Field guide on the ordovician of the Sierra Pintada, San Rafael Block, Mendoza

First day: Departure from San Juan City by bus, at 8 AM. Arrival at San Rafael City (about 370 km towards the South) in Mendoza Province at lunch time. During the trip by the plain road we can see the Eastern Precordillera and Frontal Cordillera sides and the Cuyo oil basin. This region is also famous for its vineyards and with a nice production of several wines. After accommodation at the hotel we will depart to Cerro Bola region (about 25 km towards the East of San Rafael City). The stop will be at Baños Cerro Bola (ancient spring baths) to see the more complete section of the siliciclastic sequence know as Pavón Formation. Graptolites from the Lower Caradoc age are common in black shales of this section. We can observe the sedimentary characteristics and structural style of the sequence. At about 7 PM we will return to the hotel at San Rafael City for dinner and sleeping. Second day: Departure from San Rafael City at 8.30 AM (with luggage) and we will go to the South-East side of the San Rafael Block known Ponón Trehue locality (about 70 km). The first stop will be at Ponón Trehue creek, where we can see the Precambrian basement (grenvillian crust) and the contact with Ordovician units from Tremadoc and Arenig carbonate rocks and Llanvirn-Llandeilo to Lower Caradoc clastic-carbonate sediments. The biostratigraphy of these Ordovician outcrops has been based on Conodont assemblages. The sedimentological and stratigraphical studies suggest that these units are megablocks, blocks and megaconglomerates and could be allochtonous deposits associated with an extensional regime well described in the Precordillera Terrane. After a field lunch we will go to the second stop at the Tortuga section, where the outcrops of the Ponón Trehue Formation represent the Pygodus serra Zone, Eoplacognathus robustus subzone and Eoplacognathus linstroemi subzone, and Pygodus anserinus Zone, Sagittodontina kielcensissubzone. We will observe the sedimentological characteristics of the sequences. At 5 PM we will return to Mendoza City. Arrival to Mendoza City at about 8 PM, location at the hotel and dinner. The field trip is finished.Centro de Investigaciones Geológica

Field guide on the ordovician of the Sierra Pintada, San Rafael Block, Mendoza

First day: Departure from San Juan City by bus, at 8 AM. Arrival at San Rafael City (about 370 km towards the South) in Mendoza Province at lunch time. During the trip by the plain road we can see the Eastern Precordillera and Frontal Cordillera sides and the Cuyo oil basin. This region is also famous for its vineyards and with a nice production of several wines. After accommodation at the hotel we will depart to Cerro Bola region (about 25 km towards the East of San Rafael City). The stop will be at Baños Cerro Bola (ancient spring baths) to see the more complete section of the siliciclastic sequence know as Pavón Formation. Graptolites from the Lower Caradoc age are common in black shales of this section. We can observe the sedimentary characteristics and structural style of the sequence. At about 7 PM we will return to the hotel at San Rafael City for dinner and sleeping. Second day: Departure from San Rafael City at 8.30 AM (with luggage) and we will go to the South-East side of the San Rafael Block known Ponón Trehue locality (about 70 km). The first stop will be at Ponón Trehue creek, where we can see the Precambrian basement (grenvillian crust) and the contact with Ordovician units from Tremadoc and Arenig carbonate rocks and Llanvirn-Llandeilo to Lower Caradoc clastic-carbonate sediments. The biostratigraphy of these Ordovician outcrops has been based on Conodont assemblages. The sedimentological and stratigraphical studies suggest that these units are megablocks, blocks and megaconglomerates and could be allochtonous deposits associated with an extensional regime well described in the Precordillera Terrane. After a field lunch we will go to the second stop at the Tortuga section, where the outcrops of the Ponón Trehue Formation represent the Pygodus serra Zone, Eoplacognathus robustus subzone and Eoplacognathus linstroemi subzone, and Pygodus anserinus Zone, Sagittodontina kielcensissubzone. We will observe the sedimentological characteristics of the sequences. At 5 PM we will return to Mendoza City. Arrival to Mendoza City at about 8 PM, location at the hotel and dinner. The field trip is finished.Centro de Investigaciones Geológica

Field guide on the ordovician of the Sierra Pintada, San Rafael Block, Mendoza

First day: Departure from San Juan City by bus, at 8 AM. Arrival at San Rafael City (about 370 km towards the South) in Mendoza Province at lunch time. During the trip by the plain road we can see the Eastern Precordillera and Frontal Cordillera sides and the Cuyo oil basin. This region is also famous for its vineyards and with a nice production of several wines. After accommodation at the hotel we will depart to Cerro Bola region (about 25 km towards the East of San Rafael City). The stop will be at Baños Cerro Bola (ancient spring baths) to see the more complete section of the siliciclastic sequence know as Pavón Formation. Graptolites from the Lower Caradoc age are common in black shales of this section. We can observe the sedimentary characteristics and structural style of the sequence. At about 7 PM we will return to the hotel at San Rafael City for dinner and sleeping. Second day: Departure from San Rafael City at 8.30 AM (with luggage) and we will go to the South-East side of the San Rafael Block known Ponón Trehue locality (about 70 km). The first stop will be at Ponón Trehue creek, where we can see the Precambrian basement (grenvillian crust) and the contact with Ordovician units from Tremadoc and Arenig carbonate rocks and Llanvirn-Llandeilo to Lower Caradoc clastic-carbonate sediments. The biostratigraphy of these Ordovician outcrops has been based on Conodont assemblages. The sedimentological and stratigraphical studies suggest that these units are megablocks, blocks and megaconglomerates and could be allochtonous deposits associated with an extensional regime well described in the Precordillera Terrane. After a field lunch we will go to the second stop at the Tortuga section, where the outcrops of the Ponón Trehue Formation represent the Pygodus serra Zone, Eoplacognathus robustus subzone and Eoplacognathus linstroemi subzone, and Pygodus anserinus Zone, Sagittodontina kielcensissubzone. We will observe the sedimentological characteristics of the sequences. At 5 PM we will return to Mendoza City. Arrival to Mendoza City at about 8 PM, location at the hotel and dinner. The field trip is finished.Centro de Investigaciones Geológica

The first report of South American edrioasteroids and the paleoecology and ontogeny of rhenopyrgid echinoderms

A new species of rhenopyrgid edrioasteroid Rhenopyrgus piojoensis sp. nov. is described form the Silurian (Lower Lud− low) Los Espejos Formation in the Precordillera of Argentina. This species is the first reported edrioasteroid from South America. Rhenopyrgids are widely distributed in Ordovician through Devonian deposits of most continents. Numerous juvenile specimens show that the general bodyplan is organized early in ontogeny and that the pedenculate zone lengthens with age. Phylogenetic analysis shows that rhenopyrgids are more closely related to edrioasterid edrioasteroids such as edrioblastoids and cyathocystids than to pyrgocystid isorophids.Fil: Sumrall, Colin D.. University of Tennessee; Estados UnidosFil: Heredia, Susana Emma. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rodríguez, Cecilia María. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mestre García, Ana Isabel. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Upper Ordovician cryptostomatid bryozoans and microfossils from the Don Braulio Formation, Eastern Precordillera, Argentina

En la clásica sección de la Quebrada de Don Braulio, en la Precordillera Oriental de la Provincia de San Juan, afora la Formación Don Braulio de edad hirnantiana. Fragmentos de colonias de Bryozoos,algunas espículas de esponjas mal conservadas y una placa de crinoideos, fueron recuperados de los sedimentos silicoclásticos de esta formación. Los restos de las colonias de briozoos se caracterizan por su hábito de crecimiento erecto, su diámetro pequeño y por la presencia de estriaciones longitudinales. Estos fragmentos tienen una pobre preservación, sin embrago los mismos han sido comparados con el género Nematopora perteneciente a la familia Arthrostylidae (suborden Rhobdomesina, orden Cryptostomata), que tuvo numerosos representantes durante el Ordovícico. Escasas y fragmentadas espículas de esponja hexactinéllidas y otros tipos de microfósiles también han sido recuperados de los depósitos post-glaciales de la Formación Don Braulio.In the classical section of the Don Braulio Creek at the Villicum Range, Eastern Precordillera of San Juan Province, crops out the siliciclastic Don Braulio Formation of Hirnantian age. Fragments of bryozoan colonies, few poorly preserved sponge spicules and a crinoidal plate, were recovered from these shelf sedi-ments. The bryozoan colonies remains are characterized by its erect growth habit, its small diameter, and for showing clear longitudinal striations. These fragments have a poor preservation, but they have been compared with the genus Nematopora belonging to the Arthrostylidae family (Rhobdomesina suborder, Cryptostomata order), that had numerous representatives during the Ordovician. Very scarce and highly fragmented sponge spicules are classifed as hexactins. These microfossils have been recovered in the post-glacial deposits from the Don Braulio section at the Villicum range.Fil: Jiménez Sánchez, Andrea. University of West Bohemia; República ChecaFil: Beresi, Matilde Sylvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Mestre García, Ana Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; ArgentinaFil: Heredia, Susana Emma. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; Argentin

The conodont Paroistodus horridus (Barnes and Poplawski) as a new biostratigraphical tool for the middle Darriwilian (Ordovician)

This contribution develops an analysis on the conodont Paroistodus horridus (Barnes and Poplawski) from several Argentine Precordilleran sections. From these collections, we have established that P. horridus occurs from the Lenodus crassus Zone to the Amorphognathus tvaerensis Zone (Darriwilian to early Sandbian). This study recognizes several primary morphological features of P. horridus which vary through the Darriwilian and three evolutionary morphological types can be identified: early form, middle form with two stages, and late form. The co-occurrence of index conodonts with the successive stages of this evolutionary development allowed a significant biostratigraphical value to be assigned for each different morphological type of P. horridus. Based on this information, we propose a detailed biostratigraphical control and correlation with equivalent strata from Canada, China, Australia, United States, Norway, and western Central Asia.Fil: Mestre García, Ana Isabel. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; ArgentinaFil: Heredia, Susana Emma. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; Argentin

Los Conodontes Eoplacognathus robustus Bergström y E. lindstroemi (Hamar) del Ordovícico Medio: Taxonomía y reconstrucción de sus aparatos

The Middle-Upper Ordovician Ponón Trehué Formation cropping out in the San Rafael Block (Argentina) provided a large collection of conodonts which have been published years ago. The species Eoplacognathus robustus and Eoplacognathus lindstroemi recovered from these strata have been revised and restudied. In this contribution we describe M and S elements that were assigned previously to Baltoniodus prevariabilis and Baltoniodus variabilis as belonging to the E. robustus and E. lindstroemi apparatuses. The morphological characters of the P, S and M elements as part of these late Eoplacognathus apparatus were analyzed and support the proposal of a new reconstruction of it. We have compared this apparatus with the Baltoniodus apparatus and suggest the inclusion of the Eoplacognathus genus into the Balognathidae family. The new architecture of the Eoplacognathus apparatus is comparable to the genus Lenodus. This analysis improves the knowledge about this index conodont group allowing a new insight on the evolution, phylogeny and paleobiology of this linageLa Formación Ponón Trehué del Ordovícico Medio-Superior que aflora en el Bloque de San Rafael (Argentina) ha provisto una gran colección de conodontes que se han dado a conocer a través de los años. Las especies Eoplacognathus robustus y Eoplacognathus lindstroemi recuperadas de estos estratos han sido revisadas y reestudiadas. En esta contribución describimos los elementos M y S que se asignaron previamente a Baltoniodus prevariabilis y Baltoniodus variabilis como pertenecientes a los aparatos E. robustus y E. lindstroemi. Se analizaron los caracteres morfológicos de los elementos P, S y M de estos Eoplacognathus tardíos que apoyan la propuesta de una nueva reconstrucción de sus aparatos. Se lo ha comparado con el aparato Baltoniodus y sugerimos la inclusión del género Eoplacognathus en la familia Balognathidae. La nueva arquitectura del aparato de Eoplacognathus es equiparable con la del género Lenodus. Este análisis mejora el conocimiento sobre este grupo de conodontes guía permitiendo una nueva visión sobre la evolución, filogenia y paleobiología de este linaje.Fil: Heredia, Susana Emma. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; ArgentinaFil: Mestre García, Ana Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; Argentin

New early Ordovician conodont data from the San Juan Formation, Central Precordillera (Argentina): Biostratigraphic and paleogeographic significance

The Early Ordovician conodont faunas from the Cerro La Chilca and Las Chacritas river sections (Central Precordillera) have been studied and compared to those of the well-known Talacasto section. The vertical distribution of the recovered upper Floian conodonts from Cerro La Chilca and Las Chacritas river sections is presented for the first time, recording the Oepikodus evae and O. intermedius zones, this distribution has been compared to the Talacasto section. The conodonts Bergstroemognathus hubeiensis An, and Microzarkodina n. sp. (sensu Pyle and Barnes) are recorded for the first time in the Precordillera, and these two species are described and illustrated herein. The occurrence of the B. hubeiensis and Microzarkodina n. sp. in the early Ordovician strata of the San Juan Formation, provides significant data related to the ties between Precordillera to Gondwana, peri-Gondwana, and Northwestern of the Midcontinent regions for this time interval, increasing the knowledge about the paleogeographic reconstruction of the western margin of Gondwana. The evidence of biogeographic connections between these regions let to suggest that those were in closer position than previous assumptions or at least that marine currents connected them during the late Lower Ordovician.Fil: Moreno, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; ArgentinaFil: Mestre, Ana Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; ArgentinaFil: Heredia, Susana Emma. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; Argentin

Microfósiles carbonáticos del Ordovícico Inferior de la Formación San Juan, Argentina: un nuevo tipo de calcitarch y sus implicaciones paleoambientales

The calcareous microfossils present in the Ordovician and Silurian carbonate successions around the world are limited to few studies and their biological affinities and environmental preferences remain indefinite. In the carbonate Ordovician San Juan Formation from the Cerro La Chilca section, a group of calcareous microfossils was recognized and, based on their size, they are included in the calcitarch classification. Two types of calcitarchs have been recognized, Type-III calcitarch: large spheres with a thin to medium wall (diameter ~250 μm), and Type-0 calcitarch: small spheres with a thin wall (diameter ~80 μm). The carbonate microfacies analysis of the lower part of the San Juan Formation allowed defining five successive microfacies: burrowed bioclastic wackestone (M1), peloidal intraclastic packstone-grainstone (M2), intraclastic floatstone (M3), intraclastic wackestone-packstone (M4) and bioclastic boundstone (M5). These microfacies are interpreted to range from shallow subtidal facies below wave action to shoal and reef facies. It is possible to infer that the recovered calcitarchs show variations in size in relation to the facies that contain them. The calcitarchs recognized in wackestone-type facies are the Type-0 calcitarch and those recovered from the packstone-grainstone facies are the Type-III calcitarch. The calcitarch sizes variation probably is related to a gradual increase of energy within a shallow subtidal environment. Occurrences of calcitarchs within the Floian Oepikodus evae-O. intermedius conodont zone extends their fossil record into the Early Ordovician.Fil: Moreno, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; ArgentinaFil: Mestre, Ana Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; ArgentinaFil: Heredia, Susana Emma. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; Argentin

Bio-Based Coatings for Food Metal Packaging Inspired in Biopolyester Plant Cutin.

Metals used for food canning such as aluminum (Al), chromium-coated tin-free steel (TFS) and electrochemically tin-plated steel (ETP) were coated with a 2-3-µm-thick layer of polyaleuritate, the polyester resulting from the self-esterification of naturally-occurring 9,10,16-trihydroxyhexadecanoic (aleuritic) acid. The kinetic of the esterification was studied by FTIR spectroscopy; additionally, the catalytic activity of the surface layer of chromium oxide on TFS and, in particular, of tin oxide on ETP, was established. The texture, gloss and wettability of coatings were characterized by AFM, UV-Vis total reflectance and static water contact angle (WCA) measurements. The resistance of the coatings to solvents was also determined and related to the fraction of unreacted polyhydroxyacid. The occurrence of an oxidative diol cleavage reaction upon preparation in air induced a structural modification of the polyaleuritate layer and conferred upon it thermal stability and resistance to solvents. The promoting effect of the tin oxide layer in such an oxidative cleavage process fosters the potential of this methodology for the design of effective long-chain polyhydroxyester coatings on ETP