scholarly journals Geophysical Prospecting Using ERT and IP Techniques to Locate Galena Veins

2019 ◽  
Vol 11 (24) ◽  
pp. 2923 ◽  
Author(s):  
Julián Martínez ◽  
Javier Rey ◽  
Senén Sandoval ◽  
Mª Camen Hidalgo ◽  
Rosendo Mendoza
Keyword(s):  
Sedimentary Cover ◽  
Ore Deposits ◽  
Electrode Spacing ◽  
High Resistivity ◽  
Normal Faults ◽  
Mining District ◽  
Geophysical Prospecting ◽  
Geophysical Research ◽  
Electrical Sounding

The aim of this study is to prove the effectiveness of two electrical geophysical prospecting techniques, namely electrical resistivity tomography (ERT) and induced polarization (IP), in locating thin vein structures of metal sulphides embedded in Palaeozoic materials underlying a sedimentary cover. For this purpose, a Quaternary basin known as La Garza was selected, located in the mining district of Linares-La Carolina (Southern Spain). Galena (PbS) veins appear abundantly throughout this area, hosted in the Palaeozoic granitic bedrock. The studied veins show thicknesses from 0.5 to 2.0 m, and most present a vertical planar distribution. The veins lose their continuity below the sedimentary cover due to normal fractures that control the subsidence of the basin. During the 1980s, geophysical research campaigns were carried out in La Garza using vertical electrical sounding and failed in detecting the hidden veins. For this reason, to carry out this study, a closed regular mesh was designed, composed by eight ERT and IP profiles, with variable lengths between 315 and 411 metres. An electrode spacing between 5 and 7 metres was selected, thus allowing the granite bedrock to be reached without significantly reducing the resolution capabilities of the method. Even though ERT and IP are well-known geophysical techniques for mapping ore deposits, this is a case study that shows the advantages of the simultaneous use of both techniques (ERT and IP), over their individual application. ERT allows for reconstructing the morphology of the basin and the fractures that control it due to high-resistivity contrast between the overlying sedimentary cover and the underlaying granitic basement. However, it cannot provide any insights about their degree of mineralization. At this point, it is the IP technique that makes it possible to differentiate which are the mineralized structures. Some of these fractures produce high (above 50 mV/V) and moderate (below 50 mV/V) chargeability values, suggesting the existence of several unexploited metal veins. Furthermore, the derived models enable researchers to analyse the morphology of this sedimentary basin controlled by normal faults.

scholarly journals A Mineralogical Museum as a Geotourism Attraction: A Case Study

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 582
Author(s):  
Magner Turner-Carrión ◽  
Paúl Carrión-Mero ◽  
Israel Turner-Salamea ◽  
Fernando Morante-Carballo ◽  
Maribel Aguilar-Aguilar ◽  
...  
Keyword(s):  
Qualitative Evaluation ◽  
Geological Heritage ◽  
Assessment Model ◽  
Heritage Conservation ◽  
Ex Situ ◽  
Mining District ◽  
Mining Site ◽  
Semiquantitative Evaluation ◽  
Additional Value

The Zaruma-Portovelo mining district in Ecuador, and in particular, Portovelo City, is home to the oldest mining museum in the country. This museum, named Museo Mineralógico Magner Turner (MMMT in Spanish), is a centre that reflects, through its collections, the history and culture of this territory. This work aimed to evaluate the MMMT as a possible geosite by analysing its contributions to the geomining heritage of the Zaruma-Portovelo district, and thus, to enhance it and promote its collections as a geotouristic attraction. The work involved three phases: (i) describing the museum and its surroundings; (ii) a semiquantitative evaluation of the museum using the Brilha method and a geosites assessment model (GAM); and (iii) a qualitative evaluation using the Delphi and SWOT methodologies to define strategies and proposals for museum development. The results obtained by the semiquantitative evaluation of the geosite with the Brilha method reflect high scientific (330/400), educational (380/400) and touristic (365/400) appeal. The applied GAM shows the museum as a geosite with high principal and additional value, placing it in the Z33 field of the global valuation matrix. In addition, the semiquantitative and qualitative evaluation made it possible to describe the importance of the museum and its collections in the development of the area. The study carried out qualified the museum as a mining site with an appropriate valuation, an example of ex-situ geological heritage conservation and a basis for geotourism development.

scholarly journals GEOPHYSICAL INVESTIGATION OF GROUNDWATER POLLUTION RESULTING FROM LEACHATE FLOW AT IKOTO AND ORU DUMPSITES IN OGUN STATE OF NIGERIA

2020 ◽  
Vol 6 ◽  
pp. 1
Author(s):  
Adetoro Temitope Talabi ◽  
Taiwo Olakunle Roy-Layinde ◽  
Rasaki Kola Odunaike ◽  
Hamid Titilope Oladunjoye ◽  
Aina Opeyemi Adebanjo
Keyword(s):  
Groundwater Pollution ◽  
Health Hazard ◽  
Subsurface Layer ◽  
Groundwater Table ◽  
Electrode Spacing ◽  
Geophysical Investigation ◽  
The Road ◽  
Ogun State ◽  
Electrical Resistivity Survey ◽  
Electrical Sounding

An electrical resistivity survey was carried out to detect the level of groundwater pollution on Oru and Ikoto dumpsites respectively as it was observed that the dumpsites were sited ignoring the environmental and health hazard. The survey was conducted using ABEM model terrameter with schlumberger array for 1-D vertical electrical sounding (VES) of electrode spacing ranging from 0.25m to 4m. Four VES was conducted on each dumpsite with length between 1m to 120m. The data obtained from the field were interpreted using WINRESIST from which the curve types of each study area were identified. On Oru dumpsite, measurement of VES1 was taken on the dumpsite, VES2 was taken 20m away from the dumpsite, VES3 and VES4 were taken across the road serving as control. Here, there is indication of leachate pollution in VES1 (layer 2) and VES2 (layer 3) while VES3 and VES4 are leachate free, but this leachate present in VES1 and VES2 cannot penetrate into the groundwater table because of the stratigraphy of the area.  At Ikoto dumpsite, measurement of VES4 was taken on the dumpsite, VES1 and VES2 were taken 30m away from the dumpsite on both sides, and while VES3 was taken across the Lagos/Ibadan expressway, serving as control. There is indication of leachate pollution in VES4 (layer2) while in VES1, VES2 and VES3 there is no presence of leachate flow. The leachate present in VES4 can infiltrate into the groundwater table through the highly porous and permeable material in the subsurface layer of the location.

scholarly journals Evaluation of Salt-water Intrusion in the Coastal Area of Igbokoda, Southwestern Nigeria

2018 ◽  
Vol 6 (01) ◽  
Author(s):  
Talabi A. O ◽  
Ajayi C. A ◽  
Afolagboye L. O ◽  
Oyedele A. A ◽  
Ojo O. F ◽  
...  
Keyword(s):  
Coastal Area ◽  
Salt Water ◽  
Silty Sand ◽  
High Resistivity ◽  
Salt Water Intrusion ◽  
Southwestern Nigeria ◽  
Major Threat ◽  
Sandy Clay ◽  
The World ◽  
Electrical Sounding

Saltwater intrusion into the coastal aquifer has long been recognized as a major threat to groundwater quality around the world. Groundwater evaluation of salt water intrusions in Igbokoda coastal area, southwestern Nigeria was carried out employing combined Horizontal Profiling and Vertical electrical sounding. Two traverses each with two sounding points were occupied. The result from the survey revealed 4 to 5 major layers comprising the unconsolidated silty sand and sandy clay (overburden), clayey zone, consolidated sand zone, partly intruded salt water intruded sandy clay zone and salt water intruded clay zone. The curves were the complex types KQH, KHA, QH and HKH curves. The overburden has resistivity that ranged from 253 to 1316.7Ω-m, thickness that ranged from 0.2 m to 7m. The clayey zone had resistivity of 846.0 Ω-m and thickness of 4m. The consolidated sand zone had resistivity that ranged from 2848.7 to 2865.7Ω-m and thickness that ranged between 4 and 21m. The partly intruded salt water zone is characterized by resistivity that varies between 18.4Ω-m and 93.0Ω-m and thickness of about 7-25m. The salt water intruded zone is characterized by resistivity that ranges between 4.1Ω-m and 9.7Ω-m and thickness of 4-48m. The partly-salt water intruded zones and salt water intruded zone were characterized with low resistivity while the high resistivity zones of consolidated sand layer constitute fresh water bearing zone that could serve as boreholes in the study area.

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