ORIGINAL ARTICLE Magnetic parameters, trace elements, and multivariate statistical studies of river sediments from southeastern India: a case study from the Vellar River Marcos A. E. Chaparro • Mauro A. E. Chaparro • P. Rajkumar • V. Ramasamy • Ana M. Sinito Received: 1 September 2009 / Accepted: 11 August 2010 / Published online: 25 August 2010 Ó Springer-Verlag 2010 Abstract This contribution constitutes a new study using magnetic parameters and trace element determina- tions of pollutants in river sediments from the Tamil Nadu state. The Vellar River covers a total length of about 200 km and flows into the Bay of Bengal. Sediment samples were collected at different sediment depths (up to 90 cm) from 12 sites to investigate their magnetic prop- erties (27 samples) and the contents of trace elements (21 out of 27 samples) along the river; as well as to perform magnetic studies for various grain size fractions (16 sub samples). The magnetic results of magnetic susceptibility and remanent magnetizations suggest that the magnetic signal of these sediments is controlled by ferrimagnetic minerals magnetite-like minerals and a minor contribution of antiferromagnetic carriers (such as hematite minerals). Detailed studies of selected samples showed a higher magnetic concentration in finer grain-sized fractions and a slightly different magnetic mineralogy. Magnetic concen- tration-dependent parameters evidenced high values, which, together with the background values, allowed us to identify magnetic enhancement at some sites. The Pearson correlation and multivariate statistical studies (Principal Component Analysis, Canonical Correlation Analysis) supported the relationship between the magnetic and chemical variables; in particular, magnetic susceptibility, anhysteretic and isothermal remanent magnetization are closely correlated to Co, Cr, Cu, Fe, V, Zn, and the pol- lution load index. In addition, Principal Coordinate Anal- ysis and fuzzy C-means cluster analysis allowed us to make a classification and to perform a magnetic-chemical characterization of the data into four groups, thereby identifying critical (possibly polluted) sites from the Vellar River. Keywords Environmental magnetism Á Magnetic susceptibility Á Fuzzy C-means clustering method Á Pollution Á River sediments Introduction A large number of exhaustive studies of magnetic proxies for pollution have been conducted in different environ- ments, including soils, sediments, and vegetation since the 1980s (e.g., Hunt et al. 1984; Thompson and Oldfield 1986; Beckwith et al. 1986). According to Petrovsky ´ and Ellwood (1999), atmospheric pollution is identified as one of the most harmful factors for ecosystems. Often, industrial and urban fly ashes include toxic elements and heavy metals; such airborne pollutants are diffused due to the atmo- spheric circulation. Land environments undergo a major impact because pollutants are transferred to the Earth’s surface, made available, and taken up by organisms or incorporated into sediments. M. A. E. Chaparro (&) Á A. M. Sinito Instituto de Fı ´sica Arroyo Seco (UNCPBA), CONICET, Pinto 399, B7000GHG Tandil, Argentina e-mail: chapator@exa.unicen.edu.ar M. A. E. Chaparro Instituto Multidisciplinario de Ecosistemas y Desarrollo Sustentable (UNCPBA), CONICET, Pinto 399, B7000GHG Tandil, Argentina P. Rajkumar Department of Physics, Paavai Engineering College, Pachal, Namakkal 637018, India V. Ramasamy Department of Physics, Annamalai University, Annamalainagar 608002, Tamilnadu, India 123 Environ Earth Sci (2011) 63:297–310 DOI 10.1007/s12665-010-0704-2