Datos históricos relevantes de la División Geología del Museo de La Plata : desde Rodolfo Hauthal hasta Alfredo J. Cuerda

Fil: Cingolani, Carlos Alberto. División Geología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin

La dinámica de la tierra

Fil: Cingolani, Carlos Alberto. División Geología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Ramos, Víctor Alberto. Instituto de Estudios Andino (IDEAN). UB

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

Pre-Carboniferous Tectonic Evolution of the San Rafael Block, Mendoza Province

The pre-Carboniferous evolution of the San Rafael Block is described in different stages. The first one is referred to the Mesoproterozoic basement derived from a complex plutonic and volcanic protolith of Cerro La Ventana Formation. The signature of this basement indicates a common origin with the present eastern part of Laurentia. The carbonate platform of Cuyania terrane has been drifted away during Early Cambrian to Early Ordovician times. The Ordovician silico-carbonate sequences of the San Rafael Block are unconformably deposited over the basement near the present eastern slope of the Cuyania terrane. Detrital zircon ages show a provenance derived from Mesoproterozoic source. The El Nihuil dolerites with a tholeiitic ocean floor signature considered the southern end of the Famatinian ophiolites were interpreted as a Late Ordovician–Early Silurian extensional event. The collision of Cuyania produced a new west polarity subduction and a magmatic arc, represented by the Devonian Rodeo de la Bordalesa tonalite and the granitoids of the “Agua Escondida Mining District”. The Late Silurian–Early Devonian sequences of La Horqueta and Río Seco de los Castaños formations were deformed during the collision and accretion of the Chilenia terrane against the proto-Andean margin, and recorded an east vergent cleavage developed on the previous deformed rocks. This collision produced the strong angular unconformity between the La Horqueta/Río Seco de los Castaños Formations and the El Imperial Formation (Upper Paleozoic). The new subduction with east polarity characterized the beginning of the Gondwanian cycle. The new magmatic arc was interrupted by the intense Lower Permian deformation of the San Rafael tectonic phase.Centro de Investigaciones GeológicasUniversidad de Buenos Aire

Primitive Vascular Plants and Microfossils from the Río Seco de los Castaños Formation, San Rafael Block, Mendoza Province, Argentina

In this contribution we describe fossil plant remains from Río Seco de los Castaños Formation, at San Rafael Block, Mendoza Province, Argentina. The fossil plants comprise non-forked and forked axes without or with delicate lateral expansions, which are assigned to Bowerophylloides cf. mendozaensis and Hostinella sp. We refer them to primitive land plants and discuss about their systematic affiliation. Furthermore, we mention the presence of a diverse acritarch assemblage present in the same lithostratigraphic unit. On the basis of the taxonomical information and stratigraphic correlation, we could infer that Río Seco de los Castaños Formation has an Early Devonian age. The taphonomical conditions of this fossil association would indicate that the plants were transported some distance from their presumed coastal and riverbank habitats. Finally, studying the amount and the percentage of kaolinite within charcoal levels, warm to cool temperate paleoclimatic conditions were deduced.Facultad de Ciencias Naturales y Muse

The Lomagundi-Jatuli carbon isotopic event recorded in the marble of the Tandilia System basement, Río de la Plata Craton, Argentina

The “Lomagundi-Jatuli event” corresponds to the most important δ13C positive anomaly (≥5‰) globally reported in Palaeoproterozoic marine carbonates (between ∼2.30 and 2.06 Ga). In the Tandilia System (Argentina), Río de la Plata Craton, this event was recorded in the basement marble of the San Miguel area. The calcite-diopside marble, hosted by biotite gneiss and intruded by 2.12 Ga garnet-leucogranite, was metamorphosed in amphibolite facies during the Transamazonian Cycle. PAAS-normalised rare-earth elements (REE) and Y for the carbonate rocks are HREE-enriched and display positive Eu and Y anomalies, typical of primary precipitates from a mixed hydrothermal-marine environment carbonate. Additionally, a truly negative Ce anomaly for all the samples indicates that the depositional environment was oxidising. Positive δ13C values ranging from +5.90 to +4.30‰ (V-PDB), and δ18O from +17.45 to +13.84‰ (V-SMOW) were determined in this marble, both gradually decreasing towards the contact with the leucogranites. These values indicate that devolatilization reactions took place during the crystallisation of a wollastonite-vesuvianite-grossular-diopside skarn generated by the leucogranite intrusions into the marble. δ18O values obtained from diopside and calcite crystals, in the marble sectors furthest from the contacts with leucogranite, allowed a 663–623 °C formation temperature to be calculated, considering oxygen in a calcite-diopside geothermometric pair. These temperatures are consistent with the metamorphic degree (amphibolite facies) reached in this portion of the basement. Although the San Miguel marble shows petrographic and mineralogical evidence of regional and contact metamorphism, important geochemical and isotopic characteristics, together with its estimated Palaeoproterozoic age, indicate that the marble protolith was a marine carbonate deposited during the “Lomagundi-Jatuli event”.Fil: Lajoinie, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Recursos Minerales. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Recursos Minerales; ArgentinaFil: Lanfranchini, Mabel Elena. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Recursos Minerales. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Recursos Minerales; ArgentinaFil: Recio, C.. Universidad de Salamanca; EspañaFil: Sial, A.N.. Federal University of Pernambuco; BrasilFil: Cingolani, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. 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: Ballivian Justiniano, Carlos Alberto. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Recursos Minerales. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Recursos Minerales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Etcheverry, Ricardo Oscar. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Recursos Minerales. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Recursos Minerales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentin

Semblanza : Eduardo Jorge Llambías

Fil: Cingolani, Carlos Alberto. División Geología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin