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The Cenozoic Sierra de San Carlos-Cruillas (SSCC) magmatic complex belongs to the Eastern Mexican Alkaline Province (EMAP). The SSCC mainly consists of plutonic and subvolcanic bodies displaying diverse lithological compositions. These rocks exhibit both OIB- and arc-like geochemical characteristics. In this contribution, we present new petrographic, geochemical, isotopic, and geochronological data of the Rincón Murillo Gabbro (RMG), situated in the southern part of the SSCC. The RMG is nepheline normative and displays an OIB-like intraplate character. Laser ablation ICP-MS U-Pb analyses on titanites yielded Oligocene (Rupelian) crystallization ages of 31.8 ± 1.8 and 31.0 ± 1.7 Ma. The 87Sr/86Sr(i) (0.703400–0.704159) and 143Nd/144Nd(i) (0.512732–0.512815) ratios indicate a mantle origin. Trace element data indicate the participation of different enriched mantle components in the source. One component is related to previous subduction processes, generating the HFSE-depleted arc-like magmas of San José Gabbro in the northern part of SSCC. The second component is related to deep mantle melts with a slightly carbonatitic signal and HFSE-enriched fluids derived from the subducted Hess conjugate plateau generating different enriched sources in the upper mantle under the SSCC. The passage, eclogitization, detachment and foundering of the Hess plateau gave rise to an asthenospheric upwelling that triggered the low to moderate partial melting degrees (3–15%) of an amphibole-bearing garnet peridotite, generating the OIB-like parental magmas of RMG, located in the southern part of SSCC. Two-component mixing, and AFC models indicate that variable degrees of crystal fractionation and minor crustal assimilation are involved in the evolution of Rincón Murillo Gabbro. [ABSTRACT FROM AUTHOR]

Neotectonic activity in the western margin of the Sierra Madre Oriental in northeastern Mexico was evaluated using geomorphological, geological, structural, and seismological analyses. We evaluated recent tectonic evidence in the basin of the Potosí Valley related to the Santo Domingo Fault System (SDFS), which is one of the largest active extensional fault zones documented so far in the transition zone between the Basin and Range and the Sierra Madre Oriental provinces. Two indices were used in the geomorphological analysis: transverse topographic basin asymmetry (T) and mountain front sinuosity (Smf). The results show that the studied basin is slightly tilted to the WSW, consistent with the typical basin deformation pattern in the Basin and Range province. Structural data collected in the field unveil a NW–SE striking fault system, geometrically and kinematically similar to the Cenozoic lineaments of the Basin and Range province. The local stress tensor calculated in this study indicates an extensional tectonic regime, suggesting S V > S NW > S NE . Analysis defines an azimuth trend of 298° and 036° for σ 2 (S Hmax) and σ 3 S hmin , respectively. According to the results, the SDFS is well orientated for possible future reactivation as a normal fault system. We estimate that a segmented rupture of the SDFS could produce seismic events on the order of magnitude 5 < Mw < 6. Considering a continuous rupture (~ 42 km) of the SDFS in a single event, an earthquake of Mw 7.0 could be expected. The results are essential to estimate seismic hazards in northeastern Mexico, including important urban areas, such as Monterrey, Nuevo León, and Saltillo, Coahuila. [ABSTRACT FROM AUTHOR]

The origin of the Eastern Mexican Alkaline Province has been explained by landward arc migration and subsequent asthenospheric upwelling after slab roll-back of the Farallon Plate. In this work, we present new petrographic, mineral chemical, geochemical, and geochronological data of the Sierra de San Carlos-Cruillas (SSCC), one of the most important complexes in the province. This information, together with published data, helped us to reinterpret the tectonic processes operating during the generation of this province, as well as the mantle sources involved in the partial melting process. Detailed geochemical analysis suggests the participation of two types of metasomatized mantle regions: a lithospheric source modified by past subduction processes and an asthenospheric source slightly affected by carbonatite-related metasomatism. Variations in the partial melting degrees controlled the extent of magma enrichment in the latter. Major and trace element geochemistry, together with geochronological data and field relations, evinced an older post-orogenic setting related to the arc-like rocks (Eocene) and a younger intraplate extensional environment associated with all enriched igneous rocks (Oligocene-Miocene). Bivariate diagrams of SiO2-trace element ratios and multi-element patterns indicate that magmas from the SSCC complex dominantly evolved through fractional crystallization with a limited crustal contribution. Petrographic and mineral chemistry features suggest that some of these magmas experienced open-system processes (e.g. recharge events) in a complex and dynamic magmatic feeding system. In contrast to the traditional petrotectonic model, we propound that the passage and subsequent foundering of the Hess conjugate under northeastern Mexico resulted in its eclogitization and triggered slab tearing and succeeding detachment. This latter process occasioned mantle upwelling and the partial melting of the two recognized metasomatized mantle sources, thus generating the San Carlos-Cruillas magmatism. [ABSTRACT FROM AUTHOR]

The Huizachal–Peregrina Anticlinorium basement of the Sierra Madre Oriental in north-eastern (NE) Mexico comprises a wide variety of Precambrian and Paleozoic units. A granitic unit, described in this work as the Peregrina Tonalite (PTo), intruded the Neoproterozoic Novillo Gneiss, which is the northernmost expression of the Oaxaquia microcontinent. In contrast, the PTo's contact with the Carboniferous Granjeno Schist is tectonic along vertical faults with a strike-slip component. This Paleozoic lithodeme is part of the Granjeno–Acatlán Belt. The PTo has been described as an orphaned block associated with an enigmatic Carboniferous magmatic arc located along the north-western (NW) margin of Gondwana. In this study, new U–Pb LA–ICP–MS data from PTo zircons included a youngest Late Ordovician (Katian stage) population at 448.8 ± 2.9 Ma, interpreted as the crystallisation age, and an oldest Grenvillian population interpreted as the potential age of its protolith. Additionally, major and trace element concentrations and ratios indicate a link to a continental arc that developed along the NW margin of Gondwana. Given this proposed arc's age and position, a comprehensive model for the development of the NE Mexican basement without the involvement of exotic or orphaned terranes is now proposed. The PTo outcropping near Ciudad Victoria, Tamaulipas, is interpreted to be part of a previously unreported magmatic arc in NE Mexico established during the Late Ordovician, herein described as the Peregrina–Mochonian Orogeny. It represents an extension of the South American Famatinian arc into Mexico. [ABSTRACT FROM AUTHOR]

The Cenozoic Aldama Volcanic Field (8–0.24 Ma) is located on the southeastern margin of the Sierra de Tamaulipas and is the largest field of the Eastern Mexican Alkaline Province. It contains cinder cones, tuff rings, maars, and simple cones, as well as widespread lava flows. The volcanic rocks are geochemically characterized as alkali basalts, subalkaline basalts, trachybasalts (potassic and hawaiites), latites to trachytes, and grouped in six rock types according to their Mg-content and normative composition: (a) Alkaline near-primary rocks, (b) Alkaline basic rocks, (c) Alkaline intermediate rocks, (d) Subalkaline near-primary rocks, (e) Subalkaline basic rocks, and (f) Subalkaline intermediate rocks. Trace elements and isotopic ratios show that the source of the basaltic melts displays asthenospheric characteristics and stability conditions, indicating that the partial melting (<5%) occurred in lithospheric levels within the spinel stability depth. The coexistence in time and space of alkaline and subalkaline rocks could be explained by selective alkali metasomatism of a regional HFSE and REE-enriched OIB-like source. The magma generation occurred in a typical continental intraplate setting, associated with mantle disturbances produced by the eclogitization and detachment of the Hess conjugate subducted under NE Mexico. Some alkaline and subalkaline melts evolved to intermediate members by fractional crystallization. [Display omitted] • The Aldama Volcanic Field represents the biggest Cenozoic complex related to the Eastern Mexican Alkaline Province. • A geochemical characterization and the spatial distribution of the volcanic structures are presented. • An alkaline and a subalkaline series coexist in time and space, being the alkaline promoted by mantle metasomatism. • The evolution of basaltic magmas by fractional crystallization led to the formation of trachytic magmas. [ABSTRACT FROM AUTHOR]

The Precambrian metamorphic basement exposed in the eroded core of the Huizachal-Peregrina Anticlinorium (Cd. Victoria, Mexico) is described in this contribution as Novillo Metamorphic Complex (NMC). Based on field relations, modal content, whole rock geochemistry and Nd-isotopic ratios is possible to recognize two major units: (a) Metaigneous Unit (MIU) and (b) Metasedimentary Unit (MSU). The MIU is subdivided into the Old Suite , constituted by (a) felsic gneisses from Novillo canyon, (b) felsic gneisses from Peregrina canyon, (c) metagranites, (d) mafic gneisses, and (d) migmatites; and the AMCG Suite , composed by (a) meta-anorthosites, (b) metagranite-gabbro intercalations, (c) metacharnockites, (d) garnet-rich metaferrodiorite dykes, and (e) metanelsonites. The MSU is represented by (a) meta-arkose – amphibolite intercalations and (b) calcsilicate marbles. Tectonic discrimination diagrams based on linear discriminant analysis of natural logarithm transformed ratios of elements show an island arc tectonic setting for the MIU. Nd isotopic ratios show crustal residence T DM ages of 1.49–1.44 Ga for the Old Suite (2 samples) and 1.63–1.33 Ga for the AMCG Suite (7 samples). The MSU have T DM between 1.39 a 1.25 Ga (3 samples) that support the interpretation that the protoliths were possibly deposited in a basin with sediment input from the younger MIU members. These deposits were later thrusted over MIU rather than intruded, and together metamorphosed under granulite facies conditions by the ca. 1.0 Ga Zapotecan orogeny. However, since the metaferrodioritic bodies cut discordantly the meta-anorthosites fabric, they represent a younger tectonothermal event, not yet described for the NMC. • The term Novillo Metamorphic Complex is coined in this work • The Novillo Metamorphic Complex comprises a Metamorphic Igneous Unit and a Metamorphic Sedimentary Unit. • A spatial distribution of the different metaigneous lithology is presented. • A new geochemical characterization of the Novillo Metamorphic Complex is provided. • New Nd and Sm isotope data are presented for the very first time for the Novillo Metamorphic Complex. [ABSTRACT FROM AUTHOR]

Aims: The objective of this study is to analyze how the impact of Diabetes Mellitus [DM] in patients with COVID-19 varies according to altitudinal gradient., Methods: We obtained 1,280,806 records from adult patients with COVID-19 and DM to analyze the probability of COVID-19, development of COVID-19 pneumonia, hospitalization, intubation, admission to the Intensive Care Unit [ICU] and case-fatality rates [CFR]. Variables were controlled by age, sex and altitude of residence to calculate adjusted prevalence and prevalence ratios., Results: Patients with DM had a 21.8% higher prevalence of COVID-19 and an additional 120.2% higher prevalence of COVID-19 pneumonia. The adjusted prevalence was also higher for these outcomes as well as for hospitalization, intubation and ICU admission. COVID-19 and pneumonia patients with DM had a 97.0% and 19.4% higher CFR, respectively. With increasing altitudes, the probability of being a confirmed COVID-19 case and the development of pneumonia decreased along CFR for patients with and without DM. However, COVID-19 patients with DM were more likely to require intubation when residing at high altitude., Conclusions: The study suggests that patients with DM have a higher probability of being a confirmed COVID-19 case and developing pneumonia. Higher altitude had a protective relationship against SARS-CoV-2 infection; however, it may be associated with more severe cases in patients with and without DM. High altitude decreases CFR for all COVID-19 patients. Our work also shows that women are less affected than men regardless of altitude., Competing Interests: The authors declare that no competing interests exist.

Background: The spectrum of pre-existing renal disease is known as a risk factor for severe COVID-19 outcomes. However, little is known about the impact of COVID-19 on patients with diabetic nephropathy in comparison to patients with chronic kidney disease., Methods: We used the Mexican Open Registry of COVID-19 patients 11 to analyze anonymized records of those who had symptoms related to COVID-19 to analyze the rates of SARS-CoV-2 infection, development of COVID-19 pneumonia, admission, intubation, Intensive Care Unit admission and mortality. Robust Poisson regression was used to relate sex and age to each of the six outcomes and find adjusted prevalences and adjusted prevalence ratios. Also, binomial regression models were performed for those outcomes that had significant results to generate probability plots to perform a fine analysis of the results obtained along age as a continuous variable., Results: The adjusted prevalence analysis revealed that that there was a a 87.9% excess probability of developing COVID-19 pneumonia in patients with diabetic nephropathy, a 5% excess probability of being admitted, a 101.7% excess probability of intubation and a 20.8% excess probability of a fatal outcome due to COVID-19 pneumonia in comparison to CKD patients (p<0.01).  Conclusions: Patients with diabetic nephropathy had nearly a twofold rate of COVID-19 pneumonia, a higher probability of admission, a twofold probability of intubation and a higher chance of death once admitted compared to patients with chronic kidney disease alone. Also, both diseases had higher COVID-19 pneumonia rates, intubation rates and case-fatality rates compared to the overall population.