A Mineralogical Museum as a Geotourism Attraction: A Case Study

The Zaruma-Portovelo mining district in Ecuador, and in particular, Portovelo City, is home to the oldest mining museum in the country. This museum, named Museo Mineralógico Magner Turner (MMMT in Spanish), is a centre that reflects, through its collections, the history and culture of this territory. This work aimed to evaluate the MMMT as a possible geosite by analysing its contributions to the geomining heritage of the Zaruma-Portovelo district, and thus, to enhance it and promote its collections as a geotouristic attraction. The work involved three phases: (i) describing the museum and its surroundings; (ii) a semiquantitative evaluation of the museum using the Brilha method and a geosites assessment model (GAM); and (iii) a qualitative evaluation using the Delphi and SWOT methodologies to define strategies and proposals for museum development. The results obtained by the semiquantitative evaluation of the geosite with the Brilha method reflect high scientific (330/400), educational (380/400) and touristic (365/400) appeal. The applied GAM shows the museum as a geosite with high principal and additional value, placing it in the Z33 field of the global valuation matrix. In addition, the semiquantitative and qualitative evaluation made it possible to describe the importance of the museum and its collections in the development of the area. The study carried out qualified the museum as a mining site with an appropriate valuation, an example of ex-situ geological heritage conservation and a basis for geotourism development.


Introduction
Natural diversity is a concept that integrates biodiversity and geodiversity [1]. According to [2], geodiversity is the variability of Earth's surface materials, landforms and physical processes (abiotic elements). Geodiversity is also defined as the variety of geological elements which constitute the substrate of a region on which organic activity is based, including the anthropic [3]. The need to conserve geological elements with significant value is reflected in the study of geological heritage, whose discipline constitutes one of the most recent research areas within Earth sciences [4]. In recent years, several authors [1,2,[5][6][7][8][9][10][11] have focused their research on the study of geological heritage. According to [1], geological Ecuador, museums are open to the public and have a broad vision in informative, scientific and cultural ways; they bring together geological history for society. Examples include, the Earth Sciences Museum of the Central University of Ecuador (UCE), the Natural History Museum of the National Polytechnic School (EPN) and the Paleontological Museum of the Santa Elena Peninsula University (UPSE). According to [41], the Ecuadorian museum must show society's historical, political and cultural processes. In the southwest of Ecuador, in Portovelo, there is the Museo Mineralógico Magner Turner (MMMT). This museum is the largest in the southern region of Ecuador, with approximately 400 m 2 for the collection's exhibition, and it has an on-site mine for the tourists to visit [42]. The MMMT is considered a site of potential geological interest for the Ruta del Oro Geopark project. This project originated as an academic research project by ESPOL Polytechnic University; its initiative promotes the sector's economic development through geotourism [43].
This study aimed to evaluate the MMMT as a geosite that combines information about and experiences of geology and gold mining through semiquantitative (Brilha and GAM method) and qualitative (Delphi and SWOT) assessments. We thereby aim at promoting it as part of the geomining heritage of the Zaruma-Portovelo district. In addition, we aimed to determine the museum's influence on the development of geotourism in the area.

Geographical Setting
The MMMT is located in southern Ecuador, in the El Oro province (Figure 1a,b), precisely placed in the Portovelo canton (Figure 1c,d) of Zaruma-Portovelo mining district. Geographically, the museum's territory is on the western slope of the Cordillera de los Andes (Cordillera Chilla) in the middle-upper section of the hydrographic basin Puyango River. Morphologically, the most notable characteristic is the mountainous relief, characterised by fluvial incisions with significant water flows [44][45][46]. The main characteristics of the terrain are irregular landscapes with steep slopes (30-45 • ) towards the NW and shallow slopes (20 • -35 • ) towards the SE [47]. There are V-shaped valleys and elevations between 600 and 1600 m above sea level [48]. In general, the study area presents a climate defined as semi-humid to humid, with approximate temperatures between 18 and 30 • C and average annual rainfall of 1300 mm. Precipitation occurs in two rainy seasons (January to May and October to November) [47], conditioning the flow of water in the hydrographic system [49].
From the geological perspective, in the area (Portovelo and its surroundings), continental volcanic rocks, plutonic rocks and metamorphic rocks predominate. The predominant structures present an E-W alignment, which is discordant with the northern and eastern Andean system with a dominant NNE direction [46,50,51]. The gold mineralisation in the study area is part of an intermediate sulphidation vein system (Zaruma-Portovelo deposit) of Au ± Ag ± Cu [52]. This deposit has been related to propylitic, argillic, silica and sericitic types of alterations [53,54], and it is regionally located in the extension of the southwestern segment of the Miocene metallogenic belt in Ecuador [55]. The identified ore and gangue mineral assemblages are typical for intermediate sulfidation epithermal gold vein deposits associated with Early Miocene continental arc magmatism [54,56,57], among which there are three distinguishable mineralisation stages: quartz-pyrite, quartzpolymetallic and quartz-carbonate stages [53,57]. These vein systems have been established in three mineralised domains: N-S, NE-SW, and NW-SE [53]. The main hydrothermal alteration types are propylitic, argillic, silicic and sericitic assemblages. Gold mineralisation occurs in association with pyrite, chalcopyrite, sphalerite, galena, bornite, hematite, tetrahedrite, molybdenite and electrum. Quartz and calcite are the most important gangue minerals [50,53]. important gangue minerals [50,53].
The socioeconomic activity of the Portovelo region in particular, depends mainly on four axes: gold extraction (65% of the economically active population), agriculture, livestock and tourism. In the last decade, national and international tourism have increased, and in turn the local economy has grown in response to tourism by means of businesses involved in culture, gastronomy, geology, mining history and archaeology. Portovelo city occupies an area of approximately 1 km 2 and has 12,000 inhabitants [58].

Specific Characteristics
The main mine of the Zaruma-Portovelo mining district was developed by the American company South American Development Company (SADCO, New York; NY, USA), and used from 1896 to 1950 [53,59]. During the SADCO period, mineral extraction techniques were carried out with blasting using explosives. The mine started with a vertical tunnel (called Pique Americano in Spanish) 30 m in depth, and lateral tunnels were built; this method was used to reach 13 levels of depth. The company had a pulley system that allowed the ore from veins to be transported to the surface for processing. Grinding mills carried out the mineral processing, and the gold was obtained by amalgamation with mercury. The company also installed treatment plants for gold recovery by cyanidation processes [53,[60][61][62][63].
As a result of the mining developed in the area and its importance at the national level, in 1976, Mr Magner Turner started a private collection of 1500 mineral samples and The socioeconomic activity of the Portovelo region in particular, depends mainly on four axes: gold extraction (65% of the economically active population), agriculture, livestock and tourism. In the last decade, national and international tourism have increased, and in turn the local economy has grown in response to tourism by means of businesses involved in culture, gastronomy, geology, mining history and archaeology. Portovelo city occupies an area of approximately 1 km 2 and has 12,000 inhabitants [58].

Specific Characteristics
The main mine of the Zaruma-Portovelo mining district was developed by the American company South American Development Company (SADCO, New York, NY, USA), and used from 1896 to 1950 [53,59]. During the SADCO period, mineral extraction techniques were carried out with blasting using explosives. The mine started with a vertical tunnel (called Pique Americano in Spanish) 30 m in depth, and lateral tunnels were built; this method was used to reach 13 levels of depth. The company had a pulley system that allowed the ore from veins to be transported to the surface for processing. Grinding mills carried out the mineral processing, and the gold was obtained by amalgamation with mercury. The company also installed treatment plants for gold recovery by cyanidation processes [53,[60][61][62][63].
As a result of the mining developed in the area and its importance at the national level, in 1976, Mr. Magner Turner started a private collection of 1500 mineral samples and mining equipment from the SADCO period. In the 80s, the museum was strengthened with the acquisition of 3000 pieces catalogued in a very general way. The samples acquired are mainly crystallographic, speleological and paleontological. In the 90s, the samples reached 5000 pieces exhibited in an approximate area of 400 m 2 . In the last decade, the museum reached 7000 samples and the operation of three in-situ mines. Currently, the MMMT consists of 14 different sections/areas that exhibit national and international mineral collections, fossils and rocks, pieces, photos, objects and old equipment that reflect the mining activity of the district. Outside, the MMMT has three underground mines, which encourages visitors to interact with the galleries and a stone path known as SADCO Road, which contains a historical area typical for gold mining (Figure 2). mining equipment from the SADCO period. In the 80s, the museum was strengthened with the acquisition of 3000 pieces catalogued in a very general way. The samples acquired are mainly crystallographic, speleological and paleontological. In the 90s, the samples reached 5000 pieces exhibited in an approximate area of 400 m 2 . In the last decade, the museum reached 7000 samples and the operation of three in-situ mines. Currently, the MMMT consists of 14 different sections/areas that exhibit national and international mineral collections, fossils and rocks, pieces, photos, objects and old equipment that reflect the mining activity of the district. Outside, the MMMT has three underground mines, which encourages visitors to interact with the galleries and a stone path known as SADCO Road, which contains a historical area typical for gold mining ( Figure 2). Among the MMMT's main activities are visits to the in-situ mines made up of three galleries (Ray Turner Mine, Curipamba Mine and Ecuador Mine) with a total route length of 200 m ( Figure S1). In the galleries, there are mineralogical samples (quartz drusen and pyrites), rocks (intrusive and host rock), tools and machinery and artefacts from the time of exploitation by SADCO. Inside the exhibition hall, there are approximately: 1500 samples of igneous, metamorphic and sedimentary rocks ( Figure S2); 2500 mineralogical samples that are metallic and non-metallic ( Figure S2); 550 precious and semi-precious stones ( Figure S2); paleontological units ( Figure S3); 50 caving units ( Figure S3); 450 ancient pieces, including coins and artisanal mining equipment ( Figure S4); and 700 archaeological pieces ( Figure S4).

Materials and Methods
The analysis and evaluation process consisted of three phases ( Figure 3): (i) taking a detailed inventory of the historical, cultural and touristic attractions, and analysing the infrastructure of the MMMT; (ii) an assessment of the interest and importance of the MMMT with two different evaluation methods; and (iii) defining strategies that optimise the use of the mine using Delphi analysis and strengths, weaknesses, opportunities and threats (SWOT) analysis ( Figure 3).  Figure S4); and 700 archaeological pieces ( Figure S4).

Materials and Methods
The analysis and evaluation process consisted of three phases (

Stage I: Processing and Systematisation Information
The first stage comprised the analysis of cultural and historical information from the museum and the geographic environment of the area. In addition, this phase included recording the structure and services of the museum, including the collection types and the annual registry of visits. The processed information was the basis for the evaluation developed in phase two.

Stage II: Semiquantitative Assessment
A semiquantitative assessment was carried out within this phase using two methods, GAM [64] and Brilha [1]. Five academic experts assessed geology and geotourism with each of the selected methods. To do this, the evaluators used the information obtained in phase one. The final evaluation was the average of the values assigned by each evaluator. Finally, the compilation and summary of the assessments carried out (parameters and scores) allowed us to interpret the site.

Geosite Assessment Model (GAM)
A GAM is a method that evaluates the main and additional value of the geosite, making use of different indicators [64]. Each indicator establishes specific sub-indicators that are assessed from 0 to 1 ( Table 1).
The sum of the values obtained for each subindicator placed the geosite in an analysis matrix of principal values from 0 (minimum) to 12 (maximum) vs. additional values from 0 (minimum) to 15 (maximum). The higher the values for the geosite, the higher the global value. This graphical representation type facilitates the interpretation of the current site state.

Stage I: Processing and Systematisation Information
The first stage comprised the analysis of cultural and historical information from the museum and the geographic environment of the area. In addition, this phase included recording the structure and services of the museum, including the collection types and the annual registry of visits. The processed information was the basis for the evaluation developed in phase two.

Stage II: Semiquantitative Assessment
A semiquantitative assessment was carried out within this phase using two methods, GAM [64] and Brilha [1]. Five academic experts assessed geology and geotourism with each of the selected methods. To do this, the evaluators used the information obtained in phase one. The final evaluation was the average of the values assigned by each evaluator. Finally, the compilation and summary of the assessments carried out (parameters and scores) allowed us to interpret the site.

Geosite Assessment Model (GAM)
A GAM is a method that evaluates the main and additional value of the geosite, making use of different indicators [64]. Each indicator establishes specific sub-indicators that are assessed from 0 to 1 ( Table 1).
The sum of the values obtained for each subindicator placed the geosite in an analysis matrix of principal values from 0 (minimum) to 12 (maximum) vs. additional values from 0 (minimum) to 15 (maximum). The higher the values for the geosite, the higher the global value. This graphical representation type facilitates the interpretation of the current site state.

Brilha Method
The Brilha method evaluates geosites through four indicators: (i) scientific value (SV), (ii) potential educational use (PEU), (iii) potential touristic use (PTU) and (iv) degradation risk (DR) [1]. Each indicator analyses different sub-indicators scored from 1 (minimum) to 4 (maximum) and has a weight, as shown in Table 2. When evaluating the SV, PEU and PTU indicators, a high value has a positive connotation for the geosite. However, when assessing the DR indicators, high values represent negative connotations (risk) for the geosite.  The method proposes a DR classification based on the total value of the evaluation (Table 3), which establishes ranges for DR of low, medium and high.

Stage III: Qualitative Assessment
The third stage was based on Delphi's geosite strategic analysis [65,66] and SWOT [67]. The Delphi method was the first analysis applied with the participation of five academic evaluators (stage two evaluators). The evaluation analysed three main aspects: (i) importance within the geological heritage of the area, (ii) services for tourists and (iii) natural and anthropic threats. This information can be used to describe its current potential and design improvements.
The main aspects of the Delphi method were the basis for the SWOT analysis. The SWOT analysis's objective was to determine the museum's potential for geotourism development in the area. We then wished to generate initiatives to make the use and management of the museum more efficient and effective. In addition to the academic evaluators' criteria, this phase of work will involve the participation of municipal authorities and the inhabitants of the area.

MMMT General Information
The annual registry of MMMT's national and international visits shows a tourist influx of more than 4000 tourists in the last six years (2015-2020). The museum receives 700 tourists a year, with higher values in 2015, 2016 and 2017 than in 2018, 2019 and 2020 ( Figure 4). The reasons for the visits' evolution are mainly (i) the problems derived from the land in-stabilities [68] and subsidence events in Zaruma city linked to illegal gold mining [49,69,70], which caused a decrease in the tourist influx in the district in 2018 and 2019, and (ii) the global pandemic by COVID-19 in 2020.
According to the data provided by the MMMT, the maximum capacity per visit is 20 people. The organised groups that visit the MMMT are normally students from schools, colleges and universities. When the number of visits exceeds the capacity limit, the owner distributes the times into different time slots. The average duration of a visit is approximately two hours (20 min for museum introduction and history, 50 min for viewing collections/exhibitions, 30 min for underground visits and 20 min for external exhibits of mining equipment). In addition to the guide's explanations, the MMMT has basic information (e.g., posters) to facilitate self-guided visits. As an urban museum, the visitor has within walking distance the necessary essential services (hotels and restaurants).
Minerals 2021, 11, x FOR PEER REVIEW 9 of 18 mining equipment). In addition to the guide's explanations, the MMMT has basic information (e.g., posters) to facilitate self-guided visits. As an urban museum, the visitor has within walking distance the necessary essential services (hotels and restaurants).

Semiquantitative Assessment: GAM and Brilha
The GAM assessment applied to the MMMT showed global ratings of 8.75/12 for main value and 12/15 for additional value ( Table 4). The scores obtained locate the MMMT in the Z33 field of the GAM matrix ( Figure 5), placing it as a geosite of high value.

Semiquantitative Assessment: GAM and Brilha
The GAM assessment applied to the MMMT showed global ratings of 8.75/12 for main value and 12/15 for additional value ( Table 4). The scores obtained locate the MMMT in the Z 33 field of the GAM matrix ( Figure 5), placing it as a geosite of high value. mining equipment). In addition to the guide's explanations, the MMMT has basic information (e.g., posters) to facilitate self-guided visits. As an urban museum, the visitor has within walking distance the necessary essential services (hotels and restaurants).

Semiquantitative Assessment: GAM and Brilha
The GAM assessment applied to the MMMT showed global ratings of 8.75/12 for main value and 12/15 for additional value ( Table 4). The scores obtained locate the MMMT in the Z33 field of the GAM matrix ( Figure 5), placing it as a geosite of high value.  MMMT's assessment by the Brilha method showed high results for the scientific (330/400), touristic (365/400) and educational (380/400) value. In addition, the applied method highlights the high representativeness, the uniqueness and the associations with the natural, cultural and historical value of the museum (Table 5). These characteristics reflect a high educational level for all types of tourist.  The degradation risk (210/400) ( Table 5) presents the museum as a vulnerable geosite in the face of insufficient legal protection and proximity to degrading activities. Based on the overall result, the MMMT is classified as moderately at risk according to Table 3.

Delphi Method Results
The results obtained indicate the MMMT as an ex-situ geosite of high geological importance, preserving minerals and rocks collections typical of the Zaruma-Portovelo mining district. In addition, within its collections, the museum exhibits old equipment used by mining companies that started artisanal gold extraction. However, the museum is susceptible to degrading factors such as weather, certain factors of the terrain and illegal exploitation of its surroundings. Furthermore, the evaluators exposed limitations in the services and structure of the museum, mainly as to the signage in the nearby area ( Figure 6).

The SWOT Matrix
Based on SWOT analysis, the MMMT is a site of unique geological interest, located in an area with scenic beauty, rich culture and a history of artisanal mining. The im-

The SWOT Matrix
Based on SWOT analysis, the MMMT is a site of unique geological interest, located in an area with scenic beauty, rich culture and a history of artisanal mining. The importance of MMMT's geoconservation represents opportunities for tourism development in the Ruta del Oro Geopark project. In addition, within the analysis, the needs for geoconservation laws and dissemination strategies were mainly raised to ensure the site's integrity and increase its tourist influx, respectively. The summary of the analysis carried out is presented in Table 6.

Interpretation of Results and Discussion
The evaluation methodology used allowed us to expose the main characteristics of the MMMT and its importance within the geological and mining heritage of the Zaruma-Portovelo district. Moreover, it made it possible to determine the weaknesses that should be enhanced and improved for tourism. According to [43], the MMMT corresponds to the second most valued geosite (256/400) of a total of 27 geosites and mining sites present in the study area. In one study, the IELIG method was applied [71]. In this study, the Brilha [1] and GAM [64] methods were applied, two classic methodologies for evaluating the scientific, academic and touristic interest of possible geosites. The results obtained through Brilha and GAM are similar to those obtained in the evaluation of [43] by the IELIG method. The high values obtained for both evaluation methods (Tables 4 and 5) qualify the museum as an excellent example of an ex-site geosite.
The evaluation carried out by GAM generally qualifies the museum as a geosite with high principal and additional value (Table 4). However, it reflects subindicators with poor scores that need to be strengthened (e.g., vulnerability, area, structure and tourist influx). Although the museum occupies 90% of the structure, the number of samples limits the capacity of tourists (maximum 20 people). This problem translates into an average tourist influx of fewer than 5000 people per year.
The Brilha method presents high results for the museum's scientific, educational and touristic value (Table 5). These values classify the MMMT as a geosite of much geological importance, and the best example in the study area to show the geology of the area and the processes related to pre-colonial gold extraction. The geological elements are informative to all types of patrons. In addition to its geological importance, the MMMT has historical, cultural and ecological value that increases its potential for geotourism in the area.
Regarding the degradation risk evaluation (DR), the museum presents a medium risk of degradation in the face of natural and anthropic processes (Table 5). Its main weaknesses lie in its proximity to degrading activities (e.g., illegal mining and contamination from mineral processing plants) and the lack of laws that protect geological heritage conservation areas. The limited area of the museum is a factor that influences the possible deterioration of secondary geological elements by the tourist. Due to its location, an essential factor is the economic level of the population. The area stands out for its limited economic resources that disadvantage the services offered to tourists and the implementation of new geoconservation techniques.
The subjectivity of geosite assessment methods is unavoidable. However, it is possible to decrease it. According to [72], the application of several methods generates different results so that their combination allows obtaining a better result and eliminating subjectivity to a certain degree. In addition, it is essential to have: (i) a team of evaluators with knowledge on the subject and (ii) information on the geosite in which the inhabitants and tourists are involved [73]. The participation of people outside the geoscientific field validates the evaluations, reduces subjectivity and improves the acceptance and success of geosite management plans [74].
Based on the above, the study included the museum's Delphi and SWOT analysis. The results revealed the current situation and possible future scenarios, considering their most relevant characteristics. In general, this analysis relates the geotourism potential of the museum to the natural, cultural and historical heritage as a fundamental part of the Ruta del Oro Geopark project and the area's tourism development. An important aspect of the SWOT analysis was the lack of recognition of the touristic potential of the site by government authorities. This translates into a lack of financial and promotional support for the museum.
Finally, to ameliorate the MMMT's weaknesses, a proposal is presented that includes various specific strategies (based on SWOT and the other applied analyses) that seek to improve the structure and services offered by the museum: - To increase the museum's area vertically (add one or two floors) and facilitate access for people with disabilities or mobility restrictions. - To implement a digital and physical classification system, with files identified by codes, to facilitate orderly and chronological recording of the museum's assets. - To design a museum web page containing pertinent information on the distribution of the sections and samples, focused on scientific, educational and cultural diffusion.
-To improve the in-situ mines through strategic viewpoints to observe alteration zones, mineralisation or old mining equipment, so that tourists can understand the artisanal extraction process. -To establish learning workshops for visitors: a gold-panning area (Figure 7a), interpretation of cartography (Figure 7b), identification of minerals (Figure 7c), stereoscopic visualisation of aerial photography and mineral observation under a microscope (Figure 7). - To establish regulations and legal norms with the help of municipalities whose objective is to conserve the museum; closing down all types of illegal mining activity in its surroundings. - To improve the museum's signage system, with names for each exhibition room and information panels. - To prepare the main access roads and establish an area designated as a tourist parking lot, with a capacity of at least eight vehicles.
improve the structure and services offered by the museum: -To increase the museum's area vertically (add one or two floors) and facilitate access for people with disabilities or mobility restrictions. -To implement a digital and physical classification system, with files identified by codes, to facilitate orderly and chronological recording of the museum's assets. - To design a museum web page containing pertinent information on the distribution of the sections and samples, focused on scientific, educational and cultural diffusion. -To improve the in-situ mines through strategic viewpoints to observe alteration zones, mineralisation or old mining equipment, so that tourists can understand the artisanal extraction process. -To establish learning workshops for visitors: a gold-panning area (Figure 7a), interpretation of cartography (Figure 7b), identification of minerals (Figure 7c), stereoscopic visualisation of aerial photography and mineral observation under a microscope (Figure 7). - To establish regulations and legal norms with the help of municipalities whose objective is to conserve the museum; closing down all types of illegal mining activity in its surroundings. - To improve the museum's signage system, with names for each exhibition room and information panels. - To prepare the main access roads and establish an area designated as a tourist parking lot, with a capacity of at least eight vehicles. In general, the way we addressed our case study addressed can be used as a model for museums in regions where there are mineral deposits. An improvement on the approach proposed in this study could be the inclusion of other sites for collective analysis and the introduction of other valuation methodologies. In general, the way we addressed our case study addressed can be used as a model for museums in regions where there are mineral deposits. An improvement on the approach proposed in this study could be the inclusion of other sites for collective analysis and the introduction of other valuation methodologies.

Conclusions
The MMMT has high scientific, touristic and educational value. It is an ex-situ geosite with principles oriented toward geoconservation. This geosite combines the geological, historical, cultural and natural wealth of the district. The evaluation carried out allowed us to validate its importance in the context of the Ruta del Oro Geopark project as one of the main points of interest for geotourism in the area. Combining semiquantitative and qualitative methodologies in the study allowed the exchange of criteria of experts and parties interested in the geosite. This methodological proposal decreased the subjectivity of the method and allowed for strategies in contrast to the current conditions presented by the museum.
Our improvement strategies focus on three main aspects: (i) enlargement of the area and improvement of services offered; (ii) promoting the creation of legal regulations that protect geosites from the risks linked to anthropic activities; and (iii) modern dissemination and promotion techniques at the national and international levels. Provided the proposals made in this study are realised, the museum will increase its tourist influx, contributing positively to the area's economic development.
From a technical/scientific point of view, we can reinforce the MMMT's value as a repertoire of the mineral diversity of the area and a point of interest for research. Additionally, we have revealed the limited support of regional authorities in the MMMT's development; even so, private impulses and social support, in general, have allowed the development of the museum.