Tab.1: Representative bulk-rock and trace element chemistry

High-pressure/low-temperature metabasites occupy a definite geological position within the structure of the Polar Urals and have a very important bearing on the understanding of the early history of the Ural Mountains. Recently obtained geological, petrographic, geochemical and isotope data allow some conclusions on this history. The metabasites of the Khord"yus and Dzela complexes contain relics of a Neoproterozoic (578 ±8 Ma) oceanic crust. This crust formed part of the base of the early Paleozoic (500 Ma) ensimatic island arc and experienced Ca-Al-Si±Na metasomatism and, probably, partial melting with the formation of boninite melts. However, so far no boninite volcanics have been found. The metabasites at the base of the island arc took part in the collision and as a consequence experienced glaucophane schist and greenschist facies metamorphism during the collision and obduction over the passive Baltic margin 350 ±11 Ma ago.

Identidad visual y difusión del General Rock

El presente trabajo pretende crear un sistema de comunicación integral que represente el festival de rock General Rock del Departamento de San Martín, provincia de Mendoza, a través de la creación de una identidad visual y diversas piezas gráficas para su difusión y promoción. También se plantea una propuesta de señalética ante la ausencia de elementos orientadores dentro del Teatro Griego ubicado en el Parque Agnesi de San Martín.

Micropropagación de Glandularia, género nativo con potencial ornamental

En este trabajo se estableció un protocolo de propagación in vitro de tres especies nativas del género Glandularia: G. peruviana, G. sp. y G. laciniata. Para el establecimiento in vitro se evaluó el medio de Murashige Skoog (MS) con macro y micronutrientes diluidos a la mitad adicionado con 0,05 μM de bencilaminopurina (BAP) sola o en combinación con 0,1 μM thiadiazuron (TDZ) y un testigo sin reguladores del crecimiento. En la etapa de multiplicación se evaluó el medio de cultivo MS diluido a la ½ ó ¼ y adicionado de 20 ó 40 gr.L-1 de sacarosa. Es posible establecer y micropropagar estas especies en medios de cultivo sencillos. El medio más eficiente para el establecimiento fue aquel sin reguladores, mientras que el más adecuado para la multiplicación fue MS ½ adicionado de 20 gr.L-1 de sacarosa, en el cual la tasa de multiplicación cada 30 días fue de 6 en G. sp. y G. peruviana y 4 para G. laciniata.

(Table 1) Chemical composition of plagioclase and amphibole-pyroxene containing samples from pyroxene-amphibole-asbestos rock collected in the Hess Deep

Recent sediments with distinct signs of hydrothermal alteration sampled in the Hess Deep(Galapagos Ridge, East Pacific Rise) contained a piece of ash-gray rock, which differed from other rock fragments by degree of consolidation, conchoidal fracture, and had properties of asbestos. Our studies found that the sample represented mixture of asbestos-like pyroxene of diopside-hedenbergite composition, amphibole of tremolite composition and a new mineral, which basic structure consisted of bands of triple pyroxene chains with the radical [Si6O16]. The latter can be regarded as intermediate between amphiboles and layered silicates. Also in some parts of the sample presence of trioctahedral vermiculite-chlorite was indicated. Genesis of the studied asbestos rock is considered from the standpoint of high-temperature hydrothermal-metasomatic alteration of sediment by post-magmatic mineralized halide solutions.

Rock-magnetic proxies from a sediment profile of Aike Lake

The sedimentary archive from Laguna Potrok Aike is the only continuous record reaching back to the last Glacial period in continental southeastern Patagonia. Located in the path of the Southern Hemisphere westerly winds and in the source region of dust deposited in Antarctica during Glacial periods, southern Patagonia is a vantage point to reconstruct past changes in aeolian activity. Here we use high-resolution rock-magnetic and physical grain size data from site 2 of the International Continental scientific Drilling Program (ICDP) Potrok Aike maar lake Sediment Archive Drilling prOject (PASADO) in order to develop magnetic proxies of dust and wind intensity at 52°S since 51,200 cal BP. Rock-magnetic analysis indicate the magnetic mineral assemblage is dominated by detrital magnetite. Based on the estimated flux of magnetite to the lake and comparison with distal dust records from the Southern Ocean and Antarctica, kLF is interpreted as a dust indicator in the dust source of southern Patagonia at the millennial time scale, when ferrimagnetic grain size and coercivity influence is minimal. Comparison to physical grain-size data indicates that the median destructive field of isothermal remanent magnetisation (MDFIRM) mostly reflects medium to coarse magnetite bearing silts typically transported by winds for short-term suspension. Comparison with wind-intensity proxies from the Southern Hemisphere during the last Glacial period and with regional records from Patagonia since the last deglaciation including marine, lacustrine and peat bog sediments as well as speleothems reveals similar variability with MDFIRM up to the centennial time scale. MDFIRM is interpreted as a wind-intensity proxy independent of moisture changes for southeastern Patagonia, with stronger winds capable of transporting coarser magnetite bearing silts to the lake.