排序方式： 共有7条查询结果，搜索用时 0 毫秒
1
1.
Marco Benvenuti Marco Bonini Giovanna Moratti Marianna Ricci Chiara Tanini 《Geomorphology》2008,100(3-4):269-284
Integration of geomorphology, stratigraphy, sedimentology and morphotectonics in the analysis of the lower Cecina River reach, coastal Tuscany, reveals an undocumented historical channel avulsion. Geomorphological evidence and radiocarbon dating support that, from the Last Glacial Maximum until the end of the 16th century, the Cecina River flowed north of the present course and formed a well-developed cuspate delta. Two concurrent factors, active tectonics as a preparing factor and discharge regime as an activation factor, are thus inferred to have favored the avulsion of Cecina River. Fragmentary archaeological and historical records indicate that the late Holocene Cecina River plain was virtually unpopulated until the latest 16th century. This seems the main reason why high-magnitude hydrological events and prominent river channel avulsions were not reported in historical chronicles. From this perspective, geomorphological data may provide important knowledge and understanding of recent dynamics of environmental change when historical record is lacking or missing. 相似文献
2.
This volume builds on presentations made at two thematic sessions on “The Active Tectonics of the Circum-Adriatic Region” at the EGU 2007 and 2008 General Assemblies in Vienna. In both sessions, contributions were invited from workers incorporating structural, geophysical, seismological, remote sensing, geodetic and thermochronological methods to better understand the crustal evolution and ongoing development of one of Europe's most interesting tectonic regions. The Adriatic region occupies a central position within the geodynamic framework of the Central Mediterranean. It is surrounded by actively deforming belts of diverse character including transpressional, contractional, strike-slip and extensional domains, collectively defining the structurally complex and kinematically varied boundaries of the Adria plate. Because many countries occupy the circum-Adriatic region, international collaborative research into the tectonic activity and associated natural hazards of the region is relevant and important to European society. In this context, the papers presented in this volume provide important new data that bear on various aspects of the active tectonics of the circum-Adriatic region. These contributions typically draw on multidisciplinary structural, geophysical and geochronological datasets to draw new conclusions concerning the spatial and temporal evolution of Adria's bounding deformation zones, especially the southeastern and southern Italian regions and NE Adriatic region. In this overview, we provide a state-of-the-art summary of different aspects of present-day Adria geodynamics to provide a common background for the individual contributions that follow. 相似文献
3.
Marco Bonini Chiara Tanini Giovanna Moratti Luigi Piccardi Federico Sani 《第四纪科学杂志》2003,18(8):695-708
This paper examines the morphotectonic and structural–geological characteristics of the Quaternary Martana Fault in the Umbria–Marche Apennines fold‐and‐thrust belt. This structure is more than 30 km long and comprises two segments: a N–NNW‐trending longer segment and a 100°N‐trending segment. After developing as a normal fault in Early Pleistocene times, the N–NNW Martana Fault segment experienced a phase of dextral faulting extending from the Early to Middle Pleistocene boundary until around 0.39 Ma, the absolute age of volcanics erupted in correspondence to releasing bends. The establishment of a stress field with a NE–ENE‐trending σ3 axis and NW–NNW σ1 axis in Late Pleistocene to Holocene times resulted in a strong component of sinistral faulting along N–NNW‐trending fault segments and almost pure normal faulting on newly formed NW–SE faults. Fresh fault scarps, the interaction of faulting with drainage systems and displacement of alluvial fan apexes provide evidence of the ongoing activity of this fault. The active left‐lateral kinematic along N–NNW‐trending fault segments is also revealed by the 1.8 m horizontal offset of the E–W‐trending Decumanus road, at the Roman town of Carsulae. We interpret the present‐day kinematics of the Martana Fault as consistent with a model connecting surface structures to the inferred north‐northwest trending lithospheric shear zone marking the western boundary of the Adria Plate. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
4.
Moratti G. Benvenuti M. Santo A. P. Laurenzi M. A. Braschi E. Tommasini S. 《International Journal of Earth Sciences》2018,107(7):2491-2515
International Journal of Earth Sciences - This study is based upon a stratigraphic and structural revision of a Middle Jurassic–Upper Cretaceous mostly continental succession exposed between... 相似文献
5.
Apatite fission-track (AFT) data have been obtained along a traverse across the Marrakech High Atlas to constrain its tectono-thermal evolution. AFT ages vary between 212 ± 15 Ma and 20 ± 4 Ma. An Early Miocene AFT age accompanied by long mean track length from the central part of the chain has been interpreted as the timing of the main inversion of this region with the creation of relief because of the shortening induced by the interplay between the African and Eurasian plates. Thermal modelling of samples collected south of the South Atlas Fault Zone indicates a Middle-Late Miocene or even later cooling that has been attributed to the component of the uplift of the chain related to the thermal anomaly present beneath the Atlas Mountains. 相似文献
6.
Marco Bonini Federico Sani Giovanna Moratti Marco G. Benvenuti 《Journal of Geodynamics》2011,51(2-3):125-140
We examine the structural characteristics and the tectonic evolution of some key areas along the thrust front of the Lucania sector of the Southern Apennines, which also represents the southwestern boundary of the Adria Plate. The results of our study have allowed the identification of a complex tectonic history manifested by the presence of structural elements compatible with different stress fields. Particularly, during the Pleistocene the area experienced a transition from a compressional setting, characterised by NE-ENE shortening, to a post-Middle Pleistocene strike-slip/extensional phase controlled by NE-ENE-directed lateral extension associated with a horizontal NW-NNW-trending σ1 axis. Roughly coaxial transitional stress fields apparently accompanied the progression between these two main regimes. This major change in tectonic setting can be framed into the fragmentation processes of the Adriatic Plate. We propose that the Mid-Adriatic Ridge, a WNW-ESE-trending belt of inverted Mesozoic grabens underwater the Adriatic Sea, has increasingly accommodated the NNW-directed Africa-Adria convergence giving the way to the Africa shortening to propagate into the Lucania Apennines. Furthermore, the comparison with GPS data suggests the existence of an important deep-seated tectonic boundary beneath the Apennines. This element is expected to focus seismicity and may represent an important discontinuity fragmenting Adria. 相似文献
7.
This paper presents a geological–structural study of some Neogene hinterland basins of the Northern Apennines, located on the Tyrrhenian side of the chain. These basins developed on the already delineated thrust-fold belt from middle–late Tortonian times. Their evolution has been commonly referred to an extensional tectonic regime, related to the opening of the Tyrrhenian Sea. New data have allowed us to hypothesize a different tectonic evolution for the chain, where compressive tectonics plays a major role both in the external and in the hinterland area. In this frame, the hinterland area located west of a major outcropping crustal thrust (Mid-Tuscany Metamorphic Ridge) has been the target of a geological–structural investigation. The field mapping and structural analysis has been focused on the syntectonic sediments of the Radicondoli–Volterra basin as well as on adjoining minor basins. These basins commonly display a synclinal structure and are generally located in between basement culminations, probably corresponding to thrust anticlines. Sediments of the hinterland basins have been affected by compressive deformation and regional unconformities separate stratigraphic units due to the activity of basement thrusts. In the study area, normal faulting either accommodates the thrusting processes or post-dates compressive deformation. A chronology of faulting and a six-stage evolution of this area are presented, providing further insights for the Neogene tectonic evolution of the Northern Apennines. Copyright © 1998 John Wiley & Sons, Ltd. 相似文献
1