Silicic magmas in the Michoacán-Guanajuato Volcanic Field: an overview about plumbing systems, crustal storage and genesis processes

The origin of silicic rocks in the Michoacán-Guanajuato volcanic field (MGVF) has been understudied since the volcanic field attracted the attention of researchers. Using geochemical, petrological and structural data from the literature, here we propose a model for the origin of silicic magmas. We found that all volcanic rocks known to date in the MGVF can be divided in 40 % andesite, 33 % basaltic andesite, 15 % basalt, 2 % trachybasalt to trachyandesite, and 10 % dacite-rhyolite. The structural systems that deformed the crust in the MGVF are NNW-SSE-oriented normal faults of the Taxco-San Miguel de Allende fault system, developed during the Oligocene, and the Morelia-Acambay fault system consisting of ENE-SSW to E-W sinistral strike-slip faults developed during the Oligocene-Miocene. In addition to bibliographic data, we present a gravimetric-magnetometric model to investigate the characteristics of the local basement where magmas acquire their final silicic composition, and a seismic tomography model to investigate the deep plumbing system that contribute to form the silicic rocks emplaced on the surface. The only report of assimilation experiments we found in the MGVF literature suggest that plagioclase and pyroxene are more easily digested than quartz by hotter magmas. The digestion of these mineral phases has a direct consequence on the generation of dacites and rhyolites. We propose that regardless of the genesis of andesitic melts, such intermediate magmas arrive to the upper-crust and are forced to evolve within local compression zones where they melt the local granitic basement and form crystal mushes. The compositional variability of silicic rocks in the MGVF is a consequence of the variable mixing between the intermediate magmas and the granitic partial melts.

Tourism area life cycle analysis in San Miguel de Allende Guanajuato

The Tourism Area Life Cycle model is in itself one of the most used tools to analyze tourist competitiveness. In order to solve the problem of the lack of a comprehensive tourism strategy in the city of San Miguel de Allende that can comply with sustainable development, this research establishes its objective in the documentary analysis of the evolution of the tourism indicators that it has presented in destination for its analysis and comparison with the model of the Tourism Area Life Cycle model, identifying in the corresponding stage and thereby establishing relevant tourism planning strategies. The document was developed with a descriptive quantitative approach that used documentary review and analysis techniques of various tourist indicators of the destination. In conclusion, it is highlighted that the city of San Miguel de Allende has individual indicators in various stages of the life cycle: Development, Consolidation, and Decline; globally, it has been in the Stagnation stage since 2015 with prominent features of Decline and Rejuvenation. This results in an obvious need to define sustainable tourism management strategies to boost the destination's competitiveness effectively.

Construcción de territorios alimentarios. Una experiencia de las mujeres en San Miguel Allende

San Miguel de Allende (SMA) in Guanajuato, Mexico is one of the most visited heritage cities in the country. In this city live people who have migrated from the United States as a phenomenon of second home tourism that, together, with the tourism of the national elite, have triggered a series of dynamics in the territory ranging from real estate speculation, deterritorialization, the abandonment of local crops, agroextractivism, and water extractivism, involving various types of violence against the body-territory-land. Apart from these problems, this phenomenon has allowed food resistance to take off, coordinated mainly by women where the care economy emerges as a dialogue of resistance that is established through the preservation of seeds, the continuation with the work of the land in search territorial food, the consolidation of a network of people and spaces that combine the exchange of agro-ecological food and local handicrafts that are sustained from the action and articulation of women.

Governing Urban Water Conflict through Watershed Councils—A Public Policy Analysis Approach and Critique

Cities face substantial water governance challenges, even more so when their activities are water-intensive, as global tourism is. As the lower-most level of government, municipalities face important challenges when dealing with water stress. Designing robust urban water policy thus may require us to challenge currently popular modes of governance by river basin councils, as predicated by the integrated water resources management (IWRM) paradigm. In this paper, I conduct a public policy analysis of a case study of intra-urban water conflict in the Mexican city of San Miguel de Allende (SMA), an extremely popular tourist destination with substantive water scarcity challenges. I draw insights from an application of the Institutional Grammar Tool, IGT (as proposed by Ostrom and Crawford) on a series of textual datasets derived from ethnographic, qualitative longitudinal field research, document analysis, and elite interviews with stakeholders to explain the reasons underlying community concerns about urban water supply which have derived in conflict in San Miguel de Allende and increasingly manifested over the past few years (2017–2020). My analysis suggests that to tackle growing intra-urban antagonism derived from increasing water insecurity in San Miguel de Allende, a more localized, micro-watershed approach might be more fruitful than a traditional river basin council strategy.

Foreigners as gentrifiers and tourists in a Mexican historic district

Transnational gentrification has become a key element of urban and sociocultural transformations in several Latin American countries. New urban policies and transnational real estate markets adapt the city in order to respond to the expectations of transnational middle classes. This paper explores the case of San Miguel de Allende in Mexico. Methodologically, it adopts a qualitative approach and analyses two of the most important manifestations of transnational gentrification: lifestyle migration and luxury tourism. Historical files on protected buildings in San Miguel de Allende’s historic centre were used to observe functional alterations. This is supplemented with other statistical data (including the spatial pattern of Airbnb rentals) and direct observations of public spaces. I propose that transnational gentrification leads to a heritage-led transnationalisation of real estate, evidenced by luxury housing, boutique hotels, art galleries and other high culture spaces that cater to higher-income lifestyle migrants and tourists. As a result, the new class of owners and users changes the place’s identity, which has implications for lower-income groups’ right to the city. The process in San Miguel de Allende is analogous to processes in cities such as London, New York or Paris, where notions of heritage urbanism have also helped transnationalise local real estate markets. However, it also evinces other processes that are more difficult to appreciate in the Global North (growing rent gaps, real estate companies’ aggressive pursuit of gentrification and deep historical inequalities that are exacerbated by heritage-led gentrification).