Piedmont deposits as seismic energy dissipators, Sierras Pampeanas of Argentina

This study shows the neotectonic deformation occurred in the southern piedmont of the Cumbres Calchaquíes, in the Amaicha and Tafí valleys. Neotectonic deformation manifests itself through faults, folds and diversions of drainage channels. The Amaicha valley is bounded to the north by the Tafí del Valle fault and to the south by the Los Cardones fault. The Cumbres Calchaquíes ride over the Sierra de Aconquija through the Los Cardones and Carapunco faults. The Carapunco fault also has a synestral component, responsible for generating an imbricated system of contractional fractures. In the study region many earthquakes of ≥ 3 and ≥ 4 magnitude coincide with regional faults evidencing its neotectonic activity. The seismic energy dissipated through materials with less cohesion that form the fill of the valleys, generating discrete fault scarps and strongly folded conglomerate strata. The foothills deposits of the Cumbres Calchaquíes absorbed most of the seismic energy released during the reactivation of the faults. Tectonic activity is deforming 630 a BP deposits in the Cumbres Calchaquíes piedmont.

Assessment of Neotectonic Landscape Deformation in Evia Island, Greece, Using GIS-Based Multi-Criteria Analysis

This study deals with the assessment and mapping of neotectonic landscape deformation in the northern part of the Evia Island (Central Greece). Multi-Criteria Decision Analysis (MCDA) utilizing Analytic Hierarchy Process (AHP) and Weighted Linear Combination (WLC) procedures were conducted for the calculation of the Neotectonic Landscape Deformation Index (NLDI). The study is based on the combination of morphotectonic, geomorphological and geological parameters. The GIS-based spatial MCDA led to the classification of the study area into five classes of neotectonic deformation (from very low to very high) and to a neotectonic deformation map. The results were compared with the outputs of a relative tectonic activity classification approach based on quantitative geomorphic analysis at a regional scale, including site-specific field observations. Areas of high and very high deformation are related to the major active faults of Dirfis, Kandili and Gregolimano–Telethrio. Other minor active normal faults of medium to high seismic risk level, affecting the northern and northeastern parts of the island, are also associated with areas of intense landscape neotectonic deformation.

Neotectonic deformation in the Southwestern Tian Shan, Western China: evidence from paleomagnetic study of Quaternary sediments from the Mingyaole Anticline

<p>This paleomagnetic study is located at the north-west extremity of the Tarim Basin and has aimed to constrain the style of Neotectonic deformation where indentation of the Pamir Orogen into the southward-verging Tian Shan frontal zone has produced a complex zone of thrusting, folding and strike-slip. Sampling focused on two Pliocene to Pleistocene sedimentary formations folded across the Mingyaole Anticline, the major structural feature between the two frontal zones, has yielded well-grouped characteristic remanent magnetizations at 18 of 24 sites and a positive fold test. Together with fabric evidence, the results indicate a probable post-depositional detrital origin for the remanence. The results show that only small inter-locational vertical-axis rotations have occurred within the Kashi-Atushi fold and thrust system since the Miocene and imply that the Kashi depression has behaved as a quasi-rigid block. A common 15-30º counterclockwise (CCW) rotation relative to Eurasia since the Miocene of the Kashi Depression and the bordering Tian Shan range proves to be unrelated to the right lateral motion along the Talas-Ferghana intracontinental transform fault to the north west. This contrast is provisionally interpreted as taking place along a transfer fault between different segments of the thrust belt. Ongoing CCW rotation of the Tarim Basin is interpreted as a regional response to impingement by northward movement of the larger Tibetan Block to the south east.</p>

THE MORPHONEOTECTONIC STRUCTURE OF THE TRANSITIONAL ZONE BETWEEN THE GORTYNIA MT. HORST AND THE PYRGOS-OLYMPIA BASIN (CENTRAL -WESTERN PELOPONNESE, GREECE)

The present paper aims to the understanding of the neotectonic deformation in areas where no post-alpine sediment occurs. The study area is located at the transitional zone between the horst ofGortynia Mt. (Arcadia) and the Pyrgos-Olympia basin in the central-western Péloponnèse and is tectonically and seismically active. The studied neotectonic faults can be distinguished in low to mid angle faults and high angle faults. The majority of them present striation sets with significant horizontal component that causes the change in the direction and plunge of the fold axes of Pindos unit. The younger and with more active characteristics fault zones are the Lefkohori and Ohthia ones