Paleoseismology of the Marquesado-La Rinconada thrust system, Eastern Precordillera of Argentina

Excavated trenches at two sites across the Marquesado–La Rinconada fault system along the eastern Precordilleran front south of San Juan, Argentina, reveal the earthquake history of this rapidly urbanizing region. Interpretation of earthquakes is based on both the generation of colluvial wedges and upward fault terminations, as well as folding events in fine-grained alluvium ponded behind upslope-facing fault scarps. The ages of the past five interpreted earthquakes at the Loma Negra site are E1 at 2.8 ± 2.8 ka, E2 at 7.1 ± 1.5 ka, E3 at 9.6 ± 1.3 ka, E4 at 14.4 ± 2.1 ka, and E5 at 17.2 ± 3.1 ka. At the Jejenes sites, we documented event ages of 2.7 ± 0.1 ka, 3.9 ± 0.6 ka, 5.9 ± 1.3 ka, and 11.4 ± 4 ka. These results indicate that the recurrence interval along the Marquesado–La Rinconada fault zone averages several thousand years. The inferred displacements at the Jejenes site are about 1.1 m for E1, E3, and E4 and 2.1 m for event E2, whereas the displacements at Loma Negra averaged about 1 m, but the most recent event displays less slip. Notably, the older events seem to have been larger and emergent, whereas the youngest event appears to have been smaller and blind in the ponded sediment; this may partially explain the poor expression of classic colluvial wedges associated with some events. Despite the fact that active surface faulting has an uncertain relationship with the primary seismic sources at depth in the crust, past and future events of Mw ∼7.5 are consistent with the length scale of active deformation, the ∼1–2 m slip per event scale of these ruptures, and the size of historical earthquakes

Genome-wide identification and phenotypic characterization of seizure-associated copy number variations in 741,075 individuals

Copy number variants (CNV) are established risk factors for neurodevelopmental disorders with seizures or epilepsy. With the hypothesis that seizure disorders share genetic risk factors, we pooled CNV data from 10,590 individuals with seizure disorders, 16,109 individuals with clinically validated epilepsy, and 492,324 population controls and identified 25 genome-wide significant loci, 22 of which are novel for seizure disorders, such as deletions at 1p36.33, 1q44, 2p21-p16.3, 3q29, 8p23.3-p23.2, 9p24.3, 10q26.3, 15q11.2, 15q12-q13.1, 16p12.2, 17q21.31, duplications at 2q13, 9q34.3, 16p13.3, 17q12, 19p13.3, 20q13.33, and reciprocal CNVs at 16p11.2, and 22q11.21. Using genetic data from additional 248,751 individuals with 23 neuropsychiatric phenotypes, we explored the pleiotropy of these 25 loci. Finally, in a subset of individuals with epilepsy and detailed clinical data available, we performed phenome-wide association analyses between individual CNVs and clinical annotations categorized through the Human Phenotype Ontology (HPO). For six CNVs, we identified 19 significant associations with specific HPO terms and generated, for all CNVs, phenotype signatures across 17 clinical categories relevant for epileptologists. This is the most comprehensive investigation of CNVs in epilepsy and related seizure disorders, with potential implications for clinical practice

GWAS meta-analysis of over 29,000 people with epilepsy identifies 26 risk loci and subtype-specific genetic architecture

Epilepsy is a highly heritable disorder affecting over 50 million people worldwide, of which about one-third are resistant to current treatments. Here we report a multi-ancestry genome-wide association study including 29,944 cases, stratified into three broad categories and seven subtypes of epilepsy, and 52,538 controls. We identify 26 genome-wide significant loci, 19 of which are specific to genetic generalized epilepsy (GGE). We implicate 29 likely causal genes underlying these 26 loci. SNP-based heritability analyses show that common variants explain between 39.6% and 90% of genetic risk for GGE and its subtypes. Subtype analysis revealed markedly different genetic architectures between focal and generalized epilepsies. Gene-set analyses of GGE signals implicate synaptic processes in both excitatory and inhibitory neurons in the brain. Prioritized candidate genes overlap with monogenic epilepsy genes and with targets of current antiseizure medications. Finally, we leverage our results to identify alternate drugs with predicted efficacy if repurposed for epilepsy treatment

Field imaging spectroscopy and inferring a blind thrust earthquake history from secondary faulting : 1944 San Juan Earthquake, Argentina

The studies presented in this dissertation provide new approaches to extract paleo-earthquake information from the geological record. The first chapter describes the development of Field Imaging Spectroscopy, a new methodology for data acquisition and analysis in paleoseismology. The study shows the steps followed from data acquisition, pre-processing, processing and analysis of high spatial and spectral resolution images obtained from cores and a large sample from a fault zone collected at Hog Lake, San Jacinto Fault, Southern California. The study demonstrate that hyperspectral data can be obtained in the field using portable scanners and that high spatial and spectral resolution in the visible to short wave infrared provide a way to enhance subtle or invisible stratigraphic and structural features. The second chapter focuses on the use of neural networks and naïve Bayesian classifiers to automatically classify hyperspectral image data, providing an objective mapping of the structure of cores, samples and field exposures. The results of this study show that a system integrated by a hyperspectral scanner and pattern recognition algorithms can work as an enhanced eye and an objective classifier to provide the geologist with additional information that facilitates the final description, interpretation and correlation of the geology in paleoseismic exposures and cores. The hyperspectral dataset collected together with a spectral library of the materials observed in the excavation provide a new way to archive paleoseismological data for future analysis. Finally, in chapter 3, an innovative approach to study blind thrust faults is presented. The study of the secondary La Laja fault near San Juan, Argentina shows that the earthquake history recorded in a minor fault provides an indirect way to study the occurrence of large M̃7 earthquakes at depth. This investigation also provides the first and perhaps the longest record of the earthquake activity of a blind thrust fault in the world, as well as the most detailed and complete study of past earthquakes in the Argentinean Andes. It also set a good precedent for similar studies in other structures in other regions of the world where the earthquake hazard related to blind thrust faults is largely un-assesse

Provincia del Chubut

Trabajo geológico sobre la región de El Sombrero, dentro de la provincia de Neuquén.Fil: Anselmi, Gabriela. Ministerio de Planificación Federal, Inversión Pública y Servicios. Secretaría de Minería. Servicio Geológico Minero Argentino (SEGEMAR); Argentina.Fil: Panza, José Luis Alberto. Ministerio de Planificación Federal, Inversión Pública y Servicios. Secretaría de Minería. Servicio Geológico Minero Argentino (SEGEMAR); Argentina.Fil: Cortés, José M. Ministerio de Planificación Federal, Inversión Pública y Servicios. Secretaría de Minería. Servicio Geológico Minero Argentino (SEGEMAR); Argentina.Fil: Ragone, Daniel. Ministerio de Planificación Federal, Inversión Pública y Servicios. Secretaría de Minería. Servicio Geológico Minero Argentino (SEGEMAR); Argentina.La Hoja El Sombrero se encuentra ubicada en el centro-sur de la provincia del Chubut, formando parte de la región extraandina mesetiforme de la Patagonia,extendiéndose al sur del río Chubut y al norte del lagoColhué Huapí. Su límite oriental y occidental lo constituyen las inmediaciones de la Gran Laguna Salada y Laguna Colorada (ex-Payahilé) respectivamente.Las mesetas del Canquel, El Zampal - La Media Luna, las sierras Cuadrada, del Guanaco, Mesa-Chaira, Pampa Negra y otras caracterizan el relievemesetiforme de la región, ya que conforman elevadas mesetas basálticas que cubren extensas superficies. Asimismo, las sedimentitas de edad cretácicaintegrantes del Grupo Chubut, que están bien expuestas en todo el ámbito de la Hoja, configuran unpaisaje mesetiforme debido a la presencia de bancos duros subhorizontales que favorecen la formación de planicies estructurales. La región nor-occidental de la comarca, así como las sierras Mora, Mora Chica y Loma Negra, donde aflora el basamento y vulcanitas jurásicas, conforman un relievede serranías bajas.En cuanto a la estratigrafía, las rocas más antiguas de edad proterozoica-paleozoica están representadas por la Formación Puesto La Potranca y el Granito Sierra Mora, constituyendo el basamento migmatítico-plutónico sobre el que durante el Jurásicose desarrollan distintas asociaciones volcano-sedimentarias, que están representadas por los Grupos Oviedo, Lonco Trapial y la Formación Cañadón Asfalto de edad liásica, bathoniana-bajociana ycalloviana-oxfordiana, respectivamente. El primero de ellos está formado principalmente por tobas, sedimentitas y tufitas pertenecientes a la FormaciónPuesto Lizarralde y por ignimbritas ácidas, andesitas, tobas y cenoglomerados de la Formación LosTobianos. Sobre esta última se disponen en discordancia erosiva depósitos volcaniclásticos ysedimentarios correspondientes a la Formación Cerro Carnerero, que junto a la asociación de lavasmesosilícicas y básicas de la Formación Cañadón Puelman suprayacente integran el Grupo LoncoTrapial. Sobre este último se apoya en discordanciaangular la Formación Cañadón Asfalto, dividida endos miembros; el inferior está compuesto porvulcanitas y sedimentitas, sobre el se disponen lassedimentitas epiclásticas, piroclásticas y rocastufíticas lacustres y fluviales del miembro superior. El Granito La Rueda constituye un intrusivo deedad post jurásica media en base a las relaciones estratigráficas que presenta, ya que intruye avulcanitas de la Formación Los Tobianos y muy posiblemente a vulcanitas que pueden ser asignadas al Grupo Lonco Trapial en el sector noroeste de la co-marca.Sobre el substrato jurásico y en discordancia angular afloran las sedimentitas lacustres y rocaspiroclásticas portadoras de flora fósil de la Formación Puesto Mendivé del Neocomiano, las que soncubiertas en concordancia por las extensas acumulaciones de sedimentitas continentales y piroclastitas del Cretácico, pertenecientes al Grupo Chubut.En el Daniano se produce una ingresión marinaque da origen a los depósitos integrantes de la Formación Salamanca, los que son cubiertos por las sedimentitas y tufitas de origen fluvial de la Formación Río Chico, de edad paleocena. Durante el Eoceno se produce un magmatismode tipo alcalino que da lugar a las rocas básicas de la Formación El Canquel, las que cubren y/o intruyenla cobertura cretácica-cenozoica. Esta actividad volcánica durante el Oligoceno es en un principio detipo piroclástico y conforma las capas tobáceas del Grupo Sarmiento, portadoras de una abundante eimportante fauna de mamíferos, y posteriormente detipo lávica, manifestándose por la existencia de losextensos mantos basálticos de la Formación Sierra Cuadrada, de edad oligomiocena, que se disponenen forma pseudohorizontal cubriendo significativasáreas.En el Plioceno superior se desarrollan depósitosde gravas, agrupados en la Formación Montemayor,que se disponen en discordancia sobre el Grupo Sarmiento en el cuadrante sureste de la comarca. Porotra parte, se registra en esta época e inicios del Pleistoceno una manifestación lávica representadapor el Basalto Pampa Negra.El Cuaternario está representado por los importantes depósitos de remoción en masa, consecuencia de los deslizamientos rotacionales producidos enlos bordes de las mesetas basálticas, depósitos decobertura de pedimentos, de bajos, eólicos y en menor proporción aluviales y coluviales.La estructura de la comarca se caracteriza porla existencia de un substrato precretácico, plutónico-migmatítico y volcánico y una cobertura cretácico-cenozoica. El primero se presenta fragmentado endiversos bloques de distintas dimensiones separadospor fallas, comportándose en forma rígida frente alas sucesivas fases diastróficas; estos bloques preservan la cobertura cretácico-terciaria suavementeplegada y/o deformada que refleja pasivamente larotación de los mismos.Entre los recursos minerales de relativo interésse encuentra el yacimiento uranífero Sierra Cuadrada, ubicado en el faldeo septentrional de la sierrahomónima, donde se realizaron en el pasado distintas tareas geológico-mineras que culminaron en elaño 1979. Depósitos bentoníticos alojados en la Formación Salamanca han sido explotados al nordestede las sierras Overas Chicas (cantera Carina) y surde la sierra Cuadrada (Sierra Cuadrada)

Earthquake recurrence and rupture dynamics of Himalayan Frontal Thrust, India

The Black Mango fault is a structural discontinuity that transforms motion between two segments of the active Himalayan Frontal Thrust (HFT) in northwestern India. The Black Mango fault displays evidence of two large surface rupture earthquakes during the past 650 years, subsequent to 1294 A.D. and 1423 A.D., and possibly another rupture at about 260 A.D. Displacement during the last two earthquakes was at minimum 4.6 meters and 2.4 to 4.0 meters, respectively, and possibly larger for the 260 A.D. event. Abandoned terraces of the adjacent Markanda River record uplift due to slip on the underlying HFT of 4.8±0.9 millimeters per year or greater since the mid-Holocene. The uplift rate is equivalent to rates of fault slip and crustal shortening of 9.6−3.5+7.0 millimeters per year and 8.4−3.6+7.3 millimeters per year, respectively, when it is assumed that the HFT dips 30° ± 10°

Palaeoseismology of the North Anatolian Fault near the Marmara Sea: implications for fault segmentation and seismic hazard

We conducted palaeoseismic studies along the North Anatolian fault both east and west of the Marmara Sea to evaluate its recent surface rupture history in relation to the well-documented historical record of earthquakes in the region, and to assess the hazard of this major fault to the city of Istanbul, one of the largest cities in the Middle East. Across the 1912 rupture of the Ganos strand of the North Anatolian fault west of the Marmara Sea, we excavated 26 trenches to resolve slip and constrain the earthquake history on a channel–fan complex that crosses the fault at a high angle. A distinctive, well-sorted fine sand channel that served as a marker unit was exposed in 21 trenches totaling over 300 m in length. Isopach mapping shows that the sand is channelized north of the fault, and flowed as an overflow fan complex across a broad fault scarp to the south. Realignment of the feeder channel thalweg to the fan apex required about 9±1 m of reconstruction. Study of the rupture history in several exposures demonstrates that this displacement occurred as two large events. Analysis of radiocarbon dates places the age of the sand channel as post ad 1655, so we attribute the two surface ruptures to the large regional earthquakes of 1766 and 1912. If each was similar in size, then about 4–5 m of slip can be attributed to each event, consistent with that reported for 1912 farther east. We also found evidence for two additional surface ruptures after about ad 900, which probably correspond to the large regional earthquakes of 1063 and 1344 (or 1354). These observations suggest fairly periodic occurrence of large earthquakes (RI=c. 283±113 years) for the past millennium, and a rate of c. 16 mm/a if all events experienced similar slip. We excavated six trenches at two sites along the 1999 Izmit rupture to study the past earthquake history along that segment of the North Anatolian fault. One site, located in the township of Köseköy east of Izmit, revealed evidence for three surface ruptures (including 1999) during the past 400 years. The other trench was sited in an Ottoman canal that was excavated (but never completed) in 1591. There is evidence for three large surface rupturing events in the upper 2 m of alluvial fill within the canal at that site, located only a few kilometres from the Köseköy site. One of the past events is almost certainly the large earthquake of 1719, for which historical descriptions of damage are nearly identical to that of 1999. Other earthquakes that could plausibly be attributed to the other recognized rupture of the Izmit segment are the 1754, 1878 or 1894 events, all of which produced damage in the region and for which the source faults are poorly known. Our palaeoseismic observations suggest that the Izmit segment of the North Anatolia fault ruptures every one and a half centuries or so, consistent with the historical record for the region, although the time between ruptures may be as short as 35 years if 1754 broke the Izmit segment. Release of about 4 m of seismic slip both west and east of the Marmara Sea this past century (1912, 1999) support the contention that Istanbul is at high risk from a pending large earthquake. In that historical records suggest that the last large central Marmara Sea event occurred in 1766, there may be a similar 4 m of accumulated strain across the Marmara basin segment of the North Anatolian fault

DataSheet1_Paleoseismology of the Marquesado-La Rinconada thrust system, Eastern Precordillera of Argentina.PDF

Excavated trenches at two sites across the Marquesado–La Rinconada fault system along the eastern Precordilleran front south of San Juan, Argentina, reveal the earthquake history of this rapidly urbanizing region. Interpretation of earthquakes is based on both the generation of colluvial wedges and upward fault terminations, as well as folding events in fine-grained alluvium ponded behind upslope-facing fault scarps. The ages of the past five interpreted earthquakes at the Loma Negra site are E1 at 2.8 ± 2.8 ka, E2 at 7.1 ± 1.5 ka, E3 at 9.6 ± 1.3 ka, E4 at 14.4 ± 2.1 ka, and E5 at 17.2 ± 3.1 ka. At the Jejenes sites, we documented event ages of 2.7 ± 0.1 ka, 3.9 ± 0.6 ka, 5.9 ± 1.3 ka, and 11.4 ± 4 ka. These results indicate that the recurrence interval along the Marquesado–La Rinconada fault zone averages several thousand years. The inferred displacements at the Jejenes site are about 1.1 m for E1, E3, and E4 and 2.1 m for event E2, whereas the displacements at Loma Negra averaged about 1 m, but the most recent event displays less slip. Notably, the older events seem to have been larger and emergent, whereas the youngest event appears to have been smaller and blind in the ponded sediment; this may partially explain the poor expression of classic colluvial wedges associated with some events. Despite the fact that active surface faulting has an uncertain relationship with the primary seismic sources at depth in the crust, past and future events of Mw ∼7.5 are consistent with the length scale of active deformation, the ∼1–2 m slip per event scale of these ruptures, and the size of historical earthquakes.</p

The upgraded TOMAS device : a toroidal plasma facility for wall conditioning, plasma production, and plasma–surface interaction studies

The Toroidal Magnetized System device has been significantly upgraded to enable development of various wall conditioning techniques, including methods based on ion and electron cyclotron (IC/EC) range of frequency plasmas, and to complement plasma-wall interaction research in tokamaks and stellarators. The toroidal magnetic field generated by 16 coils can reach its maximum of 125 mT on the toroidal axis. The EC system is operated at 2.45 GHz with up to 6 kW forward power. The IC system can couple up to 6 kW in the frequency range of 10 MHz-50 MHz. The direct current glow discharge system is based on a graphite anode with a maximum voltage of 1.5 kV and a current of 6 A. A load-lock system with a vertical manipulator allows exposure of material samples. A number of diagnostics have been installed: single- and triple-pin Langmuir probes for radial plasma profiles, a time-of-flight neutral particle analyzer capable of detecting neutrals in the energy range of 10 eV-1000 eV, and a quadrupole mass spectrometer and video systems for plasma imaging. The majority of systems and diagnostics are controlled by the Siemens SIMATIC S7 system, which also provides safety interlocks