ResumenCon base en una revisión cartográfica en la zona central-este de la Cuenca VMM, la colección de datos estructurales y la elaboración de 3 cortes estructurales, se definieron 3 dominios estructurales en el área de estudio. El dominio este, dominio central y dominio oeste. El dominio este se caracteriza por la presencia de fallas inversas de alto ángulo y vergencia este, que involucran rocas Jurásicas. Los dominios central y oeste se caracterizan por la presencia de fallas inversas vergencia al oeste que involucran de manera general rocas del Cretácico inferior y rocas del Paleógeno-Neógeno. El corte regional muestra que las fallas del dominio este corresponden a estructuras con inversión tectónica evidenciadas por los cambios de espesor de la Formación Girón; estas estructuras se definen como un estilo estructural dominado por una deformación tipo thick-skinned. Las estructuras de los dominios central y oeste muestran fallas inversas con despegues y rampas en las unidades Cretácicas y Paleógenas dominadas por una deformación tipo thin-skinned. El modelo regional planteado muestra un estilo estructural divergente y difiere del modelo estructural reportado en estudios previos. En el presente trabajo se propone una zona transversal para explicar las variaciones en el estilo estructural del Valle Medio del Magdalena de sur a norte. © Acad. Colomb. Cienc. Ex. Fis. Nat. 2016. Palabras clave: estilo estructural, Valle Medio del Magdalena, inversión tectónica, dominios estructurales. Structural style variation related with basement anisotropies in the Middle Magdalena Valley AbstractBased on a cartographic review of the central-eastern zone of the MMV Basin, the collection of structural data and 3 structural cross sections, it was possible to define three structural domains in the study area: The eastern domain, central domain and western domain. The eastern domain is characterized by east vergent and high angle reverse faults, involving the Girón Formation. Central and western domains are characterized by west vergent reverse faults involving Lower Cretaceous to Paleogene and Neogene rocks. A regional cross section shows that faults in the eastern domain correspond to tectonic inversion structures evidenced by changes in thickness of the Girón Formation. These structures are defined as a structural style dominated by thick-skinned deformation type. Structures of the central and western domains are characterized by flat-ramp reverse faults in the Cretaceous and Paleogene units dominated by thin-skinned deformation type. The regional model proposed shows a divergent structural style and differs from the structural model reported in previous studies. In this paper we propose a transverse zone to explain variations in the structural style of the Middle Magdalena Valley from south to north.

The prokaryotic community at the "La Cira-Infantas" oil field, located in Colombia's Middle Magdalena Valley Basin, was characterized using 16S rRNA gene sequence analysis. This characterization is a first-step in assessing the dynamics of microbial degradation and defining strategies that may increase oil recovery and quality at the site. Two 16S rRNA gene libraries were generated from the total community DNA extracted from production water using both Eubacterial and Archaea universal primers. Sequence analysis of the libraries indicated that a large percentage of Eubacteria clones were affiliated with class -, -and -Proteobacteria, Clostridia and Bacteroidetes. Archaea clones were dominated by Methanobacteria andMethanococci. Annotations at these generic level indicate that the prokaryotic community has the following metabolic capacities: i) reduction of sulfur-compounds and fermentation, ii) nitrate reduction and sulfide oxidation, iii) decomposition of aromatic compounds, and iv) methane production. These results are discussed in the context of the importance of the characterized metabolic capacities for oil biodegradation in the mesothermic and water-flooded environment of this reservoir. Geomicrobiology Journal ACCEPTED MANUSCRIPT ACCEPTED MANUSCRIPT3

The application of mineralogy in archeology has been growing in interest in particular in relation to establishing the origin of the clays used in the elaboration of ancient ceramic artifacts. The mineralogy did not show a clear relationship with the colors expressed by the pottery system defined by the archaeologists; that is, independent of the color of the slip, each group has the same mineralogical components. Fourteen Pre-Hispanic pottery sherds from the Mesa de Los Santos region (Colombia) were selected for mineralogical characterization by X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. The objective of the work was to contribute to the knowledge of the production technology and elucidate a possible regional origin of these ceramics. The observed mineralogical phases were plagiocalse, quartz, potassium fledspar, clay minerals, micas, carbonate minerals, and iron oxides. Firing temperatures are in the ranges 600-800°C for almost all the analyzed samples.

Este artículo puede compartirse bajo la licencia CC BY-ND 4.0 (https://creativecommons.org/licenses/by-nd/4.0/)Y.P Goyes Peñafiel, G Jiménez Diaz, R Mier Umaña. "Aplicación del método de inversión usando mínimos cuadrados (dls) para el procesamiento de sondeos eléctricos verticales en campo escuela colorado (Santander) -caso de estudio", UIS Ingenierías, vol. RESUMENEn el método de resistividad eléctrica se inducen corrientes eléctricas en el subsuelo y se mide la diferencia de potencial en la superficie. En un subsuelo con capas de diferentes características físicas, las medidas de resistividad y sus respectivas anomalías contribuyen con la prospección y caracterización de las propiedades eléctricas de los diferentes estratos. La resistividad es una de las propiedades físicas más variables, ya que se puede ver afectada por pequeños cambios del clima o irregularidades del subsuelo, para ciertos tipos de materiales, el agua puede modificar sus propiedades eléctricas; en suelos saturados o con niveles freáticos, la resistividad de un material tiende a disminuir. La distribución de los rangos de resistividad más bajos se analiza para diferentes puntos con el fin de estimar una distribución superficial de estos niveles saturados. En Campo Escuela Colorado se realizó un levantamiento de 8 sondeos eléctricos verticales, el procesamiento e interpretación de los datos adquiridos se realizó por medio del desarrollo de una inversión usando mínimos cuadrados para estimar la resistividad real y profundidades que mejor se ajusten a un modelamiento de la curva teórica.Palabras Clave: Método eléctrico, Campo Escuela Colorado, sondeo eléctrico vertical, nivel freático, acuífero, inversión. ABSTRACTIn the resistivity method, artificially generated electric currents are introduced into the ground and the resulting potential differences are measured at the surface, in subsurface layers of different physical characteristics, resistivity measurements and their respective anomalies provide information on the form and electrical properties of subsurface inhomogeneities. Resistivity is one of the most variable physical properties because it can be affected by small changes in climate or subfloor, for certain types of materials, water can modify their electrical properties; in saturated soil or water tables, the resistivity of a material tends to decrease. The distribution of lower resistivity ranges for different points are analyzed in order to estimate a surface distribution of these saturated levels. At Colorado Field was survey eight vertical electrical sounding; processing and interpretation of acquired data is done through the development of an investment using least squares to estimate the actual resistivity and depths that are best suited to modeling the theoretical curve.