Assessing Magnetic Susceptibility Profiles of Topsoils under Different Occupations

Abstract

Magnetic susceptibility measurements at low and high frequencies (χlf, χhf) were carried out on topsoil samples from reforested, cultivated, and pasture lands from a catchment located at the north of Morocco. The aims of this study were to investigate the impact of land use or human activity on χlf of soil overlying the same substrate, to discriminate allochthonous material or pollution from autochthonous or inherited ones, and to assess the origin and contribution of superparamagnetic (SP) grains to the global magnetic susceptibility χlf. Measurements of χlf indicated significant enhancement, with values ranging from 12.4 to 252.82 × 10-8 m3 kg−1 with a mean value of 107.087 × 10-8 m3 kg−1 for the reforested lands. In the cultivated lands, χlf were from 8.4 to 88.65 × 10-8 m3 kg1 with a mean value of 42.69 × 10-8 m3 kg−1, while in the pasture lands, χlf was comprised between 14.34 × 10-8 m3 kg−1 and 133.35 × 10-8 m3 kg−1 with a mean value of 57.33 × 10-8 m3 kg−1. The magnetic enhancement indicates high concentration of ferrimagnetic minerals in the top soil. The magnetic susceptibility enhancement decreases as the human activity increases, while the underlying bedrock is almost the same: reforested land > pastures land > cultivated land. The analysis of the variations of χlf and frequency dependent susceptibilities (χfd and %χfd), along the profiles of soil, indicate a pedogenic origin of the topsoil magnetic susceptibility enhancement.

Kajian Suseptibilitas Magnetik Tanah Sebagai Indikator Longsor di Gunung Nago, Padang

“…Berdasarkan Tabel 1 terdapat 60% sampel mengandung bulir super paramagnetik berkisar 0,00% -2,00% dan nilai χFD (%) bervariasi di Lintasan C dan Lintasan D. Nilai χFD (%) rendah di kedalaman 25 cm mengindikasikan tanah sedikit atau tidak mengandung bulir super paramagnetik (ukuran bulir halus) sehingga sulit terjadi pergerakan lateral pada tanah (longsor). χFD (%) rendah adalah awal pembentukan pedogenetik partikel magnetik di tanah (Bouhsane and Bouhlassa, 2018). Tabel 2 di Lintasan C terjadi penurunan nilai χFD (%) di bagian tengah.…”

Analiasis Suseptibilitas Magnetik Dan Kandungan Logam Berat Pada Tanah Perkebunan Jambu Mete Di Kecamatan Puriala Kabupaten Konawe

“…Logam Berat Logam berat didefinisikan sebagai kelompok unsur kimia yang berwujud mengkilap, penghantar panas yang baik, memiliki titik didih dan titik leleh yang tinggi (kecuali Hg), mempunyai bobot atom lebih besar dari kalium dengan densitasnya > 5 g/cm 3 , nomor atom 22 sampai 92, dari periode 4 sampai 7, dan terdiri lebih dari 70 unsur. Logam berat yang ditemukan di alam berasal dari tiga sumber utama yaitu lithogenic diperoleh dari batuan induk (parent material), pedogenic akibat proses fisika, kimia dan biologi dalam tanah, dan antropogenic akibat aktivitas manusia misalnya dialamatkan pada industri [10]. Konsentrasi logam berat dalam tanah dan juga profil suseptibilitas magnetic tidak saja dipengaruhi oleh bahan induk, sifat-sifat fisika-kimia, umur, temperature, aktivitas biologis, dan proses pedogenic tetapi juga oleh aktivitas manusia misalnya pemupukan yang tidak seimbang [17].…”

“…Dalam satuan internasional (SI), (𝑀𝑀 ��⃗ ), dan (𝐻𝐻 � �⃗ ) mempunyai satuan A/m sehingga (𝜒𝜒) merupakan besaran yang tidak berdimensi atau sering disebut sebagai volume suseptibilitas magnetic. Dalam pengukuran laboratorium massa spesifik suseptibiulitas dilaporkan dalam satuan berbasis massa, yaitu 10 -8 m 3 .kg -1 (satuan SI) yang identik dengan suseptibilitas volume dibagi densitas [10]. Persamaan (1) menunjukkan bahwa untuk (𝑀𝑀 ��⃗ ) dan (𝐻𝐻 � �⃗ ) yang sejajar dan sebanding, suseptibilitas magnetik 𝜒𝜒 merupakan suatu besaran scalar.…”

Magnetic Response of Heavy Metal Pollution in Soil of Urban Street Greenbelts

“…Many researchers have found that there is a strong correlation between the concentration of heavy metals and magnetic parameters through studying the soil near factories, the soil near roads and other sediments contaminated by various heavy metals [9,10]. Traditional methods of geochemical studies usually take a long time and involve complicated procedures and high costs, while environmental magnetism provides a simple, economical, rapid and non-destructive method that is useful to soil pollution monitoring [11][12][13]. Analysis of magnetic susceptibility of soil shows that some magnetic minerals in soil are produced by human activities such as vehicle emissions, and that magnetic susceptibility of topsoil is higher than that of deep soil [14,15].…”