Sierra Gorda Research Articles

Sierra Gorda 013: Unusual CBa‐like chondrite

AbstractThe new metal‐enriched anomalous chondrite Sierra Gorda 013 (SG 013) contains two different lithologies. Lithology 1 (L1) is represented by anomalous CBa‐like chondrite material containing ~80 vol% of Fe,Ni‐metal particles and globules up to 6 mm in size; chondrules and clasts of types POP, BO, and SO (up to 5 mm in diameter); rare sulfides; and shock melted silicate–metal areas. It does not contain any fine‐grained matrix. Several chondrules contain chromite–pyroxene symplectites. Lithology 2 (L2) has a recrystallized texture with evenly distributed olivine, pyroxene and plagioclase. L2 does not have any chondrules or sulfides, and contains less Fe,Ni‐ metal (~25 vol%) than L1. Both lithologies contain reduced olivine (Fa2–4) and pyroxene (Fs3.5), similar to CBa chondrites. Similar to CBa, there is no Ni‐Co correlation in the SG 013 metal. Rare sulfides in L1 are enriched in V. Chromite was observed in both lithologies. Oxygen isotope compositions of both lithologies are different but in the range of CBa chondrites. Bulk major and trace element geochemistry of nonporphyritic chondrules and bulk siderophile compositions in metal globules of L1 indicate elemental fractionation during formation of metallic and silicate objects with records of the evaporation process: depletion in moderate and volatile elements with the exception of Cr. Bulk geochemistry of porphyritic chondrules of L1 and the silicate portion of L2 is similar and also indicates evaporation processes. The rare Earth element (REE) distribution of L1 chondrules records a very fractionated signature corresponding to possible differentiated precursor material, while the REE pattern of L2 is primitive chondritic. The formation of SG 013 could be explained by collisions of planetesimals producing an impact plume, the precursor material of which could be chondritic and possibly differentiated. Both lithologies were affected by secondary processes: L1 preserved the traces of shock events and partial melting resulting in formation of symplectites in chondrules, melt pockets, and metal–silicate melt between the metal globules; L2 was affected by shock thermal metamorphism (up to 900 °C) resulting in recrystallization.

A new species of Procambarus (Decapoda, Cambaridae) from the State of Querétaro, Mexico.

With a Nearctic distribution, the family Cambaridae harbors a high species richness in Mexico, which is also evident along the Pánuco River catchment. A series of surveys carried on in five populations from the Sierra Gorda Biosphere Reserve in the State of Querétaro resulted in localizing a putative new species for science. A molecular phylogenetic study and species delimitation analyses including all the known Procambarus species from the Pánuco River catchment were conducted based on three mitochondrial genes (16S rDNA, 12S rDNA, and COI; 2,462 bp in total). Phylogeny recovered all species as monophyletic, including the populations under study. All delimitation results based on barcoding, ABGD, GMYC, bPTP, and gonopod differentiation agree in the recognition of a new taxon, to which the name Procambarus xihuisp. nov. is given, and its diagnosis and description are provided. The new species can be distinguished from the remaining species in the genus, among other characters, by a unique configuration of the terminal elements of the first pleopod of form I male, which includes a central projection lamellate, hood-like, forming a concave blade-like structure mesially directed, as well as a caudal process crest-like, mesiodistally directed, forming a lateral side of the concavity.

Bourbon-Era Mission Reform

After the Spanish colonized California in 1769, Franciscans from the Apostolic College of San Fernando (Mexico City) established missions but implemented a new model to more rapidly integrate indigenous populations into colonial society as per the expectations of royal officials. The indigenous populations were to be congregated on mission communities organized on the grid plan and were to live in European-style housing. This article examines the reform of missions in the Sierra Gorda, Baja California, on the ex-Jesuit missions among the Guarani in South America, and then those in California among the Chumash. It analyzes the process of congregation and the mission urban plan, resistance, and demographic collapse resulting from congregation.

Molecular Phylogenetics and Morphometrics Reveal a New Endemic Jumping Pitviper (Serpentes: Viperidae: Metlapilcoatlus) from the Sierra Madre Oriental of Mexico

The jumping pitvipers of the genus Metlapilcoatlus are generally associated with montane environments and are widely distributed from central and southern Mexico to Panama. In this study, we analyzed the phylogenetic position and compared the morphology of a population from the Sierra Madre Oriental, within the Sierra Gorda Biosphere Reserve, to other species of jumping pitvipers. We implemented two mtDNA gene fragments (cyt b and ND4) of 50 specimens of the five Metlapilcoatlus species for phylogenetic reconstruction using Bayesian inference and maximum likelihood. We used a linear discriminant analysis and comparative statistics of external and hemipenial characters to assess the morphological differences among Metlapilcoatlus lineages. Our analyses support a strong genetic and morphological distinction of Metlapilcoatlus nummifer populations established to the north of the Trans-Mexican Volcanic Belt (Hidalgo, Northern Veracruz, and Querétaro) from other Metlapilcoatlus taxa. Based on this evidence we describe the populations from the north as a new species.

Sierra Gorda Biosphere Reserve, Querétaro, Mexico: An Example of Sustainable Tourism

The importance of tourism in the economy and development, from countries worldwide and specifically to Mexico, makes it increasingly necessary to carry out tourism activities and create sustainable policies that reduce the impacts of the mass movement of tourists. The work aims to present the different actions carried out in the Sierra Gorda Biosphere Reserve, Querétaro, Mexico that allow it to offer ecotourism activities and develop sustainable projects, which benefit the surrounding communities and allows the tourist a low impact approach with nature. Promoting a sustainable entrepreneurship model by consolidating economic development with biodiversity conservation.

Public Buildings of North Chile’s Desert Architecture

This article discusses public buildings located in northern Chile. The Atacama Desert provides many examples of relationships between architecture and the natural and cultural landscape. From Antofagasta to San Pedro di Atacama, we can encounter many examples of such buildings, such as museums, astronomical observatories and hotels, as well as buildings housing tourist-oriented services. We can also experience large-scale changes to the landscape associated with open-cast copper mining. One example of such a landscape is that of the Sierra Gorda mine jointly owned by Polish and Japanese companies. This paper explores the emergence of new architectural forms built in the desert and using desert materials.

Phenolic compounds and antioxidant activity of methanolic extracts from leaves and flowers of chilcuague ( Heliopsis longipes , Asteraceae)

Background: Heliopsis longipes root is the widely used organ from the plant due to its culinary and medicinal importance. Nevertheless, during its collection the foliage is discarded. Therefore, it is required to perform studies about the phytochemical content with biological activity present in the different plant organs of the foliage, for a better exploitation of the plant.
 Hypothesis: The concentration of phenolic compounds with antioxidant activity varies according to the type of plant organ and the geographic location of the plant collection.
 Study species: Heliopsis longipes 
 Site and years of study: The H. longipes plants were collected in three locations (Conca, San Juan Buenaventura and Beltran) from Sierra Gorda of Mexico, between 2017 and 2018.
 Methods: In this study, they were analyzed the methanolic extracts from H. longipes leaves and flowers, in order to determine the content of the phenolic compounds and scavenging of radicals activity (DPPH• and ABTS•+). Further characterization of the extracts was carried out by chromatography (UPLC).
 Results: The total content of polyphenols, flavonoids and condensed tannins varied in depending on the type of plant organ and the origin site of H. longipes , being the leaves of Beltran those that represent the best source of phenolic compounds with scavenging activity of the radicals DPPH• and ABTS•+. In the extracts, phenolic acids and flavonoids were identified.
 Conclusions: The geographical climatic conditions influence the phenolic content and antioxidant activity of the methanolic extracts from leaves and flowers of H. longipes .

Investigation of a Nocturnal Cold-Air Pool in a Semiclosed Basin Located in the Atacama Desert

AbstractIn desert environments, intense radiative cooling of the surface during the night leads to rapid cooling of the adjacent air, resulting in a strong temperature inversion conducive to cold-air-pool formation. In this work observations are analyzed to investigate the structure of a nocturnal cold-air pool inside a semiclosed basin located near Sierra Gorda in the Atacama Desert in Chile and its effect on dust dispersion in the area. The measurement campaign was conducted over a 5-day period (14–19 August) in 2017 and included ceilometer data, vertical profiles of temperature, a grid of fixed ground stations, and mobile temperature sensors. We focus our attention on the conditions during periods of high levels of dust pollution, in order to understand the atmospheric conditions that contribute to these episodes. The analysis of the available data confirms the development of an intense nocturnal cold-air pool, which is reflected in a strong nocturnal potential temperature inversion (18 K in 150 m) and a 30°C diurnal temperature range. A comparison of the vertical distribution of dust and temperature shows that the capping inversion controls the location of the dust cloud. As a consequence, the highest dust concentrations were observed inside the cold pool, below the capping inversion, proving that within the basin the dust is confined to the layer where its source is located.

Sierra Gorda 009: A new member of the metal‐rich G chondrites grouplet

AbstractWe investigated the metal‐rich chondrite Sierra Gorda (SG) 009, a member of the new G chondrite grouplet (also including NWA 5492, GRO 95551). G chondrites contain 23% metal, very reduced silicates, and rare oxidized mineral phases (Mg‐chromite, FeO‐rich pyroxene). G chondrites are not related to CH‐CB chondrites, based on bulk O, C, and N isotopic compositions, mineralogy, and geochemistry. G chondrites have no fine‐grained matrix or matrix lumps enclosing hydrated material typical for CH‐CB chondrites. G chondrites’ average metal compositions are similar to H chondrites. Siderophile and lithophile geochemistry indicates sulfidization and fractionation of the SG 009 metal and silicates, unlike NWA 5492 and GRO 95551. The G chondrites have average O isotopic compositions Δ17O>0‰ ranging between bulk enstatite (E) and ordinary (O) chondrites. An Al‐rich chondrule from SG 009 has Δ17O>0‰ indicating some heterogeneity in oxygen isotopic composition of G chondrite components. SG 009’s bulk carbon and nitrogen isotopic compositions correspond to E and O chondrites. Neon isotopic composition reflects a mixture of cosmogenic and solar components, and cosmic ray exposure age of SG 009 is typical for O, E, and R chondrites. G chondrites are closely related to O, E, and R chondrites and may represent a unique metal‐rich parent asteroid containing primitive and fractionated material from the inner solar system. Oxidizing and reducing conditions during SG 009 formation may be connected with a chemical microenvironment and possibly could indicate that G chondrites may have formed by a planetesimal collision resulting in the lack of matrix.

Overview of operating practices of foreign concentrators processing sulfide and mixed copper ores

The article provides an overview of the concentrators of Hayden (USA), Mina Ministros Hales, Sierra Gorda (Chile), and Wushan (China), visited by the specialists of Kazakhmys Corporation LLP under the program for familiarizing with the practices of foreign copper mining enterprises. The Metso RSC300 flotation cell, installed at the Hayden concentrator, is presented. The performance, basic process parameters, ore preparation, flotation, dewatering, and tailings thickening equipment, design and layout solutions, and the copper concentrate calcining plant of the Mina Ministros Hales concentrator are described. The data on the ore preparation technology based on Polysius pressure rolls and flotation in OK-300TC pneumomechanical cells using sea water at the Sierra Gorda copper concentrator are presented. The paper also describes the practice of using heavy-duty belt feeders for unloading coarse ore stores and high-power belt conveyors with telescopic heads for feeding coarse crushed ore into medium and fine crusher hoppers. Project capital investments, operating costs, and the actual personnel numbers are presented. The results of the visit to the mechanical engineering plant of the CITIC Corporation (China) are summarized. The main technical solutions and semiautogenous grinding, flotation, and tailings thickening equipment of the Wushan copper concentrator plant are considered.

Bird species at risk in the cloud forest of five IBASIBAs of the Sierra Madre Oriental, Mexico

The presence of 125 species of birds at risk or endemic to Mexico’s montane mesophyll forest has been suggested. These birds need to be conserved. At a time of global defaunation and reduction of these forests, it is important to determine which bird species still inhabit this ecosystem. For the mesophyll forest located in the Sierra Madre Oriental of Mexico, no recent field data have been published to indicate their presence. In this analysis we report the records of bird species at risk made in 2016 in five Important Bird Areas with mountain mesophyll forest (Sierra Gorda, Tlanchinol, Huayacocotla, Cuetzalan and Metlac River) located in four states of Mexico (Querétaro, Hidalgo, Veracruz and Puebla). In total we recorded 60 bird species (48%) of the 125, 29 are considered nationally threatened and 34 have some type of endangerment. Six of the species are globally protected (Dendrortyx barbatus, Ara militaris, Contopus cooperi, Ridgwayia pinicola, Setophaga chrysoparia and Passerina ciris). This information can serve as a basis for their preservation and to establish monitoring, studies and conservation actions aimed at species in mesophyll forest areas.

Los márgenes del orden colonial: la geografía serragordana a través de las anotaciones de autoridades civiles, religiosas y militares (1780-1819)

En este artículo se estudian los discursos de las autoridades civiles, religiosas y militares que realizaron descripciones sobre la geografía de la Sierra Gorda y sus habitantes entre 1780 y 1819. Por un lado se analiza, a través del discurso, el proceso mediante el cual se conformó la imagen uniforme de la Sierra Gorda: agreste, infértil e inaccesible, a la que paulatinamente se fue asociando con las formas de vida y el temperamento de la gente que habitaba las montañas. Por el otro, se expone una aproximación analítica a la relación entre los discursos de las autoridades novohispanas y las campañas de ordenamiento y control territorial. Finalmente, se muestra cómo a través de dichas campañas, los márgenes de la Sierra Gorda fueron cambiando durante las primeras dos décadas del siglo XIX.

Changes in affinin contents in Heliopsis longipes (chilcuague) after a controlled elicitation strategy under greenhouse conditions

Heliopsis longipes (H. longipes) is an endemic plant of the Sierra Gorda, Mexico, whose root crude extract is used as an analgesic, anti-inflammatory and anti-ulcerative. Affinin is the main substance that provides these properties. Affinin concentrations have been seen to vary depending on the time of the year in which it is collected. Controlled cultivation of H. longipes may reduce the synthesis of affinin but using elicitation technique it might be possible to increase and standardize the biosynthesis of this specialized metabolite. The aim of this research was to determine the changes in the affinin contents in H. longipes roots after controlled elicitation using salicylic acid and hydrogen peroxide as elicitors under greenhouse conditions. After a period of acclimation of 150 days for chilcuague plants, both elicitors were foliarly sprayed for two weeks. Besides affinin contents, changes on the biomass production, catalase, superoxide dismutase, phenylalanine ammonia-lyase and valine decarboxylase enzymatic activities in H. longipes were evaluated. The results showed that low doses of both elicitors significantly increased affinin contents in roots in comparison with controls without affecting morphological variables. This increase in affinin was correlated with concomitant increases in enzymatic activities related to stress responses as catalase (CAT), superoxide dismutase (SOD), phenylalanine ammonia-lyase (PAL), as well as the increase in valine decarboxylase activity (VDC), an enzyme related with biosynthesis of aliphatic alkamides as affinin. Thus, controlled elicitation might be an interesting strategy to increase affinin contents in chilcuague cultivated under greenhouse conditions.

Biological diversity in protected areas: Not yet known but already threatened

Maintaining biodiversity and ecosystem function is critical on national and global scales. However, while only a fraction of the global biodiversity is known, its current decline is unprecedented, making biodiversity hotspots a conservation priority. The Sierra Gorda Biodiversity Reserve (SGBR) in Central Mexico is known for its rich biodiversity. It is an example of the juxtaposition between species discovery and extinction: aquatic species richness is mostly unknown as no efforts have investigated aquatic communities so far, but are already anthropogenically stressed. We hypothesized that invasive species are already well established in various protected areas and investigated this by assessing the threat of invasive species that are already established within the SGBR on the native biodiversity. By combining field sampling with peer-reviewed literature and local reports, we identify the presence of various non-native species in SGBR. Among these non-native species identified were opportunistic predatory fish and potentially-pathogen transmitting molluscs, but also, a habitat engineer capable of modifying ecosystem functions. Moreover, we highlight that these species were introduced despite legislation and without any knowledge among authorities. As a result, we underline the necessity to describe native species, control invasive and prevent the introduction of further non-native species. If accelerated action is not taken, we risk losing a considerable amount of described and unknown freshwater biota.

Especies de aves en riesgo en el bosque mesófilo de montaña en cinco AICA de la Sierra Madre Oriental, México

Para el bosque mesófilo de montaña en México se ha sugerido la presencia de 125 especies de aves que se encuentran en riesgo o son endémicas. Esas aves requieren ser conservadas. En un tiempo de defaunación mundial, y de reducción de estos bosques, es importante determinar qué especies de aves aún habitan en este ecosistema. Del bosque mesófilo localizado en la Sierra Madre Oriental de México no se han publicado datos recientes de campo que indiquen su presencia. En este análisis reportamos los registros de especies de aves en riesgo realizados en 2016 en cinco Áreas Importantes para la Conservación de las Aves con bosque mesófilo de montaña (Sierra Gorda, Tlanchinol, Huayacocotla, Cuetzalan y Río Metlac) ubicadas en cuatro estados de México (Querétaro, Hidalgo, Veracruz y Puebla). En total registramos 60 especies de aves (48%) de las 125, 29 son consideradas amenazadas a nivel nacional y 34 presentan algún tipo de endemismo. Seis de las especies están protegidas globalmente (Dendrortyx barbatus, Ara militaris, Contopus cooperi, Ridgwayia pinicola, Setophaga chrysoparia y Passerina ciris). Esta información puede servir como base para lograr su preservación y establecer monitoreos, estudios y acciones de conservación dirigidos a especies en las zonas de bosque mesófilo.

Photographic Records Confirming the Presence of Wild Turkey (Meleagris gallopavo ssp.) in the Sierra Gorda Biosphere Reserve of Guanajuato, Mexico

The Wild Turkey (Meleagris gallopavo sspp.) is a galliform historically distributed throughout the Sierra Madre Occidental, Sierra Madre Oriental, and central Mexico. However, it is currently extirpated from much of its original range. Herein, we report the presence of Wild Turkey in temperate forests of the Sierra Gorda Biosphere Reserve of Guanajuato (SGBRG). We also highlight the importance of our observations in the context of possible natural dispersal and potential range recovery of suitable areas within the historical range in the interior of Guanajuato State. As a result of a wildlife survey program in the SGBRG, a set of 8 photographic records provided evidence of 4 females, 3 males, and 1 juvenile. These records are encouraging, since the species was believed to be extirpated from the wild in this state.

Spatiotemporal analysis of rabies in cattle in central Mexico.

Spatial epidemiology of bat-transmitted rabies in cattle has been limited to spatial distribution of cases, an approach that does not identify hidden patterns and the spread resulting in outbreaks in endemic and susceptible areas. Therefore, the purpose of this study was to determine the relationship between the three variables average annual maximum, annual minimum temperature and precipitation in the region on the one hand, and the spatial distribution of cases on the other, using geographic information systems and co-Kriging considering that these environmental variables condition the existence of the rabies vector Desmodus rotundus. A stationary behaviour between the primary and the secondary variables was verified by basic statistics and moving window statistics. The directions of greater and lesser spatial continuity were determined by experimental cross-semivariograms. It was found that the highest risk for bovine paralytic rabies occurs in areas known as La Huasteca Potosina and La Sierra Gorda that are characterized by a maximum temperature of 29.5 °C, a minimum temperature of 16.5 °C and precipitation of 1200 mm. A risk estimation map was obtained for the presence of rabies with a determination coefficient greater than 95%, and a correlation coefficient greater than 0.95. Our conclusion is that ordinary co- Kriging provides a better estimation of risk and spatial distribution of rabies than simple Kriging, making this the method recommended for risk estimation and regional distribution of rabies.

A Wandering Black Bear (Ursus americanus, Pallas 1780) in the Sierra Gorda Biosphere Reserve, Queretaro

Black bear distribution and dispersal in Mexico are uncertain. Here we document the occurrence of a black bear in the Sierra Gorda Biosphere Reserve in the Mexican State of Queretaro. We assessed its population membership using microsatellites genetic markers and conclude the individual came from the Nuevo Leon population, which is approximately 200 km north of the study area.

NECESSITY OF INTERVENTION POLICIES FOR TAILINGS IDENTIFIED IN THE ANTOFAGASTA REGION, CHILE

The aim of this work was to establish the intervention requirements of 30 tailings deposits located in the region of Antofagasta, Chile, identified in the National Tailings Survey carried out by the National Service of Geology and Mining of the Chilean government in 2017. For the evaluation, the data of 49 geochemical characterizations of the samples registered as of October 2017 were considered. The methodology used for evaluation was based on the Dutch Soil Regulation Circular, from which two ways of assessment were developed. The first approach uses a simple graphic method that depends only on the concentration of the elements in the solid phase of tailings and the percentage of clay in the soil. The second approach considers that the information related to the clay percentage is not available, therefore, this work defines the concepts of threshold factor and adjusted threshold factor. Using the proposed method, this work presents the analysis carried out on the elements of environmental significance related to mining activity in Chile: Cu, Cr, Ni, Zn, Pb, As, Cd and Hg. The methodology allows delimiting areas of foreseeable risks for people and/or environment, resulting in three criteria for each element: 1) requires intervention, 2) requires conditional intervention, 3) does not require intervention. These results are summarized by means of a final score that determines the level of priority assigned to each sample. The analysis of results indicates that Hg intervention is not required, there being only one case requiring conditional intervention. Regarding Cu and Zn, 100 % of the measurements indicated at least the requirement of a conditional intervention. Within the region, the commune of Sierra Gorda contains 67 % of the tailings whose intervention must be prioritized according to the score obtained (greater than four out of a possible maximum of eight). On the other hand, the two tailings of greater tonnage (the sites of Talabre and Laguna Seca) do not present a requirement for priority intervention at the moment.

Frontiers of Evangelization: Indians in the Sierra Gorda and Chiquitos Missions

Frontiers of Evangelization: Indians in the Sierra Gorda and Chiquitos Missions