A proposed analysis of Shuttle Imaging Radar-B (SIR-B) data extends current research in the Sierras Pampeanas and the Puna of northwestern Argentina to the determination - by the digital analysis of mountain-front sinuousity - of the relative age and amount of fault movement along mountain fronts of the late-Cenozoic Sierras ...

... the San Luis Basin ( = Bolsón de las Salinas Basin; Flores, 1969), which is located at the southwest margin of the geologic province of Sierras Pampeanas in northwest San Luis Province, Argentina. The outc...

Whole-rock geochemical analyses using major and trace elements in combination with the Sm�Nd and Pb�Pb isotope systems, together with SHRIMP age dating on metasedimentary rocks from the Sierras de Chepes, the Sierras de C�rdoba, the Sierra Norte and the San Luis Formation in the Sierra de San Luis, have been ...

In the 30� 36�S section of the Andean Cordillera the pre-Andean basement is composed by metamorphic, igneous, and sedimentary rocks of Precambrian, Paleozoic and Lower Triassic ages. They crop out in the morphostructural units named from east to west: Sierras Pampeanas, Precordillera, Cordillera Frontal and Bloque de San Rafael in Argentina, and ...

... de las Sierras Pampeanas. In Debates actuales en Arqueolog�a y Etnohistoria, E. Olmedo and F. Ribero, eds. ... las V y VI Jornadas de Investigadores en Arqueolog�a y Etnohistoria del Centro-Oeste del Pai...

Towards unravelling the geodynamic setting of the northern Sierras Pampeanas (NW Argentina) we describe the tectono-metamorphic and geochronologic evolution of sub-greenschist to granulite facies metamorphic sediments, granitoid plutons, and pegmatites in the Ordovician Sierra de Quilmes metamorphic complex. The protoliths of the ...

The Sierra de San Luis forms the southern tip of the Eastern Sierras Pampeanas in central Argentina. Two narrow belts of low-grade phyllites and quartz arenites, i.e. the San Luis Formation, have accommodated part of the strain-related differential exhumation of the medium- to high-grade metamorphic domains that constitute to the ...

Aquifer-bearing intermontane sedimentary basins of the Sierras Pampeanas in the northwest of Argentina are in general very deep and narrow and contain economically important deposits of Tertiary sediments. This paper presents the results of a study to characterize the sedimentary basin bounded to the west by Sierra de Famatina and to ...

The 1977 Caucete (San Juan) earthquake considered in the present paper occurred near the Sierra Pie de Palo in the Sierras Pampeanas tectonic province of western Argentina. In the study reported, coseismic surface deformation is combined with seismic observations (main shock and aftershocks, both teleseismic and local data) to place ...

Deformation in the overriding plate above areas of shallow subduction extends well away from the plate margin. In the case of the Sierras Pampeanas in central Argentina, the pattern of deformation is the culmination of stresses originating from the shallowly subducting Nazca plate and rheological variations of South American lithosphere. The boundaries of ...

Stream waters draining granitic terrains from the highest part (850 to 2200 m a.s.l.) of Sierras Pampeanas (C�rdoba, Argentina, �32�S, �65�W) were sampled in order to define sources and distribution of dissolved rare earth elements (REE), and to describe the geochemical processes that govern their mobility. The contribution of the regional ...

The Sierra de C�rdoba in the eastern Sierras Pampeanas of north-central Argentina are the easternmost extent of crustal derformation in response to modern flat-slab subduction. We are combining geophysical evidence of the geometry and rate of active deformation on range-bounding faults with geological data on fault exposures and ...

The Eastern Sierras Pampeanas were structured by three main events: the Ediacaran to early Cambrian (580�510 Ma) Pampean, the late Cambrian�Ordovician (500�440 Ma) Famatinian and the Devonian-Carboniferous (400�350 Ma) Achalian orogenies. Geochronological and Sm�Nd isotopic evidence combined with petrological and structural features allow to ...

The South American Cordillera formed by the subduction of the Nazca plate beneath South America. While this is often considered a �typical� compressive upper plate subduction zone, there are several along-strike variations in both the nature of subduction and the style of deformation. From 30� to 32� S the Nazca plate flattens out at 100 km depth for ~300 km before resuming a steeper angle ...

The Sierras Pampeanas in central and north-western Argentina constitute a distinct morphotectonic feature between 27�S and 33�S. The last stage of uplift and deformation in this area are interpreted to be closely related to the Andean flat-slab subduction of the Nazca plate beneath the South American plate. K�Ar fault gouge dating and low-temperature ...

Crustal seismicity in the Andes backarc region between 28�S and 36�S is responsible for the largest damaging earthquakes in the Argentinean history. These events are related to the thin-skinned Precordillera fold and thrust belt, and the thick-skinned Sierras Pampeanas basement cored uplifts and their interaction. We have determined source parameters ...

Local network data from San Juan, Argentina, provides new information about crustal seismicity in the Andean foreland above a horizontal segment of the subducted Nazca Plate. Two areas of foreland seismicity are found, one associated with the Sierras Pampeanas basement uplifts, and the other beneath, but not within, the Precordillera foreland fold-thrust ...

Effluents from uranium milling in the Achala region in the province of Cordoba are studied. Liquids from lixiviation-recovery and from precipitation-washing of yellow-cake were analyzed. Separation of both liquids before treatment and disposal is recommen...

The central-eastern part of the Sierra de Velasco (Sierras Pampeanas, NW Argentina) is formed by the large Huaco (40 � 30 km) and Sanagasta (25 � 15 km) granite massifs and the small La Chinchilla stock (2 � 2 km). The larger granites intrude into Ordovician metagranitoids and crosscut Devonian (?) mylonitic shear zones, whereas ...

Magnetostratigraphic and paleomagnetic studies on early Andean synorogenic strata (Del Crest�n Fm.), in the Famatina Belt (28.7�S, 67.5�W) clarify details of chronology that permit calculation of sedimentation rates within the broken foreland of west Argentina. The Del Crest�n Fm represents the first record of broken foreland sedimentation within the southern Central Andean belt and the ...

The western margin of the South American continent between 30�and 32� S is characterized by the flat slab subduction of the ~43 Ma oceanic Nazca plate beneath the continental South American plate. Several arrays of broadband seismic instruments have been deployed in Chile and western Argentina to study this phenomenon (e.g., CHARGE, 2000-2002; SIEMBRA, 2007-2009; ESP, 2008-2010). The low angle ...

The South American subduction zone has extreme examples of active flat-slab subduction and is believed to be an analog for subduction that occurred during the Cretaceous-Eocene age ("Laramide") mountain building events in the Western U.S. This region is therefore ideal for gaining a better understanding of shallow slab subduction and its influences on deformation of the surrounding mantle and ...

Giant Quaternary landslide deposits occur along mountain fronts in the structural transition zone between the high-angle reverse-fault-bounded Sierras Pampeanas and the low-angle thrust belt of the Sierras Subandinas. There are two modes of occurrence: (1) chaotic masses without distinct geometry, and (2) masses with distinct lobate ...

The La Costa pluton in the Sierra de Velasco (NW Argentina) consists of S-type granitoids that can be grouped into three igneous facies: the alkali-rich Santa Cruz facies (SCF, SiO2 ~67 wt%) distinguished by the presence of andalusite and Na- and Li-rich cordierite (Na2O = 1.55-1.77 wt% and Li2O = 0.14-0.66 wt%), the Anillaco facies (SiO2 ~74 wt%) with a significant proportion ...

The crystalline basement of the Sierra de San Luis, which belongs to the Eastern Sierras Pampeanas in central Argentina, consists of three main units: (1) Conlara, (2) Pringles, and (3) Nogol� metamorphic complexes. In the Pringles Metamorphic Complex, mafic ultramafic bodies occur as discontinuous lenses along a narrow central belt ...

The Sierras Pampeanas (Pampean Ranges) of Argentina are characterized by mountain blocks bounded by reverse faults, whose last stage of uplift has been attributed to the shallowing of the Nazca plate (< 11Ma). These faulted blocks constitute a prominent surface feature of the Pampean flat-slab in the Central Andes (27�-33�S), as well as a modern ...

In northwestern Argentina the transition zone between the Puna and the Sierras Pampeanas was deformed in Late Miocene and Pliocene time. Structural observations suggest that local clockwise block rotations might be observed associated with dextral transpression. This study contributes new paleomagnetic results from four sites in Cretaceous rocks and 19 ...

Crustal seismicity in the Andean backarc between 30�S and 33�S is responsible for the largest damaging earthquakes in Argentina. This region is characterized by the presence of a northeast elongated flat subduction of the Nazca plate at about 100-km depth, a shut off of the volcanic arc and the basement cored uplifts of the Sierras Pampeanas. The ...

On the southern margin of the Puna Plateau, active normal and strike-slip faults accommodate N-S extension, overprinting earlier NW-SE and NE-SW shortening. These relationships, noted elsewhere by other researchers, can be seen north of the Fiambala Basin at the intersection of the plateau, the Cordillera Principal and the northwestern Sierras Pampeanas ...

Between 30� S and 33� S the Nazca plate subducts nearly horizontally for ~300 km beneath the South American plate at a depth of ~100 km before resuming a more normal subduction angle of ~30� near 67� W. The flat portion of the slab follows the trend of the Juan Fernandez Ridge (JFR), an east-west chain of seamounts that may be responsible for the increased buoyancy of this part of the ...

...passionvine mealybug, melon thrips, the rust fungus Puccinia pampeana, Andean...passionvine mealybug, melon thrips, the rust fungus Puccinia pampeana, Andean potato...passionvine mealybug, melon thrips, the rust fungus Puccinia pampeana, Andean...

The application of the SHRIMP U/Pb dating technique to zircon and monazite of different rock types of the Sierras de C�rdoba provides an important insight into the metamorphic history of the basement domains. Additional constraints on the Pampean metamorphic episode were gained by Pb/Pb stepwise leaching (PbSL) experiments on two titanite and garnet separates. Results ...

Within the southern part of the Sierra Pampeanas (the Sierra de San Luis, Argentina), a series of extensive intrusive bodies are regarded to post-date the Famatinian cycle but were emplaced during the Achalian, a period of heterogeneous deformation along crustal scale fault zones. The largest of those is the Las Chacras-Potrerillos ...

The most common light and heavy minerals in quartz-rich sandstones are quartz and zircon, respectively. Many studies aiming to trace the source areas of sedimentary rocks concentrate solely on U-Pb dating of zircon. We will demonstrate the provenance-discriminatory potential of combining cathodoluminescence (CL) colour wavelength spectra of detrital quartz with the morphology and in situ U-Pb ages ...

... In Mamül Mapu: Pasado y presente desde la arqueología pampeana. Berón, M., L. Luna, M. Bonomo, C. ... ...

the national forests of the Sierra Nevada in California, and for a study of ... This publication is a digital version of the set of reports titled Sierra ...

... Title : Evaluation of the Sierra Engineering Company Lightweight Helmet. ... Corporate Author : SIERRA ENGINEERING CO SIERRA MADRE CA. ...

Local network data from San Juan, Argentina, provides new information about crustal seismicity in the Andean foreland above a horizontal segment of the subducted Nazca plate. The authors find two areas of foreland seismicity, one associated with the Sierras Pampeanas basement uplifts, and the other beneath, but not within, the Precordillera foreland ...

We present laser-ablation microprobe inductively coupled mass spectrometry analyses of Y, Yb, Er, Dy, and Gd in garnet crystals from high-grade metamorphic and migmatitic rocks from the Sierras Pampeanas of Argentina. These rocks contain large garnet porphyroblasts (?4 mm) that are compositionally zoned. Rare earth element concentrations in the rims are ...

Development of a paired fold thrust-thrust belt/foreland basin is correlated to the flattening of the subducting Nazca plate between 28-33{degree}S. Magnetostratigraphic studies in neogene basin-filling continental strata determine local basin subsidence rates and provide relatively precise chronostratigraphic correlation between different depositional environments. The data demonstrate that most ...

The tectonics of central Chile and Argentina have been greatly affected by the shallow dips of the subducting Nazca plate, which controlled patterns of magmatism and deformation nearly 1000 km away from the plate boundary. We calculate receiver functions from data recorded by the CHARGE array, which transected the Andes and Sierras Pampeanas in central ...

This dissertation explores the uses far data collected at broadband seismic stations to investigate upper mantle structures. In the Barents Sea region, we use seismic waveform modeling on data collected from arrays in Norway and Finland to investigate the nature of the Hales discontinuity in this area. We find that the unusually high velocities required by the move-out of the diffracted first ...

The evolution of the provenance areas for Late Neoproterozoic, Cambrian and Early Ordovician sedimentary and meta-sedimentary rocks of north central and northwest Argentina is discussed using 123 maximum ages of detrital zircons from 42 samples from this and previously published studies. Most detrital zircon ages fall into two groups: 1,200�900 Ma and 670�545 Ma. These ages are essentially ...

Regional P- and S-wave travel-time data were jointly inverted with teleseismic P-wave residuals to obtain 3-D seismic tomography models for Vp, Vs, and Vp/Vs above the subducting slab in central Chile and Argentina. Additional constraints on the velocity model are provided by Pn and Sn apparent phase velocity data. In this region, there is an abrupt change from a normal subduction geometry south ...

A compositional study of sandstones belonging to the lower section of the Paganzo Group (Middle Carboniferous Early Permian) in the Paganzo Basin (northwestern Argentina) helps unravel the stratigraphic and paleogeographic evolution of the basin. Three morphotectonic units constitute the complex basement of the basin: (1) to the east, the igneous metamorphic basement of the ...

The Andean orogenic front between 31� S and 33� S marks the transition between west-vergent thick- skinned faulting in the Sierras Pampeanas, and east vergent thin-skinned faulting in the Precordillera. This area has experienced several devastating earthquakes in the last century, and geodetic studies indicate that this area has a long-term shortening ...

Title: SIERRA LEONE/FREETOWN,SIERRA LEONE R. Description: SIERRA LEONE/FREETOWN, SIERRA LEONE R. STS054-81-12 SIERRA LEONE/FREETOWN,SIERRA LEONE R. ...