Mineralogical characterization of sands from the Cotacachi-Cuicocha volcanic complex

This study presents the results obtained from the characterization of the sands associated with the Cotacachi-Cuicocha Volcanic Complex (CCVC), their possible applications and the identification of Rare Earth Elements (REEs). The volcanic complex is part of the Cordillera Occidental of Ecuador and is one of the most important geosites of Imbabura UNESCO Global Geopark. The complex is considered potentially active and consists of a main stratovolcano (Cotacachi), four satellite domes (Muyurcu, Loma Negra, Peribuela, and Cuicocha), and a volcanic caldera (Cuicocha) that has led to the formation of a lake with two islets inside (Yerovi and Wolf). Associated with these geoforms, a radial fluvial system has developed, which drains water from the upper parts of the volcanic complex, carrying sediments of various sizes belonging to the different lithological units of the CCVC. The fluvial courses were the source of 22 sand samples studied in this work, which were subjected to various physical processes, granulometric analysis, magnetic separation, observations using the stereomicroscope, and analytical techniques such as X-ray diffraction spectrometry (XRD), Raman spectrometry and X-ray photoelectron spectroscopy (XPS). The granulometric analysis allowed determining that the most representative fraction of each sample corresponds to the sediments retained in the 120 mesh (0.025-0.125 mm), which contains a higher percentage by weight of the sample and a lower amount of lithics. Thus, using analytical methods, it was possible to determine that the fluvial sands associated with the CCVC have a mineralogical composition constituted mainly of iron oxides (magnetite and hematite) at 59.05%, plagioclase (labradorite and andesine) at 27.55%, and pyroxenes (enstatite and augite), and amphibole (hornblende) at 13.40%. However, it was impossible to confirm the presence of REEs. Among the detected minerals, iron oxides are the most representative with respect to their mass, where their nanoparticles are widely used in different areas; however, designating an application to the iron oxides identified in the CCVC entails an analysis of their quality and the volume of material available in the area.

• Váldodahkki: Guiz Chapi, Evelyn Zulay (author)
• Materiálatiipa: bachelorThesis
• Giella: eng
• Almmustuhtton: 2024
• Fáttát: Caracterización mineralógica; Sedimentos fluviales; Minerales pesados; Mineralogical characterization; Fluvial sediments; Heavy mineral
• Liŋkkat: http://repositorio.yachaytech.edu.ec/handle/123456789/705