Demo 13. Atracción y repulsión electrostática con cintas adhesivas

Objetivo: Mostrar la atracción y repulsión de cargas eléctricas

Demo 38. Soplando sobre papel y pelota de ping-pong (Bernoulli I)

Objetivo: Demostrar que la presión disminuye en un fluido en movimiento

Do Proterozoic Metamorphic Rocks in Northern New Mexico Record One Metamorphic Event At 1.4 Ga, or Two Overprinting Events At 1.65 GA and 1.4 GA

In-situ LA-ICPMS U-Pb monazite geochronology was used to determine the timing of regional metamorphism in the Picuris Mountains and northern Taos range, New Mexico. Monazite ages from aluminous quartzite and sillimanite-kspar bearing gneisses in Cedro Canyon, northern Taos Range, yield intercept ages of ca. 1380 Ma. Subhedral to anhedral monazite range in size between 10 µm and 50 µm, are typically aligned parallel/sub-parallel to the foliation, and generally occur along mineral grain boundaries; a few grains occur as inclusions within Fe-Ti oxides. Backscatter electron imaging revealed zoning in several monazite grains, but little to no compositional zoning is exhibited in the analyzed grains. Monazite do not appear to preserve any record of ca. 1650 Ma near-granulite facies metamorphism as previously proposed for this region. Monazite in the Picuris Mountains, northern New Mexico, yield LA-ICPMS, U-Pb intercept growth ages from a variety of bulk compositions: a metarhyolite clast from the Marqueñas Fm. (1386 ± 11 Ma), a micaceous quartzite from the underlying Vadito Fm. (1362 ± 3 Ma), a garnet-biotite-staurolite schist from the Piedra Lumbre Fm. (1357 ± 6 Ma), and a metatuff layer from the Pilar Fm. (1359 ± 19 Ma). The majority of monazite grains are euhedral though some irregular boundaries are apparent due to the partial inclusion of matrix grains. Backscatter electron imaging showed little to no compositional zoning within the grains. Monazite in all samples are generally aligned parallel to the dominant regional foliation, but some clearly overgrow the foliation at a high angle and are interpreted as post-tectonic. Monazite record no evidence of an older, 1.65 Ga metamorphic and deformational event as proposed by previous studies. Younger, ca. 1430-1360 Ma monazite across northern New Mexico are interpreted to reflect a single regional high temperature metamorphic event and/or pervasive mid-crustal fluid flow event. All monazite growth events are associated with the Picuris Orogeny. Although some monazite in Colorado record multiple age domains, corresponding to at least two monazite growth events, northern New Mexico only records Mesoproterozoic metamorphism and deformation

Demo 74. Modelo de nanotubo de carbono

Objetivo: Mostrar un modelo que reproduce la estructura atómica de un nanotubo de carbono a partir de esferas imanadas

Determining the Precambrian Structure and Thermotectonic Evolution of the Central Ruby Range, southwest Montana

The Ruby Range in southwestern Montana is a fundamental location within the Archean Wyoming craton for examining Precambrian crustal architecture and determining the thermotectonic evolution of the region. Monazite, zircon, and garnet geochronology from each of the three major units within the Ruby Range reveal two distinct metamorphic age populations: an older population ca. 2.55-2.45 Ga (the Tendoy orogeny) and a second, younger population ca. 1.78-1.72 Ga (the Big Sky orogeny). Phase equilibria modeling for the Big Sky orogeny within the confines of the Mine Gulch 7.5’ quadrangle reveal discrete pressure-temperature (P-T)histories for each of the three major structural units within the range. The Christensen Ranch metasedimentary suite yields peak metamorphic pressures of ~7 kbar, however peak temperatures increase from the top of the unit towards the base from ~700 °C to ~760 °C. The Dillon Gneiss yielded peak metamorphic conditions of ~8.4 kbar and ~760 °C, and the Elk Gulch Suite on average yielded peak conditions of ~8.8 kbar and ~770 °C. Additionally, new mapping interpretations from the Mine Gulch quadrangle reveal that all three units within the Ruby Range are closely structurally related, sharing an entwined Precambrian metamorphic and deformational history. Furthermore, the separation of the ca. 2.45 Ga garnet leucogneiss from the Dillon Gneiss as a distinct unit within the range ascribes wide spread crustal melting to the Tendoy orogeny. Combining these new observations with previous work aid in constraining a revised tectonic history for southwestern Montana between ~2.55-1.72 Ga. Prior to ~2.55 Ga, sediment accumulated on the margin of the Wyoming province and was followed by continental collision, the Tendoy orogeny, between ~2.55-2.45 Ga. A second cycle of sedimentation on the cratonic margin initiated immediately after the conclusion of the Tendoy orogeny and lasted between ~2.45-1.8 Ga. Between ~2.1-2.0 Ga, the Wyoming Province experienced a short period of extensional tectonism resulting in the emplacement of mafic dikes and sills. Between ~1.9-1.8 Ga, the Wyoming Province began to subduct beneath the Medicine Hat Block, ultimately culminating in the collision between the two continents resulting in the Big Sky orogeny between ~1.78-1.72 Ga

Demo 71. Modelo de bolas rígidas para apilamiento compacto

Objetivos: Mostrar gráficamente diferentes empaquetamientos atómicos compactos

Demo 90. Buscando el centro de gravedad con los dedos

Objetivo: Encontrar el centro de gravedad de un cuerpo con simetría axial utilizando para ello la fuerza de rozamiento