Geochemistry Unit

In the past few decades, as a result of diverse international initiatives, a significant increasement in the geochemical maps at urban, regional, and continental scale have increased (e.g., Geochemical Atlas of Europe). Following this global trend, the National Geology and Mining Service included in the Plan Nacional de Geología (National Geology Plan), the creation of a Geochemical Mapping Program, in charge of the Geochemical Unit, with professionals in Santiago and Valdivia.

Through this program using standardized methodologies and a quality control process, the multi-element (61 elements and chemical compounds) chemical composition for ground and sediments in our territory is in systematically process of generation. This on a scale of 1:250,000 (IGM Nappes), with a density around 1 sample per 20 km2, and at river basin scale, with samples homogeneously distributed throughout the main tributaries of each basin.

As of date, only on a scale of 1:250,000, a surface of 108,400 km2, has been covered, corresponding to the area made up of Arica, Pisagua, Iquique, Taltal, El Salvador, Copiapó, Vallenar, and La Serena nappes, with an average of 677 points sampling in each nappe. Additionally, the program has provided geochemical information for 11 river basins, located across our country, including the Lluta, Azapa, Salado, Copiapó, Huasco, Elquí, Limarí, Rapel, Mataquito, Valdivia, and Aysén rivers.

The geochemistry sheets, scale of 1:250,000, is published (Arica, Pisagua, Iquique, La Serena, and Vallenar) or in process of being published (Copiapó and El Salvador) through the Geochemical Maps and Geochemical Databases. On the other hand, the river basins geochemistry published (Copiapó, Huasco, Rapel y Aysén rivers) or in process of being published (Salado and Valdivia rivers) through the Registered Reports. Simultaneously, this information has been fundamental to over 10 river basin geochemistry title projects, developed in the context of the program (Lluta, Azapa, Huasco, Elqui, Limarí, Valdivia, and Aysén rivers).

Therefore, the Geochemical Mapping Program of Chile contributes directly with the development of these economic and environmental areas in the country. On one hand, the geochemical data, and its associated products, allow us to define prospective zones, characterized by multi-element geochemical anomalies in the study areas or basins. These anomalies range from elements like copper, iron, or gold, to others considered as strategic elements for the development of advanced technologies, like cobalt and Earth Rare Elements.

Additionally, the program products have allowed us to define the first geochemical baselines of Chile, that include chemical element concentrations with potential impact on the human and environmental health, like arsenic, mercury, plumb, or zinc. These geochemical baselines allow for the environmental evaluation of the studied areas, the design, and monitoring plans and territorial purposing implementation, both at the regional and river basin scale.

In the future, the professional team of the Geochemistry Unit expects they will have to face new challenges, among which we find: 1) generating a new standardized database system for geochemical data; 2) the use of phone applications for collecting data in the field; 3) enhancing the generated information and obtained results; 4) promoting the delivery of information to the society.

For this, we aim to generate greater diffusion instances for the geochemical results, at public, regional, and interinstitutional government level. Besides, the former steps towards the creation of new formats for the information delivery are given, including specialized (Arcgis) and public (Google Earth, Geochemical Atlas online; and phone apps) platforms.


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