Distribution and origin of natural gas leakage in the Colorado Basin, offshore Argentina 2 Margin, South America: seismic interpretation and 3D basin modelling

The detailed analysis of a dense 2D seismic reflection dataset and data from 8 exploration wells, allowed us to identify, map out and characterize possible indications of past and present-day hydrocarbon leakage (i.e. gas chimneys, gas pockets, and seafloor mounds and pockmarks) on the continental shelf and slope of the Colorado Basin, offshore Argentina, where Permian, Jurassic and Early Cretaceous source rocks are potentially present and may be currently mature. Identified gas leakage features, developed both in the syn-rift and post-rift successions, were also analysed in relation to the structural the stratigraphic elements of the basin. A family of seabed pockmarks, located close to an array of submarine channels, was identified on the distal slope of the basin. These pockmarks are overlying a series of sub-vertical to vertical seismic chimneys in the subsurface. A calibrated basin-wide 3D petroleum system model comprising generation and migration of hydrocarbons was carried out and compared with the observations from the seismic analysis. Preliminary results from this model indicate that although synrift and early Cretaceous source rock (SR) intervals may be depleted in the central areas of the basin, an active kitchen from the Aptian SR may be present below the slope areas. Hydrocarbon migration pathways predicted by the 3D model (Hybrid method) coincide with the interpreted seismic chimneys underlying the observed seabed slope pockmarks. Hence, our results indicate that thermogenic gas may be currently generated in the distal slope of the basin from mature early post-rift source rocks within the Early Cretaceous (Aptian) sequences and migrates vertically, due to seal failure, through the stratigraphic column. This migrating thermogenic gas is feeding the seafloor pockmarks identified in the distal slope of the basin, although up-dip lateral migration along stratigraphic layers to the more proximal slope areas cannot be ruled out. The present work represents the first published study integrating detailed seismic analysis and 3D basin modelling linking observed gas-leakage indicators and associated seepage pathways, to their relative abundance, distribution and feeding systems offshore Argentina’s continental margin

Modelo de seguridad física con la aplicación de las tecnologías de información y comunicación (TIC) para el Centro de Rehabilitación Social Femenino de Quito

La ciencia y la tecnología no son creaciones aisladas sino que forman parte de la cultura y de las necesidades de las personas y de los pueblos, y debe ser preocupación de los gobiernos de cada país, por medio de políticas, planes y programas el apropiarse del conocimiento científico y tecnológico y de sus métodos para propender al desarrollo económico y el progreso social de las naciones, y que se debe basar en experiencias innovadoras, con procesos, mecanismos y herramientas que lleguen a todos los ciudadanos sin distingos de ninguna naturaleza

Distribution and origin of natural gas leakage in the Colorado Basin, offshore Argentina Margin, South America : seismic interpretation and 3D basin modelling

The detailed analysis of a dense 2D seismic reflection dataset and data from 8 exploration wells, allowed us to identify, map out and characterize possible indications of past and present-day hydrocarbon leakage (i.e. gas chimneys, gas pockets, and seafloor mounds and pockmarks) on the continental shelf and slope of the Colorado Basin, offshore Argentina, where Permian, Jurassic and Early Cretaceous source rocks are potentially present and may be currently mature. Identified gas leakage features, developed both in the syn-rift and post-rift successions, were also analysed in relation to the structural the stratigraphic elements of the basin. A family of seabed pockmarks, located close to an array of submarine channels, was identified on the distal slope of the basin. These pockmarks are overlying a series of sub-vertical to vertical seismic chimneys in the subsurface. A calibrated basin-wide 3D petroleum system model comprising generation and migration of hydrocarbons was carried out and compared with the observations from the seismic analysis. Preliminary results from this model indicate that although synrift and early Cretaceous source rock (SR) intervals may be depleted in the central areas of the basin, an active kitchen from the Aptian SR may be present below the slope areas. Hydrocarbon migration pathways predicted by the 3D model (Hybrid method) coincide with the interpreted seismic chimneys underlying the observed seabed slope pockmarks. Hence, our results indicate that thermogenic gas may be currently generated in the distal slope of the basin from mature early post-rift source rocks within the Early Cretaceous (Aptian) sequences and migrates vertically, due to seal failure, through the stratigraphic column. This migrating thermogenic gas is feeding the seafloor pockmarks identified in the distal slope of the basin, although up-dip lateral migration along stratigraphic layers to the more proximal slope areas cannot be ruled out. The present work represents the first published study integrating detailed seismic analysis and 3D basin modelling linking observed gas-leakage indicators and associated seepage pathways, to their relative abundance, distribution and feeding systems offshore Argentina's continental margin

Tectonic evolution of the Colorado Basin, offshore Argentina, inferred from seismo-stratigraphy and depositional rates analysis

International audienceBased on a dense 2D seismic reflection dataset and information from 8 exploration wells, we reinterpreted the stratigraphic evolution of the Colorado Basin. The basin is located on the continental shelf and slope within 50 to 2250 m of bathymetry. The total sediment fill can be up to 16,000 m. Seismic-to-well log correlations provide a chrono-stratigraphic framework for the interpreted seismic sequences. We show that the Colorado Basin records the development of a Permian pre-rift period, a Triassic/Jurassic to Early Cretaceous rift phase and a Lower Cretaceous to Tertiary drift phase. This passive margin represents the evolution of lithospheric extension from active rifting to the thermal subsidence/drift stage. Several Cretaceous to Cenozoic slumping episodes were identified and related to progradation of the sequences and sediment build-up in the slope, as well as to the development of seaward dipping extensional faults

Genetic variants in the PPARD-PPARGC1A-NRF-TFAM mitochondriogenesis pathway are neither associated with muscle characteristics nor physical performance in elderly

We studied the influence of genetic polymorphisms involved in the PPARD-PPARGC1A-NRF-TFAM mitochondriogenesis pathway (rs6949152, rs12594956, rs2267668, rs8192678, and rs1937) on muscle phenotypes (thigh muscles’ cross-sectional, maximal handgrip-strength and 30-second chair stand-test) and Barthel index in Caucasian (Spanish) community-dwelling old people (n=75, 21 men, 54 women; 71–94 years). We found no significant genetic associations with the studied phenotypes. Multiple, com- plex gene-environment and gene-gene interactions which are yet to be determined are likely to play a more determinant role

Effects of xylanase supplementation on feed intake, digestibility and ruminal fermentation in Rambouillet sheep

8 páginas, 3 tablas.The present study aimed to investigate the effects of adding xylanase enzyme (XY) to a basal diet containing 300 g maize stover and 700 g concentrate/kg dry matter (DM) on feed intake, ruminal fermentation, total tract and ruminal digestibility, as well as some blood parameters. Four male Rambouillet sheep (39 ± 1·8 kg body weight), with permanent rumen and duodenum cannulae were used in a 4 × 4 Latin square design. Sheep were fed a basal diet without xylanase addition (control, XY0), or with the addition of xylanase at 1 (XY1), 3 (XY3) or 6 (XY6) ¿l/g of diet DM for 84 days, with four 21-day experimental periods. Feed intake, digestibility and rumen fermentation parameters were determined on days 16¿21 in each experimental period, and the apparent ruminal neutral detergent fibre (NDF) digestibility was determined on days 16 and 17. Treatments XY1 and XY3 increased feed intake, whereas digestibility was increased with XY6. Ruminal NDF digestibility increased when sheep were fed diets treated with xylanase. Ruminal pH, ammonia-N and acetic acid increased with xylanase treated diets. Propionic acid concentration increased with diet XY1 at 3 h post-feeding, but after 9 h post-feeding its concentration decreased in the rumen of sheep fed xylanase treated diets. Xylanase had no effect on blood urea, phosphorus and triglycerides. Addition of xylanase at 6 µl/g DM in a diet containing 300 g maize stover and 700 g concentrate/kg DM and fed to Rambouillet sheep improved feed digestibility and ruminal fermentation without affecting blood parameters.The authors acknowledge the financial support from the IAEA (Vienna, Austria) Research Contract number MEX16307 within the D3·10·27 Coordinated Research Project.Peer Reviewe

Variation in natural frequency of stamens with different morphologies and its relationship to bee vibrations

During buzz pollination, bees use vibrations to remove pollen from flowers. Vibrations at the natural frequency of pollencarrying stamens are amplified through resonance, resulting in higher amplitude vibrations. Because pollen release depends on vibration amplitude, bees could increase pollen removal by vibrating at the natural frequency of stamens. However, few studies have characterized the natural frequencies of stamens and compared them to the frequencies of buzzpollinating bees. We use laser Doppler vibrometry to characterize natural frequencies of stamens of six morphologically diverse, buzz-pollinated, heterantherous Solanum taxa and compare the frequency of bumblebee buzzes produced on two Solanum spp. with different natural frequencies. We found that stamen morphology and plant identity explain variation in their natural frequency. The natural frequencies of the stamens in the studied Solanum taxa fell between 45 and 295 Hz; in five out of six taxa the frequencies were < 190 Hz, which only partly overlaps floral vibrations of buzzpollinating bees. We show that captive bumblebees produce vibrations at a frequency of 345 Hz and do not change their floral vibrations to match the natural frequency of the visited flowers. Our results suggest that pollen release induced by vibrating stamens at their natural frequencies might only play a role in a subset of buzz pollination interactions

Particulate organic carbon in the deep-water region of the Gulf of Mexico

Ocean eddies play a major role in lateral and vertical mixing processes of particulate organic carbon (POC), as well as in the transport of heat, salinity, and biogeochemical tracers. In the open waters of the Gulf of Mexico (GoM), however, there are limited observations to characterize how these mesoscale structures affect the spatial distribution of POC in the upper water column, which is important for organic matter cycling and export. We present the distribution patterns of POC relative to mesoscale features throughout the water column in the deep-water region of the GoM during three oceanographic cruises held during the summer months of 2015, 2016, and 2017. Samples were collected under well-stratified upper ocean conditions, which allowed us to assess the spatial and temporal distribution of POC as a function of non-steric sea surface height, density, apparent oxygen utilization, and chlorophyll fluorescence. We further explored the variability of integrated surface layer POC concentrations at stations located within the cores and the edges of cyclonic and anticyclonic eddies, and those collected outside these structures. Although our results indicate mesoscale eddies modulate several important physical and biogeochemical variables and POC concentrations in the upper ocean, these features do not fully explain the spatial distribution of POC concentrations throughout the deep-water region of the GoM. Relatively lower POC concentrations were observed in the border of the cyclonic and the center of the anticyclonic eddies, in contrast to the relatively higher POC concentrations at the center of the cyclonic and the border of anticyclonic eddies. We observed high variability in POC concentration variability outside mesoscale structures, which may be attributed to other processes such as upwelling over the shelves, and the contribution by rivers during the summer especially in the northern and southern GoM

Trends in Metal Oxide Stability for Nanorods, Nanotubes, and Surfaces

The formation energies of nanostructures play an important role in determining their properties, including the catalytic activity. For the case of 15 different rutile and 8 different perovskite metal oxides, we find that the density functional theory (DFT) calculated formation energies of (2,2) nanorods, (3,3) nanotubes, and the (110) and (100) surfaces may be described semi-quantitatively by the fraction of metal--oxygen bonds broken and the bonding band centers in the bulk metal oxide