Mapping of apparent magnetic susceptibility and the identification of fractures: A case study from the Eye-Dashwa Lakes pluton, Atikokan, Ontario

Geophysics ◽  
2010 ◽  
Vol 75 (3) ◽  
pp. B147-B156 ◽  
Author(s):  
Madeline D. Lee ◽  
William A. Morris ◽  
Hernan A. Ugalde
Keyword(s):  
Magnetic Susceptibility ◽  
Forward Modeling ◽  
Local Scale ◽  
Magnetic Data ◽  
Susceptibility Map ◽  
Magnetic Minerals ◽  
Data Set ◽  
Susceptibility Data ◽  
Apparent Susceptibility

In situ magnetic-susceptibility measurements are only possible on outcrops, which are often limited by overburden and water bodies. An alternative approach is to derive an apparent susceptibility map from total-magnetic-intensity (TMI) surveys, which was done in this study for the Eye-Dashwa Lakes pluton near Atikokan, Ontario. Susceptibility logs of cores directly link alteration to systematic changes in the amount and composition of magnetic minerals. The surficial distribution of alteration zones was originally estimated from a limited number of in situ magnetic-susceptibility measurements. Here, through forward modeling of the TMI data set, susceptibility data are used to validate the apparent susceptibility data set. The modeling accounts for the bathymetric surface of all lakes that cover the area. A two-step process of bulk and local-scale modeling was used to estimate apparent susceptibility patterns. Bulk magnetic susceptibility is used as an indicator of overall alteration content, and local-scale apparent magnetic-susceptibility values are computed using a forward-modeling routine. The new apparent magnetic data set indicates northwest and northeast linears, which are the same as those seen in previous studies.

Anisotropy of out-of-phase magnetic susceptibility as a tool for tracking heavy metals pollution: a new approach to environmental magnetism study

2020 ◽  
Author(s):  
Katarzyna Dudzisz ◽  
Szymon Oryński ◽  
Beata Górka-Kostrubiec ◽  
Wojciech Klityński
Keyword(s):  
Heavy Metals ◽  
Magnetic Susceptibility ◽  
Magnetic Fabric ◽  
Magnetic Data ◽  
Clear Correlation ◽  
Magnetic Minerals ◽  
Severe Problem ◽  
Magnetic Fabrics ◽  
Migration Pathways

<p>Soil contamination by heavy metals has become a severe problem in many parts of the world, affecting people and other living organisms. The anisotropy of magnetic susceptibility (AMS) was successfully used to track deformation and flow directions in rocks and unconsolidated sediment, however, it has been very rarely applied to soils. In this study, magnetic susceptibility, electromagnetic (EM) methods and AMS of soils around three historical mining areas at the Sudetes Mountains (Poland) were studied. These sites are diversified in terms of exploitation time and type of ore (Zloty Stok – gold and arsenic, Janowa Gora – iron and Szklary - nickel). They were selected in order to examine the spatial spread of contamination from mine tailings, their potential sources and to test the potential use of the AMS to study migration pathways.</p><p>Magnetic susceptibility (к), GCM (ground Conductivity Electromagnetic Method) and magnetometric measurements were carried out in situ to get a spatial resolution of the magnetic data. Bartington MS2 magnetic susceptibility meter was used for mapping of к, whereas GCM measurements were made to obtain conductivity distribution from 6 different depth ranges. Magnetometric measurements were conducted with GEM GSM-19T Overhauser Magnetometer integrated with GPS, allowing for measurement of the total magnetic field and its vertical gradient. Moreover, soils samples were taken for further analyses in the laboratory. For AMS measurements, all samples were oriented northward and carefully placed into 8 ccm plastic, non-magnetic cubic boxes to prevent artificial modification of in situ magnetic fabrics. Then, these samples were measured in three mutually perpendicular positions using KLY-5 Kappabridge (Agico).</p><p>The highest values of magnetic susceptibility (1-5x10<sup>-3</sup> SI) are observed around nickel tailings, whereas the lowest values (60-120x10<sup>-6</sup> SI) characterise iron mining area. Preliminary results of GCM and magnetometry indicate the occurrence of overlapping anomalies in the studied area. Mapping of in situ magnetic susceptibility shows variability within particular sites. For Szklary, all three methods indicate the presence of the elongated anomaly roughly NE-SW oriented. Although AMS axes of in-phase susceptibility are randomly distributed for all sites, the magnetic fabric created by ferromagnetic minerals (out-of-phase, opAMS) indicate well grouped maximum susceptibility axes mainly oriented NE-SW. There is a clear correlation between mapped anomaly around nickel tailings (Szklary) and opAMS lineation. Outside the anomaly, opAMS directions are oriented SE-NW. For other sites, opAMS is also in line with the results of EM methods. Taking into account these results, as well as landforms and hydrological conditions, it could be concluded that magnetic minerals accompanied with heavy metals, most likely, migrate with subsurface runoff and opAMS is capable of detecting changes in the direction of the pollution spread. However, more study is necessary to fully explain this mechanism.</p>

ESTIMATION OF SOURCE PARAMETERS IN IBADAN, SOUTH – WESTERN NIGERIA USING DIGITIZED AEROMAGNETIC DATA

2018 ◽  
Vol 14 (2) ◽  
pp. 15-28
Author(s):  
A A ALABI ◽  
O OLOWOFELA
Keyword(s):  
Magnetic Susceptibility ◽  
Source Parameters ◽  
Granite Gneiss ◽  
Geological Structure ◽  
Magnetic Data ◽  
Susceptibility Map ◽  
Rock Types ◽  
Upward Continuation ◽  
Magnetic Basement ◽  
Local Wavenumber

Airborne magnetic data covering geographical latitudes of 7000‟N to 7030‟N and longitudes of 3 30′E to 4 00′E within Ibadan area were obtained from Nigeria Geology Survey Agency. The data were ana-lyzed to map the sub surface structure and the source parameters were deduced from the quantitative and qualitative interpretation of magnetic data. The upward continuation technique was used to de-emphasize short – wavelength anomaly while the depth to magnetic sources in the area was deter-mined using local wavenumber technique, the analytic signal was also employed to obtain the depths of the magnetic basement. Analysis involving the local wavenumber, upward continuation and appar-ent magnetic susceptibility techniques significantly improves the interpretation of magnetic data in terms of delineating the geological structure, source parameter and magnetic susceptibility within Iba-dan area.. These depth ranges from 0.607km to 2.48km. The apparent susceptibility map at the cut-off wavelength of 50 m ranges from -0.00012 to 0.00079 which agree with the susceptibility value of some rock types; granite gneiss, migmatite biotite gneiss, biotite muscovite granite, hornblende granite, quartz and schists. The result of the local wavenumber suggests variation along the profiles in the surface of magnetic basement across the study area.

Linking cave sediments and soil magnetism in the Urșilor cave (Romania)

2021 ◽  
Author(s):  
Cristian George Panaiotu ◽  
Cristian Necula ◽  
Relu D. Roban ◽  
Alexandru Petculescu ◽  
Ionut-Cornel Mirea ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Frequency Dependence ◽  
Remanent Magnetization ◽  
Rock Magnetism ◽  
Magnetic Mineral ◽  
Magnetic Data ◽  
Sediment Samples ◽  
Superparamagnetic Particles ◽  
Susceptibility Data ◽  
Cave Sediments

<p>Cyclical changes in the magnetic mineral assemblages have been observed in numerous sedimentary records confirming the relationship between rock magnetism and past global change. Several studies have shown that the magnetic susceptibility data of cave sediments reflect both long- and short-term climatic oscillations. These magnetic susceptibility variations are attributed to changes in climate-controlled pedogenesis which influence the production of low coercivity magnetic mineral phases, magnetite, and maghemite outside the cave. These soils with climate-dependent magnetic properties are then washed, blown, or tracked into the cave where they accumulate, creating the changes observed in rock magnetic data. We present a rockmagnetism study of the sediments from the Urșilor cave and the soils above the cave. Our focus is the detailed characterization of the ferromagnetic mineralogy preserved in the cave sediments and its links with potential soil sources. In the cave, we sampled four sections (2-3 m high) consisting mainly of silts and clays, with some sand layers. The age of the sediments is older than 40 ka. At the surface, we sampled various types of soils from 9 sites. For all samples, we measured: variation of magnetic susceptibility with frequency (976 and 15616 Hz), the anisotropy of magnetic susceptibility, isothermal remanent magnetization, and anhysteretic remanent magnetization. Because soils are characterized by the presence of superparamagnetic magnetite produced by pedogenesis which can be detected by the frequency dependence of magnetic susceptibility, we also measured the frequency dependence of soils and selected cave sediment samples at 13 frequencies (between 128 and 512000 Hz). Multi-frequencies measurements of the magnetic susceptibility of recent soils show that all the sampled soils have a strong frequency dependence indicating the presence of superparamagnetic particles produced by pedogenesis. Most of the sediment samples have an important frequency dependence similar to the one observed in the recent soils. As a preliminary conclusion, we can state that most of the fine cave sediments contain superparamagnetic particles, which can be probably attributed to soils transported into the cave by erosion. These results suggest that during the deposition of high magnetic susceptibility sediments it was a climate favorable for intense pedogenesis. The interpretation of the intervals with lower values of magnetic susceptibility is still under investigation to decide if represents a climatic signal or a change in the dynamics of sediment transport. <strong>Acknowledgment:</strong> The research leading to these results has received funding from the EEA Grants 2014-2021, under Project contract no. EEA-RO-NO-2018-0126.</p>

Magnetic susceptibility mapping of the Sudbury area, Ontario, Canada: evaluating pollution distributions decades later

2016 ◽  
Vol 53 (5) ◽  
pp. 466-484 ◽  
Author(s):  
A. Yurtseven-Sandker ◽  
M.T. Cioppa
Keyword(s):  
Magnetic Susceptibility ◽  
Iron Sulfide ◽  
Mine Waste ◽  
Low Frequency ◽  
Temporal Variations ◽  
Health Concern ◽  
Laboratory Measurements ◽  
Magnetic Minerals ◽  
Mining Sites

This study evaluates the use of magnetic susceptibility and magnetic parameter measurements in assessing spatial and temporal variations of pollutants that emanated from mining industries in and around Sudbury, Ontario, Canada. For this purpose, in situ magnetic susceptibility (κin situ) was measured at 106 sites on a grid of 10 km × 10 km and 5 km × 5 km. The κin situ values ranged from 2 × 10−5 to 149 × 10−5 SI, and the highest κin situ values were observed near the active (Copper Cliff) and inactive (Coniston) mining sites. The lowest κin situ values were measured at increased distances from possible pollution sources; therefore, mapping of in situ magnetic susceptibility values is a proxy to polluted areas in and around Sudbury. To evaluate potential anthropogenic and (or) lithogenic input to κin situ, low-frequency mass specific magnetic susceptibility (χlf) variations with depth were classified into four different types of profiles. For further investigation of magnetic minerals in the samples, laboratory measurements of magnetic susceptibility, frequency dependence of magnetic susceptibility, hysteresis properties, thermosusceptibility curves, anhysteretic and isothermal magnetizations, and scanning electron microscopy – energy-dispersive X-ray spectroscopy (SEM–EDS) were also conducted on the soil samples. Laboratory measurements indicated that ferrimagnetic minerals (e.g., magnetite) of variable grain size were the dominant magnetic minerals, with the exception of one site that contained an iron sulfide (greigite) phase near a mine waste site. Magnetic spherules observed in SEM micrographs are of variable sizes (6–60 μm), suggesting that suspended particulate matter (PM10) is present, and may be a health concern. At some sites, EDS analysis showed that heavy metals (Co, Al, and Ni), which threaten human health, are also present in the study area.

Palaeomagnetic and anisotropy of magnetic susceptibility data bearing on the emplacement of the Western Granite, Isle of Rum, NW Scotland

2008 ◽  
Vol 146 (3) ◽  
pp. 419-436 ◽  
Author(s):  
M. S. PETRONIS ◽  
B. O'DRISCOLL ◽  
V. R. TROLL ◽  
C. H. EMELEUS ◽  
J. W. GEISSMAN
Keyword(s):  
Magnetic Susceptibility ◽  
Country Rock ◽  
Anisotropy Of Magnetic Susceptibility ◽  
Magnetic Fabric ◽  
Contact Aureole ◽  
Data Set ◽  
The North ◽  
Early Paleocene ◽  
Magma Emplacement

AbstractThe Western Granite is the largest of several granitic bodies around the margin of the Rum Central Igneous Complex. We report palaeomagnetic and anisotropy of magnetic susceptibility (AMS) data that bear on the emplacement and deformation of the Western Granite. The collection includes samples from 27 sites throughout the Western Granite, five sites in adjacent feldspathic peridotite, and two sites in intermediate to mafic hybrid contact aureole rocks. Palaeomagnetic data from 22 of the 27 sites in the granite provide an in situ group mean D = 213.2°, I = −69.5°, α95 = 5.5° that is discordant to an early Paleocene reverse polarity expected field (about 184°, −66°, α95 = 4.3°). The discrepancy is eliminated by removing an inferred 15° of northwest-side-down tilting about a best fit horizontal tilt axis trending 040°. Data from the younger peridotite and hybrid rocks of the Rum Layered Suite provide an in situ group mean of D = 182.6°, I = −64.8°, α95 = 4.0°, which is statistically indistinguishable from an early Paleocene expected field, and imply no post-emplacement tilting of these rocks since remanence acquisition. The inferred tilt recorded in the Western Granite, which did not affect the younger Layered Suite, suggests that emplacement of the ultrabasic rocks resulted in roof uplift and associated tilt of the Western Granite to make space for mafic magma emplacement. Magnetic fabric magnitude and susceptibility parameters yield two subtle groupings in the Western Granite AMS data set. Group 1 data, defined by rocks from exposures to the east and south, have comparatively high bulk susceptibilities (Kmean, 29.51 × 10−3 in SI system), stronger anisotropies (Pj, 1.031) and oblate susceptibility ellipsoids. Group 2 data, from rocks in the west part of the pluton, have lower values of Kmean (15.89 × 10−3 SI) and Pj (1.014), and triaxial susceptibility ellipsoids. Magnetic lineations argue for emplacement of the granite as a tabular sheet from the south–southeast toward the north and west. Moderate to steeply outward-dipping magnetic foliations, together with deflection of the country rock bedding in the north, are consistent with doming accompanying magma emplacement.

scholarly journals THE USE OF ALTERNATIVE METHODS FOR DIFFERENTIATION OF BANDED IRON FORMATIONS AND IRON ORE IN THE BODY N4WS, SERRA NORTE – CARAJ´AS MINERAL PROVINCE

2016 ◽  
Vol 34 (1) ◽  
Author(s):  
Vitor Nascimento Nascimento ◽  
Adalene Moreira Silva ◽  
Catarina Laboué Benfica Toledo ◽  
Marta Henriques Jácomo ◽  
Luciano Mozer de Assis ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Physical Properties ◽  
Iron Ore ◽  
Gamma Ray ◽  
Unsupervised Classification ◽  
Alternative Methods ◽  
Magnetic Data ◽  
Mafic Rocks ◽  
Iron Formations

ABSTRACT. The use of non-traditional geophysicalmethods is becoming increasingly common in activities involving iron ore, as the increasing ore demand intensified the competition in the international market. This motivated us to integrate the physical properties of the rocks to better understand the relations of the iron ore with the proto-ore and host rocks. The work was conducted in N4WS body, Serra Norte, Caraj´as Mineral Province (CMP), located in the state of Par´a. The Caraj´asMineral Province hosts some of the largest world-class iron ore deposits in the world, operated by Vale S.A. The results of airborne magnetic data showed that the mineralized bodies previously mapped are not directly linked to the high gradients observed in the amplitude of the analytic signal. This response is related to the proto-ore, constituted by jaspilites with low values of K, eU and eTh. An unsupervised classification of these properties permitted to map individualized ore bodies. Measurements of the magnetic susceptibility and gamma radiation emission in drill holes were satisfactory. There was a clear differentiation between iron ore, jaspilites and mafic rocks, mainly in the magnetic susceptibility parameter. The gamma ray results from radioelements separated iron formations and associated mineralization from the adjacent mafic rocks. The use of the unsupervised classification k-means was useful for distinguishing between jaspilites within the same package and to show anomalous areas not previously mapped. The integration of rock physical properties, geological data and airborne geophysical data produced excellent results. There was a direct correlation between what was measured and what was observed in situ at the surface. Thus, it was possible to individualize the lithotypes in the N4WS using the physical properties. This confirms the feasibility of using these methods as an alternative to the currently used tools for iron ore exploration, with the potential to increase the efficient use of human and financial resources investments.Keywords: multisource data integration, jaspilites, gamma-ray spectrometry, rock physical properties. RESUMO. A utilização de métodos geofísicos não tradicionais está se tornando cada vez mais comum em atividades que envolvem o minério de ferro, uma vez que a alta demanda impulsiona o mercado internacional. Este avanço nos leva a integrar a assinatura das propriedades físicas de rocha para melhor entendimento do minério de ferro com o protominério e suas rochas adjacentes. O trabalho foi realizado no corpo N4WS, Serra Norte, Província Mineral de Carajás (CMP), localizado no estado do Pará. A Província Mineral de Carajás abriga alguns dosmaiores depósitos de minério de ferro de classe mundial domundo, todos explorados pela Vale S.A.Os resultados dos dados aeromagnéticos mostraram que os corpos mineralizados previamente mapeados não possuem uma ligação direta com os gradientes elevados observados na amplitude do sinal analítico. Esta resposta é relacionada ao protominério, constituído por jaspilitos de assinatura gamaespectrométrica relacionados aos baixos valores de K, eU e eTh. Uma classificação não-supervisionada confirma este padrão e individualiza as áreas mapeadas como corpos de minério. As respostas das medidas de susceptibilidade magnética e emissão de radiação gama realizadas nas sondagens dentro do prospecto foram satisfatórias. Houve uma clara diferenciação entre o minério de ferro, jaspilitos e rochas máficas, principalmente no parâmetro susceptibilidade magnética. Os resultados da gamaespectrometria separaram as formações ferríferas e minério das rochas máficas adjacentes. O uso da classificação não-supervisionada K- médias foi útil para distinção entre jaspilitos dentro do mesmo pacote e identificação de áreas anômalas não mapeadas anteriormente. A integração entre propriedades físicas de rocha, dados geológicos e dados aerogeofísicos mostrou excelentes resultados. Houve uma correlação direta entre o que foi medido e observado in situ na superfície. Dessa forma, foi possível individualizar os litotipos em N4WS utilizando as propriedades físicas de rocha. Isto confirma a viabilidade dos métodos aplicados como uma alternativa para as ferramentas utilizadas atualmente na exploração de minério de ferro, com o potencial para aumento da eficiência dos recursos humanos e investimentos financeiros.Palavras-chave: integração de dados multifonte, jaspilitos, gamaespectrometria, propriedades físicas de rocha.

Ferromagnetic exchange coupling in sodium biscarbonatocuprate(II) trihydrate

1982 ◽  
Vol 35 (8) ◽  
pp. 1537 ◽  
Author(s):  
AK Gregson ◽  
NT Moxon ◽  
RR Weller ◽  
WE Hatfield
Keyword(s):  
Magnetic Susceptibility ◽  
Linear Chain ◽  
Data Set ◽  
Magnetic Susceptibility Data ◽  
Temperature Range ◽  
Susceptibility Data ◽  
Ferromagnetic Exchange ◽  
Ferromagnetic Interactions ◽  
G Value ◽  
Best Fit

The magnetic properties of sodium biscarbonatocuprate(II) trihydrate, Na2Cu(CO2)2,3H2O, have been measured in the temperature range 1.8-42 K. Magnetic susceptibility and magnetization measurements provide evidence for ferromagnetic interactions in this linear-chain compound. The magnetic susceptibility data are compatible with a Heisenberg linear chain; the best-fit parameters for the complete data set are: J 1.22 �0.04cm-1, g 2.18 � 0.01, and zJ'-0.28 � 0.02cm-l. Data in the temperature range 7-42K yield the best-fit parameters J1.37 � 0.08 cm-1, g 2.12 � 0.01, and zJ' 0.0 cm-1. The g value from this fit agrees with the g value of 2.10 obtained from a fit of the data in the temperature range 10-42 K to the Curie-Weiss law.

scholarly journals Magnetic Susceptibility Mapping of Rocks and Depth Estimation of Anomalies: A Case Study of Igarra and Its Environs

2019 ◽  
pp. 1-11
Author(s):  
V. N. Nwugha ◽  
D. O. Ikoro ◽  
C. N. Okeke-Oguegbe ◽  
A. C. Ezebunanwa
Keyword(s):  
Magnetic Susceptibility ◽  
Mineral Exploration ◽  
Depth Estimation ◽  
Susceptibility Mapping ◽  
Susceptibility Map ◽  
Magnetic Minerals ◽  
Strike Direction ◽  
Southwest Nigeria ◽  
Exploration Exploitation

Magnetic Susceptibility Mapping and Depth Estimation of Anomalies were carried out on Igarra and its environs, Southwest Nigeria. This was to assist in mineral exploration in the area. The study area is located within the Igarra schist belt which is underlain by rocks of Precambrian basement complex. The Total Magnetic Field over the study area was obtained by digitizing the aeromagnetic map of Auchi (Sheet 226) acquired from the Nigerian Geologic Survey Agency (NGSA). A total of 19 (nineteen) magnetic anomalies were identified on the map; 5 magnetic highs and 14 lows. 8 anomalies have a NW-SE strike direction, 4 in the NE-SW and 7 in the E-W direction. The amplitude of the anomalies and strength of the total field were used to determine the susceptibility values for each of the anomalies. The Susceptibility values were used to generate a Magnetic Susceptibility map of the study area on SURFER 13 software. TMI plots on the anomalies were carried out on MICROSOFT EXCEL 2010. Depth estimates of the anomalies were got using three methods: The Half Width rule, Hannel rule and Tirburg rule. The Susceptibility map shows a noticeable pattern of increase in magnetic minerals from the Southwestern to the Northeastern part of the map. The Depth of the basement anomalies were relatively shallow ranging from 0.8 km to 2.6 km. The results of this work provide a preliminary guide to those that engage in mineral exploration / exploitation in the area.

scholarly journals APPLICATION OF MAGNETIC SURVEY TO EXPLORE THE IRON ORE DEPOSITS IN THE NUSAWUNGU COASTAL REGENCY OF CILACAP CENTRAL JAVA

2017 ◽  
Vol 7 (2) ◽  
pp. 79 ◽  
Author(s):  
S Sehah ◽  
Sukmaji Anom Raharjo
Keyword(s):  
Magnetic Susceptibility ◽  
Iron Ore ◽  
Research Area ◽  
Ore Deposits ◽  
Magnetic Data ◽  
Magnetic Survey ◽  
Magnetic Minerals ◽  
The Third ◽  
Central Java ◽  
Iron Ore Deposits

The research aiming to explore the iron ore deposits in the Nusawungu coastal Regency of Cilacap has been conducted using the magnetic survey. The acquisition of magnetic data was conducted in April – Mei 2017, covering the area in the ranges of 109.314° – 109.345°E and 7.691° – 7.709°S. The obtained magnetic field strength data were corrected, reduced, and mapped to obtain the contour map of local magnetic anomaly. The modeling process was carried out along the path extending over the map from the positions of 109.314°E and 7.695°S to 109.335°E and 7.699°S, so that some subsurface anomalous objects are obtained. The lithological interpretation was performed to identify the types of subsurface rocks and their formations based on the magnetic susceptibility value of each anomalous objects and supported by the geological information of the research area. Based on the interpretation results, three rocks deposits of alluvium formations were obtained, which are estimated to contain iron ore. The first deposit has a length of 164.85 m, a depth of 0.57 – 8.43 m, and a magnetic susceptibility value of 0.0097 cgs. The second deposit has a length of 376.28 m, a depth of 2.56 – 19.66 m, and a magnetic susceptibility value of 0.0108 cgs. The third deposit has a length of 1,306.26 m, a depth of 3.70 – 58.69 m, and a magnetic susceptibility value of 0.0235 cgs. Out of the whole rocks deposits, the third rock deposit is interpreted to have the most prospective iron ore. This interpretation based on its high magnetic susceptibility value, which indicates the presence of many magnetic minerals (i.e. iron ores) in the rock.

scholarly journals Anthropogenic pollutants on top soils along a section of the Salaria state road, central Italy

2016 ◽  
Vol 59 (5) ◽  
Author(s):  
Alessandra Venuti ◽  
Laura Alfonsi ◽  
Andrea Cavallo
Keyword(s):  
Magnetic Susceptibility ◽  
Central Italy ◽  
Traffic Density ◽  
Magnetic Minerals ◽  
Anthropogenic Pollutants ◽  
The Road ◽  
Anthropogenic Contribution ◽  
Different Grain Size ◽  
High Traffic Density

Magnetic susceptibility (MS) is employed among others magnetic parameters to investigate pollution along a high traffic density road. In this study, MS field survey and magnetic laboratory analyses were applied to five sites along the Via Salaria road in the northern districts of Rome. Scanning electron microscope and energy dispersive spectroscopy analyses have also been employed to reveal the nature of Fe rich particles of anthropogenic origin. In general, the soil samples revealed to contain low coercivity minerals (e.g., magnetite) with different grain size, Fe-oxides occurring in various forms (spherules, aggregates, octahedral crystals and angular particles) are typically found close to the road side border at some of the analyzed sites. Magnetic minerals concentration in proximity of the road border resulted higher at sites with higher traffic volume and, in general, decreases with the distance from it. Evidences of anthropogenic material in topsoils were found within the first 5 m from the road border. The study confirms that the in situ measurements of the magnetic susceptibility are a valuable tool to rapidly investigate variations in the magnetic susceptibility profile related to anthropogenic contribution.

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