not more than (14 %) that related to shallow depth levels and presents through power spectrum analysis. Previously, Ghulaissan-1 well which drilled in (1960) depend on a positive gravity and magnetic anomaly interpret, which is considered as an anticline structure in sub surface. It did not indicate any hydrocarbon shows after drilling, the integration study shows, that the positive anomaly appear in gravity record may be results from extension of presence thick Ophiolites and syn-tectonic gabbro.
UBLICATIONS OF PROFESSOR DR AHMAD SHAHAB AL BANNA
Publications of Professor Dr. Ahmad Shahab Al Banna
1 post • Page 1 of 1
1 post • Page 1 of 1