scholarly journals The Magnetometry—A Primary Tool in the Prospection of Underground Water

2020 ◽  
Author(s):  
Héctor López Loera
Keyword(s):  
High Probability ◽  
Underground Water ◽  
Arid Zones ◽  
Magnetic Survey ◽  
Aeromagnetic Survey ◽  
Electrical Sounding ◽  
Electrical Methods ◽  
Ground Magnetic ◽  
The One ◽  
Semi Arid

One of the most important problems in arid and semi-arid zones in the Mexican Mesa Central is the one related to the exploration and exploitation of groundwater. It is found at depths over 200 m, and movement is primarily through fractures. This work presents a geophysical methodology, which shows the potential of combining natural and induced methods to locate confined aquifers in fault zones. The study begins by interpreting the aeromagnetic survey, mainly by searching alignments associated with low magnetic anomalies, which are correlated with faults zones, and/or fractures and/or geologic contacts where ferromagnetic minerals have undergone oxidation due to their association with recharged zones. These aeromagnetic alignments are confirmed on land by a ground magnetic survey. Based on these interpretations, electrical methods include sections and vertical electrical sounding are used to verify if the zones are correlated to the underground moisture. If both permeability and moisture are met together, then they considered as zones with a high probability of locating ground water in the Mexican Mesa Central.

Magnetic survey – ground technology, aeromagnetic survey on aircraft and unmanned aerial vehicles: a comparative analysis of the results (on the example of Eastern Transbaikalia)

2020 ◽  
Vol 26 (8) ◽  
pp. 6-15
Author(s):  
R. Gruzdev ◽  
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Geophysical Methods ◽  
Work Productivity ◽  
Field Work ◽  
Magnetic Survey ◽  
Aeromagnetic Survey ◽  
Aerial Vehicles ◽  
Eastern Transbaikalia ◽  
Actual Material ◽  
Ground Magnetic

The use of unmanned aerial vehicles (UAVs) in geophysical work is becoming a very popular area in the field of modern geological exploration. The advantage of unmanned systems is the optimal ratio of the quality of research results with a significant increase in work productivity and a decrease in cost. In this regard, the improvement of field techniques and the processing of UAV materials is of particular interest for exploration. On the subject, there are a number of unresolved issues that have been revealed to some extent as a result of the author’s comparison of ground-based magnetic exploration and aeromagnetic survey data. The purpose of the study was to assess the possibility of a full-fledged replacement of ground magnetic exploration work for aeromagnetic survey using unmanned aerial vehicles. The comparison of different types of magnetic survey is relevant, since on the basis of the actual material, the possibility of using an alternative more productive method – aeromagnetic survey using modern UAVs – instead of traditional expensive ground-based magnetic exploration works is analyzed. To compare the results of the studies, actual material obtained from field work on an area of 13,4 km2 was used. Based on the databases, maps of anomalous magnetic field and graphs on several geophysical profiles are built. Results of magnetic survey in air and ground versions are analyzed; correlation relationships between data of ground pedestrian magnetic survey and aeromagnetic system on An-3 and UAV aircraft are established. Based on the results of the study, correlation and determination coefficients were obtained, which indicate that geophysical methods on UAVs adequately occupy their place between classical aerogeophysics and ground-based pedestrian survey. Moreover, aeromagnetic survey using UAVs is able to replace pedestrian magnetic exploration during work at the same heights. Based on the results of the study, methodological recommendations for the production of aeromagnetic survey on UAVs were compiled

Interpretation of the magnetic anomaly over the Omaha Oil Field, Gallatin County, Illinois

Geophysics ◽  
1994 ◽  
Vol 59 (7) ◽  
pp. 1092-1099 ◽  
Author(s):  
Mark A. Sparlin ◽  
Richard D. Lewis
Keyword(s):  
Magnetic Anomaly ◽  
Primary Source ◽  
Oil Field ◽  
Magnetic Feature ◽  
Magnetic Survey ◽  
Aeromagnetic Survey ◽  
Data Set ◽  
Interesting Possibility ◽  
Ground Magnetic ◽  
Structural Closure

A 40 nanoTesla (nT) magnetic anomaly identified in an aeromagnetic survey over southern Illinois contours as a localized magnetic high on the west flank of a regional magnetic low. This magnetic anomaly is generally coincident with the Omaha Oil Field in northwest Gallatin County, Illinois. It was initially assumed that cultural sources of steel associated with this oil field were the primary source of the magnetic feature; however, similar oil fields overflown by the survey do not exhibit magnetic anomalies in the data set. The Luther Rister et ux ♯1 well, drilled near the apex of the Omaha structural dome, encountered two zones of ultramafic intrusive rock containing 9.0 percent by volume magnetite. These intrusives were identified to be alnöites which are a class of mantle‐derived ultramafic rock that can be associated with the incipient stages of crustal rifting. A ground magnetic survey verified the presence of the anomaly, and provided detailed data for 3-D modeling of the source. Petrophysical evaluations, magnetic susceptibility measurements and thin section modal analysis were made on drill cuttings from the ultramafic intrusives encountered in the Luther Rister ♯1 well. These measurements were made to constrain the 3-D magnetic modeling by the petrophysical characteristics of the source. After removal of the regional magnetic field, the resulting 140 nT residual magnetic anomaly was successfully modeled using two ultramafic sills with an igneous feeder plug. The two igneous sills adequately account for the structural closure exhibited in the Omaha Oil Field and raise the interesting possibility of other hydrocarbon trapping structures generated by intrusives emplaced into the sedimentary section.

Airborne geophysical surveys in Greenland – 1996 update

1997 ◽  
pp. 75-79
Author(s):  
Robert W. Stemp
Keyword(s):  
Mineral Exploration ◽  
Geological Mapping ◽  
Digital Data ◽  
Magnetic Survey ◽  
Aeromagnetic Survey ◽  
West Greenland ◽  
South West ◽  
Geophysical Surveys ◽  
The Government ◽  
Airborne Geophysical Data

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Stemp, R. W. (1997). Airborne geophysical surveys in Greenland – 1996 update. Geology of Greenland Survey Bulletin, 176, 75-79. https://doi.org/10.34194/ggub.v176.5069 _______________ Two major airborne geophysical surveys were carried out in 1996, the third year of a planned five-year electromagnetic and magnetic survey programme (project AEM Greenland 1994–1998) financed by the Government of Greenland, and the second year of an aeromagnetic survey programme (project Aeromag) jointly financed by the governments of Denmark and Greenland; both projects are managed by the Geological Survey of Denmark and Greenland (GEUS). The two 1996 surveys were: 1) Project Aeromag 1996 in South-West and southern West Greenland;2) Project AEM Greenland 1996 in South-West Greenland. All areas surveyed and planned for future surveys as of March 1997 are shown in Figure 1. Results of both the 1996 surveys were released in March 1997, as a continuation of a major effort to make high quality airborne geophysical data available for both mineral exploration and geological mapping purposes. The data acquired are included in geoscientific databases at GEUS for public use; digital data and maps may be purchased from the Survey. The main results from the 1996 surveys are described in Thorning & Stemp (1997) and Stemp (1997). Two further new airborne surveys have already been approved for data acquisition during the 1997 field season, with subsequent data release in March 1998. A summary of all surveys completed, in progress or planned since the formal inception of project AEM Greenland 1994–1998 is given in Table 1. The programme was expanded to include a separate regional aeromagnetic survey in 1995, provisionally for 1995–1996, with extension subject to annual confirmation and funding.

Ground magnetic survey for the investigation of magnetic minerals at Iboro Village, Abeokuta, south-western Nigeria

2021 ◽  
Vol 20 (2) ◽  
pp. 99-106
Author(s):  
O.I. Popoola ◽  
O.A. Adenuga ◽  
E.O. Joshua
Keyword(s):  
Magnetic Anomalies ◽  
Geological Structure ◽  
Magnetic Survey ◽  
Magnetic Minerals ◽  
Contour Maps ◽  
Ogun State ◽  
Geological Map ◽  
Regional Gradient ◽  
Ground Magnetic ◽  
Iron Ore Deposit

The geological map of the old western region of Nigeria indicates the presence of iron ore deposit at Iboro village Ogun state (7.9983o - 7.99933o N, 3.5790o - 3.5890o E). Hence a ground magnetic survey was carried out at a location at Iboro village so as to delineate the subsurface magnetic anomalies and to know whether the anomalies favour accumulation of magnetic minerals. The survey was carried out using high resolution proton precession magnetometer model G-856X. Eight traverses were run at 5m separations and earth magnetic intensity values were measured at 10m intervals along each traverse; the acquired data were corrected for drift. The residual anomalies obtained by removal of regional gradient from observed data using trend analysis were presented as profiles and maps. The treated data were qualitatively and quantitatively interpreted and the results gave values for the total ground magnetic anomalies that varied between a minimum and maximum peak values of about -33.0 and 30.6nT respectively. Depth to the basement rock was estimated using Peter’s half slope method which gave a maximum depth of about 13m. The contour maps and the total relative graphs present the subsurface picture of the geological structure that is assumed to harbour the metallic minerals through the action of the field towards the concentration of anomalies. It was suspected that the overburden was relatively thin in the study area and the minerals were at a shallow depth.

Resolving Optimum Magnetic Signatures for Drill-Hole Targeting in Gold Exploration – A Case Study for Mbudzane in Gwanda, Zimbabwe

2013 ◽  
Vol 3 (1) ◽  
pp. 9-29
Author(s):  
Dumisani John Hlatywayo ◽  
Emmanuel Sakala
Keyword(s):  
Drill Hole ◽  
Magnetic Survey ◽  
Gold Exploration ◽  
Rock Formations ◽  
Induced Polarisation ◽  
Line Spacing ◽  
Magnetic Signatures ◽  
Ground Magnetic ◽  
Tilt Derivative ◽  
Resistivity Image

Optimum magnetic signatures for drill-hole targeting in gold exploration in Mbudzane were resolved from induced polarisation-resistivity and magnetic anomalies. Total magnetic field and a gold-in-soil map showed the area is magnetically quiet with high anomalous values along old gold workings. Induced polarisation was carried out along a grid for lines of 500m length, 50m separation and a baseline oriented at 330˚. The survey comprised a gradient array and three real sections. The magnetic survey was conducted over the same grid as the induced polarisation. Stations were set at 5m intervals for a line spacing of 50m. The results show intense anomalies that suggest different degrees of magnetic alteration and a set of conjugate lineaments and faults that possibly control the mineralisation in Mbudzane. The tilt derivative of the reduced-to-pole image resolves the separation between anomalies, giving information on the faulting. High chargeability is confined to the sheared and silicified mafic schist. The gradient resistivity image revealed contact between rock formations. Real section IP shows coincident low chargeability – low resistivity anomalies close to the surface. Chargeability intensity increases with depth, suggesting incipient development of disseminated sulphide replacement zones. A strong correlation between ground magnetic inferred contacts and apparent resistivity-chargeability anomalies forms the basis for suggesting a new drill-hole targeting. They dictate both the depth and angle at which drilling should be carried out. These results should be applicable to any region where drill-hole targeting in gold exploration may be required.

scholarly journals The demography of desert Australia

2008 ◽  
Vol 30 (1) ◽  
pp. 29 ◽  
Author(s):  
Dominic Brown ◽  
John Taylor ◽  
Martin Bell
Keyword(s):  
Economic Policy ◽  
Arid Zone ◽  
Policy Implications ◽  
Population Projections ◽  
Research Centre ◽  
Arid Zones ◽  
Demographic Information ◽  
The Impact ◽  
First Time ◽  
Semi Arid

In recent years, with the formation of organisations such as the Desert Knowledge Cooperative Research Centre, social science interest in the Australian desert has re-surfaced with a research emphasis that is focused on creating sustainable futures for the region. One consequence of this is a demand for detailed demographic information to allow an assessment of different quanta of need in social and economic policy, and for assessment of the impact of these in environmental policy. However, demographic analysis on human populations in the desert to date has attracted very little research attention. In this paper we begin to address this lack of analysis by focusing on the populations, both aboriginal and non-aboriginal, of the arid and semi-arid zones of Australia. We extend earlier analysis by including for the first time demographic information on the semi-arid as well as the arid zone to establish the spatial pattern of population growth within the whole desert area drawing attention to the resulting settlement structure as an outcome of prevailing social, cultural and economic conditions. By examining population structure and demographic components of population change we also present for the first time population projections for the semi-arid zone and, therefore, in combination with the arid zone, for the entire Australian desert. All of this provides a basis for considering social and economic policy implications and the nature of underlying processes that drive change in this region.

scholarly journals Advances in Agronomic Management for Ensuring Fodder Security in Semi Arid Zones of India- A Review

2018 ◽  
Vol 7 (2) ◽  
pp. 1912-1921
Author(s):  
Hanamant M. Halli ◽  
S.S. Rathore ◽  
N. Manjunatha ◽  
Vinod Kumar Wasnik
Keyword(s):  
Arid Zones ◽  
Agronomic Management ◽  
Semi Arid

scholarly journals Biochemical profile and bioactive potential of wild folk medicinal plants of Zygophyllaceae from Balochistan, Pakistan

2020 ◽  
Author(s):  
Alia Ahmed ◽  
Amjad Hameed ◽  
Shazia Saeed
Keyword(s):  
Medicinal Plants ◽  
Total Phenolic ◽  
Arid Zones ◽  
Standard Drug ◽  
Aerial Parts ◽  
Fruit Samples ◽  
Pharmaceutical Industries ◽  
Inhibitory Potential ◽  
Bioactive Potential ◽  
Semi Arid

AbstractRecent focus is on analysis of biological activities of extracts from plant species. Zygophyllaceae is exceedingly important angiosperm family with many taxa being used in folk medicines widely dispersed in arid and semi-arid zones of Balochistan, Pakistan. Only a small proportion of them have been scientifically analyzed and many species are nearly facing extinction. Therefore present investigation explores the biochemical and bioactive potential of fourteen folk medicinal plants usually used for treatments of different ailments. Fresh aerial parts of nine taxa and two fruit samples were collected from plants growing in arid and semi-arid zones of Balochistan and analyzed for enzymatic, non-enzymatic and other biochemical activities. Higher phytochemical activities were detected in the aerial parts. Superoxide dismutase was detected maximum in Fagonia indica, (184.7±5.17 units/g), ascorbate peroxidase in Tribulus longipetalus subsp. longipetalus (947.5±12.5 Units/g), catalase and peroxidase was higher in Peganum harmala (555.0±5.0 and 2597.8±0.4 units/g respectively). Maximum esterase and alpha amylase activity was found in Zygophyllum fabago (14.3±0.44 and 140±18.8 mg/g respectively). Flavonoid content was high in T. longipetalus subsp. longipetalus (666.1±49 μg/ml). The highest total phenolic content and tannin was revealed in F. olivieri (72125±425 and 37050±1900 μM/g. respectively). Highest value of ascorbic acid was depicted in F. bruguieri var. rechingeri (448±1.5 μg/g). Total soluble Proteins and reducing sugars were detected higher in P. harmala (372.3±54 and 5.9±0.1 mg/g respectively). Maximum total antioxidant capacity (TAC) was depicted in Z. simplex (16.9±0.01 μM/g). Pigment analysis exhibited the high value of lycopene and total carotenoids in T. terrestris (7.44±0.2 and 35.5±0.0 mg/g respectively). Chlorophyll a, b and total chlorophyll content was found maximum in T. longipetalus subsp. pterophorus (549.1±9.9, 154.3±10 and 703.4±20.2 ug/g respectively). All taxa exhibited anti-inflammatory activity as well as anti-diabetic inhibitory potential. Seed extracts of Zygophyllum eurypterum (96%) exhibited highest inhibitory potential, along with twelve other taxa of Zygophyllaceae indicated (96-76%) activity when compared with the standard drug diclofenac sodium (79%). Seeds of T. longipetalus subsp. longipetalus (85%) exhibited the highest anti-diabetic activity; other eleven taxa also exhibited inhibitory activity of α-amylase ranging from (85-69%) compared with Metformin (67%) standard drug. Phytochemical screening revealed that selected taxa proved to be the potential source of natural antioxidants and could further be explored for in-vivo studies and utilized in pharmaceutical industries as potent therapeutic agents validating their ethno-pharmacological uses.

scholarly journals The Effect of Formation Processes on The Frequency of Palaeolithic Cave Sites in Semi-Arid Zones: Insights From Kazakhstan

2021 ◽  
Author(s):  
Aristeidis Varis ◽  
Christopher Miller ◽  
Patrick Cuthbertson ◽  
Abay Namen ◽  
Zhaken Taimagambetov ◽  
...  
Keyword(s):  
Central Asia ◽  
Arid Zones ◽  
Arid Environments ◽  
Formation Processes ◽  
Cave Deposits ◽  
Central Asian ◽  
Cave Sediments ◽  
Analytical Potential ◽  
Sediment Cover ◽  
Semi Arid

Central Asian caves with Palaeolithic deposits are few but they provide a rich record of human fossils and cultural assemblages that has been used to model Late Pleistocene hominin dispersals. However, previous research has not yet systematically evaluated the formation processes that influence the frequency of Palaeolithic cave sites in the region. To address this deficiency, we combined field survey and micromorphological analyses in the piedmont zone of south Kazakhstan. Here we present our preliminary results focusing on selected sites of the Qaratau mountains. Sediment cover varies among the surveyed caves and loess-like sediments dominate the cave sequences. The preservation of cave deposits is influenced by reworking of cave sediments within the caves but also by the broader erosional processes that shape semi-arid landscapes. Ultimately, deposits of potentially Pleistocene age are scarce. Our study provides new data in the geoarchaeologically neglected region of Central Asia and demonstrates that micromorphology has great analytical potential even within the limitations of rigorous survey projects. We outline some of the processes that influence the formation and preservation of cave deposits inKazakhstan, as well as broader implications for the distribution of Palaeolithic cave sites in Central Asia and other semi-arid environments.

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