TRANSTENSIVE ORIGIN OF THE ENCADENADAS-VALLIMANCA CORRIDOR (BUENOS AIRES, ARGENTINA): A REVISION AND A NEW PROPOSAL FROM SATELLITE IMAGES: Origem transtensiva do Corredor Encadenadas-Vallimanca (Buenos Aires, Argentina): uma revisão e uma nova proposta a partir de imagens de satélite

The Encadenadas-Vallimanca Corridor (EVC) corresponds to a morphostructural linear feature defining the northern boundary of the Sierra de la Ventana and Tandil hills in the Buenos Aires province. The scarcity of concluding geological studies has resulted in diverse tectonic and hydrographic interpretations regarding the genesis of the corridor. A new analysis of surface morphology, mainly derived from satellite imagery, led to the identification of a series of gentle and elongated en échelon left-stepping relief features or ridges with cross-sectional asymmetric flanks, having an average length of 20 km and oriented sub-latitudinally at 20° to the ENE strike of the corridor. The arrangement of these ridges reminds a tectonic scenario of right-lateral transcurrent faulting, for which, the limiting parallel faults fulfill the function of synthetic Riedel type shear. Besides, the cross-sectional asymmetry of the ridges suggests extensional normal faulting coherent with a transtensional right-lateral flower structure. Shallow seismicity of Mw 4.0 registered by the year 2016 in the proximities of the lineament could suggest recent fault activity. Also, previous gravity potential field mapping in the area seems to highlight basement anomalies underneath the sedimentary cover, coinciding with the main lineament of the Corridor. Based on all this information, the EVC is considered to be the surface expression of dextral transtensional fault activity.El Corredor Encadenadas-Vallimanca (EVC) corresponde a una característica lineal morfoestructural que define el límite norte de la Sierra de la Ventana y las colinas de Tandil en la provincia de Buenos Aires. La escasez de concluir estudios geológicos ha dado lugar a diversas interpretaciones tectónicas e hidrográficas con respecto a la génesis del corredor. Un nuevo análisis de la morfología de la superficie, derivado principalmente de imágenes satelitales, condujo a la identificación de una serie de características o crestas de relieve escalonadas suaves y alargadas en escalón con flancos asimétricos de sección transversal, que tienen una longitud promedio de 20 km y orientación sub -latitudinalmente a 20 ° a la huelga ENE del corredor. La disposición de estas crestas recuerda un escenario tectónico de fallas transcurrentes en el lado derecho, para las cuales las fallas paralelas limitantes cumplen la función de corte sintético tipo Riedel. Además, la asimetría de la sección transversal de las crestas sugiere fallas extensionales normales coherentes con una estructura floral transtensional lateral derecha. La sismicidad superficial de Mw 4.0 registrada para el año 2016 en las proximidades del lineamiento podría sugerir actividad de falla reciente. Además, el mapeo de campo potencial de gravedad anterior en el área parece resaltar las anomalías del sótano debajo de la cubierta sedimentaria, coincidiendo con el lineamiento principal del Corredor. En base a toda esta información, el EVC se considera la expresión superficial de la actividad de falla transtensional dextral.O corredor Encadenadas-Vallimanca (EVC) corresponde a uma característica linear morfoestrutural que define o limite norte das montanhas Sierra de la Ventana e Tandil, na província de Buenos Aires. A escassez de concluir estudos geológicos resultou em diversas interpretações tectônicas e hidrográficas sobre a gênese do corredor. Uma nova análise da morfologia da superfície, derivada principalmente de imagens de satélite, levou à identificação de uma série de características ou sulcos suaves e alongados de relevo em échelon, com flancos assimétricos de seção transversal, com um comprimento médio de 20 km e submarinos orientados -latitudinalmente a 20 ° em relação à batida ENE do corredor. O arranjo dessas cordilheiras lembra um cenário tectônico de falha por corrente contínua lateral direita, para a qual as falhas paralelas limitantes cumprem a função de cisalhamento sintético do tipo Riedel. Além disso, a assimetria de seção transversal das cristas sugere falha normal extensional coerente com uma estrutura de flor lateral direita e transtensional. A sismicidade rasa de Mw 4.0 registrada até o ano de 2016 nas proximidades do lineament pode sugerir atividade recente de falha. Além disso, o mapeamento de campo potencial potencial gravitacional anterior na área parece destacar anomalias no subsolo sob a cobertura sedimentar, coincidindo com o principal lineamento do corredor. Com base em todas essas informações, o EVC é considerado a expressão superficial da atividade de falha transtensional dextral

TRAMPAS NO CONVENCIONALES ASOCIADAS CON OFIOLITAS DE LA FAJA SEPTENTRIONAL DE HIDROCARBUROS (LA HABANA-MATANZAS, CUBA)

The geological characteristics of the Cuban territory are the result of a multi-episodic tectosedimentary history, represented by a series of sequences and structures closely related to the evolution of the Western Caribbean. Mafic and ultramafic rocks, mainly serpentinized peridotites, gabbros and basalts, are distributed throughout the northern margin of Cuba (~ 200 km of exposure) and are mostly associated with ophiolitic complexes linked to the evolution of the Carribean plate. The northern hydrocarbon belt comprises oceanic volcano-sedimentary sequences forming a stack of thrust sheets (ophiolites-Mesozoic sedimentary carbonates); such configuration is the responsible for the reservoir and seal conditions of the many hydrocarbon fields in the area. Oil accumulations occur mainly at depths around 500 to 800 m, locally up to 3,000 m, with oil-saturated thicknesses up to 400 m and 9º to 19º API. Reservoirs are mainly fractured serpentinites, with mean log porosity values of ~ 6% (and up to 8% SWC) with permeabilities varying between 0.001 to 21.4 mD. Porous to dual porous-fractured reservoirs occur in other fields as tectonic slabs of cataclastic serpentinites, peridotites, gabbros and diabases, with porosities < 3% (in log) and up to 9% (SWC) and permeabilities ranging between 0.001 - 290 mD (7,400 mD average). The highest porosities in the area are recorded in fractured and weathered peridotites and grabbros, with log-derived porosity values up to 11% (4% average) and sidewall core up to 8%. Good quality seals are locally formed by the weathering of serpentinites. New concepts in oil exploration involve the analysis of ophiolitic complexes and related rocks in the Pacific margin as potential promising targets. Thus, the resemblance of these Cuban ophiolitic complexes with their under-explored South American analogs opens a new opportunity for hydrocarbon exploration in the offshore of Colombia, Peru and Chile.Las rocas máfico-ultramáficas son muy abundantes en Cuba a lo largo de unos 200 km del margen septentrional que deben su origen a una corteza oceánica, compuesta por serpentinitas, gabros, diabasas y basaltos conocidos como complejo ofiolítico. Las características geológicas del territorio cubano son el resultado de una historia tectosedimentaria multiepisódica, representada por una serie de secuencias y estructuras relacionadas estrechamente con la evolución del Caribe Occidental. En la Faja Septentrional de Hidrocarburos de Cuba, las ofiolitas intercaladas como escamas tectónicas entre niveles carbonáticos mesozoicos proporcionan en muchos campos buenas condiciones de reservorios y sellos. Las acumulaciones petroleras se encuentran generalmente entre 500 – 800 m y hasta 3 km de profundidad con espesores de hasta 400 m saturados de petróleos con 9º a 19º API. Los reservorios son serpentinitas fracturadas, con valores promedio de porosidad en testigo de 5,6%, mientras que por perfilajes alcanza 8,0%, aunque los valores promedios sólo llegan a 1,1% y las permeabilidades varían entre 0,001 a 21,4 mD. Otros campos se relacionan con escamas tectónicas de cataclasitas de serpentinitas, peridotitas, gabros y diabasas, determinantes de un reservorio de tipo poroso o poroso-fracturado con porosidad en testigos entre 0,2 – 3,3% y por registros hasta 9,0 %, la permeabilidad se reconoce entre 0,001 - 290 mD (como promedio 7,370 mD). También, peridotitas, gabros y diabasas con reservorios de tipo fracturado poroso–fracturado por lixiviación del olivino en gabros olivínicos con porosidades por núcleo de 0,12 – 10,6% (promedio 3,63%) y por registros hasta 8,0%. Niveles de serpentinitas alteradas por hidratación con propiedades semejantes a las arcillas constituyen sellos locales. Estos yacimientos pueden considerarse modelos análogos a los aun no completamente explorados de los márgenes Pacíficos del continente sudamericano de Colombia, Perú y Chile que exhiben contextos convergentes con presencia de ofiolitas semejantes

El potencial gasífero de la Formación Zapallal en el área Curumuy y la interferencia de un pozo hidrogeológico (cuenca Sechura, Perú)

The drilling of the Alejandrina hydrogeological well at 209 m bbp, below the usual depth of water wells in the area, reached a sandy level of the Zapallal Formation with unexpected gas content that caused strong blow-up, venting, liquefaction of the ground, collapse of the drilling equipment and contamination of the traditionally producing levels of the confined aquifer. To mitigate this invasion of gas and it upwelling to the surface, the following wells were drilled: i) Papayal interference well, to carry out capture and cementing maneuvers with 5 horizontal attempts until intercepting the Alejandrina well, and ii) Curumuy 1X exploratory well to reduce the pressure of the gas invasion and discover its possible abnormal origins at such shallow depths. The objective of the work is to present the stratigraphy of this potentially exploratory sector with proved gas resources of the Sechura basin and to describe the sequence of events of the interference in the management and relationships between the hydrogeological and gas resources that share the same sandstone reservoirs of the Zapallal Formation. For this, petrophysical data are provided from the drilling records of the Alejandrina, Papayal and Curumuy 1X wells and a simulated model of loading and handling of the gas responsible for the contamination. In this way, a case of interference of different subsoil objectives is presented with the intention of preserving and reestablishing the behavior of the producing wells of the aquifer and at the same time producing gas.La perforación del pozo hidrogeológico Alejandrina a los 209 m bbp, muy por debajo de la profundidad habitual de los pozos de agua de la zona, alcanzó un nivel areniscoso de la Formación Zapallal con contenido gasífero inesperado que determinó un fuerte venteo, licuefacción de la plataforma de perforación, colapso del equipo de perforación y la contaminación de los niveles tradicionalmente productores del acuífero confinado. Para mitigar esta invasión de gas y surgencia a superficie, se perforaron los pozos: i) de alivio Papayal, para efectuar maniobras de captura y cementación donde se requirieron 5 intentos de perforación direccional hasta interceptar el pozo Alejandrina y ii) exploratorio Curumuy 1X para disminuir la presión de la invasión de gas y conocer sus posibles orígenes anormales a esas profundidades tan someras. El objetivo del trabajo es informar la estratigrafía de este sector potencialmente exploratorio con probada presencia de recursos de gas de la cuenca Sechura y describir la secuencia de acontecimientos de la interferencia en el manejo y producción entre los recursos hidrogeológicos y gasíferos que comparten los mismos reservorios areniscosos de la Formación Zapallal. Para ello, se aportan datos petrofísicos a partir de los registros de perforación de los pozos Alejandrina, Papayal y Curumuy 1X y un modelo simulado de carga y manejo del gas responsable de la contaminación. De esta manera, se presenta un caso de interferencia de objetivos del subsuelo con la intención de preservar y restablecer el comportamiento de los pozos productores del acuífero y a la vez producir gas

Hydrocarbons and petroleum geology of Tierra del Fuego, Argentina

The history of the hydrocarbon exploration and present production, as well as a compilation of their main tectosedimentary features in the Argentine territory of Tierra del Fuego Island are summarized in this paper. The exploration and production of hydrocarbons in the studied region is mostly restricted to both onshore and offshore portions of the Austral-Magellan Basin. Their infil is constituted by a Late Cretaceous to Tertiary sedimentary and volcanoclastic 8,000 m thick succession deposited on a folded and eroded basement cropping out along the northern foothill of the Fueguian Andes. The main productive levels are sandy layers of the Springhill Fm and Tobífera Fm in the eroded basement highs. Also, levels of the Tertiary sequences are currently under evaluation adding an exploratory potential ranging from conventional plays related to transpression and inversion structure to new scenarios based upon tectosedimentary concepts

Amphilimus- vs. zotarolimus-eluting stents in patients with diabetes mellitus and coronary artery disease: the SUGAR trial

Aim: Patients with diabetes mellitus are at high risk of adverse events after percutaneous revascularization, with no differences in outcomes between most contemporary drug-eluting stents. The Cre8 EVO stent releases a formulation of sirolimus with an amphiphilic carrier from laser-dug wells, and has shown clinical benefits in diabetes. We aimed to compare Cre8 EVO stents to Resolute Onyx stents (a contemporary polymer-based zotarolimus-eluting stent) in patients with diabetes. Methods and results: We did an investigator-initiated, randomized, controlled, assessor-blinded trial at 23 sites in Spain. Eligible patients had diabetes and required percutaneous coronary intervention. A total of 1175 patients were randomly assigned (1:1) to receive Cre8 EVO or Resolute Onyx stents. The primary endpoint was target-lesion failure, defined as a composite of cardiac death, target-vessel myocardial infarction, and clinically indicated target-lesion revascularization at 1-year follow-up. The trial had a non-inferiority design with a 4% margin for the primary endpoint. A superiority analysis was planned if non-inferiority was confirmed. There were 106 primary events, 42 (7.2%) in the Cre8 EVO group and 64 (10.9%) in the Resolute Onyx group [hazard ratio (HR) 0.65, 95% confidence interval (CI) 0.44 to 0.96; pnon-inferiority <0.001; psuperiority = 0.030]. Among the secondary endpoints, Cre8 EVO stents had significantly lower rate than Resolute Onyx stents of target-vessel failure (7.5% vs 11.1%, HR 0.67, 95% CI 0.46 to 0.99; p = 0.042). Probable or definite stent thrombosis and all-cause death were not significantly different between groups. Conclusions: In patients with diabetes, Cre8 EVO stents were non-inferior to Resolute Onyx stents with regard to target-lesion failure composite outcome. An exploratory analysis for superiority at 1 year suggests that the Cre8 EVO stents might be superior to Resolute Onyx stents with regard to the same outcome

Amphilimus- vs. zotarolimus-eluting stents in patients with diabetes mellitus and coronary artery disease: the SUGAR trial.

AIM: Patients with diabetes mellitus are at high risk of adverse events after percutaneous revascularization, with no differences in outcomes between most contemporary drug-eluting stents. The Cre8 EVO stent releases a formulation of sirolimus with an amphiphilic carrier from laser-dug wells, and has shown clinical benefits in diabetes. We aimed to compare Cre8 EVO stents to Resolute Onyx stents (a contemporary polymer-based zotarolimus-eluting stent) in patients with diabetes. METHODS AND RESULTS: We did an investigator-initiated, randomized, controlled, assessor-blinded trial at 23 sites in Spain. Eligible patients had diabetes and required percutaneous coronary intervention. A total of 1175 patients were randomly assigned (1:1) to receive Cre8 EVO or Resolute Onyx stents. The primary endpoint was target-lesion failure, defined as a composite of cardiac death, target-vessel myocardial infarction, and clinically indicated target-lesion revascularization at 1-year follow-up. The trial had a non-inferiority design with a 4% margin for the primary endpoint. A superiority analysis was planned if non-inferiority was confirmed. There were 106 primary events, 42 (7.2%) in the Cre8 EVO group and 64 (10.9%) in the Resolute Onyx group [hazard ratio (HR): 0.65, 95% confidence interval (CI): 0.44-0.96; Pnon-inferiority < 0.001; Psuperiority = 0.030]. Among the secondary endpoints, Cre8 EVO stents had significantly lower rate than Resolute Onyx stents of target-vessel failure (7.5% vs. 11.1%, HR: 0.67, 95% CI: 0.46-0.99; P = 0.042). Probable or definite stent thrombosis and all-cause death were not significantly different between groups. CONCLUSION: In patients with diabetes, Cre8 EVO stents were non-inferior to Resolute Onyx stents with regard to target-lesion failure composite outcome. An exploratory analysis for superiority at 1 year suggests that the Cre8 EVO stents might be superior to Resolute Onyx stents with regard to the same outcome. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov: NCT03321032

Tectonic and paleoenvironmental significance of the Paleogene coal seams of Estancia La Correntina, Fuegian Andes

Se describen afloramientos de sedimentitas continentales con restos carbonosos localizados sobre el Río San Pablo en la Estancia La Correntina, provincia de Tierra del Fuego (54° 33´ 01" S, 64° 00´ 20" W). La asociación palinológica recuperada es comparable con la descripta para la Formación Sloggett y se refiere al Eoceno tardío - Oligoceno temprano. La palinoflora está dominada por Podocarpaceae y Fagaceae con pteridofitas subordinadas e indicaría un ambiente de sedimentación húmedo, probable­mente lacustre o pantanoso, con alta disponibilidad de agua, desarrollado bajo un clima templado. La correlación de estas sedimentitas con las de Bahía Sloggett permite avalar la existencia en la Cordillera Fueguina de un corredor de rumbo NNW-SSE desarrollado sobre las unidades pre - paleógenas, que habría controlado el emplazamiento de los depocentros continentales durante el Eoceno/ Oligoceno.The continental sedimentary coaly outcrop of Estancia La Correntina, San Pablo River (54° 33' 01" S, 64° 00' 20" W), is described. The palynological assemblage compare closely with the similar one described from the Sloggett Formation, and is referred to the late Eocene-early Oligocene. Podocarpaceae and Fagaceae are the most abundant forms. Pteridophyta are subordinate. The palynological assemblage would probably reflect a lacustrine or swampy environment, with regular levels of moisture and a temperate climate. Correlations between Estancia La Correntina and Bahía Sloggett outcrops support a NNW trending tectonic corridor, developed on pre-Paleogene units that controlled the deposition of continental sequences during the Eocene/ Oligocene in the Fueguian Cordillera.Fil: Rossello, Eduardo Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Ottone, Eduardo Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Haring, C. E.. Repsol-YPF; ArgentinaFil: Nevistic, V. A.. Repsol-YPF; Argentin

The 4300-Yr 14C Age of Glyptodonts at Luján River (Mercedes, Buenos Aires, Argentina) and Comments on 'Did the Megafauna Range to 4300 BP in South America' by Cione et al.

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