This paper discusses the morphological and geological evidence for Pleistocene neotectonic faulting and uplift in the northeastern part of the Sowie Mountains where the Sudetic Marginal Fault has its maximum deplacement and uplift rates. Although
the greatest uplift was during the Neogene tectonic phases, Pleistocene fault activity was significant and influenced the development of river valleys and foreland alluvial fans. This contradicts with former views.
Baja California Sur ; Fault ; Marine quaternary ; Marine terrace ; Mexico ; Plate tectonics ; Sea level ; Seismic hazard ; Vertical movement
Quaternary faulting and coastal uplift characterize the rifted margin of Baja California near Loreto. This study seeks to document the rate of uplift of the Loreto basin and the history of Quaternary faulting on the Loreto fault. To determine
the rate of uplift, the AA. examine the coastal uplift of the Loreto basin indicated by the altitudinal distribution of marine terraces. Evidence of Quaternary movement on the Loreto fault consists of morphologically young fault scarps and surfaces
such as fluvial terraces that are displaced by recurrent faulting.
Development of offset channels across the San Andreas fault
California ; Channel geometry ; Fault ; Fluvial capture ; Longitudinal section ; Stream ; Strike-slip fault ; Tectonics ; United States of America
The San Andreas fault offsets some small gullies incising the relatively flat surfaces in the Carrizo Plain, California. This study analyzes the field-measured planform geometry and longitudinal profiles of some channels offset by the San Andreas
fault as a trial to define the manner of response or adjustment of streams to strike-slip fault displacement.
A deep-sea hydrothermal site on a strike-slip fault
Faille ; Fond sous-marin ; Géographie physique ; Hydrothermal ; Marge continentale ; Pacifique Est ; Pacifique, îles ; San Clemente fault zone ; Source thermale ; Volcanisme
Submersible exploration of a young scarp in the San Clemente fault zone, at 1,800m in the California Borderland, discovered tall piles of hydrothermal barite and dense colonies of large benthic animals. Phenomena along this active strike-slip fault
Indicators of faulting events and periods of quiescence in desert alluvial fans
Alluvial cone ; Arid area ; Desert ; Fault ; Israel ; Negev ; Reg ; Structural stability ; Tectonics
The main objective of this paper is to present an integrated approach to the study of faulting stages in coarse alluvial deposits. The study site is the alluvial fan of Nahal Shehoret, presently under an extremely arid regime. The exposure of fault
scarps on the fan surfaces enables the identification of several geomorphic indicators employed in analysing and separating faulting events and periods of quiescence: the nature of fault scarp topography; soil catenary development on fault scarps; buried
paleosols in alluvial deposits; colluvial bodies; rotated clasts along fault planes.
The aim of this study is the definition of the geometry and structural style of the extensional fault system involved during the L’Aquila 2009 seismic sequence. The surface tectonic setting of the late Quaternary faults in the epicentral areas (i.e
., the Paganica, Mt. Gorzano and Montereale faults in northwestern Abruzzo) was defined by integrating data from the literature with original field work. Consistent geometric and kinematic correlations between the geological and seismological data were observed
. The seismic sequence reactivated 4 well-distinguished fault sources differing in geometry, size and the degree of involvement. The L’Aquila 2009 seismic sequence did not reactivate the entire surface of the involved faults. Nevertheless, on the basis of other
geological and seismological constraints, the overall fault extent is schematically reconstructed and parameterised. Some considerations related to the structural style of the intra-Apennine Quaternary extensional structures and their patterns at depth
Asymmetrical valleys created by the geomorphic response of rivers to strike-slip fault
China ; Earth surface processes ; Fault ; Fluvial erosion ; Huang He ; Mountain ; Stream ; Strike-slip fault ; Tibet ; Valley
The larger rivers with higher erosional rates may widen their valleys asymmetrically downstream of strike-slip faults, rather than being beheaded or deflected. Examples are described from the Yellow River near the NE margin of the Tibetan Plateau
. River beheading and asymmetrical widening are 2 end-members of a fluvial valley's response to strike-slip faulting, whereas deflection is a combination of both. Recognition of the formation of such asymmetrical valleys related to strike-slip faulting
will help to understand fault activity better over longer time spans and enable a re-evaluation of many fault histories worldwide.
A partir du Paléocène inférieur et jusqu'à l'Oligocène inférieur, le mouvement transformant continent-continent, qui se produit entre l'ouest du Spitsberg et le nord-ouest du Groenland, s'effectue en régime de transpression de direction NNE-SSO. Une
Reappraisal of existing data and evidence derived from new geological investigations illustrates the often complex association between fault geometry and seismic activity that characterise five seismically active areas of mainland Greece
seismotectonic setting in which E-W trending active fault zones accommodate N-S extension.
Active faulting and neotectonic deformation on the eastern flank of Mount Etna, Sicily
Neotectonics and active faulting
Fault ; Global tectonics ; Italy ; Neotectonics ; Sicilia ; Structural geomorphology ; Volcano
The AA. present new structural and morphotectonic evidence regarding the kinematics and rates of fault movement along the Timpe fault zone as well as new data on the broader pattern of Holocene crustal motions in the Etna region in an attempt
The AA. present the results obtained by using two distinct approches to the characterization of the seimic potential of the Irpinia and Messina faults. These two earthquakes highlight the importance of considering a broader range of geological
indicators than surface faulting and obvious geomorphological evidence for locating and characterizing a seismogenic structure.
Analysis of fault block movement by the 1995 Kobe earthquake
Earthquake ; Fault ; Honshu ; Japan ; Marine terrace ; Seismicity ; Strike-slip fault ; Tectonics ; Vertical movement
Horizontal ground displacement associated with the 1995 Kobe earthquake reflects the developmental process of a block mountain under tectonic E-W compression. The focal mechanism of the earthquake is of the strike-slip type. Surface faults specify
the block boundaries. Comparison of the tilting obtained from levelling of benchmarks with the dated marine terraces on one fault block yields a recurrence period of the earthquake of approximately 500 years. The result is in harmony with historical records
Quantitative topographic method of fault morphology recognition
Crimea ; Fault ; Lineament ; Methodology ; Model ; Numerical model ; Topography ; Ukraine
A quantitative method for morphology recognition of topographically expressed faults is developed. The method is based on the analysis of digital elevation models (DEMs). Kh mapping correspond mostly to structures like strike-slip faults, while
lineaments revealed by Kv mapping indicate mainly structures as dip-slip faults and thrusts. Some aspects of the method precision, requirements for initial data and further development of the method are discussed.
The AA. carried out mineralogical and micromorphological approaches for a deformed weathering profile and associated fault gouge to find recurrence characteristics from a microcopic point of view and report here a more complex cataclastic history
Neotectonics and Quaternary geology of the Hunter Mountain fault zone and Saline Valley region, southeastern California
Aerial photography ; California ; Earthquake ; Fault ; Geomorphological mapping ; Geomorphology ; Landslide ; Neotectonics ; Quaternary ; Regional geology ; United States of America
The AA. present surficial geologic maps of 5 sections along the Hunter Mountain fault zone. The map observations are then used to place loose bounds on the paleoearthquake history and fault slip rate in late Quaternary time, as well as the role
the fault zone plays in the accomodation of slip through the southern Walker Lane.
Flume experiments, in which the middle section of an erosion channel is displaced horizontally, have been conducted to assess the response of streams to horizontal displacement by a strike-slip fault. The experimental erosion channel was developed
in a mixture of sand and clay, at the Hydro-Geomorphology Laboratory, Tokyo Metropolitan University, Japan. Downstream degradation and upstream aggradation as a response to horizontal displacement by a strike-slip fault cause local convexity in the longitudinal
The relationship between pluvial fan and terrace morphology and differential tectonic movement along the North Qinling fault zone, Shaanxi Province, China
The North Qinling fault zone is the southern boundary of the Weihe basin. The fault zone may be divided into 3 segments by the analysis of the pluvial fans and river terraces developed along the North Qinling piedmont. The inset and buried types
of pluvial fans along the fault zone show that the activities are quite different in different segments of the fault. The characteristics of the vertical fault movement agree well with the results obtained from the analysis of the river terraces : the Qinling
Soil catenas to estimate ages of movements on normal fault scarps, with an example from the Wasatch fault zone, Utah, USA
Catena ; Dating ; Earthquake ; Fault ; Fault scarp ; Geochronology ; Palaeogeography ; Pedogenesis ; Semi-arid area ; Soil ; Stratigraphy ; United States of America ; Utah
Trenches excavated across fault scarps on a 13 ka delta surface at Brigham City, Utah, document 4 types of soil-catena phenomena. 2 soil catenas were used to evaluate the applicability of a continuity approach to paleoearthquake dating, by which
percentages of total development time represented by each soil at a fault scarp footslope could be estimated.