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Northwestern Mexico is characterized by different metallogenic provinces that are included along the Basin and Range, the Sierra Madre Occidental, and the Baja California geological provinces. With the purpose of contribute to the current understanding of the mineralizing processes, the present study focused on two important copper metallogenic provinces: the Cananea Porphyry District in Sonora, and the Sediment-hosted Stratiform Copper- and Mn-deposits in Baja California Sur. The U-Pb zircon ages from the mineralizing porphyries from Cananea district suggest a continued magmatic activity period of ~6 Ma. Also suggests a period of ~20 Ma for the entire magmatic activity in the district. The Re-Os molybdenite ages demonstrate five well-constrained mineralization events in the district; the main mineralization is constrained over a short period of time (~4 Ma). The new molybdenite age from the Pilar deposit documents the oldest mineralizing pulse, suggesting possibly the initiation of the Laramide mineralization in northern Sonora. A detailed study of Mariquita porphyry Cu and Lucy Cu-Mo deposits in the Cananea district was performed. Four hydrothermal stages were defined in Mariquita, whereas a single hydrothermal pulse characterizes Lucy. Emplacement depths between 1-1.2 km, and temperatures between 430-380ºC characterized the mineralization from Mariquita, whereas deeper emplacement depths and higher mineralization temperatures characterized Lucy. The stable isotope systematic and fluid inclusion data determined that the mineralizing fluids in Mariquita deposit are essentially magmatic during the earlier hydrothermal stages, whereas the last stage is the mixing between magmatic and winter meteoric-waters. The mineralizing fluids from Lucy deposit are magmatic in origin. A comprehensive study was performed in the Cu-Co-Zn-Mn ineralization of the Boléo District, and Mn-oxide mineralization along the eastern coast Baja California Sur. The REE and trace element in the Mn-oxides demonstrated the exhalative nature of the mineralizing hydrothermal fluids, and exclude the hydrogenous nature. The stable isotope systematic in ore and gangue minerals, along with the Cu-isotope data helped to decipher the nature of mineralizing and non-mineralizing fluids. The application of Pb, Sr and Re-Os isotope systems was applied to constrain the nature of the fluids involved during the mineralization processes and that the metal sources.

This research explores the politics of development on the East Cape of Baja California Sur, Mexico. Based upon twelve months of ethnographic research and participant observation, primarily in the coastal community of Cabo Pulmo, the researcher investigates and documents how local residents respond to the social and political implications of impending mass tourism development in the region. Rising land values, real estate speculation, and intensifying conflicts over land ownership were some of the earliest symptoms of this process. The central argument is that social conflicts over development are often based in deeper, fundamental political struggles over land—and the ability to participate in the development process itself. This represents an important contribution to our understanding of the political and social dynamics of development, which, in the literature, are often framed in abstract terms of debate that remain highly detached from the lived realities of the people who stand to lose the most if development goes awry. Using the concepts of value, development, community, and sustainability as theoretical starting points, this research argues that conflicts over development should be seen as struggles for inclusion and participation above all else. Ultimately, the conclusion of this research is that conflicts over ownership of and access to land continue to impede alternative forms of development that seek to avoid the negative social, political, and economic consequences of traditional mass tourism models.

Thesis (Ph. D.)--University of Texas at Austin, 1995. / Vita. Includes bibliographical references (leaves 287-313).

abstract: An array of north-striking, left-stepping, active normal faults is situated along the southwestern margin of the Gulf of California. This normal fault system is the marginal fault system of the oblique-divergent plate boundary within the Gulf of California. To better understand the role of upper-crustal processes during development of an obliquely rifted plate margin, gravity surveys were conducted across the normal-fault-bounded basins within the gulf-margin array and, along with optically stimulated luminescence dating of offset surfaces, fault-slip rates were estimated and fault patterns across basins were assessed, providing insight into sedimentary basin evolution. Additionally, detailed geologic and geomorphic maps were constructed along two faults within the system, leading to a more complete understanding of the role of individual normal faults within a larger array. These faults slip at a low rate (0.1-1 mm/yr) and have relatively shallow hanging wall basins (~500-3000 m). Overall, the gulf-margin faults accommodate protracted, distributed deformation at a low rate and provide a minor contribution to overall rifting. Integrating figures with text can lead to greater science learning than when either medium is presented alone. Textbooks, composed of text and graphics, are a primary source of content in most geology classes. It is essential to understand how students approach learning from text and figures in textbook-style learning materials and how the arrangement of the text and figures influences their learning approach. Introductory geology students were eye tracked while learning from textbook-style materials composed of text and graphics. Eye fixation data showed that students spent less time examining the figure than the text, but the students who more frequently examined the figure tended to improve more from the pretest to the posttest. In general, students tended to examine the figure at natural breaks in the reading. Textbook-style materials should, therefore, be formatted to include a number of natural breaks so that learners can pause to inspect the figure without the risk of losing their place in the reading and to provide a chance to process the material in small chunks. Multimedia instructional materials should be designed to support the cognitive processes of the learner. / Dissertation/Thesis / Ph.D. Geological Sciences 2011

abstract: The historic Cacachilas mining district is located in Baja California Sur, approximately 20 kilometers east of La Paz, and has a series of gold- and silver-hosted veins, faults, and shear zones within Cretaceous granodioritic plutons. The remote geographic location and past political events within Mexico left the district essentially unexplored after the late 1800s, when the Mexican Revolution began. More recent discovery of gold deposits along the Baja peninsula instigated a renewed interest in mineralization in the Sierra Cacachilas. The area lacks detailed previous geologic data, so this study focused on characterizing the controls of mineralization and the locations of mineralized trends of deposits within the northeastern Sierra Cacachilas, with a goal toward helping assess economic viability of the deposits. I mapped surficial geologic data, such as outcrop locations, alteration assemblages, limonite intensities, and structural measurements. I then synthesized these into geologic maps and cross sections. I combined field data with geochemical assays and structural plots to better characterize individual historic district trends and newly located trends to understand the distribution of mineralization at surface and at depth. Lastly, I synthesized geology of the Sierra Cacachilas with other gold and silver deposits located in the southern Baja peninsula to better characterize the mineralization and deposit style of the Cacachilas district. Mineralization in the northeastern Sierra Cacachilas is mainly restricted to steeply dipping quartz veins, faults, and brittle-ductile shear zones that trend generally northeast. Some veins are en-echelon within the mineralized zones, implying some lateral movement along the zones. Veins are dominated by milky to clear quartz with trace sulfides, abundant limonite (after sulfides), and local open-space textures. Mineralization is interpreted to be intermediate between classic epithermal and mesothermal veins. Within mineralized trends and commonly associated with mineralization are greisen-like zones that are defined by intense sericitic to muscovitic overprint, trend northeast, and are with or without sulfides. The intensity of sulfide abundance and limonitic alteration after sulfides within and near mineralized zones is overall a good guide to mineralization. Based on past reports and on my recent studies, the Cacachilas district has very promising potential for relatively small, high-grade deposits. / Dissertation/Thesis / Masters Thesis Geological Sciences 2015

[EN] Water and soil are essential for the development and maintenance of ecosystem resources. Watersheds are units of management, where the aim of the regulation and management of them is to prevent soil erosion, loss of vegetation control and regulate the hydrological cycle, protecting natural resources and promoting sustainable development. This research proposes an original methodology of Watershed Management (MOCAS) that adequately reflects the problems in the Mexican arid area of BCS and innovatively integrated management approaches that classical methods do not take into account. This methodology provides answers to the problems of land degradation and desertification in eroded areas and extrapolated to biogeographically like basins selected study areas. This thesis analyzes and compares classical watershed management methodologies such as sorting according to the Universal Soil Loss Equation (USLE) based management criteria Mintegui Aguirre and Lopez, and watershed management under the N-SPECT model. Subsequently, the proposal for a system of watershed management in arid areas, where it is necessary to cover not only the influence of surface hydrology, but groundwater hydrology, as well as vulnerability dominated areas. These methods were applied to a study area with obvious characteristics of aridity in the Northwest region of Mexico. Specifically in six watersheds typology high mountain and lowland mixed in Baja California Sur, Mexico. Finally the proposed management methodology is applied, resulting in the mostly appropriate uses of the territory as areas and surfaces, and thematic maps implemented activities for watershed management, which were obtained values for action surfaces of each methodology. Once the quantitative results obtained from each of the methodologies adapted from common land use for activities resulting from each method is generated. The inherent subjectivity of the application thereof be eliminated. Of the work done and comparison of methodologies, we have obtained a number of conclusions that provide future research in the field of watershed management to establish an effective, comprehensive and simple system for the study and analysis of watersheds basins in arid areas. / [ES] El agua y el suelo son recursos naturales imprescindibles para el desarrollo y mantenimiento de los ecosistemas. Las cuencas hidrográficas son unidades de gestión, en las que el objetivo del ordenamiento y manejo de las mismas es evitar la erosión del suelo, controlar la pérdida de vegetación y regular el ciclo hidrológico, protegiendo los recursos naturales y fomentando el desarrollo sostenible. La presente investigación propone una metodología original de Ordenación de Cuencas Hidrográficas (MOCAS) que recoge adecuadamente la problemática existente en el ámbito árido sudcaliforniano mexicano y que novedosamente integra criterios de ordenación que las metodologías clásicas no tienen en cuenta. Esta metodología proporciona respuestas a los problemas de degradación y desertificación en zonas erosionadas y es extrapolable a zonas biogeográficamente similares a las cuencas de estudio seleccionadas. En esta Tesis se analizan y comparan metodologías clásicas de Ordenación de Cuencas como la Ordenación según la Ecuación Universal de Pérdidas de Suelo (USLE), la Ordenación basada en los criterios de Mintegui Aguirre y López, y la Ordenación de cuencas bajo el modelo N-SPECT. Posteriormente se plantea la propuesta de un sistema de Ordenación de Cuencas hidrográficas en zonas áridas, donde es necesario abarcar no solo la influencia de la hidrología superficial, sino de la hidrología subterránea, así como también la vulnerabilidad en zonas dominadas. Las anteriores metodologías fueron aplicadas a una zona de estudio con características evidentes de aridez, en la región Noroeste del territorio mexicano. Específicamente en seis cuencas hidrográficas con tipología de alta montaña, mixta y de llanura, en Baja California Sur, México. Finalmente se aplica la metodología de Ordenación propuesta, obteniendo como resultado los usos mayormente adecuados del territorio según zonas y superficies, y los mapas temáticos de actividades planteadas para la Ordenación, de los cuales se han obtenido los valores de superficies de actuación para cada metodología utilizada. Una vez obtenidos los resultados cuantitativos entre cada una de las metodologías se genera una adaptación de usos comunes del suelo para las actividades resultantes de cada metodología. Con ello se eliminaría la subjetividad inherente de la aplicación de la misma. De los trabajos realizados y comparación entre las metodologías, se han obtenido una serie de conclusiones que aportan futuras líneas de investigación en el ámbito de la Ordenación de Cuencas a fin de establecer un sistema eficaz, integral y sencillo para el estudio y análisis de las cuencas hidrográficas en zonas áridas. / [CAT] L'aigua i el sòl són recursos naturals imprescindibles per al desenrotllament i manteniment dels ecosistemes. Les conques hidrogràfiques són unitats de gestió, en les que l'objectiu de l'ordenament i maneig de les mateixes és evitar l'erosió del sòl, controlar la pèrdua de vegetació i regular el cicle hidrològic, protegint els recursos naturals i fomentant el desenrotllament sostenible. La present investigació proposa una metodologia original d'Ordenació de Conques Hidrogràfiques (MOCAS) que arreplega adequadament la problemàtica existent en l'àmbit àrid sudcaliforniano mexicà i que novament integra criteris d'Ordenació que les metodologies clàssiques no tenen en compte. Esta metodologia proporciona respostes als problemes de degradació i desertificació en zones erosionades i és extrapolable a zones biogeogràficament semblants a les conques d'estudi seleccionades. En esta Tesi s'analitzen i comparen metodologies clàssiques d'Ordenació de conques com l'ordenació segons l'Equació Universal de Pèrdues de Sòl (USLE), l'Ordenació basada en els criteris de Mintegui Aguirre i Lopez, i l'Ordenació de Conques davall el model N-SPECT. Posteriorment es planteja la proposta d'un sistema d'Ordenació de Conques hidrogràfiques en zones àrides, on és necessari comprendre no sols la influència de la hidrologia superficial, sinó de la hidrologia subterrània, així com també la vulnerabilitat en zones dominades. Les anteriors metodologies van ser aplicades a una zona d'estudi amb característiques evidents d'aridesa, en la regió Nord-oest del territori mexicà. Específicament en sis conques hidrogràfiques amb tipologia d'alta muntanya, mixta i de plana, en Baixa Califòrnia Sud, Mèxic. Finalment s'aplica la metodologia d'Ordenació proposada, obtenint com resultat els usos majorment adequats del territori segons zones i superfícies, i els mapes temàtics d'activitats plantejades per a l'Ordenació, dels quals s'han obtingut els valors de superfícies d'actuació per a cada metodologia utilitzada. Una vegada obtinguts els resultats quantitatius entre cada una de les metodologies es genera una adaptació d'usos comuns del sòl per a les activitats resultants de cada metodologia. Amb això s'eliminaria la subjectivitat inherent de l'aplicació de la mateixa. Dels treballs realitzats i comparació entre les metodologies, s'han obtingut una sèrie de conclusions que aporten futures línies d'investigació en l'àmbit de l'Ordenació de Conques a fi d'establir un sistema eficaç, integral i senzill per a l'estudi i anàlisi de les conques hidrogràfiques en zones àrides. / Z Flores López, M. (2016). Metodología para la ordenación de cuencas hidrográficas en el ámbito biogeográfico árido sudcaliforniano (México) [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/64874 / TESIS