Dr. King-St-Onge, Robert

Geotourism as a tool for local and social development requires evaluating how geology is perceived by society and how the geology can contribute to solve society’s needs and perspectives. This research is the result of a survey undertaken in the “Litoral del Biobío” geopark project (Chile) from April to September 2019. This survey consists of over 400 people and is a direct geoturistic demoscopic study on local communities. It covers a large diversity of social setting (ranging from urban to rural indigenous) and also a diverse level of education. Salient points of the results includes more than 80% of the community are aware of the sites of tourist interest in their community, while less than 20% recognize the geology and/or geosites of the territory. The need for economic development (21%) and tourism in natural areas (82.5%) stand out as the main tourism focus and tool for generating sustainable economic resources for the territory. Geodiversity and geotourism play an important role (48.1%), but are subordinate to biodiversity (76.7%) in the territory. Furthermore, geotourism is far from the perceptions of crime (23%), given that it is still a minority tourism sector. Finally, there is a certain level of resignation in the community regarding the medium-term development of its territory (52%), with education on geological and environmental risks (77%) being one of the main priorities. This study shows that, although there are basic needs to be covered in the territory, such as security and public infrastructure, there is also a great interest in developing tourism in natural areas. In this scenario, geotourism becomes relevant as a tool that can contribute to local sustainable economic development, education on geological risks, awareness of the geological value of the territory, as well as the revaluation of the cultural heritage in the study area.

The effect of rock weathering on geotechnical parameters can become substantial in geotechnical design. The weathering degree (WD) has usually been divided into five levels from fresh rock to completely weathered rock. In this study, the above five WDs are adopted to analyse the variation of several regularly used geotechnical properties. To that aim, a series of laboratory tests on a Chilean granitic rock in different stages of weathering was carried out. The results of the tests have been analysed by normalizing each geotechnical parameter with respect to the value obtained for slightly weathered samples instead of for fresh rock samples as is usually adopted. In this way, it was found that the unconfined compressive strength reduces steadily and considerably with each WD, as has been previously reported. Conversely, the modulus of deformation and P-wave velocity tend to stabilize the rate of reduction for highly and completely weathered rock samples, which does not agree with the trend and higher rate reductions found by other researchers. This stabilization reduction rate with WD was also found for compaction density, friction angle and Poisson's ratio.

Purpose: The objectives of this study were (1) to determine the concentrations and background concentrations of Ba, Co, Cr, Mn, and Ni in the urban soils of Talcahuano (Chile); (2) assess the level of contamination in the urban soils based on different pollution indexes; and (3) to identify natural or anthropogenic sources in order to obtain a spatial distribution of the pollutants. Material and methods: A total of 420 samples were collected from the study area as follows: 140 topsoil samples (TS) (0–10 cm), 140 subsoil samples (SS) (10–20 cm), and 140 deep soil samples (DS) (150 cm). The soils were characterized, and the concentrations of Ba, Co, Cr, Mn, and Ni were analyzed by atomic absorption photospectrometry following aqua regia digestion. Correlations and principal component analysis combined with spatial analysis were implemented in order to distinguish the sources and their classification as geogenic or anthropogenic. Several simple and robust statistical methods were applied to datasets in order to explore their potential in the evaluation of a useful and robust background values. The degree of contamination along with the geoaccumulation index, enrichment factor, and contamination factor were also evaluated. Results and discussion: The median concentrations obtained for various elements includes Ba 461 mg kg−1, Co 82.7 mg kg−1, Cr 134 mg kg−1, Mn 311 mg kg−1, and Ni 56.1 mg kg−1. In general, the concentrations of Ba, Co, Cr, Mn, and Ni decrease with depth. Correlations and principal component analysis suggest that Cr, Mn, and Ni are contributed by external sources. The spatial distribution of Cr, Mn, and Ni in TS displays a spatial pattern extending along industrial environments and emission sources. Conclusions: The estimated background values determined with the iterative 2σ-technique includes 536 mg kg−1 for Ba, 95.9 mg kg−1 for Co, 208 mg kg−1 for Cr, 464 mg kg−1 for Mn, and 90.5 mg kg−1 for Ni. The geochemical index, enrichment factor, and the contamination factor register a moderate to considerable contamination in some soil samples.

As a common component of urban ecosystems, urban soils generally have elevated concentrations of potentially hazardous elements originating from both point and diffuse sources of pollution in cities. This study focuses on the port city of Arica in northern Chile, where anthropogenic activities may have led to contamination of the uppermost topsoil layer. The purpose of this study is to (1) establish background content levels of potentially hazardous elements in topsoils of different land uses using different statistical approaches and (2) assess the degree of topsoil pollution and identify the local sources of pollution using multivariate statistical and geostatistical methods. Data from a Chilean Government CONAMA report were analyzed. Geostatistical methods such as kriging were applied to identify the spatial distribution of potential hazards elements. Potentially hazardous elements' background values were determined by median + 2MAD, inflection points within cumulative frequency plots and upper whisker of a Tukey's boxplot. Multivariate statistical methods were applied in the identification of trace metal sources (anthropogenic vs natural origin). Soil pollution assessment was performed using the geoaccumulation index (Igeo), enrichment factor (EF), contamination factor (Cf) and integrated pollution index (IPI). The maps obtained show high baseline values for some elements (As, Cu, Pb and Zn), which denote a clear anthropogenic contribution due to the long period of constant human activities in the study area. Therefore, background values are estimated with the median + 2 × MAD procedure and yielded As (17.4 mg kg− 1), Ba (23.3 mg kg− 1), Cr (13.6 mg kg− 1), Cu (37.4 mg kg− 1), Ni (8.3 mg kg− 1), Pb (313 mg kg− 1), V (101 mg kg− 1) and Zn (235 mg kg− 1). The calculated soil pollution indexes Igeo, EF, Cf and IPI revealed significant ecological impacts. Copper and As are the two trace elements with the highest contaminated soil values; however, Cu, Pb and Zn have greater numbers of soil sample sites in the moderately to heavily contaminated range. The IPI showed extremely high pollution index in ten soil sites in Arica. Moreover, significant differences were observed with different land uses, where soils along the railway line and industrial area are the most polluted.

The objective of this study is to ascertain the spatial distribution of Cu, Pb and Zn in order to determine the degree of contamination in urban soils from Talcahuano (Chile) and to identify the influence of possible contamination sources. A total of 420 samples were collected from the study area based on the following criteria: 140 topsoil samples (TS) (0–10 cm), 140 subsoil samples (SS) (10–20 cm) and 140 deep soil samples (DS) (150 cm). The soils were characterized for their physical characteristics such as grain size distribution, pH, organic matter content etc. and the concentrations of Cu, Pb and Zn were analyzed by Atomic Absorption Photospectrometry following Aqua Regia digestion. Correlations combined with spatial analysis were implemented in order to distinguish the sources of the trace metals and whether they are geogenic or anthropogenic of origin. Several simple and robust statistical methods were applied to the data sets in order to evaluate useful and robust background values. The degree of contamination along with the geoaccumulation index, enrichment factors and contamination factors were also evaluated. The median concentrations obtained for the studied trace metals includes: Cu 23.1 mg kg− 1, Pb 10.2 mg kg− 1 and Zn 56.7 mg kg− 1. In general, the concentrations of Cu, Pb and Zn decrease with depth however, in certain sites the subsoil samples (SS) levels show higher concentrations than topsoil samples (TS). A possible explanation could be related to the uncontrolled clandestine landfill sites using both construction material debris and/or industrial solid wastes. Correlation analysis suggests that Cu, Pb and Zn are contributed by external sources. The spatial distribution of Cu, Pb and Zn in topsoil samples (TS) displays a spatial pattern extending along major roadway environments and emission sources. Estimated background values determined with the iterative 2σ-technique yields 43.7 mg kg− 1 for Cu, 17.5 mg kg− 1 for Pb and 91.7 mg kg− 1 for Zn respectively. The geochemical index, enrichment factor and the contamination factor all register a moderate to high contamination level in some of the soil samples.