Cuencas triásicas del Oeste argentino: origen y evolución

The Triassic basins of western Argentina and northern Patagonia are located along fhe Pacific margin of Southwest Gondwana. They are narrow and elongated depressions oriented NW-SE, floored by a thick continental crust composed of Precarnbrian and Lower Palaeozoic magmatic rocks, and an Upper Palaeozoic plutonic-volcanic complex (Gondwana Magmatism). These basins are associated with the Choiyoi Magmatic Province, the Central Patagonian Batholith and the Comallo Volcanic Complex. For the Triassic of western Argentina the following stages are recognised: Barrealian (Early to Mid Triassic), Cortaderitian (Mid to early Late Triassic) and Florian (Late Triassic). During the Barrealian severa1 passive rfts are opened (Ischigualasto - Villa Unión, Marayes, Las Salinas - Beazley, Cuyo and the short-lived San Rafael basins). They are characterised by a synrift phase related to the activity of the main fracture systems along the active flank of the half-grabens, high accommodation space and frequent coarsegrained sediment supply (usually vocaniclastic) from the active margins. Intercalations of basic lava flows are common. In the Cortaderitian protracted extension, maximum regional development of the Triassic bgsins occurred. Most basins were controlled by thermal-tectonic subsidence. High accommodation space, limited coarse-grained cbntributions and high lacustrine base levels are the more characteristic conditions for basin sedimentary infill. In the Florian stagelthe Ischigualasto-Villa Unión, the Marayes and the Cuyo basins are characterised by fluvial-dominated red-bed successions, related to a transtensional stage of evolution. Several half-grabens (Malargüe, Paso Flores and Chacaico) are opened as precursors of the Neuquén Basin. In northwestern Patagonia, the combInation between regional strike-slip displacement along the Gastre Fault System and protopacific subduction, causes the development of the arc magmatism represented by the Central Patagonian Batholith and the thick volcano-sedimentary Comallo complex

The Cambrian-Ordovician siliciclastic platform of the Balcarce Formation (Tandilia System, Argentina) : Facies, trace fossils, palaeoenvironments and sequence stratigraphy

The Lower Palaeozoic sedimentary cover of the Tandilia (Balcarce Formation) is made up of thick quartz arenite beds together with kaolinitic claystones and thin fine-grained conglomerates. The Balcarce Formation was formed in the nearshore and inner shelf environments of a tide-dominated and storm influenced open platform. It shows many features suggesting tidal sedimentation. Coarse-grained facies were formed by sand bar migration and accretion. Heterolithic packages are interpreted as interbar (swale) deposits. Subordinated HCS sandstones indicate storm events. The recognition of thick progradational clinoforms allows to confirm that the Balcarce sea was open to the south, as suggested years ago through palaeocurrent interpretation. The great abundance and variety of trace fossils is among the most outstanding characteristics of this unit. The ichnotaxa that have been recognised so far are: Ancorichnus ancorichnus, Arthrophycus alleghaniensis, Arthrophycus isp., Bergaueria isp., Cochlichnus isp., Conostichus isp., Cruziana furcifera, Cruziana isp., Daedalus labeckei, Didymaulichnus lyelli, Didymaulichnus isp., Diplichnites isp., Diplocraterion isp., Herradurichnus scagliai, ?Monocraterion isp., Monomorphichnus isp., Palaeophycus alternatus, Palaeophycus tubularis, Palaeophycus isp., Phycodes aff. pedum, Phycodes isp., Plagiogmus isp., Planolites isp., Rusophycus isp., Scolicia isp. and Teichichnus isp. Trace fossils have traditionally been used to assign the Balcarce Formation to the Lower Ordovician, due to the presence of Cruziana furcifera. However, Plagiogmus is typical of Cambrian successions world-wide

Pirfenidone in idiopathic pulmonary fibrosis: real-life experience in the referral centre of Siena

Background: Idiopathic pulmonary fibrosis (IPF) is the most common idiopathic interstitial pneumonia and has a median survival after diagnosis of 2–5 years. Pirfenidone is the first approved antifibrotic drug for the treatment of IPF. Here we report the functional progress, side effects and survival data of a population of patients with IPF, diagnosed at our centre and treated with pirfenidone. Methods: We enrolled 91 patients with IPF (71 males) treated with pirfenidone. Clinical, survival and functional details were collected retrospectively at start of therapy and after 12, 24, 36 and 48 months of treatment. Lung function tests at least 12 months before starting therapy were available for 40 patients and were entered in the database, as well as side effects. Results: During the observation period (922 ± 529 days), 27 patients died, 5 patients underwent lung transplant and 10 patients interrupted therapy due to adverse events or IPF progression. The median survival was 1606 days. There was a significant reduction in disease progression rate, as measured by trend of forced vital capacity, after 1 year of therapy with respect to before treatment (p = 0.0085). Forced vital capacity reduction rate was progressively higher in the subsequent years of treatment. Treatment-related side effects were reported in 25 patients and were predominantly mild. Overall, four patients discontinued therapy due to severe photosensitivity. Conclusions: Our findings confirm the efficacy of pirfenidone in reducing functional progression of IPF and its excellent safety profile in a real-life setting. This study, designed on a long-term follow up, contributes to the growing evidence on safety, tolerability and efficacy of pirfenidone in IPF. The reviews of this paper are available via the supplemental material section

Orogenias paleozoicas en los Andes de Argentina y Chile y en la Península Antártica

Congreso Geológico Argentino (20º. 2017. San Miguel de Tucumán, Argentina). Simposio de Téctonica pre-andinaDurante el Neoproterozoico y Paleozoico, los Andes de Argentina y Chile, y desde fines del Paleozoico también la Península Antártica, formaron parte del margen SO de Gondwana. Durante este tiempo se acrecionaron a dicho margen varios fragmentos continentales de tamaño y aloctonía variable; denominados de N a S: Antofalla, Chi-Cu, Patagonia Occidental y Antártida Occidental. Estos fragmentos formaban parte de placas litosféricas, en ocasiones divididas en subplacas. La colisión de dichos fragmentos continentales con Gondwana y una última subducción bajo dicho margen, dieron lugar a 6 orogenias de extensión temporal y espacial limitada.Instituto Geológico y Minero de España, EspañaDepartamento de Geología, Universidad de Oviedo, EspañaUniversidad de Río Negro, ArgentinaServicio Geológico y Minero Argentino, ArgentinaInstituto De Bio y Geociencias Del NOA, Consejo Nacional de Investigaciones Científicas y Técnicas, ArgentinaInstituto De Bio y Geociencias Del NOA, Universidad Nacional de Salta, ArgentinaDepartamento de Geodinámica, Universidad del País Vasco, EspañaFacultad de Geología, Universidad de Barcelona, EspañaDepartamento de Geología, Universidad de Chile, ChileUniversidad Andrés Bello, ChileUnidad de Tectónica, Consejo Nacional de Investigaciones Científicas y Técnicas, ArgentinaFacultad de Geología, Universidad de Buenos Aires, ArgentinaÁrea de Geología, Universidad Rey Juan Carlos, EspañaUniversidad de Salta, ArgentinaInstituto de Investigación en Paleobiología y Geología, Universidad de Río Negro, ArgentinaInstituto de Investigación en Paleobiología y Geología, Consejo Nacional de Investigaciones Científicas y Técnicas, ArgentinaCentro de Investigaciones Geológicas, Universidad de La Plata, ArgentinaUniversidad de San Juan, ArgentinaPeer reviewe

The Cambrian-Ordovician siliciclastic platform of the Balcarce Formation (Tandilia System, Argentina) : Facies, trace fossils, palaeoenvironments and sequence stratigraphy

The Lower Palaeozoic sedimentary cover of the Tandilia (Balcarce Formation) is made up of thick quartz arenite beds together with kaolinitic claystones and thin fine-grained conglomerates. The Balcarce Formation was formed in the nearshore and inner shelf environments of a tide-dominated and storm influenced open platform. It shows many features suggesting tidal sedimentation. Coarse-grained facies were formed by sand bar migration and accretion. Heterolithic packages are interpreted as interbar (swale) deposits. Subordinated HCS sandstones indicate storm events. The recognition of thick progradational clinoforms allows to confirm that the Balcarce sea was open to the south, as suggested years ago through palaeocurrent interpretation. The great abundance and variety of trace fossils is among the most outstanding characteristics of this unit. The ichnotaxa that have been recognised so far are: Ancorichnus ancorichnus, Arthrophycus alleghaniensis, Arthrophycus isp., Bergaueria isp., Cochlichnus isp., Conostichus isp., Cruziana furcifera, Cruziana isp., Daedalus labeckei, Didymaulichnus lyelli, Didymaulichnus isp., Diplichnites isp., Diplocraterion isp., Herradurichnus scagliai, ?Monocraterion isp., Monomorphichnus isp., Palaeophycus alternatus, Palaeophycus tubularis, Palaeophycus isp., Phycodes aff. pedum, Phycodes isp., Plagiogmus isp., Planolites isp., Rusophycus isp., Scolicia isp. and Teichichnus isp. Trace fossils have traditionally been used to assign the Balcarce Formation to the Lower Ordovician, due to the presence of Cruziana furcifera. However, Plagiogmus is typical of Cambrian successions world-wide

Anatomy of a fluvial lowstand wedge: the Avile Member of the Agrio Formation (Hauterivian) in central Neuquen Basin (northwest Neuquen Province), Argentina

The Hauterivian Avilé Member of the Agrio Formation constitutes a non marine lowstand wedge dominated by fluvial and aeolian deposits that sharply overlie deep-marine, ammonite-bearing shales of the Lower Member of the Agrio Formation in the central part of the Neuquén basin. Detailed sedimentlogical logging in twelve localities allowed the identification of eleven sedimentary bodies that record the evolution of fluvial environments through this lowstand wedge. Channel units identified include complex sheets and ribbons as well as simple ribbons developed under contrasting accommodation/supply conditions. Small-scale sandy and heterolithic channels are related to fine-grained floodplain/lacustrine deposits together with small-scale bars and sandstone lobes indicating overbank splays. In addition, large-scale lacustrine bars are also present, associated with complex ribbons, suggesting the development of distributary systems that fed relatively deep water bodies. Locally, aeolian reworking of fluvial channels and aeolian deposits (dunes and sandsheets) are present. Regional and vertical changes in fluvial style were recorded within this lowstand wedge. The up-dip area is characterised by a relatively small thickness and almost completely dominated by the superimposition of complex sandstone sheets. Towards the north of the study area, in a down-dip position, the studied unit shows a much greater thickness and a high proportion of fine-grained floodplain deposits. However the intercalation of bedload dominated and mixed load, high sinuosity fluvial intervals is recorded. This alternation represents contrasting accommodation/sediment supply conditions associated either with climatic fluctuations or with oscillations in fluvial base level that could be related to eustatic changes due to orbital processes. Although the vertical evolution in the upstream sector is obscured by reduced accommodation, in the downstream area the increase in the proportion of fine-grained facies and the gradual change to a mixed-load fluvial system reflect a gradual increase in accommodation (relative to coarse-grained sediment supply) that could be associated with an overall (low frequency) transgressive trend developed after the relative sea level fall that produced the onset of non-marine accumulation in the central part of the basin.Fil: Veiga, Gonzalo Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: Spalletti, Luis Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: Flint, Stephen S.. University of Liverpool; Reino Unid

Internal anatomy of an Erg sequence from the aeolian-fluvial system of the De La Cuesta Formation (Paganzo Basin, northwestern Argentina)

Permian red beds of the De La Cuesta Formation in the Sierra de Narváez (Paganzo Basin, northwestern Argentina) are essentially composed of sandstones associated with mudstones and subordinate conglomerates. Facies distributions and stacking patterns indicate that these sediments resulted from the interaction between aeolian and ephemeral fluvial systems, and are represented by aeolian dune, dry aeolian interdune and aeolian sand sheet, mudflat, wet aeolian interdune, and fluvial deposits. The De La Cuesta Formation is characterised by aeolian (erg) sequences alternating with non-aeolian (terminal alluvial fan - mudflat) sequences. Each erg sequence is bounded at its base by a regionally extensive sand-drift surface and at the top by an extinction surface. A number of architectural elements, including aeolian dunes limited by interdunes, grouped crescentic aeolian dunes, longitudinal dunes, and draa with superimposed crescentic dunes are recognised in the erg sequences. The sand sea developed during phases of increasing aridity, whereas non-aeolian deposition might have occurred during more humid phases. Thus, the styles of aeolian-fluvial interaction are considered to result from cyclical climatic changes. Within the drier hemicycles, the rhythmic alternation between draa deposits and aeolian dune and interdune deposits indicates higher frequency cycles that could be attributed to subtle climatic oscillations and/ or changes in sand supply and availability. The development of the Permian sand sea in the inland Paganzo Basin seems to be related to the growth of a volcanic chain to the west. This topographic barrier separated the Paganzo Basin from the Chilean Basin, located along the western margin of Gondwana and characterised by shallow marine carbonate sedimentation. The correlation between the Permian erg and the shallow marine carbonates suggests a regional warming period during the Middle Permian in western Gondwana