ПРИМЕНЕНИЕ МЕТОДОВ ЭЛЕКТРОМЕТРИИ ПРИ ИЗУЧЕНИИ РОССЫПНЫХ МЕСТОРОЖДЕНИЙ ЗОЛОТА ХАБАРОВСКОГО КРАЯ

Cassava mill effluent (CME) contains a significant concentration of different hazardous inorganic components, especially cyanide (CN) and cyanogenic glucosides which can result in environmental problems. This study seeks to evaluate the impacts of CME on groundwater and the level of leachate infiltration into the subsurface in a cassava processing site using integrated geophysical and geochemical techniques in Apete. 3-D Electrical Resistivity Imaging (ERI), Vertical Electrical Sounding (VES) and geochemical evaluations alongside well inventories were used to characterize and delineate the subsurface lithology to determine the extent of leachate infiltrations in the study area. A 2D electrical resistivity survey was performed along five (5) profile lines, each 70m long and spaced 5m apart, using the Wenner configuration with varying electrode spacings. This survey was complemented by a 1D electrical survey to produce a 3D output and three (3) Vertical Electrical Soundings (VES) at locations where cassava effluents accumulated. The measured resistivity values were multiplied by the geometric factors to calculate apparent resistivity, which was then processed through ZONDRes3D resistivity and IP inversion software to create inverted 3D resistivity models. The resulting models were analyzed using X, Y, and Z directional slice cuts. The 3-D resistivity images of the array were meticulously analyzed in terms of depth slices, resistivity inclines, and crosslines. The depth slices revealed leachate infiltration extending up to 40m, characterized by a resistivity ranging from (6-63Ωm Ωm) across the x-direction, displaying a diminishing trend with profile depth where points of low resistivity value (≤10 Ωm) were identified as highly contaminated with CME. Varied levels of infiltration were observed at different distances. The results of three (3) VES revealed low resistivity values ranging from 13.0 to 65.5Ωm in APETEVES1, 18 to 104.6Ωm in VES 2 while the control VES displayed resistivity values of 103.8 to 340.9 Ωm in all the identified four layers. The results of the water level measurement and geochemical evaluations revealed depths of 1.77m to 4.60m which were inferred to be very shallow while Mn, Cd and Pb in the groundwater samples were found to be above the limits of set standard and occurrences were b attributable to the infiltration of CMEs into the subsurface groundwater system. The study found varying resistivity values in the soil, indicating leachate contamination that diminishes with depth. The low resistivities and shallow wells highlighted the extent of the groundwater system’s vulnerability to contamination from cassava effluents.

Oceanographic conditions associated with high abundances of the radiolarian Cycladophora davisiana

The marine and continental sediments which occur in Imperial Valley may be divided into the following formations. 1. Split Mountain formation: Miocene (?) marine and continental sediments. 2. Alverson Canyon formation: Miocene (?) non-marine sediments and associated volcanic flows. 3. Imperial formation: Miocene marine sediments. 4. Palm Spring formation: Miocene and/or Pliocene marine and non-marine sediments. 5. Borrego formation: Lower Pleistocene (?) non-marine sediments. Surface and well data indicate that at least 14,000 feet of sediments were present west of Salton Sea at the end of deposition of Borrego formation and as much as 25,000 feet of sediments may be present in the central part of Salton Sink. Structurally Imperial Valley is a series of parallel fault blocks. The general trend of the major faults is N. 55° W. Two of these faults which are well known and extend beyond Imperial Valley are the San Jacinto and San Andreas. The sediments have two structural alignments, one sub-parallel with the major faults and the other trending east-west. On the basis of surface data the possibility of obtaining commercial quantities of natural gas or crude oil appear to be very meager. Although a composite section of 22,000 feet of sediments is exposed at many places in the western part of Imperial Valley, only 3,600 feet are of definite marine origin. The writer has observed no indication of petroleum except for small quantities of methane gas, comparable to that in many present-day swamps, in the non-marine sediments of the Palm Spring and Borrego formations. End_of_Article - Last_Page 2385------------

Assessment of groundwater potential zones using the electrical resistivity method was carried out in Hong, Hong local government of Adamawa State, northeastern Nigeria, for the purpose of determining possible sites for drilling boreholes, the lithology of the area, and the thickness of the geo-electric layers. Ten Vertical Electrical Soundings (VES) were sounded in the area with ABEM SAS 1000 Terameter. The maximum electrode spacing was 100 m. The Schlumberger array was used for the geophysical survey and data acquisition. Qualitative and quantitative techniques were used for data interpretation of the raw data obtained from the fieldwork; 1XD Interpex software was used to interpret the data. Possible groundwater potential zones were detected out of ten (10) VES points. VES 5, 6, 7, 8, 9, and 10 were potential zones for groundwater exploration due to the presence of fractured/weathered basement zones and low resistivity values. It has depth ranging from 50 m to 30 m to aquifer level. While VES points 1, 2, 3, and 4 do not possess groundwater because they were of high resistivity values.

This work is meant to set a new stratigraphic framework of the Quaternary Hergla Sea Cliff deposits in eastern Tunisia including vital precisions concerning depositional environments and climatic conditions. Infrared stimulated luminescence (IRSL) data previously obtained at the Hergla region show that the Khniss unit is Tyrrhenian in age (MIS 5.5), while the Rejiche unit dates to the MIS 5.3/5.1 undifferentiated by the IRSL for the marine deposits and attributed to the MIS 4 for the dunes continental deposits. The sedimentological studies showed that the whole of the marine units of the Upper Pleistocene of Hergla were deposited in a shallow marine environment and also highlighted at least two major transgressive cycles interrupted by drops of the sea level leading to emergence. The first cycle corresponds to the Khniss unit deposit. The second cycle corresponds to the transgression of the Rejiche unit. The end of the MIS 5.5 is marked by a lagoonal sedimentation with a regressive tendency followed by an emergence period materialized by the presence of a paleosol. During the MIS 5.3/5.1, the marine deposits of the Rejiche unit correspond to infratidal carbonate sediments subjected to storms currents. They are characterized by the reworking of lithoclasts, due to the action of the storm currents. Eventually, the study of cements in the continental deposits of the Rejiche unit indicates a late evolution in a continental vadose environment, subjected to the action of meteoric waters. In terms of climatic conditions, the MIS 5.5 was hotter and wetter than the subsequent MIS 5.3/5.1.

Based on novel data and a literature review, an inventory of Harpacticoida from the northern part of the East Sea and the southern part of Sea of Okhotsk is compiled. A total of 151 species belonging to 70 genera and 26 families, of which 16 species are deemed to be new to science, are recognized from the region. Twelve harpacticoid species assemblages are described from marine and brackish water soft sediments and the phytal zone. Estuarine faunas were similar throughout the East Sea and Sea of Okhotsk, both in species composition and dominant-taxon structure. Conversely, the fauna of marine soft sediment and phytal zones differed greatly throughout this region. This distinction may have been caused by differences in dispersal rates or by differences in environmental conditions. The distribution of littoral and sublittoral harpacticoids was determined primarily by climatic factors and the temperature of surface waters. Three basic sub-regions were distinguished within the survey area: Korean, which includes many tropical taxa (39%) and a smaller amount (about 20%) of boreal taxa; Primorye, where boreal and subarctic-arctic species (>40%) predominate, and representatives of the tropical complex are rare (17%); and Soya, with a mix of tropical (22%) and boreal (31%) faunal elements. The faunas of the Korean and the Primorye sub-regions are distinct, whereas that of the Soya has intermediate features.

A geoelectric study of aquifers in the Essaouira coastal region, Morocco

The Shantar Islands is an archipelago in the western part of the Sea of Okhotsk, at a distance of about 50 km from the mainland coast. In August 2019, we have carried out mycological studies on the islands of Bolshoi Shantar and Prokofiev. An annotated list is given of 103 species first found in the national park; 21 species of them were found in Khabarovsk Territory for the first time. The Shantar Islands are geographically the northernmost area in the Khabarovsk Territory, where specialized mycological studies were carried out. Such new species for the region as Cortinarius acutus, C. bivelus, C. traganus, Chromosera lilacina, Laccaria bicolor, in the Russian Far East were previously known only from more northern regions: Magadan Region, Kamchatka, Chukotka, Yakutia and from the taiga zone of Amur Region. Taking into account previously published data, a total of 105 species of agaricoid basidiomycetes are known for the national park.

Aquatic macrophytes of the Kava River basin in northern Okhotsk area are represented by 4 species of macroalgae and 51 species and 4 hybrids of vascular plants. Flora of the Magadan Region was completed by 3 species and 3 hybrids: Aegagropilopsis moravica, Equisetum arvense × E. scirpoides, Elatine aff. triandra vel americana, Potamogeton × vepsicus, Sparganium chlorocarpum and S. chlorocarpum × S. gramineum. Almost all species of aquatic vascular plants protected in the Magadan Region (10 out of 11) are concentrated and abundant in the Kava River basin, 3 “red listed” species in the Khabarovsk Territory were also found in its basin and with a high abundance. Basing on floristic diversity, water bodies are grouped according to the similarity of environmental conditions, and not according to their geographical location. Almost all diversity of aquatic macrophytes is concentrated in lakes. The lake-river system of the Chukcha River, one of the major tributary of the Kava River, is distinguished here by the greatest diversity and concentration of rare taxa, because it is the most isolated from the cold sea winds. Rich aquatic flora and vegetation in the Kava River basin had emerged and are now sustained due to the special favorable microclimatic conditions of the closed valley of a large river, the existence of numerous water bodies of different ages and genesis with a wide variation in hydrological and hydrochemical parameters, the possibility of moving the propagules of aquatic plants along a well-developed lake-river network. The unique lake-river system of the Kava River requires increased attention and protection.

Based upon a comprehensive study of 123 copper deposits in China, this paper reaches the following conclusions: 1. The crust in China was solidified pretty late; with the accretion of the plate, the copper mineralization moved towards its margin in space and became successively younger in age. 2. The major copper ore types ever found in the world have mostly been discovered in China, in which the porphyry type seems to be the most important and the massive sulfide type in the transitional bed between marine clastic and carbonate rocks is clearly defined. 3. Carbonate strata are widespread in China and their deposition lasted for a long geological period, so the proportion of copper deposits occurring in them is large as compared with other parts of the world. 4. Seven metallogenic epochs can be recognized, in which the Mesozoic one plays the leading role and the middle (late) Palaeozoic and Cenozoic ones are next in importance. Mineralization was comparatively simple in the early geological period, and became diversified later on. In the early epochs copper deposits related to basaltic magmatism and metamorphosed marine sediments predominated, whereas in the later epochs those. related to granitic magmatism and continental sedimentation were dominant. 5. There exist in China thirteen metallogenic provinces, of which the Lower Yangtze downwarping belt, Sanjiang fold system, Jiangnan axis and Xikang‐ Yunnan axis are of greater significance. 6. The crustal mobility in China was rather pronounced, the polycyclic evolution of the crust has resulted in such obvious phenomena as the inheritance of mineralization, the coexistence of various types and the superposition of different genetic types.

Integrated geophysical techniques including resistivity image, vertical electrical sounding (VES), and seismic refraction have been conducted to investigate the Wadi Hanifah water system. The groundwater in Wadi Hanifah has problems caused by the high volumes of sewage water percolating into the ground. The combination of VES, resistivity image, and seismic refraction has made a valuable contribution to the identification of the interface between the contaminated and fresh water in Wadi Hanifah area. The contaminated groundwater has lower resistivity values than fresh groundwater due to the higher concentration of ions which reduces the resistivity. Resistivity image and sounding in this area clearly identified the nature of the lithological depth and proved useful at identifying water-bearing zones. Fresh groundwater was found in the study area at a depth of 100 m within the fractured limestone. Water-bearing zones occur in two aquifers, shallow contaminated water at 10 m depth in alluvial deposits and the deeper fresh water aquifer at a depth of about 100 m in fractured limestone. The interface between the contaminated water (sanitary water) and fresh water marked out horizontally at 100 m distance from the main channel and vertically at 20 m depth.

Groundwater resources across the country are swiftly heading towards depletion and quality deterioration. This study extensively examines the geological and hydrostratigraphic complexities in Thal Doab area, Punjab, Pakistan offering valuable insights into its subsurface lithology and groundwater quality. Data from twenty five (25) Vertical Electrical Soundings (VES) using Schlumberger electrode configuration were carefully analyzed, and calibration of resistivity models was performed by comparing them to lithological borehole logs to ensure their accuracy. The study establishes a fundamental connection between subsurface lithology and resistivity values, revealing four to six geo-electric sub-layers comprising the intermixing of clay, silt, sand, gravel, and kankar inclusions. These layers exhibit resistivity ranging from very low (<20 Ω-m) to very high (>230 Ω-m) at various depths. 2D/3D aquifer models identify the higher resistivity areas with promising good-quality groundwater primarily within sand, gravel, and kankar layers, while lower resistivity values indicate marginally suitable or saline/brackish groundwater within fine sediments like clays/silts. Groundwater quality improves significantly at depths below 75 m, suggesting sustainable water extraction potential. However, caution is advised while drawing water from depths below 50 m due to the presence of saline or brackish water, posing challenges due to limited recharge potential. The study emphasizes the importance of Indus and Chenab rivers, canal systems, and precipitation in the processes that recharge groundwater.

An integrated geophysical and hydro-chemical investigation was carried out in the area around the Stadium-Apollo Market waste dump located in Igboya area of Ile-Ife. It was with the aim of determining the geoelectric characteristics and groundwater chemistry which were used in delineating the subsurface sequence and evaluating the possible pollution of groundwater in the area. Eight Vertical Electrical Sounding (VES) stations were occupied along two traverse lines trending North-South and East-West directions. Dipole-Dipole profilings were also carried out along same traverses. Eight water samples were collected from hand dug wells and analyzed for some chemical elements such as total acidity, major ions (Na+, K+, Cl-, Mg2+, Ca2+), NO3- and heavy metals (Cd, Cu, Fe, Hg, and Pb). Results of the investigation indicate that a maximum of four subsurface layers- the top soil, clay/sandy clay unit, the weathered layer and the basement bedrock exist in the area. The weathered layer constitutes the main aquifer unit with thicknesses of between 7 and 38 m. From the 2-D resistivity structures, contaminant plumes characterized by relatively low resistivity values (< 150 ohm-m) were identified down to depth of about 40 m in some places. Hydro-chemical results showed that the total acidity and concentration of Na+ Cl- and heavy metals (Cd, Cu, Fe, Hg and Pb) in wells closest to and down slope of the waste dump (total acidity 5.1-10.0 mg/l; Na+ 8.92-11.07 mg/l; Cl- 127.62-297.78 mg/l; Cd, 0.006-0.009 mg/l; Cu, 0.330-1.840 mg/l; Fe, 2.300-4.600 mg/l; Hg, 1.247 mg/l and Pb, 0.260 Mg/l) are higher than concentrations in distant wells, and most of them (Cl-, Cd, Cu, Fe, Hg, and Pb) exceeded national and international drinking water quality standards. It can be concluded that the groundwater in the area had been contaminated and the plume had migrated to a significant depth.KEYWORDS: Geophysical, Hydro-chemical, Waste Dump, Groundwater Quality, Pollution

One well-known cause of groundwater contamination in developing nations that produce oil is oil leaks. Oil leaks are typically caused by a variety of circumstances, such as inadequate management and upkeep of oil facilities, equipment failure, and pipeline vandalism by oil criminals. This research evaluates the movement of underground oil contaminants in an oil production field at the Okordia clan's Ikarama hamlet in the Yenagoa Local Government Area in the state of Bayelsa. Schlumberger array was utilized in order to apply the electrical resistivity tomography technique along three (3) VES surrounding the oil spill spot. Values for resistivity were found. In the locations under study, three (3) vertical electrical soundings (VES) were conducted. Comparison of theoretical soil resistivity to measured fluid resistivity for various caption exchange Values of capacity have been researched. The resistivity values, when reversed, ranged from 0.17 m to 146.8 m. The hydrocarbon contamination (oil plumes) is the cause of the high resistivity values (21.54 – 146.8 Ωm) and the low resistivity values (0.1–15.8 Ωm). The 2D resistivity approach is an effective tool for examining pollution caused by hydrocarbon in a coastal environment, as this study has proven.

Mesozoic gold mineralization in Hainan Province of South China: Genetic types, geological characteristics and geodynamic settings