Resumen La noción de teología natural es clave dentro de la obra de Agustín que, en tanto romano formado a partir de las coordenadas del canon clásico, construye dentro de su obra los dispositivos necesarios para dar entrada legítima, aunque parcial, a elementos grecorromanos que habrán de orientar su propia argumentación en el territorio de las letras cristianas. El octavo libro de su tratado La ciudad de Dios nos permite observar la extracción de aquella noción de su ámbito de procedencia, especialmente los textos de Varrón y Cicerón, que tienen a su vez sus antecedentes en la tradición filosófica académica y estoica, su adaptación al horizonte de significado bíblico-cristiano y su uso interesado dentro de este. La operación llevada a cabo por Agustín nos deja entrever su conocimiento y capacidad de manipulación de la tradición letrada romano-republicana, además de ciertas concepciones procedentes de la vulgata doxográfica vigentes en su contexto, tales como las de “escuelas” y “sucesiones” filosóficas. Nos interesa enfocar, sobre todo, los juegos de amalgamas y corrimientos semánticos que ensaya Agustín sobre el perfil de Sócrates, con unos fines muy puntuales, y que nos llevan a observar, asimismo, la circulación de ideas en el espacio romano del norte de África, para el cual disponemos de algunos antecedentes de interés, como los textos de la apologética en lengua latina de Tertuliano y Minucio Félix, entre los siglos II y III.

Abstract The notion of natural theology is a key one in the work of Augustine who, as a Roman formed from the coordinates of the classical canon, builds within his work the necessary devices to give legitimate, although partial, entry to Greco-Roman elements that will be guide his own argument in the territory of Christian literature. The eighth book of his treatise The City of God allows us to observe the extraction of that notion from its area of origin, especially the texts of Varro and Cicero, which in turn have their antecedents in the academic and Stoic philosophical tradition, their adaptation to the horizon of biblical-Christian meaning and its interested use within it. The operation carried out by Augustine gives us a glimpse of his knowledge and ability to manipulate the Roman-Republican literary tradition, in addition to certain conceptions from the doxographic vulgate in force in his context, such as those of “schools” and philosophical “successions.” We are interested in focusing, above all, on the games of amalgamations and semantic shifts that Augustine rehearses on the profile of Socrates, with very specific purposes, and which lead us to observe, also, the circulation of ideas in the North African Roman area, for which we have some interesting antecedents, such as the Latin apologetics books of Tertullian and Minutius Felix, between the 2nd and 3rd centuries.

Abstract The calcareous microfossils present in the Ordovician and Silurian carbonate successions around the world are limited to few studies and their biological affinities and environmental preferences remain indefinite. In the carbonate Ordovician San Juan Formation from the Cerro La Chilca section, a group of calcareous microfossils was recognized and, based on their size, they are included in the calcitarch classification. Two types of calcitarchs have been recognized, Type-III calcitarch: large spheres with a thin to medium wall (diameter ~250 μm), and Type-0 calcitarch: small spheres with a thin wall (diameter ~80 μm). The carbonate microfacies analysis of the lower part of the San Juan Formation allowed defining five successive microfacies: burrowed bioclastic wackestone (M1), peloidal intraclastic packstone-grainstone (M2), intraclastic floatstone (M3), intraclastic wackestone-packstone (M4) and bioclastic boundstone (M5). These microfacies are interpreted to range from shallow subtidal facies below wave action to shoal and reef facies. It is possible to infer that the recovered calcitarchs show variations in size in relation to the facies that contain them. The calcitarchs recognized in wackestone-type facies are the Type-0 calcitarch and those recovered from the packstone-grainstone facies are the Type-III calcitarch. The calcitarch sizes variation probably is related to a gradual increase of energy within a shallow subtidal environment. Occurrences of calcitarchs within the Floian Oepikodus evae-O. intermedius conodont zone extends their fossil record into the Early Ordovician.

Resumen Microfósiles carbonáticos del Ordovícico Inferior de la Formación San Juan, Argentina: un nuevo tipo de calcitarch y sus implicaciones paleoambientales. Los microfósiles calcáreos presentes en las sucesiones carbonáticas ordovícicas y silúricas están limitados a unos pocos estudios, por lo que sus afinidades biológicas y preferencias ambientales aún están indefinidas. En los niveles carbonáticos de la Formación San Juan en la sección Cerro La Chilca, se reconoció un grupo de microfósiles calcáreos que, en función de su tamaño, se incluyen en la clasificación de calcitarch. Se han reconocido dos tipos de calcitarchs, calcitarchs tipo-III: esferas grandes con una pared delgada a mediana (diámetro ~250 μm) y calcitarchs tipo-0: esferas pequeñas con una pared delgada (diámetro ~80 μm). El análisis de las microfacies carbonáticas de los niveles inferiores de la Formación San Juan permitió definir cinco microfacies sucesivas: wackestone bioclástico bioturbado (M1), packstone-grainstone intraclástico peloidal (M2), floatstone intraclástico (M3), wackestone-packstone intraclástico (M4) y boundstone bioclástico (M5). Se interpreta que estas microfacies van desde facies submareales poco profundas por debajo de la acción de las olas hasta facies de barras y arrecife. Es posible inferir que los calcitarchs recuperados presentan variaciones de tamaño en relación con las facies que las contienen. Los calcitarchs reconocidas en las facies tipo wackestone son las calcitarchs tipo-0 y las recuperadas de las facies packstone-grainstone son las calcitarchs tipo-III. La variación del tamaño de los calcitarchs probablemente esté relacionada con un aumento gradual de energía dentro de un ambiente submareal poco profundo. La ocurrencia de calcitarchs dentro del intervalo comprendido por las zonas de Oepikodus evae-O. intermedius (Floiano) extiende su registro fósil hasta el Ordovícico Inferior.

Abstract Mass movements naturally occurring along slopes, especially after heavy rains, cause heavy losses of materials and life and affect highways, pipelines, and bridges, among other structures. Among the most common mass movements, landslides and subsequent mass flows especially stand out. Remote sensing and geoprocessing techniques are useful tools for geological and geotechnical analysis, here applied to characterization of mass movements from the analysis of the influence of slopes, lineaments or fractures, and geological-geotechnical at the junction of the Curral homocline and the Moeda syncline, Quadrilátero Ferrífero, Southeast Brazil. The area consists of Archean granitic-gneissic basement and the greenstone belt sequence of the Rio das Velhas Supergroup with Proterozoic metasedimentary rocks of the Minas Supergroup covering these two older successions. Based on satellite images, a preliminary map of lineaments was created, and fractures were grouped according to their direction before being rasterized. Each lineament group was associated with a previously known geological and/or structural feature. Geological units mapped in the area were numerically classified according to their mass movement susceptibility and related geotechnical units. Using a Shuttle Radar Topography Mission (SRTM) image, a terrain slope raster was generated. The objective was to obtain a raster indicating low and high probabilities of mass movements. Four sets of lineaments were identified: the first set associated with the northeast strike stratification of the rocks of the Moeda Formation; the second set related to eastward-trending warp axis lineations; the third set related to the southeast trend of stretch lineaments or mafic dykes directions; and the fourth set evidently associated with the watershed pattern of the Curral Range crest, perpendicular to the strike of the rocks in the area. Simulations with different combinations of parameters produced eight scenarios were generated were constructed to classify the area as to its susceptibility to rupture through changes in slope, lithotype, and lineament density; the first four (1 to 4) were classified by using the slope percentage raster without interval reclassification, so its values in the cartographic algebra were not grouped. The last for (5 to 8), consider the slope percentage classified. This methodology successfully combines mathematical models for predicting mass movements and determining areas in the urban landscape most susceptible to these phenomena. As such, it comprises a useful tool for government planning of preventative actions for areas of high risk. slopes rains highways pipelines bridges structures out geologicalgeotechnical syncline Ferrífero Brazil graniticgneissic granitic gneissic successions images created rasterized andor feature SRTM (SRTM image identified Formation eastwardtrending eastward trending lineations directions crest lithotype density 1 ( 4 reclassification 5 8, 8 , 8) phenomena such risk

Abstract The Parauapebas Formation and Igarapé Cigarra Formation constitute two Neoarchean extrusive units inserted in the metavolcanosedimentary sequence (~2.76 Ga) of the Grão Pará Group, Itacaiúnas Supergroup, being represented by basaltic seeps underlain and overlain by jaspillites, rhyolites, volcanoclastic rocks, and gabbro dikes/sills, thus being inserted in the Serra Sul district in the Mineral Province of Carajás, Pará. This study aimed to understand the igneous processes involved in the genesis of these basalts from both geological formations, supported by field, petrographic, and geochemical data. Inserted in the metavolcanosedimentary sequence of the Grão Pará Group (Carajás Domain), the basalts and basalt andesites, the most abundant types of the Parauapebas and Igarapé Cigarra Formations, occur as successions of massive and amygdaloidal lava flows. The study of core samples from nine stratigraphic holes that intersected basaltic rocks of the two geological formations in body S11D (Serra Sul) showed that these rocks reach thick layers with different characteristics, ranging from aphanitic to phaneritic. The basalts are dark green, aphanitic, phaneritic, thin to medium, and hypocrystalline. They show preserved igneous texture being commonly seriated as inequigranular, intersertal, ophitic, subophytic, intergranular, branching, and swallow tail. Its essential primary constituents are plagioclase, orthopyroxene, and clinopyroxene, and its accessory constituents are titanite and apatite. Chlorite, epidote, quartz, and calcite occur as secondary phases and are interpreted as the products of ocean-bottom hydrothermal alteration and/or incipient metamorphism. In general, the studied volcanic rocks stand out for SiO2 content between 47.00 and 56.04%, high alkali contents (4.70–7.50%), K2O contents between 0.40 and 3.97%, TiO2 (< 1.0%), and MgO between 4.90 and 8.16%. In the classification diagrams, the samples are situated in the fields of basalts, basalt andesites, trachyandesite, and trachybasalt basalts, in the transition of the toleitic and calc-alkaline series. The basalts of the Parauapebas and Igarapé Cigarra Formations were probably formed in an intraplate continental environment influenced by subduction zones. Therefore, the Grão-Pará Basin was probably formed in a convergent regime related to a subduction-type environment. The geochemical data indicate that the studied rocks of the Parauapebas Formation and the Igarapé Cigarra Formation correspond to basalts of calc-alkaline affinity. Two facies were identified in the Parauapebas Formation, namely, the Amendoim and Violão facies. In the Igarapé Cigarra Formation as well, the following facies were identified: Jacaré and Três Marias. Based on the geochemical interpretation, it is assumed that the rocks studied are arc-like continental basalts, which are formed in a subduction environment with influence from a possible asthenospheric source and modified by crustal contamination. ~2.76 276 2 76 (~2.7 Ga Supergroup jaspillites rhyolites dikessills dikes sills dikes/sills Carajás field petrographic Domain, Domain , Domain) andesites flows SD S D characteristics phaneritic green medium hypocrystalline inequigranular intersertal ophitic subophytic intergranular branching tail plagioclase orthopyroxene clinopyroxene apatite Chlorite epidote quartz oceanbottom ocean bottom andor or metamorphism general SiO 4700 47 00 47.0 5604 56 04 56.04% 4.70–7.50%, 470750 4.70–7.50% 4 70 7 50 (4.70–7.50%) KO K O 040 0 40 0.4 397 3 97 3.97% TiO < ( 1.0%, 10 1.0% 1 1.0%) 490 90 4.9 816 8 16 8.16% diagrams trachyandesite calcalkaline calc alkaline series zones Therefore GrãoPará subductiontype type affinity namely well Marias interpretation arclike arc like contamination ~2.7 27 (~2. 470 47. 560 5 56.04 47075 4.70–7.50 (4.70–7.50% 0. 39 9 3.97 1.0 49 4. 81 8.16 ~2. (~2 56.0 4707 4.70–7.5 (4.70–7.50 3.9 1. 8.1 ~2 (~ 56. 4.70–7. (4.70–7.5 3. 8. ~ 4.70–7 (4.70–7. 4.70– (4.70–7 4.70 (4.70– 4.7 (4.70 (4.7 (4. (4

ABSTRACT Off-season crops diversification and gypsum under minimal tillage can improve soil fertility and reduce soil compaction. The objective of this work was to evaluate changes on soil physical and chemical properties and soybean yield grown over off-season crops in combination with gypsum and chiseling. Treatments consisted of gypsum application (0 and 3,5 t ha-1), two tillage systems (no tillage [NT] and minimal tillage [MT] with chiseling) and four soybean off-season crop successions: maize (M); maize+brachiaria (M+B); millet+crotalaria/wheat (Mi+C/W) and maize+black oats (M+O). Gypsum application reduced resistance to penetration (PR) by 12% in M+B system (1.12 kPa), when compared to the same treatment without gypsum. Gypsum increased surface soil Ca contents, mainly in M/O (from 3.81 to 5.66 cmolc dm-3). MT decreased PR in M+B, Mi+C/W and M/O, from 1.28 kPa in NT to 0.98 kPa. MT lowered total soil porosity from 66.9 to 63.1%, but reduced Ca contents compared to NT. Cultivation of crotalaria in the off-season reduced Al levels on the soil surface and grasses increased K and P in depth. Despite the improvements in the soil properties, crop rotations, chiseling and gypsum were not able to increase soybean yields in this 18-month experiment, averaging 3904 kg ha-1. Offseason Off season compaction offseason off 0 ( 35 3 5 3, ha1, ha1 ha 1 , ha-1) no [NT [MT successions M (M) maizebrachiaria brachiaria MB B (M+B) milletcrotalariawheat millet wheat MiCW Mi C W (Mi+C/W maizeblack black M+O. MO M+O . O (M+O) (PR 12 1.12 112 (1.1 kPa, kPa) 381 81 3.8 566 66 5.6 dm3. dm3 dm dm-3) 128 28 1.2 098 98 0.9 669 9 66. 631 63 63.1% depth rotations 18month month 18 experiment 390 ha1. 1. ha-1 (M (M+B (M+O 1.1 11 (1. 38 8 3. 56 6 5. dm-3 2 09 0. 63.1 39 ha- (1 dm- 63.

Abstract We evaluated the seasonal phosphorus (P) status of the plankton community in the Ombla Estuary (OE) by using its specific alkaline phosphatase activity (sAPA). Microphytoplankton (MICRO) indicated a substantially higher P deficiency than nanophytoplankton (NANO) and picoplankton (PICO). We found that the prolonged increase in the temperature of the surface estuarine water supported a notable growth of the dinoflagellate Prorocentrum spp. in late spring-early summer (June). In the summer (August), we found the maximum microphytoplankton sAPA (MICRO sAPA) (307.8 nmol μg C-1 h-1) in the surface water, in which (84%) dinoflagellates predominated within MICRO with the maximum alkaline phosphatase activity (APA) in all size fractions, including free enzymes. Persistently low discharge of Ombla during summer-early autumn caused a transition from phosphorus- to potentially nitrogen-limited MICRO in the surface water in early autumn (October). Nutrient stress disappeared in winter, in which a significant amount of dissolved orthosilicate, dissolved inorganic nitrogen (DIN), and soluble reactive phosphorus (SRP) enriched the estuary via maximal river discharge and inflow of nutrient-rich coastal waters. MICRO (coccolithophorids and diatoms) had very low APA (surface water) and quantitatively undetectable APA (bottom water) in the nutrient-rich water column in January. This study shows a more significant impact of nutrient concentrations on MICRO than other size classes of the plankton community. Because of the similarity in seasonal hydrological features, we assume that the general pattern of switching from P- to N-limitation of phytoplankton growth also occurs in other highly stratified estuaries along the coastal karst of the eastern Adriatic Sea during the lowest river discharges and groundwater activities in summer-early autumn before the rainy season. This study indicates that a common highly stratified estuary on the eastern Adriatic coast can serve as a natural laboratory to explore connections between nutrient limitations and phytoplankton successions. (P OE (OE sAPA. . (sAPA) NANO (NANO PICO. PICO (PICO) spp springearly spring June. June (June) August, August , (August) 307.8 3078 307 8 (307. C1 C 1 C- h1 h h-1 84% 84 (84% (APA fractions enzymes summerearly nitrogenlimited limited October. October (October) winter orthosilicate DIN, DIN (DIN) SRP (SRP nutrientrich rich waters coccolithophorids diatoms bottom January features Nlimitation N limitation season successions (sAPA (PICO (June (August 307. 30 (307 h- (84 (October (DIN 3 (30 (8 (3 (

RESUMEN Numerosos ejemplos de macro plantas fósiles pueden ser encontrados en las sucesiones del Jurásico Temprano y Medio de la región de Kerman. Las formaciones Ab-e-Haji, Badamu, y Hojedk se encuentran entre estos patrones. Una de las regiones adecuadas para estudios paleobotánicos es el sección Chatroud. En esta región, el Jurásico Inferior-Medio tine aproximadamente 210 metros de espesor. 18 especies de macrofósiles de plantas de 14 géneros, incluyen Nilssonia polymorpha, Pterophyllum nathorsti, Podozamites distans, Elatocladus zamioides, Elatides thomasii, Nilssonia feriziensis, Nilssonia herriesi y Beania sp., los cuales son identificados y descritos en este estudio, además de Pterophyllum schenki, Anomozamites marginatus y Klukia exilis. En esta región existen dos zonas de asociación de plantas, conocidas como: Zona Anomozamites marginatus-Pterophyllum schenki y Zona Klukia exilis. La edad Hettangian-Bajocian está preservada en la sección Chatroud.

ABSTRACT Numerous examples of macro plant fossils can be found in the Kerman region’s Early and Middle Jurassic successions. The Ab-e-Haji, Badamu, and Hojedk formations were among these patterns. One of the suitable regions for paleobotanical study is the Chatroud section. In this region, the Lower-Middle Jurassic is approximately 210 meters thick. 18 species of macro plant fossils from 14 genera, including Nilssonia polymorpha, Ptero phyllum nathorsti, Podozamites distans, Elatocladus zamioides, Elatides thomasii, Nilssonia feriziensis, Nilssonia herriesi, and Beania sp., which are identified and described in this study, along with Pterophyllum schenki, Anomozamites marginatus, and Klukia exilis. In this region, there are two plant assemblage zones known as Anomozamites marginatus-Pterophyllum schenki Zone and Klukia exilis Zone. The Hettangian-Bajocian age is preserved at the Chatroud section.

RESUMEN El Grupo Sierra Madre de Chiapas tiene informalidades en su nomenclatura estratigráfica que han sido transmitidas a través de la literatura geológica. Este trabajo describe las características de tres sucesiones litoestratigráficas que hacen comprensible la división tripartita del Grupo Sierra Madre. Una litología particular, que aquí se define sucesión El Chango, separa las sucesiones Cantelhá y Cintalapa para integrar a este grupo. Adicionalmente, la sucesión El Chango hace posible realizar una cartografía apropiada y su correlación permite interpretar la distribución regional de facies sedimentarias que presentan estas sucesiones. La epifluorescencia de rocas de la sucesión El Chango (Cenomaniano) exhibe compuestos orgánicos. Datos de pirólisis indican ⁓0.22% de carbón orgánico total en roca carbonatada, su reflectancia equivalente es 0.7 y 1.0, que ubica a la roca en la ventana de generación del aceite y gas metagénico, los valores de S2 menores de 0.2 mg HC/g hacen cuestionable el bajo potencial de expulsión de hidrocarburos, por lo que se requieren análisis adicionales. La porosidad impregnada con asfalto en rocas del Grupo Sierra Madre sugiere la existencia de roca almacén, cubierta regionalmente por rocas pelíticas como sello y los cambios de facies y deformación indica la existencia de trampas potenciales. Los datos de este trabajo proponen explorar un play hipotético petrolero en esta región.

ABSTRACT The Sierra Madre Group of Chiapas has informalities in its stratigraphic nomenclature that have been transmitted through geological literature. This work describes the characteristics of three lithostratigraphic successions that make the tripartite division of the Sierra Madre Group understandable. A particular lithology, which here is defined as the El Chango succession, separates the Cantelhá and Cintalapa successions to integrate this group. Additionally, the El Chango succession makes it possible to do an appropriate mapping and its correlation allows interpreting the regional distribution of sedimentary facies that these successions. Epifluorescence of rocks from the El Chango succession (Cenomanian) exhibits organic compounds. Pyrolysis data indicate ⁓0.22% of total organic carbon in carbonate rock, its equivalent reflectance is 0.7 and 1.0, which places the rock in the generation window of metagenic oil and gas, S2 values less than 0.2 mg HC/g make the low hydrocarbon expulsion potential questionable, so additional analyzes are required. The porosity impregnated with asphalt in rocks of the Sierra Madre Group suggests the existence of reservoir rock, regionally covered by pelitic rocks as a seal, and the changes in facies and deformation indicate the existence of potential traps. The data from this work proposes to explore a hypothetical oil play in this region.

Resumen La extracción minera tiene un fuerte impacto sobre el suelo y la cobertura vegetal. Sin embargo, poco se conoce sobre el efecto de esta actividad en la flora y los microrganismos asociados a este tipo de ambientes, los cuales son fundamentales para la cadena trófica de muchos organismos. Los hongos formadores de micorrizas arbusculares (HFMA) forman asociaciones con las plantas y pueden ayudar a mejorar su desarrollo en ambientes contaminados con metales pesados, entre otros beneficios. Las plantas nativas y los HFMA de los suelos degradados por la minería tienen un papel importante en el establecimiento de programas de recuperación de áreas influenciadas por estas actividades; por lo tanto, el objetivo de este estudio fue caracterizar la abundancia y diversidad de la vegetación y HFMA en una zona afectada por la minería de oro. La vegetación se evaluó en dos áreas: una adyacente a depósitos mineros y con vegetación nativa (SI-N) y otra intermedia con desechos mineros e inicio de sucesión vegetal natural (SI-SV) y los HFMA en el área SI-N y el área de desechos de minería (SI-M). La vegetación se cuantificó mediante el método de RAP y los HFMA por medio de tamizado en húmedo a partir de suelo directo y cultivos trampa. En las plantas, se identificaron 605 individuos, pertenecientes a 29 familias, 46 géneros y 54 especies vegetales y de HFMA, 13 especies y 11 géneros; la diversidad, se determinó mediante los números de Hills, donde el área SI-N fue mayor en la vegetación (Q1: 11,94) y el área SI-M en los HFMA (Q1: 3.07). Los metales pesados y la vegetación fueron factores que disminuyeron la diversidad y abundancia de HFMA en SI-M. Se destacan las especies vegetales de los géneros Agrostis, Baccharis y Miconia y el HFMA Glomus microcarpum como las especies más frecuentes y con potencial para la recuperación de áreas degradadas.

Abstract Mining extraction has a substantial impact on soil and vegetation cover. However, little is known about its effect on the flora and microorganisms associated with these environments. Arbuscular Mycorrhizal Fungi (AMF) form associations with plants, improving their development in environments contaminated with heavy metals, among other benefits. Native plants and AMF found in the soil degraded by mining play an essential role in establishing programs dealing with recovering areas influenced by these activities. Therefore, this study aimed to characterize vegetation and AMF abundance and diversity in an area affected by gold mining in Colombia. Vegetation was evaluated in two areas, one adjacent to mining deposits with native vegetation (SI-N) and the other in an intermediate area with mining waste and initial natural plant successions (SI-SV). AMF was assessed in the SI-N and the mining waste area (SI-M). Vegetation was quantified using the RAP method, and AMF was assessed using wet sieving from direct soil samples and trap crops. Vegetation evaluations identified 605 individuals belonging to 29 families, 46 genera, and 54 species, and AMF assessment identified 11 species and five genera. Diversity was established using Hill numbers, finding that SI-N was more diverse for vegetation (Q1: 11.94) and SI-M for AMF (Q1: 3.07). Heavy metals and vegetation decreased the diversity and abundance of AMF in the SI-M. Plant species of the genera Baccharis, Agrostis, Miconia, and the AMF Glomus microcarpum were the most frequent species with potential for recovery in degraded areas.

RESUMEN Las sucesiones tropicales son ambientes de gran importancia por sus funciones ecológicas y extensión. En el Ecuador, los estudios sobre el almacenamiento de carbono de estos ecosistemas son escasos y la mayoría de ecuaciones desarrolladas se concentran en zonas húmedas de tierras bajas. El objetivo de la presente investigación fue generar modelos alométricos para la estimación de biomasa aérea de bosques secundarios montanos del noroccidente de Ecuador. Se realizó un inventario forestal en tres áreas de sucesión de 18, 30 y 50 años aproximadamente. Se construyeron modelos alométricos utilizando el diámetro a la altura del pecho (DAP) y la altura total (Ht) como variables independientes y se estimó la materia viva y el carbono aéreo acumulado. La variable combinatoria DAP2Ht fue la mejor predictora según los criterios de ajuste y validación. Las ecuaciones desarrolladas mostraron un R2 mayor al 95 %, por lo que son confiables para la estimación de las variables estudiadas. Se determinó que los bosques almacenan 36,56, 70,36 y 156,27 Mg.C.ha-1 respectivamente, siendo el fuste el componente de mayor almacenaje en un intervalo de 65,76 - 73,44 %, mientras que ramas y hojas representan un 20,98 -25,50 % y 5,58 - 8,74 % del carbono aéreo total respectivamente. Estos modelos podrían aplicarse de manera efectiva en ecosistemas en condiciones ambientales similares.

ABSTRACT Tropical successions are environments that cover large areas and are of great importance due to their ecological functions and extension. In Ecuador, studies on the carbon storage of these ecosystems are scarce and most of the equations are developed for humid lowland areas. The aim of this research was to generate allometric models for estimation of aerial biomass of secondary montane forests in northwestern Ecuador. A forest inventory was carried out in three secondary forests of 18, 30, and 50 years old approximately. Allometric models were developed using diameter at breast height (DBH) and total height (Ht) as independent variables, and the organic matter and accumulated aerial carbon were estimated. The DAP2Ht combinatorial variable was the best predictor variable according to the adjustment and validation criteria. The model equations showed an R2 greater than 95 %, consequently the variables studied are reliable. It was determined that forests store 36.56, 70.36, and 156.27 Mg.C.ha-1 respectively, where the stem is the component with the highest storage with a range between 65.76 and 73.44%. Both branches and leaves represent between 20.98 - 25, 50% and 5.58 - 8.74% of the total aerial carbon respectively. These models could be applied effectively in ecosystems with similar environmental conditions.

Resumen. Objetivo/Contexto: El artículo se centra en la evolución del consumo de bienes durables (heladeras eléctricas y cocinas a gas) -que constituyen electrodomésticos para uso del hogar-, y de bienes para el entretenimiento que gastan tiempo (autos y radios) en Argentina durante el periodo 1920-1970. Se investiga sobre los actores sociales de este proceso, atendiendo a la interacción entre los mismos y el consumo de bienes. A continuación, se analizan las razones del éxito de los bienes para el entretenimiento y su posterior ralentización entre las décadas de 1920 y 1940 y de las razones técnicas entabladas en la masificación de los electrodomésticos por la reducción en el precio de la electricidad y el gas. Finalmente, se estudian las razones del avance de los electrodomésticos con la estrategia de las empresas. Metodología: Se investiga en la información cuantitativa relativa a la producción, la oferta y la demanda de los bienes durables estudiados a la luz de fuentes de diverso tipo (visuales, demográficas, así como sucesiones y reportajes de prensa) en las que quedó evidencia sobre las expectativas, los gustos y las transformaciones de las clases medias argentinas, así como los distintos tipos de relaciones que sus integrantes establecieron con vehículos, aparatos eléctricos y a gas en la época que cubre este trabajo. Originalidad: Este artículo establece que la ampliación de las clases medias, que permitió un aumento en la demanda y que llevó a transformar la industria y la actividad productiva local, fue la que, a su vez, contribuyó a afianzar la idea de que el bienestar estaba asociado directamente con la posesión de bienes durables que hacían más cómoda la vida en el hogar. Las relaciones establecidas entre consumo y ascenso de las clases medias consolidaron y transformaron la industria y se volvieron factores decisivos en la cultura del consumo. Conclusiones: El análisis de la evolución del consumo de bienes durables muestra cómo se desarrollaron las estrategias en la esfera de la oferta y la demanda de tales artículos, evidenciando la interacción entre los actores sociales y dichos bienes en el periodo estudiado. Como conclusión, se puede ver que tal interacción permitió un cambio en el estilo de vida de los argentinos durante el periodo analizado.

Abstract. Objective/Context: This article focuses on the evolution of the consumption of durable goods (electric refrigerators and gas stoves)-appliances for household use that save time-and entertainment goods to occupy spare time (cars and radios) in Argentina during the 1920-1970 period. It studies the social actors of this process, considering the interaction between them and the consumption of goods. Next, it analyzes the reasons for the success of entertainment goods and their subsequent slowdown between the 1920s and 1940s, as well as the technical reasons for the mass use of household appliances due to a reduction in electricity and gas prices. Methodology: The analysis of quantitative information on the production, supply, and demand of durable goods using diverse sources (visual, demographic, as well as successions and press reports) offers insight on the expectations, tastes, and transformations of the Argentine middle classes, as well as different types of relationships their members established with vehicles and electrical and gas appliances during the study period. Originality: This article suggests that the expansion of middle classes allowed an increase in demand that led to the transformation of the industry, and local productive activity, in turn, contributed to consolidating the idea that well-being was directly associated with the possession of durable goods that made life at home more comfortable. The relations established between consumption and the rise of the middle classes consolidated and transformed the industry and became decisive factors in the culture of consumption. Conclusions: The analysis of the evolution of durable goods consumption shows how different strategies were developed in the supply and demand of such items and evidences an interaction between the social actors of the period and the consumption of the studied goods. As a conclusion, it can be stated that such interaction allowed a change in the lifestyle of Argentines during the period analyzed.

Resumo. Objetivo/contexto: este artigo está centralizado na evolução do consumo de bens duráveis (geladeiras elétricas e fogões a gás), eletrodomésticos para o uso doméstico que economizam tempo, e dos bens para o entretenimento que gastam o tempo (automóveis e rádios) na Argentina entre 1920 e 1970. A pesquisa é sobre os atores sociais desse processo, atendendo a interação entre eles e o consumo de bens. A seguir, são analisadas as razões do sucesso dos bens para o entretenimento e sua posterior desaceleração durante as décadas de 1920 e 1940, e das razões técnicas estabelecidas na massificação dos eletrodomésticos pela redução no preço da eletricidade e do gás. Finalmente, são estudadas as razões do avanço dos eletrodomésticos com a estratégia das empresas. Metodologia: pesquisa com base em informações quantitativas relativas à produção, à oferta e à demanda dos bens duráveis estudados à luz de fontes diversas (visuais, demográficas, acontecimentos e reportagens de imprensa) nas quais se evidenciaram expectativas, gostos e transformações das classes médias argentinas, bem como os diferentes tipos de relações que seus integrantes estabeleceram com veículos, aparelhos elétricos e a gás no período estudado. Originalidade: este artigo estabelece que a ampliação das classes médias que permitiu o aumento na procura que levou à transformação da indústria e da atividade produtiva local a que, por sua vez, contribuiu para consolidar a ideia de que o bem-estar estava associado diretamente com a posse de bens duráveis que tornavam a vida mais confortável no lar. As relações estabelecidas entre consumo e ascensão das classes médias consolidaram e transformaram a indústria e se tornaram fatores decisivos na cultura do consumo. Conclusões: a análise da evolução do consumo de bens duráveis mostra como foram sendo desenvolvidas as estratégias na esfera da oferta e da demanda de tais produtos, o que evidencia a interação entre os atores sociais do período e o consumo dos bens estudados. Como conclusão, pode ser visto que essa interação permitiu uma mudança no estilo de vida dos argentinos durante o período analisado.

ABSTRACT The El Escorial marbles (Cushamen Metamorphic Complex) along with amphibolites form metamorphic septa within the permian granitoids of the Mamil Choique Formation (261-286 Ma). The metamorphism, determined in granulite facies migmatic gneisses septa cropping out 120 km southwest of El Escorial, occurs at 311±27 Ma (CHIME method in monazite). The marbles are calcitic (calcite >95%, R.I.: 0.5 to 2.5%) and show 87Sr/86Sr ratios between 0.70768 and 0.70825 (n=10). The data provided in this work, added to previous contributions, allow to constraints the sedimentation age of the silicic-carbonate successions of the Cushamen Metamorphic Complex between ca. 385 and 335 Ma. This suggests the existence of a mixed carbonate-siliciclastic platform at least in the southernmost portion of southwestern Gondwana between Middle Devonian and early Carboniferous (Middle Mississippian).

RESUMEN: Los mármoles de El Escorial (Complejo Metamórfico Cushamen) se encuentran asociados a anfibolitas que forman septos metamórficos dentro de los granitoides pérmicos de la Formación Mamil Choique (261-286 Ma). El metamorfismo de los septos, determinado en gneises migmáticos en facies de granulita aflorantes 120 km al suroeste de El Escorial, ocurre a los 311±27 Ma (método CHIME en monacita). Los mármoles son de composición calcítica (calcita >95%, R.I.: 0,5 a 2,5%) y presentan razones de 87Sr/86Sr entre 0,70768 y 0,70825 (n=10). Los datos aportados en este trabajo, sumado a contribuciones previas, permiten acotar la edad de sedimentación de las sucesiones silícico-carbonáticas del Complejo Metamórfico Cushamen entre los ca. 385 y 335 Ma. Esto sugiere la existencia de una plataforma mixta (carbonática-siliciclástica) al menos en la porción más austral del suroeste de Gondwana entre el Devónico Medio y el Carbonífero inferior (Misisipiano Medio).

Abstract Microbialites are the most abundant life evidence in Precambrian sedimentary rocks. They are produced by microbial interaction activity and sedimentary processes reflecting paleoenvironmental conditions. The Ediacaran-Cambrian carbonate and siliciclastic successions in the Southern Amazon Craton in Central Brazil, provide a key opportunity to understand how the metazoan life coexisted with the microbial communities. The spatial and temporal distribution of microbialites as well as morphological and paleoenvironmental changes have been assessed, reinterpreting previous works and including new data from the Araras-Alto Paraguai and Corumbá basins. The deposition was controlled by subsidence and sea-level changes that affected these basins, considered extensions of epicontinental seas during the Gondwana assembly. The stromatolites are restricted to coastal deposits and experienced thriving flourishment intervals after the Marinoan Glaciation (635 Ma). Post-glacial transgression was marked by microbial colonization in shallow platforms represented by stratiform and giant domical stromatolites in the Araras-Alto Paraguai Basin. The continuity of the transgression generated a moderately deep aragonite sea at about 622 Ma. A progressive sea-level fall caused the implantation of coastal environments under greenhouse conditions with tidal flat and sabkha settings colonized by centimetric-scale stromatolites. The sea retreat was accompanied by progressive uplift, causing a moderate inversion of the basin and erosion of the succession until ~560 Ma with the deposition of the last preserved tidal flat deposits with the occurrence of thrombolites. The subsiding Corumbá Basin was the site of microbially-induced deposition of carbonates in a shallow platform connected to an offshore setting with the proliferation of metazoan straddling the Ediacaran-Cambrian boundary. Microbial communities were restricted to lagoon deposits during the Lower Cambrian transgression in the Araras-Alto Paraguai Basin and the last phase refers to the sea retreat towards southeast, developing a fluvial system connected with the arid and evaporitic tidal flats colonized by microbialites that lasted until the upper Cambrian. Except for the post-glacial stromatolites, the columnar and domal microbialite indicate that the coastal settings dominated the Ediacaran-Cambrian transition. The preservation of microbialites in the post-glacial intervals can be associated with the Mg-Ca-CO3 oversaturation in dolomitic platforms. The rapid calcification and ability to resist the dissolution and replacement have increased the stromatolites’ preservation potential reported here, where its well-preserved occurrence in tidal flats and sabkha occurs due to intense early diagenetic silicification. The change from carbonate accumulation to siliciclastic-rich environments contributed to the demise of microbially-induced strata. In general, the scarce coexistence between coastal stromatolite and metazoan-bearing marine deposits makes it challenging to establish a competitive relationship between these organisms, as previously postulated.

RESUMEN Las rocas de la Formación Ahuichila han sido objeto de atención en la literatura por casi 80 años. Durante este tiempo sólo se han publicado descripciones estratigráficas generalizadas de la Formación Ahuichila. En este artículo se incluye la descripción de secciones estratigráficas medidas entre el Bajío de Ahuichila (localidad tipo de esta formación) y el Valle Nazareno. Las rocas estudiadas fueron agrupadas en cuatro asociaciones de litofacies: I. Ortoconglomerado que se presenta, dependiendo de la sección, ya sea en la base o en la cima de la formación, pero que en ninguna sección fue observado en ambas posiciones; II. Litarenita-limolita-lutita; III. Yeso-dolomía-limolitalutita y IV. Caliza con microbialitas. Se interpreta que las cuatro asociaciones se acumularon en una cuenca continental cerrada, con sub-ambientes de pie de monte, fluvial y lacustre somero. La presencia de evaporita y microbialita es consistente con un clima árido durante su depósito. Los icnogéneros Planolites, Palaeophicus y Cochlichnus pertenecen a la icnofacies Mermia indicativa de ambiente lacustre. En el área estudiada no se observa vulcanismo intracuenca, esto contrasta con la litología de otras sucesiones de capas rojas continentales en el centro y norte de México equivalentes a la Formación Ahuichila, en donde las rocas volcánicas de intracuenca son comunes. Tobas intercaladas en la sucesión Ahuichila sugieren vulcanismo extracuenca contemporáneo, al menos, en parte, con la sedimentación. El contacto inferior de la Formación Ahuichila cuando aflora es una superficie de erosión. Según la localidad sus capas pueden ser paralelas a la inclinación de la sucesión sedimentaria marina del Mesozoico, o presentar una clara discordancia angular con ésta. Cuando el contacto es una discordancia paralela, la actitud estructural de las rocas mesozoicas y continentales de la Formación Ahuichila es igual y en lugares llega a ser sub-vertical, por lo que se interpreta que la Formación Ahuichila fue deformada junto con las rocas subyacentes. En donde la discordancia es angular hay evidencias de al menos un pulso de deformación compresiva anterior a la acumulación de Ahuichila. La forma inferida de la paleocuenca de Ahuichila es alargada y paralela a las estructuras en el Sector Transversal de Parras de la Sierra Madre Oriental, el límite occidental de la paleocuenca posiblemente fue el Levantamiento de Villa Juárez, y el límite oriental se cree fue el Levantamiento de San Julián. La deformación documentada en la Formación Ahuichila sugiere interpretar que su depósito fue sin-tectónico, acumulada sobre una cuenca tipo piggy-back sobre la Napa de Parras, en el Sector Transversal de Parras.

ABSTRACT Rocks in the Ahuichila Formation have been described in the literature for the last 80 years. In this time only generalized descriptions of the Ahuichila Formation have been published up to now. This paper includes the description of stratigraphic logs measured at the Bajío Ahuichila (type locality of this formation) and the Nazareno valley. The studied rocks are grouped into four lithofacies associations: I. Orthoconglomerate, which depending on the locality, occurs as either at the base or at the top of the formation, but never both in the same stratigraphic positions in the same section, II. Litharenite-limolite-shale, III. Gypsumdolomite-limolite-shale, and IV. Limestone with microbialites. The four lithofacies associations are interpreted as consistent with deposition in a closed continental basin, and correspond to fluvial, alluvial, and shallow lake sub-environments. The occurrence of evaporite and microbialite is consistent with an arid climate at the sedimentation time. The Planolites, Palaeophicus and Cochlichnus ichnogenera belong to the Mermia ichnofacies in a lacustrine environment. Intrabasinal volcanic lava flows are not founded in the Ahuichila Formation at the study area, this feature is a difference with similar lithologies in other continental red beds successions in central and northern Mexico, where intrabasinal volcanic rocks are common. Distal tuffs interlayered in the Ahuichila succession suggest extrabasinal volcanism contemporaneous, at least in part, with the sedimentation. The lower contact of the Ahuichila Formation, where is exposed out is always an erosional surface. Depending on the location, a disconformity with the beds in the underlying Mesozoic marine sedimentary rocks, or a clear angular unconformity can be observed. In those places where the contact is a disconformity, the structural attitude of the Mesozoic marine sediments and the continental Ahuichila rocks is the same, despite the fact that in some places, it might be sub-vertical; this is interpreted as clear evidence that the Ahuichila Formation was deformed together with the Mesozoic rocks. In those places where a clear angular unconformity exists it is obvious that at least one shortening pulse occurred prior to the Ahuichila deposit. The inferred shape of the Ahuichila paleobasin is elongated and parallel to the structures in the Parras Transversal Sector of the Sierra Madre Oriental, the paleobasin limits could be in the west at the Villa Juárez uplift and at the San Julián uplift in the east. The documented deformation in the Ahuichila Formation suggests the assumption of a syn-tectonic deposit, on a piggy-back type basin located atop the Parras Nappe, next to the Parras Tranversal Sector.

ABSTRACT The Coahuila Block has marine and continental rocks from the Paleozoic to the Recent, which outcrop in a vast region of northeastern Mexico. This work provides surface and subsurface data from confirm the presence of Nazas arc on this block. Stratigraphic sections describ the transgressive process of marine flooding on this block during the Aptian and a thick deposit of limestone, dolostone and evaporitic during the Albian and lower Cenomanian. The stratigraphic succession from the Upper Cretaceous is composed of the gradual passage among the Indidura, Parras, Cerro del Pueblo and the Cerro Huerta formations and the Soledad beds, all of them as foreland facies, with ~1000 m thickness, these rocks show a stratigraphic condensation on this block compared to similar stratigraphic successions in neighboring the Sabinas, Central Mexico and Chihuahua basins, which has thickness than more 2000 m same age rocks. In this work structural data are confronted with previous ideas that considered a soft deformation affected by normal-type faults. In the Coahuila Block three structural styles are distinguished: one of them closely related to broad curvature folds, other style composes by narrow and long folds with reverse faults, this style is restricted at the austral border of the Coahuila Block, which are tectonically cover for the Parras nappe, this nappe covers pre-Aptian marginal sedimentary facies of this block, both structural groups are closely related to the orientation of the structures of the phase that deformed the mexican Orogen. The third style is composed by acute folds with a stepped geometry and associated by structural complexes with roughly oriented north-south axes, with opposite vergences and diverse faults. This last structural style has not a defined extension or shortening component and their deformation possibly is post-shortening to the deformation of the mexican Orogen. The data presented define the southwestern geographical border of the Coahuila Block.

RESUMEN El Bloque de Coahuila tiene rocas marinas y continentales del Paleozoico al Reciente que afloran en una vasta región del noreste de México. Este trabajo aporta datos de superficie y subsuelo que constatan la presencia del arco Nazas sobre este bloque. Se describen secciones estratigráficas que indican el proceso de transgresión marina sobre este bloque durante el Aptiano, así como el depósito de un potente espesor de caliza, dolomía y evaporita de edad Albiano y Cenomaniano temprano. La sucesión estratigráfica del Cretácico Superior está compuesta por el paso gradual entre las formaciones Indidura, Parras, Cerro del Pueblo, Cerro Huerta y capas La Soledad que representan depósitos de antepaís (foreland) con ~1000 m de espesor, estas rocas muestran una condensación estratigráfica al confrontar su espesor con secciones estratigráficas similares en las cuencas vecinas de Sabinas, del Centro de México y Chihuahua, las que tienen más de 2000 m de espesor de rocas de la misma edad. En este trabajo hay datos estructurales que se confrontan con ideas previas que consideraban una deformación tenue afectada por fallas de tipo normal. En el Bloque de Coahuila se distinguen tres estilos estructurales: uno está relacionado con pliegues de curvatura amplia, otro está formado por pliegues angostos y alargados, con fallas inversas, este estilo está restringido al borde austral del Bloque de Coahuila en dónde es traslapado tectónicamente por la napa de Parras, está napa sepulta las facies sedimentarias marginales pre-Aptiano de este bloque. Ambos estilos estructurales están estrechamente vinculados con la orientación de estructuras de la fase que deformó al Orógeno mexicano. El tercer estilo es representado por pliegues agudos y geométricamente escalonados, así como conjuntos estructurales con varios ejes burdamente orientados norte-sur, con vergencias opuestas y fallas diversas. Este último estilo estructural no tiene una componente de extensión o acortamiento definida y su deformación posiblemente es posterior a la fase que deformó el Orógeno mexicano. Los datos presentados definen la extensión geográfica del borde suroeste del Bloque de Coahuila.