Native Peoples of Central Mexico Since Independence

Properties of the subduction system in Mexico

Central and southern Mexico represents a strategic place to understand the dynamics of Pangaea break-up and its influences on the evolution of the Pacific margin of North America. Lower–Middle Jurassic volcano-sedimentary successions, and scarce magmatic rocks, crop out discontinuously across this region and have been interpreted either as a vestige of a continental arc or as several deposits of syn-rift magmatism. At present, their origin is controversial. Available geochemical data on these igneous rocks suggest that they represent almost pure crustal melts produced in a rift environment rather than in an arc. In fact, the studied rocks exhibit the high silica contents and moderate to strong peraluminous character typical of sediment melts. The enriched isotopic composition (high86Sr/87Sr and low143Nd/144Nd) and the age distributions of inherited zircon grains readily identify the widespread Upper Triassic metasedimentary sequences presently exposed in southwestern and central Mexico as the most likely crustal source of these Jurassic igneous rocks. Accordingly, we argue that these Early–Middle Jurassic magmas originated in a syn-rift igneous province associated with extensional-driven crustal attenuation in the context of Pangaea fragmentation. Our findings also constrain post-Pangaea subduction initiation to be younger than Middle Jurassic time in central and southern Mexico.

Distribution of hydrous minerals in the subduction system beneath Mexico

Biomass burning from grassland, forests, and agricultural waste results in large amounts of gases and particles emitted to the atmosphere, which affect air quality, population health, crop development, and natural vegetation. Regional atmospheric circulations can transport those plumes of pollutants over hundreds of kilometers, affecting vulnerable environments such as those considered protected natural areas (PNAs). This study evaluates the spatiotemporal distribution of active fires detected, and associated emissions, in central and southern Mexico from satellite data between March and June 2017, to assess the impact of the smoke plumes on protected ecosystems. The arrival of smoke plumes to selected PNAs (both near large urban centers and in remote areas) is assessed using airmass forward trajectories from selected emission sources. The spatial distribution of the remotely derived aerosol optical depth confirms the regional impact of particle emissions from the observed fires on PNAs, particularly in central Mexico. The identified areas of high fire density are also associated with large coarse particle concentrations at the surface. Moreover, there is a significant contribution of organic carbon to the total coarse particle mass, 60% on average. Finally, while most of the impact in ambient pollution is observed in PNAs located close to the regions with active fires in southern Mexico and Central America, the long-range transport of smoke plumes reaching the USA was also confirmed.

In Mexico, ultramafic complexes are present in different regions from the northwest (Baja California Norte) to the southeast (Chiapas). In this paper, we present the results of the exploration of three ultramafic (serpentine) habitats in central and southern Mexico: Cuicatlán–Concepción Pápalo (Oaxaca), Tehuitzingo–Tecomatlán (Puebla), and San Juan de Otates (Guanajuato). Previous geology studies showed that these complexes are mainly made up of serpentinized peridotites. Soil analyses demonstrated typical ultramafic characteristics such as high content of Mg in relation to Ca, and high concentrations of Fe, Cr, Co, and Ni. Soil samples from Oaxaca and Puebla had similar Ni contents around 2300 mg kg−1, while samples of Guanajuato showed the lowest Ni levels with an average of 200 mg kg−1 as well as for other metals such as Co, Cr, Mn, and Zn. During this study, 83 plant specimens were collected, of which 52 were identified at genus level and 40 at species level. The collected plants belong to 19 different families such as Anacardiaceae, Fabaceae, Acanthaceae, Asteraceae, Sterculiaceae, and Verbenaceae which are also widely present in other ultramafic areas in Iran, Brazil, Sri Lanka, and Costa Rica. Only two Mexican endemic species are included in the collection. Ni hyperaccumulators were not detected at any of the studied sites. Therefore, hyperaccumulation, as a tolerance mechanism of the flora in response to ultramafic geochemical stress, does not seem to be developed in Central Mexico, as observed in the close Costa Rican site of Santa Elena.

This volume furthers our understanding of key basins in central and southern Mexico, and establishes links to exhumed sediment source areas in a plausible paleogeographic framework. Authors present new data and models on the relations between Mexican terranes and the assembly and breakup of western equatorial Pangea, plate-tectonic and terrane reconstructions, uplift and exhumation of source areas, the influence of magmatism on sedimentary systems, and the provenance and delivery of sediment to Mesozoic and Cenozoic basins. Additionally, authors establish relationships between basement regions (sediment source) in the areas that supplied sediment to Mesozoic rift basins, Late Cretaceous foreland systems, and Cenozoic basins developed in response to Cordilleran events.

The Euphorbia adiantoides complex is here considered to consist of four species. This group is readily distinguished from other New World Euphorbia by the combination of two unusual features: entire styles with capitate stigmas and dichasial bracts with relatively long, filiform stipules. Euphorbia sonorae is reduced to a synonym of Euphorbia adiantoides, a taxon disjunctly distributed between Mexico and western South America. The other species of the complex are all restricted to Mexico. Two of these are described as new: E. zamudioi, an endemic to the Sierra Madre Oriental, and E. breedlovei, which is widespread in central and southern Mexico. A key to distinguish the species is provided, as too are data concerning their morphology, distribution, habitat, phenology, common names, and uses. Phylogenetic analyses were conducted using the nuclear ITS and the chloroplast psbA-trnH regions and including multiple samples of each species. The phylogenetic results are not always congruent with morphology, and of the four species herein recognized, only Euphorbia zamudioi is suggested to form an exclusive, well-supported lineage. This species is nested within E. breedlovei, and two collections of E. breedlovei from central Mexico are more closely related to E. zamudioi than they are to other E. breedlovei from southern Mexico. We hypothesize that E. zamudioi arose through peripatric speciation, in which a northern population of E. breedlovei became reproductively isolated and morphologically differentiated from the remainder of the populations of E. breedlovei.

The 3DVp,Vp/Vs, P‐ and S‐wave attenuation structure of the Cocos subduction zone in Mexico is imaged using earthquakes recorded by two temporary seismic arrays and local stations. Direct P wave arrivals on vertical components and direct S wave arrivals on transverse components from local earthquakes are used for velocity imaging. Relative delay times for P and PKP phases from teleseismic events are also used to obtain a deeper velocity structure beneath the southern seismic array. Using a spectral‐decay method, we calculate a path attenuation operatort* for each P and S waveform from local events, and then invert for 3D spatial variations in attenuation (Qp−1andQs−1). Inversion results reveal a low‐attenuation and high‐velocity Cocos slab. The slab dip angle increases from almost flat in central Mexico near Mexico City to about 30° in southern Mexico near the Isthmus of Tehuantepec. High attenuation and low velocity in the crust beneath the Trans‐Mexico Volcanic Belt correlate with low resistivity, and are probably related to dehydration of the slab and melting processes. The most pronounced high‐attenuation, low‐Vpand high‐Vp/Vsanomaly is found in the crust beneath the Veracruz Basin. A high‐velocity structure dipping into the mantle from the side of Gulf of Mexico coincides with a discontinuity from a receiver functions study, and provides an evidence for the collision between the Yucatán Block and Mexico in the Miocene.

The conquest of Mesoamerica has long been and continues to be an alluring subject of historical and interdisciplinary inquiry. Indeed, much work has emerged in the last few decades that has significantly enhanced—and at times radically transformed—our understanding of this fascinating and foundational episode in transatlantic history. This shift in conquest historiography—often referred to as the New Conquest History—is characterized by, among other things, the revisiting and rereading of long-familiar published primary sources, the recentering of native peoples and their perspectives and interpretations in our historical narratives, and a disregard for traditional disciplinary boundaries. Paul Scolieri's Dancing the New World accomplishes all these objectives and is an excellent addition both to conquest scholarship and to the cultural history of colonial Mexico.Scolieri's aim is to use dance as a “lens into the broader ‘encounter’ between Europeans and Indians in the New World,” specifically sixteenth-century central Mexico (p. 1). Through writings about dance, Scolieri sees an opportunity not only to enrich our understanding of Nahua performance but also to explore the “political unconscious” of sixteenth-century Iberia (p. 2). Scolieri demonstrates that texts about dance reflect important political, theological, and epistemological debates among Spaniards (whether native peoples are noble or savage, what the best methods of conversion were, and what happened in the past and how one knows it) in addition to elusive ethnographic information on pre-Hispanic and colonial-era dance in the Americas. This is a book that blurs the line between conventional definitions of history and performance and challenges us to answer one of Scolieri's central questions: “When does choreography (the writing of dance) become historiography (the writing of history), and vice versa?” (p. 151).The work is divided into five chapters, which proceed chronologically. Scolieri begins in the Caribbean with Europeans' first encounters with the peoples of Hispaniola and Europeans' descriptions of native dances. The “song-dances” of Hispaniola achieved some fame in sixteenth-century Europe through the writings of explorers such as Christopher Columbus and Amerigo Vespucci, who called them areítos. The explorers' writings about the areítos—which tended, in general, to create what Scolieri calls a “discourse of wonder” around native peoples—serve as a benchmark against which to measure later accounts of dance in central Mexico (p. 27).The book then moves the reader to central Mexico to examine writings on dance by two famed missionary ethnographers of the Nahuas, Motolinia (Fray Toribio de Benavente) and Fray Bernardino de Sahagún. Scolieri argues that Motolinia rejected the Caribbean discourse of wonder and instead used descriptions of Nahua dancers to portray them as penitent Christian native commoners, ready to be received into the Catholic Church and the Spanish empire. Sahagún and his Nahua collaborators, meanwhile, were understandably less concerned with either wonder or penitence and instead attempted an exhaustive description of the intricacies of Nahua dance in the context of the feasts of the pre-Hispanic solar calendar. Scolieri's treatment of Sahagún's work deserves special comment, as it is both masterful and enthralling. And this has to be one of the most enlightening and satisfying discussions of Nahua human sacrifice currently in print.The book then takes on—through the lens of dance—one of the more controversial episodes in the conquest narrative: the Toxcatl massacre. While Scolieri gets us no closer to the truth of what happened that night, he has nonetheless produced a very patient analysis of dance and dancers in the various and often contradictory sources for this episode to reveal “the range of competing and complementary meanings that conquistadors, chroniclers, missionaries, and natives brought to and drew from the massacre” (p. 122). The book concludes with a look at the colonial period. Drawing on the colonial-era writings of Diego Durán, José de Acosta, and Andrés Pérez de Ribas, Scolieri explores the degree to which native peoples retained control of their dancing in the context of forced Christianization.This is a clearly written work that will appeal to a variety of readers, from the sixteenth-century Mexicanist to the upper-level undergraduate student. A great strength of this book is Scolieri's primary source analysis. While he does not make much use of the kind of mundane archival material that many historians so esteem, he reevaluates the canon of published sources—by conquistadores and chroniclers, missionaries and missionized—to great effect. Happily, excerpts of many of these accounts are included in translation in a series of ten appendixes. Scolieri also draws on an abundance of pictorial sources produced by both Europeans and natives, and the University of Texas Press's characteristic care and attention to publishing copious and high-quality images of these sources is gratifying. Indeed, Scolieri's interdisciplinarity is another of the book's strengths; the fields of dance and performance studies, art history, ethnography, and history come together seamlessly in this very fine contribution to conquest historiography.

Deep crustal structure of central Mexico derived from interpretation of Bouguer gravity anomaly data

The ancient city of Teotihuacan was a great urban and ceremonial center, whose population grew exceptionally in the Classic Period (300 – 700 AC). Settlement patterns, culture and burials have indicated an occupation that consisted of groups of neighboring apartment compounds or barrios. We investigated the genetics of three apartment compounds in the Teotihuacan Valley through ancient DNA analysis to prove multiethnicity during the Classic Period. Amerindian mitochondrial haplogroups were identified in 10 burials from San Francisco Mazapa, 7 from San Sebastian Xolalpan, and 19 human bone tools from La Ventilla. These samples had a wide genetic diversity. Differences in genetic structures were slight but significant (p< 0.001) between the three households and 7 ancient populations from Central and Southern Mexico by FST analysis between the three barrios studied, and Xaltocan (post-conquest) was congruent with the number of migrants estimated. Tlailotlacan, another household of Teotihuacan, was different following a small interaction with Mazapa, Xolalpan and La Ventilla. Through the estimation of immigrants, the three households studied seem to have come into contact with Mayans from Xcaret in Yucatan, and this coincides with archaeological data reported. Genetic data could indicate that migration and less genetic drift may possibly lead to a more effective role in the Teotihuacan groups, suggesting that interchange with other groups was not only for commercial, service or governmental purposes, which implicated demographic integration and genetic fusion, culminating in multiethnicity during the Classic Period in Teotihuacan. Further studies can be directed to examine others households.

The widespread but endemic mud turtle species Kinosternon integrum Le Conte, 1854 currently ranges throughout most of Mexico, from southern Sonora in the northwest to and through western, central and southern Mexico at least to eastern Oaxaca. Broad and convincing evidence indicates that Kinosternon integrum actually represents a taxonomically complicated species complex; however, as the holotype has allegedly been lost for more than a sesquicentennial and the specimen’s original collection locality data is lacking, a comprehensive systematic revision of the original concept of the species is required before convincing taxonomic subdivision of the complex can proceed. In this contribution we designate a neotype specimen, drawing from the species junior subjective synonym Cinosternon rostellum Bocourt, 1876 and subsequent junior objective synonym Cinosternon guanajuatense Dugès, 1888. We review nomenclatural history and application, argue for the ambit of locality data of the lost holotype collected during the Mexican-American War (1846-1848) and provide a sensu-stricto morphological redescription of, K. integrum based on the museum accessioned and living specimens documented throughout the range. Even though this study now confines its distribution to the majority of states within central Mexico, K. integrum retains its honorific of the most vagile and widely distributed mud turtle in the country.

Opuntia ficus-indica is a long-domesticated cactus crop that is important in agricultural economies throughout arid and semiarid parts of the world. The biogeographic and evolutionary origins of this species have been obscured through ancient and widespread cultivation and naturalization. The origin of O. ficus-indica is investigated through the use of Bayesian phylogenetic analyses of nrITS DNA sequences. These analyses support the following hypotheses: that O. ficus-indica is a close relative of a group of arborescent, fleshy-fruited prickly pears from central and southern Mexico; that the center of domestication for this species is in central Mexico; and that the taxonomic concept of O. ficus-indica may include clones derived from multiple lineages and therefore be polyphyletic.

Genetic structure, phylogeography, and migration routes of Bouteloua gracilis (Kunth) Lag. ex Griffiths (Poaceae:Chloridoideae)

Mesozoic tectono-magmatic evolution of Mexico: An overview