Environmental conditions affecting concentrations of He,CO2, O2 and N2 in soil gases

The measurement of concentrations of volatile species in soil gases has potential for use in geochemical exploration for concealed ore deposits and for monitoring of subsurface contaminants. However, the interpretation of anomalies in surficial gases can be difficult because soil-gas concentrations are dependent on both meteorological and environmental conditions.For this study, concentrations of He, CO₂, O₂ and N₂ and meteorological conditions were monitored for 10–14 months at eight nonmineralized sites in both humid and dry environments. Gases were collected at 0.6–0.7-m depth at seven sites. At one site, gases were collected from 0.3-, 0.6-, 1.2-, and 2.0-m depths; diurnal monitoring studies were conducted at this site also. Rain and snowfall, soil and air temperatures, barometric pressure, and relative humidity were monitored at all the sites. The sand, silt and clay content, and the organic carbon content of surficial soil were measured at each site.Meteorological conditions generally affected He and CO₂ concentrations in the same way at all the sites; however, these effects were modified by local environmental conditions. Both seasonal and diurnal concentration changes occurred. The most important seasonal concentration changes were related to rain and snowfall and soil and air temperatures. Seasonal changes tended to be larger then the diurnal changes, but both could be related to the same processes. Local conditions of soil type and organic content affected the amount of pore space and moisture present in the soil and therefore the soil-gas concentrations.     

Geochemistry of soil gas in the seismic fault zone produced by the Wenchuan Ms 8.0 earthquake, southwestern China

The spatio-temporal variations of soil gas in the seismic fault zone produced by the 12 May 2008 Wenchuan Ms 8.0 earthquake were investigated based on the field measurements of soil gas concentrations after the main shock. Concentrations of He, H₂, CO₂, CH₄, O₂, N₂, Rn, and Hg in soil gas were measured in the field at eight short profiles across the seismic rupture zone in June and December 2008 and July 2009. Soil-gas concentrations of more than 800 sampling sites were obtained. The data showed that the magnitudes of the He and H₂ anomalies of three surveys declined significantly with decreasing strength of the aftershocks with time. The maximum concentrations of He and H₂ (40 and 279.4 ppm, respectively) were found in three replicates at the south part of the rupture zone close to the epicenter. The spatio-temporal variations of CO₂, Rn, and Hg concentrations differed obviously between the north and south parts of the fault zone. The maximum He and H₂ concentrations in Jun 2008 occurred near the parts of the rupture zone where vertical displacements were larger. The anomalies of He, H₂, CO₂, Rn, and Hg concentrations could be related to the variation in the regional stress field and the aftershock activity.     

Fracture detection and groundwater flow characterization using He and Rn in soil gases,Manitoba, Canada

Surveys of the distribution and migration of He and Rn were carried out in the well-characterized granitic terrane of the AECL Underground Research Laboratory (URL), Manitoba as part of a joint AECL Research, United Kingdom Department of the Environment, and United States Department of Energy research initiative. The investigations were designed to determine whether concentrations of He and Rn in soil gases could be used to identify locations of groundwater recharge and discharge from bedrock fractures. The results obtained indicate that subsurface transport of He and possibly Rn in this setting appears to be controlled largely by the groundwater flow system in the bedrock. Release of dissolved gases near the ground surface causes soil gas anomalies, which reflect discharge from the deeper flow system. In the recharge area of the deep groundwater flow system at the URL site, He abundances are close to the atmospheric level, but the discharge area of the deep flow system is characterized by significant He anomalies (up to 0.5 ppm above atmosphere levels). For Rn, the recharge area has broadly distributed high concentrations, probably caused by local Rn production in U-rich overburden, while the discharge area has only localized concentrations of Rn, which are not at the same location as the He anomalies. The general nature of the groundwater flow regime in both areas is reflected in the presence and distribution of the soil gas anomalies. In addition, major fractures in bedrock, which act as preferential groundwater flow paths, have been located from soil gas anomalies, even when obscured by overburden of variable thickness and character. The distribution of He in soil gas appears to be most representative of groundwater recharge and discharge conditions in the granitic rock, while Rn may be useful for locating specific channels where more rapid groundwater discharge is occurring from deep fracture zones.     

Analysis of long- and short-term temporal variations of the diffuse CO2 emission from Timanfaya volcano,Lanzarote, Canary Islands

Reported herein are the results of eight soil CO₂ efflux surveys performed from 2006 to 2011 at Timanfaya Volcanic Field (TVF), Lanzarote Island with the aim of evaluating the long- and short-term temporal variations of the diffuse CO₂ emission. Soil CO₂ efflux values ranged from non-detectable up to 34.2 g m⁻² d⁻¹, with the highest values measured in September 2008. Conditional sequential Gaussian simulations (sGs) were applied to construct soil CO₂ efflux distribution maps and to estimate the total CO₂ output from the studied area at the TVF. Soil CO₂ efflux maps showed a high spatial and temporal variability. Total CO₂ emission rates ranged between 41 and 518 t d⁻¹, February 2011 (winter) being the season when maximum diffuse CO₂ emission rates were observed. To investigate the influence of external variables on the soil CO₂ efflux, a geochemical station (LZT01) was installed at TVF to measure continuously the soil CO₂ efflux between July 2010 and March 2012 Since external factors such as barometric pressure, rainfall, soil water content, soil and air temperatures, and wind speed influence strongly the observed soil CO₂ effluxes, multiple regression analysis was applied to the time series recorded by the automatic geochemical station LZT01 to remove the contribution of these external factors. The influence of meteorological variables on soil CO₂ efflux oscillations accounts for 13% of total variance, with barometric pressure, rainfall and/or soil water content having the most influence in the control of the soil CO₂ efflux. These observations along with the results from the eight soil gas surveys performed at TVF indicate that the short and long-term trends in the diffuse CO₂ degassing are mainly controlled by environmental factors.     

Meteorological noise in crustal gas emission and relevance to geochemical exploration

The emission of gas from the earth's crust is a complex process influenced by meteorological and seasonal processes which must be understood for effective application of gas emission to geochemical exploration. Free mercury vapor emission and radon emanation are being measured in a shallow instrument vault at a single nonmineralized site in order to evaluate these influences on gas emission.Mercury concentrations in the instrument vault average 9.5 ng/m³ and range from < 1 ng/m³ to 53 ng/m³ with a strong seasonal effect. Mercury has a direct relationship to vault temperature, air temperature, soil temperature, barometric pressure, water table, and the frozen or thawed state of the soil. Air and soil temperature, barometric pressure, and relative humidity are most important in influencing mercury emission while soil moisture is also important in radon emanation. Diurnal cycles are common but do not occur on all days. A heavy precipitation event on a dry soil seals the soil resulting in a rise in mercury concentration. Precipitation on a soil that is already wet does not increase mercury emission because of the compensation caused by lowering of the soil temperature by the precipitation event. Freezing of the soil changes the physical state of the vault-soil-soil gas-atmosphere system and emits the lowest concentrations of mercury. Phase lag effects are likely important. Stepwise multiple regression of mercury as dependent variable with meteorological and seasonal parameters as independent variables gives a cumulative R value of 0.563 and R² of 0.317. The short-term noise coupled with phase lags are an important factor.The radon measurements integrated over weekly intervals smooth out much of the short-term noise. Stepwise multiple regression of radon as dependent variable with meteorological and seasonal parameters as independent variables gives a cumulative R value of 0.967 and R² of 0.934. In this portion of the study the variation in the radon emanation is adequately predicted by meteorological and seasonal parameters.     

Radon in soil gas: How to identify anomalies caused by earthquakes

Anomalies have been observed in Rn content in soil gas from 3 boreholes at the Orlica fault in the Krško basin, Slovenia. To distinguish the anomalies caused by environmental parameters (air and soil temperature, barometric pressure, rainfall) from those resulting solely from seismic activity, the following approaches have been used: (i) deviation of Rn concentration from the seasonal average, (ii) correlation between time gradients of Rn concentration and barometric pressure, and (iii) regression trees within a machine learning program. Approach (i) is much less successful in predicting anomalies caused by seismic events than approaches (ii) and (iii) if ±2σ criterion is used and is equally successful if ±1σ is used. Approaches (ii) and (iii) did not fail to observe an anomaly preceding an earthquake, but show false seismic anomalies, the number of which is much lower with (iii) than with (ii). Model trees are shown to outperform other approaches. A model has been built which, in the seismically non-active periods when Rn is presumably influenced only by environmental parameters, predicts the concentration with a correlation of 0.8. This correlation is reduced significantly in the seismically active periods.     

Seasonal variations of helium,radon, and uranium in lake waters near the Key Lake uranium deposit,Saskatchewan

To test the usefulness of the He method for the detection of buried U ore, a lake-water survey of the Key Lake area was carried out during March 1977 and repeated in June 1977. A set of 87 lake-water samples from 37 sites in eight different lakes were collected from the same sites in each survey. These samples were analyzed for He, Rn, O₂, Eh, pH, conductivity, alkalinity, and U.In the lakes the highest He concentrations, of nearly four times atmospheric equilibrium concentrations, were obtained during the winter survey. This was under the ice in two bottom lake samples where the sandy overburden extends for some 50 m directly to the ore zone. Radon and U values at these sites were also anomalous, but the highest values of Rn and U were obtained in a shallow lake about 2 km south of the ore zone where concentrations of radioactive boulders occur.The average net He and Rn contents dropped from 21 standard nanolitres/litre (nl/l) and 25 picocuries/litre (pCi/l) in the winter under the ice to 3 nl/l and 8 pCi/l in the summer, respectively. Average U and conductivity dropped from 2.3 ppb and 15 μmho/cm to 1.5 ppb and 11 μmho/cm, respectively, in the same suites of samples. The drop in the ionic species probably reflects the effect of snow and ice meltwater dilution and the much larger drop in the dissolved He and Rn reflects the combined effects of meltwater dilution, wind turbulence over ice-free lakes, and change in thermal gradients.The He results must be viewed with guarded optimism until a detailed investigation is completed to ascertain what fraction of the detected He is from the ore, what fraction from basement He that may have found its way into the lakes via the fracture zone in which the ore is located, and what effect drilling has had on the He flow into the lakes from the ore zone.     

玉树Ms7.1级地震甘达村段构造地球化学特征

为探究地震对断层带气体逸出的影响和震后气体地球化学特征随时间的变化,以及地震动力学特征,利用土壤气地球化学方法,于2010年4月14日青海玉树Ms7.1级地震断层甘达村段测量地表破裂特征和震后断层气氡和汞浓度,发现断层带土壤的气氡和汞浓度的平均值分别为9246 Bq/m3和4.2 ng/m3。破裂带中Rn浓度变化幅度大,而Hg的浓度变化较小。断层主滑面附近Rn浓度相对降低,为地表破裂后断层气逃逸所致。泉水气氡观测发现,震前氡浓度增高,表明地震断层活动性增强。因此巴颜喀拉地块向东不均匀挤压,使深部气体沿地震断裂逃逸至地表,这也是造成断层带气氡、汞浓度的增高的原因。     

Source apportionment and distribution of atmospheric mercury in urban Beijing,China

The concentration of gaseous elemental mercury (GEM) in the atmosphere of urban Beijing was measured from October 2003 to September 2004 to investigate the origins and spatial-temporal variations of atmospheric Hg. The mean value of Hg concentration is 17.1 ng·m-3 (n=653). The atmospheric Hg data showed spatial-temporal variations throughout the duration of our observation. The maximum GEM concentration (53.7 ng·m-3) was observed at Gucheng in the western area of urban Beijing. The GEM concentrations increased from the north to the south of the studied area, and were higher in winter than in summer. The highest and lowest monthly averages of GEM concentrations were measured to be 23.3 and 4.1 ng·m-3 in January and July, respectively. In addition, GEM concentrations are higher in the daytime than at night in Autumn and from 14 March to 15 April, but daily GEM variation showed an inverse pattern from 22 April to 22 May. In winter, two peak values of GEM concentrations occurred at 13:30 and 21:30. Daily variation of GEM concentrations in summer was the lowest in the four seasons. Mercury from coal combustion was estimated to be the main source of anthropogenic emissions in Beijing from October 2003 to September 2004. Additionally, Hg emission from natural gas burning was estimated to be another dominant source of atmospheric Hg in Beijing.     

Soil radon in winter months under snowpack in Hokkaido, Japan

Soil radon (²²²Rn) has been monitored during winter months under cool-temperate deciduous stands of different surface geology in Tomakomai and in Sapporo, Hokkaido, Japan. Radon level was lower in Tomakomai of immature soil of porous volcanic ash emitted from an active volcano (Mt. Tarumae), compared with those in Sapporo of alluvial sediments. In Tomakomai, mean value of the ²²²Rn activity concentration was higher in winter (570 Bq m^?3) than in summer (350 Bq m^?3) at a depth of 1 m, which is consistent with the results in cold and dry winter reported in the literature. In contrast, soil radon decreasing with decreasing soil temperature from mid-September (5.0 kBq m^?3) remained low (2.6 kBq m^?3) under persistent snow in Sapporo, which had already been observed in the same location. Measurements of the activity concentrations of ²²²Rn in snow and in snow air as well as in soil air indicate that the small amount of ²²²Rn is released from the ground surface to the overlying snowpack with a ²²²Rn flux density of 0.4 mBq m^?2 s^?1 under thick snow cover in Sapporo.     

汶川M_s 8.0地震破裂带CO_2、CH_4、Rn和Hg脱气强度

地震活动断裂带能够向大气释放大量的温室气体、放射性气体和有毒气体(CO_2、CH_4、Rn和Hg),并对大气环境的影响产生复杂的影响。利用静态暗箱法,对汶川M_s8.0地震破裂带CO_2、Rn和Hg脱气强度进行实地测量,并计算了CO_2和Hg脱气对大气的年贡献量。结果表明:(1)破裂带土壤气中CO_2、CH_4、Rn和Hg异常浓度最大值分别可以达到7.98%、2.38%、524.30k Bq/m~3和161.00ng/m~3;破裂带CO_2、Rn和Hg脱气平均通量是34.95g·m~(-2)d~(-1)、36.11m Bq·m~(-2)s~(-1)和26.56ng·m~(-2)h~(-1),最大值分别达到259.23g·m~(-2)d~(-1)、580.35m Bq·m~(-2)s~(-1)和387.67ng·m~(-2)h~(-1);(2)汶川Ms8.0地震破裂带向大气脱气的CO_2年贡献量是0.95Mt,Hg的年贡献量是15.94kg。汶川Ms8.0地震破裂带破裂CO_2、CH_4、Rn和Hg等的脱气强度,不仅与破裂带渗透率有关,还与断裂带浅部存在的气藏、煤层以及磷矿层等气体源有重要的联系。     

Soil–gas monitoring: A tool for fault delineation studies along Hsinhua Fault (Tainan), Southern Taiwan

Many studies have shown the soil gas method to be one of the most reliable investigation tools in the research of earthquake precursory signals and fault delineation. The present research is aimed finding the relationship between soil gas distribution and tectonic systems in the vicinity of the Hsinhua Fault zone in the Tainan area of Southern Taiwan. More than 110 samples were collected along 13 traverses to find the spatial distribution of Rn, He, CO₂ and N₂. The spatial congruence of all the gases shows that N₂ is the most probable carrier gas of He, whereas CO₂ seems to be a good carrier gas of Rn in this area. From the spatial distribution of Rn, He, CO₂ and N₂ the trace of Hsinhua Fault and neotectonic features can be identified. The spatial distribution of studied gases shows a clear anomalous trend ENE–SWS along the Hsinhua Fault.     

Radon concentrations in soil gas,considering radioactive equilibrium conditions with application to estimating fault-zone geometry

A calculation method for determining the amount of Rn isotopes and daughter products at the start of measurement (CRAS) is proposed as a more accurate means of estimating the initial Rn concentration in soil gas. The CRAS utilizes the decay law between ²²²Rn and ²²⁰Rn isotopes and the daughter products ²¹⁸Po and ²¹⁶Po, and is applicable to α-scintillation counter measurements. As Rn is both inert and chemically stable, it is useful for fault investigation based on the soil gas geochemistry. However, the total number of α particles emitted by the decay of Rn has generally been considered to be proportional to the initial Rn concentration, without considering the gas condition with respect to radioactive equilibrium. The CRAS method is shown to be effective to derive Rn concentration for soil gases under both nonequilibrium conditions, in which the total number of decays increases with time, and equilibrium conditions, which are typical of normal soil under low gas flux. The CRAS method in conjunction with finite difference method simulation is applied to the analysis of two active fault areas in Japan, and it is demonstrated that this combination could detect the sharp rises in ²²²Rn concentrations associated with faults. The method also allows the determination of fault geometry near the surface based on the asymmetry variation of the Rn concentration distribution when coupled with a numerical simulation of ²²²Rn transport. The results for the new method as applied to the two case studies are consistent with the data collected from the geological survey. It implies that the CRAS method is suitable for investigating the fault system and interstitial gas mobility through fractures. The present analyses have also demonstrated that high Rn concentrations require the recent and repeated accumulation of ²²²Rn parents (²³⁰Th and ²²⁶Ra) in fault gouges through deep gas release during fault movement.     

Laboratory investigation of factors affecting mercury emissions from soils

This study was performed to identify the individual and combined effects of the most important parameters that control mercury (Hg) emissions from soil surfaces: temperature, UV-B exposure, and soil water content. Both soil temperature and UV-B exposure positively affected Hg emissions; however, the increment in Hg emissions was significantly different between wet and dry soils. Mercury emissions from wet soil were more sensitive to an increase in soil temperature than dry soil; however, at constant temperature dry soil emissions were more sensitive than wet soil to changes in UV-B exposure. It was also observed that even after the relative humidity in the soil pores (RH_sp) dropped to nearly 0, the Hg emissions were still higher for initially wet soil than for dry soil, suggesting that initially high water content continued to promote Hg reduction mechanisms for an extended period. These results show the interacting effects of soil moisture with other important parameters. At constant water content, Hg emissions increased the most when the soil was exposed to UV-B radiation, followed by UV-A radiation. With UV-C exposure, atmospheric Hg deposition and O₃ destruction were simultaneously observed.     

Helium, carbon dioxide and oxygen soil gases: Small-scale variations over fractured ground

To investigate the control on small-scale variation of He in soil gas exercised by minor fracturing, shallow surveys have been carried out over a cave system formed along an approximately orthogonal set of fractures in Devonian limestone in southwest England. The possibilities that He variation could be related to deep-seated, major fractures or hidden mineralisation, and that other soil gases may also be affected by minor fracturing were assessed by contemporary surveys for CO₂ and O₂. Comparisons of soil gas values with variations in electrical apparent resistivity were also carried out. Location of fractures with direct connection to the cave system was determined by spiking the cave atmosphere with He and then resurveying after equilibration.The results for CO₂ and O₂ show anomalies of low magnitude (with respect to atmospheric concentrations), and although they display an antithetic relationship, this is generally poor. There is also no strong correlation with the results of the He surveys either before or after spiking, or with the apparent resistivity values. Moreover, anomalies in CO₂ + O₂ do not support the pattern of variation shown by the individual gases. These negative results suggest the absence of deep-seated fractures or hidden mineralisation, and show that CO₂ and O₂ values are independent of minor fracturing. The origin of the variation is attributed to bacteriological productivity.He soil gas concentrations were obtained as disequilibrium values relative to Field Atmospheric Air (ΔHe/ppb-FAA). Positive ΔHe values were generally found to correlate with areas of thin, dry soil cover, enhancement occurring along fracture lines. Negative ΔHe values were also found to correlate with fracture lines, but in these areas the fractures are overlain by a thick soil cover with a high moisture content. It is considered that distinctions can be drawn between water-conducting and dry fractures, and that negative ΔHe values are likely only to be encountered with shallow soil gas samples. Results of spiking with He show a clear distribution of enhanced values along the set of orthogonal fractures, irrespective of the sign of the natural He anomaly. It is considered, therefore, that major deep-seated fractures may result in positive He anomalies superimposed upon negative ΔHe values. This implies that He anomalies must always be related to a local datum value. It is concluded that resolution of interacting variables in the interpretation of soil gas data is facilitated by integrated soil gas surveys.     

Uranium prospecting with Rn in frozen terrain

Published reports show that ²²²Rn contents of soil gas can increase under snow-covered or frozen soils. By utilizing these observations and results of field tests described here, it can be stated that U prospecting with ²²²Rn in frozen terrain is practicable.Rn profiles in frozen and snow-covered soils over U mineralization in the Bancroft area of Ontario outlined known radioactive zones more clearly than did scintillometer profiles.Tests in Gatineau Park, Quebec, in the proximity of a radioactive pegmatite dike showed that lake ice acts as a restrictive barrier to Rn movement from lake waters beneath. Water samples, collected and allowed to freeze in plastic bottles, retained dissolved Rn quite effectively thus permitting sample collection and storage under the most severe winter conditions. Rn sampling of through-ice lake waters is therefore a feasible prospecting tool.Samples of spring run-off (snow-melt) waters and slushy snow collected from within a known weakly radioactive zone near South March, Ontario, were shown to contain less Rn than found in the same stream waters in the summer. No pronounced Rn degassing event of frozen soils was apparent early in the spring thaw in percolating run-off waters draining from the zone. The usefulness of spring thaw hydrogeochemistry using Rn is discussed.     

冻土地区三角形块石路基与水平块石路基的保冷效果研究

Time varying temperatures and pore-air velocities in two gravel embankments, horizontal and triangular gravel embankments, are studied using the "Rock-Block model" and the results are visualized in the form of isotherms and velocity vectors for different times of the year. Simulation results show that for both the two embankments there is a counter-clockwise rotation of pore-air extending throughout most of the embankment during winter months, whereas in summer the pore-air rotation changes to the opposite. The pore-air velocities in the triangle gravel embankment are somewhat higher than those obtained from the horizontal gravel embankment. The stronger convection in winter enhances the upward transport of heat out of the triangle gravel embankment, thus having more apparent cooling effect than the horizontal gravel embankment. During summer months, the pore-air velocities are nearly the same for both the two embankments. The results of the present study show that though the two gravel embankments have the effect of cooling the permafrost beneath, the temperature fields in the triangle gravel embankment are a little lower and more stable compared with those gotten from the horizontal gravel embankment, showing that the triangle gravel embankment has more apparent cooling effect than the horizontal one.     

A 12,000-Year Pollen Record from Lake Maliq, Albania

Pollen data from Lake Maliq, the first from Albania, contribute new information to the discussion of the vegetational, hydrological, and climatological history of the Balkans since 12,000 yr B.P. During late-glacial time, a perennial lake expanded at Maliq. It was surrounded by a complex vegetation association composed of steppe and mixed forest elements. The highly diverse forest flora suggest that late-glacial forest refugia were more developed here at middle altitude, rather than at higher altitude as previously suggested. The forest developed after 9800 yr B.P., while the water level remained high in the Korçë basin until 5000 yr B.P. Different environmental conditions, characterized by lower available moisture and warmer winters, progressively took place after this date. Human activity in the Korçë basin ca. 4500 yr B.P. was coeval with conditions characterized by an increase in winter temperatures and a decrease in summer moisture.     

藏北高原土壤湿度时空变化分析

使用2009年DOY (Day of Year) 145~288时段与2001~2010年夏季(DOY 161~240时段)的Terra/MODIS 16 d合成的植被指数产品数据MOD13 A2和8 d合成的地表温度(Land Surface Temperature,T_LS)产品数据MOD11 A2,构建T_LS~I_EV(Enhanced Vegetation Index,I_EV)特征空间,从而得到了条件温度植被干旱指数(Temperature Vegetation Drought Index,I_TVD)反映的藏北土壤湿度空间分布。对藏北高原2009年植被生长季内土壤湿度的季节性变化及2001~2010年夏季土壤湿度的年际变化特征进行分析,研究结论表明:随着植被盖度的增大,干、湿边斜率逐渐变小,植被对环境温度的变化具有缓冲效应;藏北高原土壤湿度的季节性变化明显,主要受温度、降水、植被覆盖和冻土过程等季节性变化的影响;近10年研究区内土壤湿度有轻微的旱化趋势,但不同气候区内的年际变化表现不一致;气温表现不同程度的显著升温趋势,部分站点的降水有不显著减少趋势,其它站点降水表现为年际波动,而区域统计的I_TVD值年际波动与站点气温的变化大体一致。     

Study of radon in soil gas,trace elements and climatic parameters around South Kordofan state,Sudan

This study was conducted primarily to measure and map radon activity concentration in soil gas and to understand the effect of geology and lithology and meteorology on radon concentration. Portable radon meter has been used for the measurement of soil gas radon at 30 different locations around Uro and Korn area in eastern Nuba Mountain South Kordofan State. The results indicate that the activity concentrations of ²²²Rn in soil gas fall within the range of 20–1,359 Bq/m³ with geometric mean of 102.80 Bq/cm³. The obtained data show that samples around Uro have anomaly of ²²²Rn concentrations than the sample around Korn. The reason could be attributed to differences in the geological structure, lithology and climate parameters. GIS predicative map has shown that the elevated levels of radon concentration were measured in North study area. Upon comparing the results with global data, it was found that the obtained values are far below the reported range of India, Slovenia, Portugal and Syria. However, the range of ²²²Rn concentrations in the soil observed in this study is significantly high relative to similar data reported from Libya. The regression analysis has shown that no correlation was noted between radon concentrations, climatic parameters and trace element.