Asbestiform and non-asbestiform morphologies in a talc and vermiculite mine from the province of Córdoba (Argentina): a case study

Abstract

In this work, a talc and vermiculite mine from the province of Córdoba (Argentina) was investigated with special emphasis on the occurrence of asbestiform and nonasbestiform phases. The meta-ultramafic rock was studied by a multimethodological approach, complementing field studies with petrographic-mineralogical, compositional and morphological analyses. Samples were examined by stereomicroscopy, polarizing light microscopy, SEM-EDS, XRD, DSC-TGA and FTIR. Complementary, compositional and textural analyses were performed with FE-SEM-EDS and EPMA. Talc-rich veins with a laminar and fibrous appearance were at first recognized. However, the fibrous morphology observed both in the field and by microscopy is due to an apparent habit because of the sample orientation. To avoid erroneous interpretations, studies by secondary electron images (SEM) are fundamental to carrying out this type of analysis. Tremolite was identified in different zones of the outcrop; however, only *40% of the crystals located in the vermiculite zone have dimensions to be considered as asbestiform fibres in the range of respirable particles. In these types of complex deposits affected by superimposed metamorphic, igneous and deformational events, multimethodological approaches are necessary to develop models of occurrence of asbestiform morphologies that may be applicable to other with similar characteristics.

Multi-Analytical Approach for Identifying Asbestos Minerals In Situ

“…These p-XRF data could be used to make a sampling plan aimed at identifying hotspot areas of heavy metal contamination such as the asbestos quarries/mines in Italy, Canada, India, and Argentina [20,41,[57][58][59]. Collected Raman spectra as p-XRF spectra, were conducted exclusively on fibrous morphologies observed inside the serpentinite veins (Figure 3a) using Raman microscope and p-DM.…”

Characterization of Talcose Rocks Derived from Serpentinite—Pilot Study in the Ultramafic Complex of Cabo Ortegal (Spain) for Potential Use and Commercialization

“…However, talc is subject to contamination from other surrounding materials (i.e., serpentinites), such as heavy metals or even asbestos [9,20], which is known to be a carcinogenic material. For example, talc ore extracted in the state of New York is heavily contaminated from tremolite asbestos, which results in a high mortality rate among workers [21][22][23].…”

Naturally Occurring Asbestos in Argentina: A Compilation of Case Studies

“…Amphibole groups are present in all the vermiculite deposits studied, but only in "Los Guanacos" and "Rosarito" mines ( Fig. lc) asbestiform tremolite was identified (Lescano et al 2013a(Lescano et al , 2017b.…”