Earth Science

This paper presents structural and tectonic analysis of Udi and Okigwe part of the Anambra basin using aeromagnetic data and Landsat imagery. The study targets to achieve the following objectives: to delineate major surface and subsurface structural lineaments and their trends, to determine the influence of structure on the sedimentation in the area as well the delineation of the basement topography. The aeromagnetic data processing was carried out by subjecting it to low pass filtering and the use of some analytical methods such as reduction to pole, upward continuation, trend surface analysis and first vertical derivative. Similarly, the Landsat imagery processing involves enhancement and transformation routines. Result of the study revealed that the dominant structural trend directionof the study area is in the NE-SW direction. The NE-SW trend is suspected as a continental extension of the Chain and Charcot Oceanic fracture system. Other structural trends are in the NW-SE, NNE-SSW and N-S directions. Lineament density map revealed a suspected megafracture zone around Lokpaukwu and environs. The 3-D basement map revealed a folded topography which reflects the level of tectonism within the study area. The residual polynomial surfaces revealed deep seated anomalies around Lokpaukwu. Finally, the abundance of pyroclastics within part of the study area makes the area viable for ore mineral and quarrying explorations.

Geophysical investigations are increasingly applied to urban planning development for mapping and monitoring. Vertical electric sounding method and seismic refraction technique were used in Imam Khomeini International Airport (IKIA) Iran, in an attempt to define the subsurface structure, variation in thickness and strength of layers and also, determine the earthquake prone zones in the area. Distribution of electrical resistivity indicated that the study area can be divided into two parts of northern-southern or northeast-southwest. The fine grain silt, clay, marble and chalk deposits with low resistivity are created thick layers in southern and southwest parts of area. In depths 30, 50, 100 and 150 m we are faced to change in soil materials, in the other word change in layer composition mainly occurred at these depths. Also, the real and vast aquifer cannot be considered for this site and just local small mounding of groundwater in some positions such as northern part of area, in deep old alluvial deposits can be guessed. It seems that fault or discontinuity is passed from northwest to the southeast of the study area and is caused the change in geology and sedimentary conditions. According to Iranian Seismic Code (Standard 2800), most of the land around the airport are in class 2 and 3 and the future construction in this region will be required to comply with the standard design principles.

Geophysical exploration using electrical resistivity surveys have been taken up as method to delineate the thickness and resistivities of different layers and identification of potential zones for groundwater development in Naguleru Sub-Basin of Guntur District, Andhra Pradesh, India. It is part of Cuddapah Basin of Peninsular India. Vertical Electrical Sounding were carried out up to 100 meters with 1/2 meter electrode spacing. The absolute resistivity values in the first layer of these formations range from 2 to 160 ohm-meters. and thickness ranges from 1.2 to 29meters, second layer ranges from 4 to 1160 ohm-meters and thickness ranges from 1.3 to 38.4 meters. The third layer commonly represents hard rock displaying the resistivity values ranging from 7 to 1621 ohm-meters to as high as infinite. The co-efficient of anisotropy varies from 1 to 2.59 and the spatial distribution of anisotropy values correlate with the water table fluctuation data. Groundwater potential zones have been demarcated by using interpreted geophysical analysis.

In this study, we compare the mineralogical properties of two different kind of Peat and Swamp. To achieve this goal, Samples from a highland peat and a peat swamp forest in Golestan Province, have been considered. These studies were carried out using thin sections, XRF, and XRD. Quartz, muscovite, biotite, pyroxene, and Fe in forest swamp and Fe–Mn component, Quartz, aluminum and clay in high land peat are composed mainly mineral. Result shows the concentration of aluminum and quartz in highland peat swamp and the concentration of sodium, sulphur, calcium and L.O.I in peat swamp forest is more.

Helwan named one of the important cities of the Sassanian period (652-226 AD) the building is attributed to G. Sasanian. The provincial capital city called "Shazfyrvz" It has been five Tasoojs to "win Quazi" "Mountains," "Symr", "Erbil" and "Khanaqin" has taken on. In this study, some of the specification gay nature and the source of ancient city located at the Bridge drainage analysis and the study of their nature and characteristics of the formation of the bridge, drainage, and religious minorities in the city explains the result religious formation and location of the city is reached.

In the present study, an attempt was made to evaluate and identify hydrogeochemistry of water and the involved chemical processes using Durov and Piper diagrams. The prominent hydrochemical facies was Ca2+-Mg2+-Cl--SO42- in both methods although slight variation in terms of Ca2+-Mg2+-HCO3- was also observed in few water samples. Piper diagrams indicated the dominance of mixed water type (70.84%) having no one cation-anion pair exceeds 50%, while Durov specified the dominance of simple dissolution or mixing (83.34 %) with no dominant major anion or cation. Thus, both the diagrams signify non-identification of the water types with neither anions dominant nor cations dominant. Piper diagram, Durov plot and chloroalkaline indices indicated the abundance and dominance of alkaline earth elements were over alkalies in majority of samples due to direct exchange of Ca2+ and Mg2+ from the Aquifer matrix with Na+ and K+ from the groundwater. Further, SAR (0.41>SAR< 2.78), percent sodium (7.3 > %Na < 42.4) and WQI (13.56 >WQI < 112.99) values recommended the suitability of 100, 91.67 and 62.5% of samples for domestic and irrigation purposes.

A 222Rn survey was carried out in order to explore the pattern of geographical and seasonal changes of 222Rn activity in soil-gas at different locations in Chitradurga district of Karnataka State using RAD7 radon detector coupled with special accessories, without dilution by outside air technique. Radon activity in the soil gas varied from 0.5 to 812.9 (mean: 93.78 Bq/m3) and 0.8 to 810.4 Bq/m3 (mean: 92.84 Bq/m3) during pre- and post-monsoon seasons respectively, with an annual mean of 0.65 to 811.65 Bq/m3 (mean: 93.31 Bq/m3). A significant spatial and insignificant temporal variation in soil radon activity has been observed in the study area, which is in the order of Hosadurga taluk (346.56 Bq/m3)> Hiriyur taluk (95.10 Bq/m3) > Challakere taluk (36.45 Bq/m3) > Chitradurga taluk (20.40 Bq/m3) > Holalkere taluk (2.87 Bq/m3). The results showed the radon values in the soil-gas of Chitradurga district are low (< 0.8 kBq/m3) enough to categorize them under low radon risk areas (viz., 10 kBq/m3).

Field study of Basaanga and Fugar Sandstone was embarked upon in order to determine lithostratigraphy profile, their relationship and laboratory studies including granulometric, heavy mineral, and petrographic analysis. The research studies were aimed towards understudying stratigraphic stacking pattern, textural parameters such as grain size, sorting, transportation history, paleoenvironment of deposition and provenance. The Bassanga Sandstone revealed angular grained basal conglomerate deposited on basement rock by flash flood (fluvial) processes deposited close to the source; overlain by fining-upward sequence in cyclic manner with azimuth of ~2500 paleocurrent direction. Laboratory data deductions show that the average grain size (-0.05 to 2.67 ?) vary from fine to coarse; sorting (0.18 to 0.86) varies from moderately sorted through moderately well sorted to very well sorted; skewness (0.16 to 4.15) varies from fine to strongly fine skewed. ZTR index (10.0 to 43.2%) from heavy mineral study suggests submature to matured sediment while thin section analysis shows texturally and compositionally mature to sub-mature sublitharenite tending strongly to quartzarenitic rock. The Bassanga sediments were transported by southwest paleocurrent and deposited in fluvial setting. However, Fugar Sandstone is fine grained (2.14-2.98?), herringbone structured, fairly bioturbated unit deposited in marginal marine environment; very well sorted (0.18 to 0.28), and strongly fine skewed (2.78-4.5). ZTR index varies from 35.9-50.0% suggestive of mineralogically immature sediments sourced from metamorphic rock (NW) and deposited by paleocurrent in southeasterly direction.

The relationship between p wave and s wave is dynamic, and it is majorly a function of terrain. Knowing the relationship between p wave and s waves for any particular terrain is of vital important for both seismic exploration and geotechnical analysis. The aim of this research work is to establish an absolute relationship between the p waves and s wave seismic velocities within the basement complex. This factor (ratio) will be a guide to a better estimate of shear wave velocity during data analysis that will enhance exploration and site characterization in areas where vertical geophones will be exclusively used for data acquisition. With a bid to achieving this aim, seismic survey was carried out within some locations in the basement complex. The data was processed to generate the p wave velocity models and s wave velocity models independently. The result revealed that both the p waves and s waves from the tomographic model generally increase with depth. The ratio of these p waves and s waves velocities ranges between 1.767981 to 1.999435347. The average representative value for these p waves and s waves velocities ratio was determined to be 1.794860218. The result also revealed that the ratio of p waves and s waves does not genially increase with depth. Therefore, a value of 1.8 approximated to one decimal place, can be taken as a representative value for the ratio between p waves and s waves down to a depth of 40 m within the basement complex. However a value of 1.9 to 2.0 can be adopted as a ratio between p and s wave velocity within the basement complex beyond the depth of 40 m.