Condiciones geológicas favorables de las sedimentitas cretácicas de la Cordillera Oriental de Colombia para la existencia de depósitos exhalativos submarinos de Plomo y Zinc

The Eastern Cordillera of Colombia has the following common features with the areas that contain sediment hosted submarine exhalative lead zinc deposits in the world: (1) Existence of a major sedimentary basin with several hundreds of kilometers in size, that contain a thick sedimentary sequence and underlain by cratonic basement. (2) Existence of minor second order basins with several tenths of kilometers in size; these basins are evidenced by lateral changes of sediment thickness and facies. (3) Faults and alignments along the margins of the first and second order basins. These faults were active during sedimentation. (4) Small igneous intrusions indicating minor igneous activity during sedimentation. (5) Existence of minor restricted basins (third order basins) with sediments deposited in an euxinic low energy environment. (6) Evidence of faults that were tectonically active during sedimentation in third order basins. In conclusion the Cretaceous sedimentary rocks of the Colombian Eastern Cordillera offer an excellent posibility to find sediment hosted exhalative lead zinc deposits. As an example the favorable geological conditions of the Villeta area are discussed.La geología de la Cordillera Oriental de Colombia presenta las siguientes características comunes con otras áreas geológicas del mundo, que contienen depósitos exhalativos sedimentarios estratiformes de metales base encajados en rocas sedimentarias: (1) Existencia de una cuenca mayor de sedimentación con dimensiones del orden de varios centenares de kilómetros o cuenca de primer orden, que contiene una secuencia gruesa de sedimentitas y que esta infrayacida por basamento de naturaleza cratónica. (2) Existencia de cuencas menores de segundo orden con dimensiones del orden de varias decenas de kilómetros; estas cuencas están evidenciadas por variaciones laterales de facies y espesor de las sedimentitas. (3) Fallas y alineamientos en las márgenes de las cuencas de primer y segundo orden. Estas fallas fueron activas durante la sedimentación. (4) Intrusiones pequeñas que evidencian actividad ígnea menor contemporánea con la sedimentación. (5) Existencia de cuencas menores restringidas (cuencas de tercer orden) en donde la sedimentación ocurrió en un medio euxínico de baja energía. (6) Evidencias que indican actividad tectónica de fallas simultáneamente con la sedimentación, en las cuencas de tercer orden. A partir de lo anterior, se concluye que las sedimentitas Cretácicas de la Cordillera Oriental de Colombia ofrecen excelentes posibilidades para el hallazgo de depósitos exhalativos de metales base. A manera de ejemplo se discute brevemente la favorabilidad geológica del área de la plancha 208, Villeta

Condiciones geológicas favorables de las sedimentitas cretácicas de la Cordillera Oriental de Colombia para la existencia de depósitos exhalativos submarinos de Plomo y Zinc

The Eastern Cordillera of Colombia has the following common features with the areas that contain sediment hosted submarine exhalative lead zinc deposits in the world: (1) Existence of a major sedimentary basin with several hundreds of kilometers in size, that contain a thick sedimentary sequence and underlain by cratonic basement. (2) Existence of minor second order basins with several tenths of kilometers in size; these basins are evidenced by lateral changes of sediment thickness and facies. (3) Faults and alignments along the margins of the first and second order basins. These faults were active during sedimentation. (4) Small igneous intrusions indicating minor igneous activity during sedimentation. (5) Existence of minor restricted basins (third order basins) with sediments deposited in an euxinic low energy environment. (6) Evidence of faults that were tectonically active during sedimentation in third order basins. In conclusion the Cretaceous sedimentary rocks of the Colombian Eastern Cordillera offer an excellent posibility to find sediment hosted exhalative lead zinc deposits. As an example the favorable geological conditions of the Villeta area are discussed.La geología de la Cordillera Oriental de Colombia presenta las siguientes características comunes con otras áreas geológicas del mundo, que contienen depósitos exhalativos sedimentarios estratiformes de metales base encajados en rocas sedimentarias: (1) Existencia de una cuenca mayor de sedimentación con dimensiones del orden de varios centenares de kilómetros o cuenca de primer orden, que contiene una secuencia gruesa de sedimentitas y que esta infrayacida por basamento de naturaleza cratónica. (2) Existencia de cuencas menores de segundo orden con dimensiones del orden de varias decenas de kilómetros; estas cuencas están evidenciadas por variaciones laterales de facies y espesor de las sedimentitas. (3) Fallas y alineamientos en las márgenes de las cuencas de primer y segundo orden. Estas fallas fueron activas durante la sedimentación. (4) Intrusiones pequeñas que evidencian actividad ígnea menor contemporánea con la sedimentación. (5) Existencia de cuencas menores restringidas (cuencas de tercer orden) en donde la sedimentación ocurrió en un medio euxínico de baja energía. (6) Evidencias que indican actividad tectónica de fallas simultáneamente con la sedimentación, en las cuencas de tercer orden. A partir de lo anterior, se concluye que las sedimentitas Cretácicas de la Cordillera Oriental de Colombia ofrecen excelentes posibilidades para el hallazgo de depósitos exhalativos de metales base. A manera de ejemplo se discute brevemente la favorabilidad geológica del área de la plancha 208, Villeta

High-cadence spectroscopy of M-dwarfs – II. Searching for stellar pulsations with HARPS

Stellar oscillations appear all across the Hertzsprung–Russell diagram. Recent theoretical studies support their existence also in the atmosphere of M dwarfs. These studies predict for them short periodicities ranging from 20 min to 3 h. Our Cool Tiny Beats (CTB) programme aims at finding these oscillations for the very first time. With this goal, CTB explores the short time domain of M dwarfs using radial velocity data from the High Accuracy Radial velocity Planet Searcher (HARPS)-European Southern Observatory and HARPS-N high-precision spectrographs. Here we present the results for the two most long-term stable targets observed to date with CTB, GJ 588 and GJ 699 (i.e. Barnard's star). In the first part of this work we detail the correction of several instrumental effects. These corrections are especially relevant when searching for subnight signals. Results show no significant signals in the range where M dwarfs pulsations were predicted. However, we estimate that stellar pulsations with amplitudes larger than ∼0.5 m s−1 can be detected with a 90 per cent completeness with our observations. This result, along with the excess of power regions detected in the periodograms, opens the possibility of non-resolved very low amplitude pulsation signals. Next generation more precise instrumentation would be required to detect such oscillations. However, the possibility of detecting pulsating M-dwarf stars with larger amplitudes is feasible due to the short size of the analysed sample. This motivates the need for completeness of the CTB survey

Designing Mobile Apps to Promote Numeracy and Statistical Reasoning

Developing countries typically do not perform well in international benchmarks of mathematics achievement. This may be partially explained by students’ immersion in classrooms characterized by superficial strategies or rote-learning methods. This paper reports on the design of mobile applications (apps) developed by the authors as part of an ongoing project funded by a national government agency and intended to promote structural thinking and statistical reasoning. It describes the general features of the apps, as well as the pedagogical principles upon which the apps’ designs were anchored on. These principles are grounded on research and established practices on number sense and statistical learning. Collaborations with the Philippine Department of Education for widespread implementation and sustainability are also discussed

The nutrition transition in Colombia over a decade: A novel household classification system of anthropometric measures

Q2Q2Background: Overweight and underweight increase the risk of metabolic impairments and chronic disease. Interventions at the household level require the diagnosis of nutritional status among family members. The aim of this study was to describe the prevalence and patterns of various anthropometric typologies over a decade in Colombia using a novel approach that considers all children in the household as well as the mother. This approach also allows identifying a dual burden of malnutrition within a household, where one child may be overweight and another one undernourished. Methods: This study used data from the Demographic and Health Survey and the Colombian National Nutrition Survey [2000 n = 2,876, 2005 n = 8,598, and 2010 n = 11,349]. Four mutually exclusive household (HH) anthropometric typologies - normal, undernourished, overweight/obese, and dual burden - were created. Anthropometric information of height-for-age Z-scores (HAZ) and body-mass-index-forage Z-scores (BMIz) in children under the age of 5 y, and on body mass index (BMI) in mothers, 18–49 y was used. Results: Prevalence of overweight/obese HHs increased between 2000 (38.2%) and 2010 (43.1%) (p < 0.05), while undernourished and dual burden HHs significantly decreased between 2005 (13.7% and 10.6%, respectively) and 2010 (3.5% and 5.1%, respectively) (p < 0.05). A greater increase of overweight/obesity was observed for the lowest quintile of wealth index (WI), with an increase of almost 10% between 2000 and 2010, compared to 2% and 4% for the fourth and highest WI, respectively. Although in 2010 there is still a higher prevalence of overweight/obesity HHs in urban areas (43.7%), the prevalence of overweight/obesity HHs in rural areas increased sharply between 2000 (34.3%) and 2010 (41.6%) (p < 0.05). Conclusion: The observed prevalence of dual burden households was not different from the expected prevalence. Results from this study indicate that although overweight/obesity continues to be more prevalent among highincome Colombian households, it is growing at a faster pace among the most economically disadvantaged.Revista Internacional - Indexad

On the thermodynamics of the Swift–Hohenberg theory

We present the microbalance including the microforces, the first- and second-order microstresses for the Swift–Hohenberg equation concomitantly with their constitutive equations, which are consistent with the free-energy imbalance. We provide an explicit form for the microstress structure for a free-energy functional endowed with second-order spatial derivatives. Additionally, we generalize the Swift–Hohenberg theory via a proper constitutive process. Finally, we present one highly resolved three-dimensional numerical simulation to demonstrate the particular form of the resulting microstresses and their interactions in the evolution of the Swift–Hohenberg equation