Earth Science

Natural environmental conditions of Iran and its geographical location that falls in the arid belt in one hand, and overuse of non renewable resources in the other hand, cause series of problems and conditions that brings the country into a rapid deterioration. the two main factors of degrdation are natural factors and human factors. Of major natural factors, three factors are notable: climatic, geomorphologic and morphologic. In this study to evaluate the desertification condition regarding to local conditions of the study area, two processes of water and wind erosion were selected and assessment of desertification condition was conducted Based on these processes, wheightening indicators and MEDALUS model. The results showed that Qs and NQts all responsible for much of sentiment delivery and erosion and as a result, desertification severity of these two geological units considered as severe and very severe.

Estimating the annual volume of the aquifer basin is of the main issues in designing the aquifer projects. Since the aquifer basin of central Iran covers half of country and a great number of the aquifer basins are situated in the arid and semi arid regions of the hydrometric stations, their watering figures are estimated by experimental models. The general structure of these models in some cases brings about considerable differences in the estimated and observed figures resulted from an incorrect selection of a model. This study has made use of 9 experimental formulas of Justin, Lisi, the world Meteorology Organization ratio, Agricultural Research Association of India, ICAR, Khosla, Turc, the Irrigation Department of India, and Inglis and De Souza for calculating the annual runoff in the water basin of Iran. Therefore for selecting the basins with the least annual natural and artificial Debi changes, the equal aquifer basins with an area less than 300 square kilometer which had no stank and vast agricultural lands which had little to middle degree of penetrability were firstly chosen. In selecting and determining the basin border two soft wares, Google earth, and ArcGIS were used, then the geological, climatological, and land applicability maps of the studied basin were prepared and their hydro climatologic statistics in the common 30-year-old time limit (1976- 2005) were extracted. At the end, the annual runoff altitude of the selected stations was determined using the aforementioned 9 ratios and these outcomes were compared with the observed data of the stations using four methods MAPE, RMSE, t distribution, and the unilateral analysis variance. The results show the superiority of Khosla to the other methods in the arid and semi arid regions. The estimated data in both arid and semi arid climates were studied separately, in both cases Khosla was selected as the most appropriate method.

Twenty five ditch cutting samples from southwest Niger Delta basin were analysed to determine the palynostratigraphic studies. The samples contained very rich and diverse palynomorphs dominated by pollen grains which consist of 12 species distributed among ten genera. Pollen preservation is good with concentration ranging from 1,640 to 34,900 grains/g. The stratigraphic ranges of Circulina parva, Monoporites annulatus, Psilatricolporites operculatus, Multiareolites formosus, Zonocostites ramonae, Podocarpus milanjianus, Echitricolporites spinosus, Retibrevitricolporites obodoensis, R. protrudens and Retitricolpites bendensis and some other marker species were used to demarcate nine palynozones in the study area. These palynomorphs are mainly made up of mangrove swamp floras which suggest the predominance of a high sea level and wet climatic condition in Miocene-Pliocene during the deposition of the studied sediments.

Gurpi formation (Companian-Maestrichtian) is one of the importance formations that include as a Cap rock for reservoirs Sarvak in south west of Iran. Assessment of Gurpi formation facies in the wells A,B and C lead to know ten microfacies that related to facies belts of middle ramp and outer ramp. Outer ramp’s facies are allocate the maximum thickness in these wells. Field studies and assessment of vertical facies changes in sequence lead to know main surface of sequence in studied area. This formation have been formed of two sequences (3rd cycles). Sequences are separated by sequence boundaries type of 1 and 2 (SB1 and SB2).

Twenty one (21) rock samples were systematically collected during geological mapping of the study area, while 10 representative samples were selected for geochemical and petrography studies. Six lithologies including Quartzite, Quartz-biotite schist, Banded gneiss, pegmatite, biotite gneiss and biotite schist with well defined boundaries were recognized and mapped in the study area. Thin sections were prepared from the rock, and were studied under the research Petrological Microscope. The results of the petrographic analysis of the thin sections revealed that minerals such as quartz, biotite, muscovite and feldspar (plagioclase, orthoclase and microcline) of variable composition were present in the slides. The presence of these minerals could be as a result of the type and nature of magma responsible for the emplacement of these rocks. However, quartz is the most resistant and dominant mineral in all the slides analyzed. Geochemical analysis was also carried out on the rock samples to determine the trace and rare earth elements in them. The results of the trace elements detected in (ppm) includes; Ba (338), Cd (0.054), Ce (42.19), Rb (129.99), S (0.036), Sr (42.7), Th (4.94), Y (4.97), Zn (29.39), Co (39.18), Cs (1.97), Cu (3.86), Li (5.02) Ni (18.05) and W (179.05). The rare earth elements include; Dy (1.68), Eu (0.58), Ga (9.89), Gd (2.70), Hf(1.07), La (20.69), Nd (18.05), Pr (4.92) and Sm (3.40). The results above revealed that Ba, W, Rb, Ce are extremely high in the rocks of the study area which indicate that the rocks are highly radioactive in nature. The concentration of radioactive elements such as Ba, Rb, Ce are useful in energy provision and modern warfare business. Nevertheless, radioactive elements may produce X-ray which can affect the skin and causes skin cancer and other related diseases. Therefore, detailed exploration program to discover hidden natural resources is hereby recommended for the study area.

This study attempts the evaluation of the geogenic release metals due to weathering of basement rock on the shallow groundwater system around Ilesha and environs. The study involves collection of twelve (12) soil samples over four (4) soils profiles. In addition to a total of nineteen (19) groundwater samples obtained from shallow dug wells <25m in areas surrounding the sampled soil profiles. Geochemical analysis revealed the presence of SiO2, Al2O3, MgO, CaO, Na2O, K2O, MnO, P2O5 and Cr2O3 as the major oxides. Ruxton Ratio depicts weathering intensity decreasing from Muscovite schist (MS) > Amphibolite (AS) > Talc schist (TS) > Quartzite quartz schist (QS). Physico-Chemical results of water samples revealed a slightly acidic to basic water with electric conductivity values of 443µS/cm, 94µS/cm and 267µS/cm for the AM, QS and MS respectively. Hydro-geochemical analysis of the groundwater samples indicate the presence of major cations and trace elements and further analysis revealed the order of mean cations abundance for the mafic unit to be Ca2+>Mg2+>Na+>K+, and Ca2+>Na+>K+>Mg2+ for the felsic. Groundwater around the mafic bedrocks shows high concentration of the major cations, except for Potassium (K), thereby revealing a relationship that correspond to the mineralogy of the bedrock and weathered profile.

In recent decades, drought events caused many adverse effects on humans and environment, notably in arid and semi-arid regions of the world. This many worsen the desertification process and throw away many opportunities. Several droughts have been occurred in Sistan plain south eastern Iran, and the most recent one (1999-2006) said to be the worst drought in the past 600 years and has much negative environmental, economical and social effects. In this study, changes of vegetation cover was assessed using the pre and past drought data. After interpreting the results, it was found that quantity and quality of plants reduced by 100% and that much of changes occurred in abandoned lands. Moreover, it was discovered that the main causes of plant cover desertification are natural factors and human factor of mismanagement.

This study was conducted with a view to identify the socio-economic characteristics of processors of Vitellaria paradoxa and Parkia biglobosa; to examine the role of the rural dwellers in the sourcing and processing of V. paradoxa and P. biglobosa; to examine the different benefits that accrue to commercial processing of V. paradoxa and P. biglobosa and to investigate strategies put in place for sustainable use of V. paradoxa and P. biglobosa in the study area. Three (3) Local Government Areas were purposively selected for the study and purposive random sampling method was adopted for the selection of respondents. Primary data were obtained through the use of questionnaires while secondary data was gathered from relevant literature. Data collected were analyzed using descriptive statistical tools and gross margin analysis. The result showed that 90% of Vitellaria paradoxa and 94.3% of Parkia biglobosa processors were female. Majority of the processors of V. paradoxa (77.1%) and P. biglobosa (58%) fell within the age range of 21-40 years. Fruits of V. paradoxa (84.3%) and seeds of P. biglobosa (77.1%) were obtained from processors farmlands as a result of the relative availability of the trees on their farmlands. The remaining processors of V. paradoxa (15.7%) and P. biglobosa (22.9%) had no trees on their farmlands so they gathered the fruits and seeds from and around forest lands. 84.37% of V. paradoxa and 88.5% of P. biglobosa processors indicated that income was the main economic benefit derived from this business while social benefits highlighted by the respondents ranged from produce been used as food, medicine, condiment and cosmetic. The result also showed that processors of V. paradoxa incurred more costs, produced more output and had a higher average gross return in processing than P. biglobosa processors. The RORI for the processing business in the study area was 51% and 96%. To promote sustainability the people have adopted local means of sustaining production by preventing indiscriminate livestock grazing and bush burning.

Bitumen is a hydrocarbon material that accumulates near the earth's surface in the form of asphalt springs or in other forms under the act of hydrostatic pressures of oil reservoirs, it will form bitumen mines after undergoing polymerization process. This mineral (organic) matter is in close relationship to oil reservoirs present in the area, i.e. when oil moves or migrates from one place to another place some part of it will be separated and will remain in the form of streaks, lenses and etc. In this work, the exploration of bitumen resources in Saleh-Abad area, Ilam is carried out using geoelectrical data that were gathered in two-dimensional form, exploration drilling data and also geological data. Today the best method for underground studies and mineral explorations is geophysical studies and drilling exploration wells meanwhile. One of the best data acquisition methods in the Geoelectricity is two-dimensional data acquisition or in other words electrical imaging in two dimensions. Tomography or electrical apparent resistivity tomography is a geophysical technique that investigates underground structures in two or three dimensions. The advantage of ERT method in comparison with other traditional and routine methods is that it investigates the changes of electrical apparent resistivity either laterally (constant spacing traversing or CST) or vertically (vertical electrical sounding, VES) in space. Geophysical data acquisition of the mentioned mine was done using dipole-dipole array in two profiles upon which some points were proposed for exploration drilling. Exploration drilling was done in powder method on the geophysical profiles in six 15-meter bores which proved the high precision of apparent resistivity method for bitumen exploration. Interpretation and modeling of two profiles was carried out using RES2DINV and modeling of drilling Logs was done using LOGPLOT that both had a good conformity with geological data and surface outcrops.

The application of finite-difference time-domain (FDTD) numerical modeling and Hilbert transformation for the image enhancement and detection of buried engineering utilities using surface ground-penetrating radar (GPR) technique is demonstrated in a typical sedimentary terrain of Lagos Nigeria. Accurate delineation and precise location of such subsurface features is of effective use for engineering and environmental studies. A traverse magnetic (TM-) mode formulation was adopted for the models; and perfectly matched layer (PML) absorbing boundaries were implemented for wave absorption at the modeling grid edges. Four synthetic models were developed; three single-layer models of a single pipe buried at depth (z) of 2m, two pipes 10m apart and concrete bars buried at z=1.5m, and one double-layered model of multiple pipes buried at z=1.5m. The electrical properties of the models are; single-layered earth-system (vadose zone): ?_r=9, ?=1mS/m ; pipes: ?_r=12, ?=1mS/m, bars: ?_r=16, ?=1mS/m. The two-layered subsurface, had a thin-layer of air-earth interface of ?_r=1 and ?=0, upper layer of vadose zone sediment and lower-layer (saturated zone) of ?_r=25 and ?=5mS/m. The µ was set equal to its free space value, µ_0 for all the materials. The 2D GPR data acquired in some parts of Southwestern Nigeria and processed using basic functions such as dewow, filtering and application of gains. The resulting GPR radargrams were subjected to advanced attribute analysis using Hilbert transformation (HF) in order to establish the suitability of HF for GPR signal image enhancement that would aid the interpretation of the location of the buried utilities. The model investigations revealed that the electrical and the magnetic properties of the medium hosting the buried utilities, and the depth of burial plays a major role in controlling the image resolution obtained in a sedimentary terrain. The results from the field data are in general agreement with the numerical FDTD modeling experiments.