Sedimentology, stratigraphic context, and implications of Miocene intrashelf bottomset deposits, offshore New Jersey

Drilling of intrashelf Miocene clinothems onshore and offshore New Jersey has provided better understanding of their topset and foreset deposits, but the sedimentology and stratigraphy of their bottomset deposits have not been documented in detail. Three coreholes (Sites M27–M29), collected during Integrated Ocean Drilling Program (IODP) Expedition 313, intersect multiple bottomset deposits, and their analysis helps to refine sequence stratigraphic interpretations and process response models for intrashelf clinothems. At Site M29, the most downdip location, chronostratigraphically well-constrained bottomset deposits follow a repeated stratigraphic motif. Coarse-grained glauconitic quartz sand packages abruptly overlie deeply burrowed surfaces. Typically, these packages coarsen then fine upwards and pass upward into bioturbated siltstones. These coarse sand beds are amalgamated and poorly sorted and contain thin-walled shells, benthic foraminifera, and extrabasinal clasts, consistent with an interpretation of debrites. The sedimentology and mounded seismic character of these packages support interpretation as debrite-dominated lobe complexes. Farther updip, at Site M28, the same chronostratigraphic units are amalgamated, with the absence of bioturbated silts pointing to more erosion in proximal locations. Graded sandstones and dune-scale cross-bedding in the younger sequences in Site M28 indicate deposition from turbidity currents and channelization. The sharp base of each package is interpreted as a sequence boundary, with a period of erosion and sediment bypass evidenced by the burrowed surface, and the coarse-grained debritic and turbiditic deposits representing the lowstand systems tract. The overlying fine-grained deposits are interpreted as the combined transgressive and highstand systems tract deposits and contain the deepwater equivalent of the maximum flooding surface. The variety in thickness and grain-size trends in the coarse-grained bottomset packages point to an autogenic control, through compensational stacking of lobes and lobe complexes. However, the large-scale stratigraphic organization of the bottomset deposits and the coarse-grained immature extrabasinal and reworked glauconitic detritus point to external controls, likely a combination of relative sea-level fall and waxing-and-waning cycles of sediment supply. This study demonstrates that large amounts of sediment gravity-flow deposits can be generated in relatively shallow (~100–200 m deep) and low-gradient (~1°–4°) clinothems that prograded across a deep continental shelf. This physiography likely led to the dominance of debris flow deposits due to the short transport distance limiting transformation to low-concentration turbidity currents

Processes and architectures of deltas in shelf-break and ramp platforms : examples from the Eocene of West Spitsbergen (Norway), the Pliocene paleo-Orinoco Delta (SE Trinidad), and the Cretaceous Western Interior Seaway (S. Wyoming & NE Utah)

textThis research investigates different scenarios of deltaic deposition, both in shelfbreak and ramp settings. I address four ancient cases with particular characteristics: 1) A shelf-margin case from the Eocene Battfjellet Formation, West Spitsbergen, Norway, in which deltas were able to migrate to the shelf-edge during rising and sea-level highstand conditions despite the low-supply character of the system (low progradation/aggradation rates compared to analogous margins), with consequent sand starvation on the slope and deeper areas of the basin. The delta system was overall wave-dominated, with restricted tide-influence at the mouth of the distributaries and more accentuated tide-influence during the transgressive transit of the deltas; 2) A shelf-margin case from the Pliocene paleo-Orinoco Delta System, Mayaro Formation, SE-Trinidad, in which high rates of sediment supply from the paleo-Orinoco River and exceptionally high subsidence rates due to growth-faulting, produced a spectacular stacking of sandstones on the outer shelf and shelf-edge areas, but with apparently limited sand delivery into deeper waters. The delta system was overall storm-wave dominated, with fluvial-influence in the lower segment of the system and some tide-influence in association with the fluvial-influence; 3) A case from a shallow-water ramp, Campanian Rock Springs Formation (Western Interior Seaway), in which deltas accumulated along relatively straight, north-south oriented shorelines highly impacted by wave-storm processes. Tide-influence was limited to the mouth of the distributaries, and fluvial deposits mostly developed within the coastal-plain areas; and 4) A case from the same ramp setting as (3) but in an outer-ramp site, Campanian Haystack Mountains Formation, in which a lowering in sea-level translated the delta system tens of kilometers eastwards into the basin. As a consequence of a shallower and narrower seaway, southerly-oriented tidal currents were enhanced and subsequently skewed or re-aligned the delta system to the south. The key contributions of this research concern (1) the feasibility of shelf-margin accretion during rising and highstand of sea level, (2) the critical importance of shelf width and sediment supply (and not only sea-level behavior) to bring deltas to the shelfedge, and (3) the possible tendency for tides enhancement in the distal reaches of shallow seaway ramps, caused by narrowing of the seaway and fault-topography enhancement during falling sea level.Geological Science

Factores del dominio afectivo en el proceso de enseñanza-aprendizaje de la física en la educación media superior :planteamiento de una estrategia basada en el aprendizaje cooperativo a partir de

Docencia para la Educación Media Superio

El vínculo profesor-alumno en las clases de Física de bachillerato

Recent research in Neuroeducation and Cognitive Psychology has shown the relevant role of emotions into the teachinglearning process, this process is facilitating by emotions such as curiosity, surprise and empathy, whereas it is hindered by emotions as boredom, apathy and frustration. In the classroom, high school students experience different emotions that modify factors of affective domain. The teacher-student relationship is one of the most important factors that teachers can modify through the emotions of students toward knowledge, in this work we interpret the relationship as the interaction between teacher and student, where the student is willing to learn and accept to the teacher as the mediator between him and the knowledge. Under this hypothesis, in order to improve the physics learning for students in high school, we elaborate a teaching strategy based on cooperative learning, whose main element is promoting of the teacherstudent relationship. The evaluation of this teaching strategy reflects qualitatively and comparatively that its application helped to the students to develop different cognitive processes in three types of knowledgeEn investigaciones recientes en Neurociencias y Psicología Cognitiva se ha demostrado la importancia de las emociones en el proceso de enseñanza-aprendizaje, emociones como la curiosidad, la sorpresa y la empatía lo facilitan; mientras las emociones como el aburrimiento, la apatía y la frustración lo dificultan. En el salón de clases, los estudiantes de bachillerato experimentan diferentes emociones que pueden modificar factores del dominio afectivo. Uno de los factores más importantes que el docente puede modificar a través de las emociones de los estudiantes hacia el conocimiento es el vínculo profesor-alumno, el cual se interpreta como la interacción entre el docente y el estudiante, donde el alumno está dispuesto a aprender y acepta al profesor como el mediador entre él y el conocimiento. Bajo esta hipótesis, para mejorar el aprendizaje de la física en los estudiantes de bachillerato, se elaboró una estrategia didáctica basada en el modelo de aprendizaje cooperativo cuyo elemento principal es el fomento del vínculo profesor-alumno. Los resultados que se obtuvieron en la aplicación de la estrategia ante un grupo de bachillerato, reflejan de manera cualitativa y comparativa que se desarrollaron en los estudiantes diferentes procesos cognitivos en tres tipos de conocimiento

Caso clínico: Proceso de enfermería en una paciente con preeclampsia

“El Colegio Americano de Obstetras y Ginecólogos (ACOG) define actualmente la preeclampsia como una enfermedad hipertensiva específica del embarazo con compromiso multisistémico. En México, la preeclampsia constituye la principal causa de muerte materna en las instituciones que conforman el Sistema Nacional de Salud. El aporte científico a través de los cuidados que la enfermera specialista en cuidados intensivos puede otorgar a una persona con dicho estado de salud es indiscutible. Objetivo: Diseñar y aplicar un plan de cuidados especializado a una paciente adulta con diagnóstico de preeclamsia, por medio de la implementación del Proceso Enfermero. Metodología: se ha realizado una búsqueda bibliográfica en bases a datos de guías de práctica clínica, revistas científicas y artículos encontrados en internet, se implementó la metodología del proceso de enfermería. Resultados: se logró observar que los datos de buena práctica en las guías coincidieron con las intervenciones realizadas y analizadas en este proceso de enfermería. Discusión:

Constraints on the numerical age of the Paleocene/Eocene boundary

Here we present combined radio-isotopic dating (U-Pb zircon) and cyclostratigraphic analysis of the carbon isotope excursion at the Paleocene/Eocene (P/E) boundary in Spitsbergen, to determine the numerical age of the boundary. Incorporating the total uncertainty from both radio-isotopic and cyclostratigraphic datasets gives an age ranging from 55.728-55.964 Ma, within error of a recently proposed astronomical age of ~55.93 Ma. Combined with the assumption that the Paleocene Epoch spans twenty-five 405 kyr cycles, our new age for the boundary suggests an age of ~66 Ma for the Cretaceous/Paleogene (K/Pg) boundary. Furthermore, our P/E boundary age is consistent with the hypothesis that the onset of the Paleocene-Eocene thermal maximum (PETM) at the boundary occurred on the falling limb of a 405 kyr cycle, suggesting the event was initiated by a different mechanism to that which triggered the other early Eocene hyperthermals