Uplift and active tectonics of southern Albania inferred from incision of alluvial terraces

2009 ◽  
Vol 71 (3) ◽  
pp. 465-476 ◽  
Author(s):  
J. Carcaillet ◽  
J.L. Mugnier ◽  
R. Koçi ◽  
F. Jouanne
Keyword(s):  
Active Faults ◽  
Active Tectonics ◽  
Slip Rate ◽  
Age Dating ◽  
Normal Faults ◽  
Published Data ◽  
Fluvial Terraces ◽  
Thrust System ◽  
Alluvial Terraces

AbstractIn Albania, the Osum and Vjoje rivers cross the active graben system and the active frontal thrust system of the Albanides. The effects of climatic and geodynamic forcing on the development of these two rivers were investigated by the means of field mapping, topographic surveying and absolute exposure-age dating. We established the chronology of terraces abandonment from the compilation of new dating (14C and in situ produced 10Be) and previously published data. We identified nine fluvial terraces units developed since Marine Isotope Stage 6 up to historic times. From this reconstituted history, we quantified the vertical uplift on a time scale shorter than the glacial climatic cycle. Regional bulging produces an overall increase of the incision rate from the west to the east that reaches a maximum value of 2.8 m/ka in the hinterland. Local pulses of incision are generated by activation of normal faults. The most active faults have a SW–NE trend and a vertical slip rate ranging from 1.8 to 2.2 m/ka. This study outlines the geodynamic control in the development of rivers flowing through the Albanides on the scale of 103–105ka.

A Case Study Using 10Be-26Al Exposure Dating at the Xi’an AMS Center

Radiocarbon ◽  
2016 ◽  
Vol 58 (1) ◽  
pp. 193-203 ◽  
Author(s):  
Li Zhang ◽  
Zhenkun Wu ◽  
Hong Chang ◽  
Ming Li ◽  
Guocheng Dong ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Luminescence Dating ◽  
Age Dating ◽  
Published Data ◽  
Exposure Dating ◽  
Fluvial Terraces ◽  
Exposure Age ◽  
Close Relationship ◽  
Dating Method

ABSTRACTExposure age dating using in situ10Be and 26Al is a very useful technique for dating fluvial terraces. This is especially true in semiarid regions where other methods suffer from a paucity of suitable dating materials. This article describes sample preparation procedures and analytical benchmarks established at the Xi’an Accelerator Mass Spectrometry (AMS) Center for the study of in situ10Be and 26Al. Four intercomparison samples were analyzed in the study, using an improved sample preparation method. The exposure age results are shown to be in good agreement with published data, and demonstrate the reliability of the dating method. This article also presents new 10Be and 26Al results from quartz samples collected from a series of fluvial terraces from Guanshan River, along the Qilian Shan, northeastern Tibetan Plateau. The ages of three fluvial terraces from the Jinfosi site are shown to be (56.4±5.3) ka for T3, (10.7±1.0) ka for T2, and (7.2±1.0) ka for T1. The dating results are consistent with published data from the same region (10Be, 14C, and optically stimulated luminescence dating methods). A comparison of high-resolution climate records with age constraints for the terrace formation shows a close relationship between terrace formation and climate change.

scholarly journals Temporal and spatial earthquake clustering revealed through comparison of millennial strain-rates from 36Cl cosmogenic exposure dating and decadal GPS strain-rate

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Francesco Iezzi ◽  
Gerald Roberts ◽  
Joanna Faure Walker ◽  
Ioannis Papanikolaou ◽  
Athanassios Ganas ◽  
...  
Keyword(s):  
Seismic Hazard ◽  
Strain Rate ◽  
Active Faults ◽  
Slip Rate ◽  
Normal Faults ◽  
Fault Activity ◽  
Exposure Dating ◽  
Extensional Strain ◽  
Temporal And Spatial

AbstractTo assess whether continental extension and seismic hazard are spatially-localized on single faults or spread over wide regions containing multiple active faults, we investigated temporal and spatial slip-rate variability over many millennia using in-situ 36Cl cosmogenic exposure dating for active normal faults near Athens, Greece. We study a ~ NNE-SSW transect, sub-parallel to the extensional strain direction, constrained by two permanent GPS stations located at each end of the transect and arranged normal to the fault strikes. We sampled 3 of the 7 seven normal faults that exist between the GPS sites for 36Cl analyses. Results from Bayesian inference of the measured 36Cl data implies that some faults slip relatively-rapidly for a few millennia accompanied by relative quiescence on faults across strike, defining out-of-phase fault activity. Assuming that the decadal strain-rate derived from GPS applies over many millennia, slip on a single fault can accommodate ~ 30–75% of the regional strain-rate for a few millennia. Our results imply that only a fraction of the total number of Holocene active faults slip over timescales of a few millennia, so continental deformation and seismic hazard are localized on specific faults and over a length-scale shorter than the spacing of the present GPS network over this time-scale. Thus, (1) the identification of clustered fault activity is vital for probabilistic seismic hazard assessments, and (2) a combination of dense geodetic observations and palaeoseismology is needed to identify the precise location and width of actively deforming zones over specific time periods.

scholarly journals Methodology for Earthquake Rupture Rate estimates of fault networks: example for the Western Corinth Rift, Greece

2017 ◽  
Author(s):  
Thomas Chartier ◽  
Oona Scotti ◽  
Hélène Lyon-Caen ◽  
Aurélien Boiselet
Keyword(s):  
Active Faults ◽  
Slip Rate ◽  
Seismic Hazard Assessment ◽  
System Level ◽  
Fault System ◽  
Normal Faults ◽  
Accurate Estimation ◽  
Probabilistic Seismic Hazard Assessment ◽  
Earthquake Rupture ◽  
Multiple Faults

Abstract. Modelling the seismic potential of active faults is a fundamental step of probabilistic seismic hazard assessment (PSHA). An accurate estimation of the rate of earthquakes on the faults is necessary in order to obtain the probability of exceedance of a given ground motion. Most PSHA studies consider faults as independent structures and neglect the possibility of multiple faults or fault segments rupturing simultaneously (Fault to Fault -FtF- ruptures). The latest Californian model (UCERF-3) takes into account this possibility by considering a system level approach rather than an individual fault level approach using the geological , seismological and geodetical information to invert the earthquake rates. In many places of the world seismological and geodetical information long fault networks are often not well constrained. There is therefore a need to propose a methodology relying only on geological information to compute earthquake rate of the faults in the network. In this methodology, similarly to UCERF-3, a simple distance criteria is used to define FtF ruptures and consider single faults or FtF ruptures as an aleatory uncertainty. Rates of earthquakes on faults are then computed following two constraints: the magnitude frequency distribution (MFD) of earthquakes in the fault system as a whole must follow an imposed shape and the rate of earthquakes on each fault is determined by the specific slip-rate of each segment depending on the possible FtF ruptures. The modelled earthquake rates are then confronted to the available independent data (geodetical, seismological and paleoseismological data) in order to weigh different hypothesis explored in a logic tree. The methodology is tested on the Western Corinth Rift, Greece (WCR) where recent advancements have been made in the understanding of the geological slip rates of the complex network of normal faults which are accommodating the ~15 mm/yr North-South extension. Modelling results show that geological, seismological extension rates and paleoseismological rates of earthquakes cannot be reconciled with only single fault rupture scenarios and require hypothesising a large spectrum of possible FtF rupture sets. Furthermore, in order to fit the imposed regional Gutenberg-Richter MFD target, some of the slip along certain faults needs to be accommodated either with interseismic creep or as post-seismic processes. Furthermore, individual fault’s MFDs differ depending on the position of each fault in the system and the possible FtF ruptures associated with the fault. Finally, a comparison of modelled earthquake rupture rates with those deduced from the regional and local earthquake catalogue statistics and local paleosismological data indicates a better fit with the FtF rupture set constructed with a distance criteria based on a 5 km rather than 3 km, suggesting, a high connectivity of faults in the WCR fault system.

Across-strike variations of fault slip-rates constrained using in-situ cosmogenic 36Cl concentrations.

2020 ◽  
Author(s):  
Francesco Iezzi ◽  
Gerald Roberts ◽  
Joanna Faure Walker ◽  
Ioannis Papanikolaou ◽  
Athanassios Ganas ◽  
...  
Keyword(s):  
Seismic Hazard ◽  
Strain Rate ◽  
Active Faults ◽  
Slip Rate ◽  
High Temporal Resolution ◽  
Strain Rates ◽  
Time Intervals ◽  
The Holocene ◽  
Regional Strain

<p>It is important to constrain the spatial distribution of strain-rate in deforming continental material because this underpins calculations of continental rheology and seismic hazard. To do so, it is becoming increasingly common to use combinations of GPS and historical and instrumental seismicity data to constrain regional strain-rate fields. However, GPS geodetic sites, whether permanent or campaign stations, tend to be widely-spaced relative to the spacing of active faults with known Holocene offsets. At the same time, the interpretation of seismicity data can be difficult due to lack of historical seismicity in cases where local fault recurrence intervals are longer than the historical record. This causes uncertainty on how regional strain-rates are partitioned in time and space, and hence with uncertainty regarding calculations of continental rheology and seismic hazard. To overcome this issue, we have gained high temporal resolution slip-rate histories for three parallel faults using in situ <sup>36</sup>Cl cosmogenic dating of the exposure of three parallel normal fault planes that have been progressively exhumed by earthquakes. We study the region around Athens, central Greece, where there also exists a relatively-dense GPS network and extensive records of instrumental and historical earthquakes. This allows to compare regional, decadal strain-rates measured with GPS geodesy with strain-rates across the faults implied by slip since ~40,000 years BP. We show that faults have all had episodic behaviour during the Holocene, with alternating earthquake clusters and periods of quiescence through time. Despite the fact that all three faults have been active in the Holocene, each fault slips in discrete time intervals lasting a few millennia, so that only one fault accommodates strain at any time. We show that magnitudes of strain-rates during the high slip-rate episodes are comparable with the regional strain-rates measured with GPS (fault strain-rates are 50-100% of the value of GPS regional strain-rate). Thus, if the GPS-derived strain-rate applies over longer time intervals, it appears that single faults dominate the strain-accumulation at any given time, with crustal deformation and seismic hazard localised within a distributed network of faults.</p><p> </p>

scholarly journals Discrete changes in fault free-face roughness: constraining past earthquakes characteristics

2020 ◽  
Author(s):  
Olaf Zielke ◽  
Lucilla Benedetti ◽  
P. Martin Mai ◽  
Magali Rizza ◽  
Jules Fleury ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Active Tectonics ◽  
Slip Rate ◽  
Fault Scarp ◽  
Rock Properties ◽  
Normal Faults ◽  
Earthquake Recurrence ◽  
Face Surface ◽  
Free Face ◽  
Face Morphology

<p>A driving motivator in many active tectonics studies is to learn more about the recurrence large and potentially destructive earthquakes, providing the means to assess the respective fault’s future seismic behavior. Doing so requires long records of earthquake recurrence. The lack of sufficiently long instrumental seismic records (that would be best suited for this task) has led to the development of other approaches that may constrain the recurrence of surface rupturing earthquakes along individual faults. These approaches take different forms, depending on the specific tectonic and geographic conditions of an investigated region.</p><p>For example, around the Mediterranean Sea, we frequently find bedrock scarps along normal faults. Assuming that bedrock (i.e., fault free-face) exposure is caused by the occurrence of sub-sequent large earthquakes, we may measure certain rock properties to constrain the time and size of past earthquakes as well as the fault’s geologic slip-rate. A now-classic example in this regard is the measurement of <sup>36</sup>Cl concentrations along exposed fault scarps in limestones.</p><p>For the presented study, we looked at another property of the exposed fault free-face, namely its morphologic roughness. We aim to identify whether fault free-face roughness contains information to constrain earthquake occurrence and fault slip-rates following the assumption that  sub-sequent exposure to the elements and sub-areal erosional conditions may leave a signal in how rough (or smooth) the fault free-face is (assuming a somewhat uniform pre-exposure roughness). Here, we present observations of fault free-face surface roughness for the Mt. Vettore fault (last ruptured in 2016) and the Rocca Preturo fault (The underlying models of fault free-face morphology were generated using the Structure-from-Motion approach and a large suite of unregistered optical images.). Employing different metrics to quantify morphologic roughness, we were indeed able to observe a) an increase in surface roughness with fault scarp height (i.e., longer exposure to sub-areal erosion causes higher roughness), and b) distinct (rather than gradual) changes in surface roughness, suggesting a correlation to individual exposure events such as earthquakes. Hence, fault free-face morphology of bedrock faults may serve as an additional metric to reconstruct earthquake recurrence patterns.</p>

Tectonic and Climatic Inferences from the Terrace Staircase in the Meduna Valley, Eastern Southern Alps, NE Italy

2015 ◽  
Vol 83 (1) ◽  
pp. 229-242 ◽  
Author(s):  
Giovanni Monegato ◽  
Maria Eliana Poli
Keyword(s):  
Middle Miocene ◽  
Slip Rate ◽  
Southern Alps ◽  
Structural Element ◽  
Fluvial Terraces ◽  
Ne Italy ◽  
Thrust Front ◽  
Fold And Thrust Belt ◽  
Thrust System ◽  
Depositional Units

AbstractResults of stratigraphic and morphotectonic analyses on fluvial terraces at the outlet of the Meduna valley in the eastern Southern Alps are used to investigate on the tectonics and paleoclimate. The Meduna valley, prone to destructive earthquakes, belongs to the front of the eastern Southern Alps, a south-verging fold and thrust belt in evolution from the Middle Miocene to the present, constructed by ENE–WSW striking, SSE-verging medium to low-angle thrusts, gradually propagating in the Venetian–Friulian plain. In the study area, located south of the Periadriatic thrust, the main structural element is the ENE–WSW striking Maniago–M. Jouf thrust system. Seven depositional units, ranging in age from Pliocene to Holocene, and a hierarchy of four numbered terrace complexes were identified. Stratigraphic and geometric relationships between sedimentary units, basal surfaces and terraces allow the reconstruction of the chronology of the depositional events. The study shows that the valley configuration has been shaped during the Pliocene–Quaternary with long-lasting steady intervals, interspaced with periodic tectonic pulses of the thrust front of the eastern Southern Alps. The most recent pulse related to the Maniago thrust shows an upper Pleistocene–Holocene slip rate of about 0.6 mm/yr.

scholarly journals Potentially active normal faulting zone identified in the eastern margin of Palu City, Central Sulawesi, Indonesia

2021 ◽  
Vol 873 (1) ◽  
pp. 012071
Author(s):  
Anggraini Rizkita Puji ◽  
Mudrik Rahmawan Daryono ◽  
Danny Hilman Natawidjaja
Keyword(s):  
Active Faults ◽  
Digital Terrain Model ◽  
Slip Rate ◽  
Normal Fault ◽  
Provincial Government ◽  
Economic Losses ◽  
Normal Faults ◽  
Normal Faulting ◽  
Eastern Margin ◽  
Central Sulawesi

Abstract The 2018 Mw 7.5 earthquake in Palu, Central Sulawesi, resulting in ~2,000 fatalities and estimated economic losses of ~22.8 trillion Indonesian Rupiah, according to the report of BAPPENAS and Central Sulawesi Provincial-Government. Therefore, it is necessary to prevent similar disaster in the future by further detailed studies of any other potential sources that are capable of generating such hazards. Palu City is in the vast depression valley bordered by mountains in its eastern and western margins. The 2018 earthquake source is the Palukoro Fault, which runs through the western margin of onshore Palu Valley then continued under the bay. Along the eastern margin of the valley, we also identified a wide zone of many potentially active faults strands orienting N-S and NW-SE, showing predominantly normal faulting. These faults are observed from their normal fault scarps as inspected from Light Detection and Ranging Digital Terrain Model (LiDAR DTM) data with 90-cm resolution and field ground checks. The faults deformed the old terrace sediments (Late Pleistocene, ~125 kya), but it is unclear whether they also cut the Holocene young alluvial like the ruptured fault of 2018 event. Further paleoseismology investigation is then necessary to obtain further information about these potentially-active normal faults, including their slip-rate and the past ruptures.

scholarly journals Hillslope denudation and morphologic response across a rock uplift gradient

2019 ◽  
Author(s):  
Vincent Godard ◽  
Jean-Claude Hippolyte ◽  
Edward Cushing ◽  
Nicolas Espurt ◽  
Jules Fleury ◽  
...  
Keyword(s):  
High Resolution ◽  
Strong Dependence ◽  
Active Faults ◽  
Digital Terrain Model ◽  
Slip Rate ◽  
Joint Analysis ◽  
Deformation Model ◽  
Denudation Rates ◽  
Blind Thrust ◽  
Thrust System

Abstract. Documenting the spatial variability of tectonic processes from topography is routinely undertaken through the analysis of river profiles, as a direct relationship between fluvial gradient and rock uplift has been identified by incision models. Similarly, theoretical formulations of hillslope profiles predict a strong dependence on uplift rates. However, the reduced sensitivity of near-threshold hillslopes and the limited availability of high resolution topographic data, has often been a major limitation for their use to investigate tectonic gradients. Here we combined high resolution analysis of hillslope morphology and cosmogenic nuclides derived denudation rates to unravel the distribution of rock uplift across a blind thrust system at the Southwestern Alpine front in France. Our study is located in the Valensole Mio-Pliocene molassic basin, where a series of fold and thrust has deformed a plateau surface. We focused on a series of catchments aligned perpendicular to the main structures. Using a 1-m LiDAR Digital Terrain Model, we extracted hillslopes topographic properties such as hilltop curvature CHT or non-dimensional erosion rates E*. We observed a systematic variation of these metrics coincident with the location of a major underlying thrust system identified by seismic surveys. Using a simple deformation model, the inversion of the E* pattern allows to propose a location and dip for a blind thrust, which are consistent with available geological and geophysical data. We also sampled clasts from eroding conglomerate at several hilltops locations for 10Be and 26Al concentration measurement. Calculated hilltops denudation rates range from 40 to 120 mm/ka. These denudation rates appear to be correlated with E* and CHT extracted from the morphological analysis, and are used to derive absolute estimates for the fault slip rate. This high resolution hillslope analysis allows to resolve short wavelength variations in rock uplift, that would not be possible to unravel using commonly used channel profiles based methods. Our joint analysis of topography and geochronological data supports active thrusting at the Southwestern alpine front, and such approaches may bring crucial complementary constraints to morphotectonic analysis for slip rates on slow active faults.

scholarly journals Patterns of incision and deformation on the southern flank of the Yellowstone hotspot from terraces and topography

2021 ◽  
Author(s):  
Daphnee Tuzlak ◽  
Joel Pederson ◽  
Aaron Bufe ◽  
Tammy Rittenour
Keyword(s):  
Late Quaternary ◽  
Slip Rate ◽  
Snake River Plain ◽  
Fault System ◽  
Snake River ◽  
Normal Faults ◽  
Localized Deformation ◽  
Fluvial Terraces ◽  
Yellowstone Hotspot ◽  
River Plain

Understanding the dynamics of the greater Yellowstone region requires constraints on deformation spanning million year to decadal timescales, but intermediate-scale (Quaternary) records of erosion and deformation are lacking. The Upper Snake River drainage crosses from the uplifting region that encompasses the Yellowstone Plateau into the subsiding Snake River Plain and provides an opportunity to investigate a transect across the trailing margin of the hotspot. Here, we present a new chronostratigraphy of fluvial terraces along the lower Hoback and Upper Snake Rivers and measure drainage characteristics through Alpine Canyon interpreted in the context of bedrock erodibility. We attempt to evaluate whether incision is driven by uplift of the Yellowstone system, subsidence of the Snake River Plain, or individual faults along the river’s path. The Upper Snake River in our study area is incising at roughly 0.3 m/k.y. (300 m/m.y.), which is similar to estimates from drainages at the leading eastern margin of the Yellowstone system. The pattern of terrace incision, however, is not consistent with widely hypothesized headwater uplift from the hotspot but instead is consistent with downstream baselevel fall as well as localized deformation along normal faults. Both the Astoria and Hoback faults are documented as active in the late Quaternary, and an offset terrace indicates a slip rate of 0.25−0.5 m/k.y. (250−500 m/m.y.) for the Hoback fault. Although tributary channel steepness corresponds with bedrock strength, patterns of χ across divides support baselevel fall to the west. Subsidence of the Snake River Plain may be a source of this baselevel fall, but we suggest that the closer Grand Valley fault system could be more active than previously thought.

scholarly journals Evidence of active tectonics in the Augusta Basin (eastern Sicily, Italy) by Chirp sub-bottom sonar investigation

2014 ◽  
Vol 56 (5) ◽  
Author(s):  
Claudia Pirrotta ◽  
Maria Serafina Barbano ◽  
Daniela Pantosti ◽  
Paolo Marco De Martini
Keyword(s):  
Active Faults ◽  
Active Tectonics ◽  
Fault System ◽  
Normal Faults ◽  
Strong Earthquakes ◽  
The Holocene ◽  
Regional Seismicity ◽  
Holocene Sediments ◽  
Recent Activity ◽  
Fault Scarps

<p>A Chirp sub-bottom sonar investigation was performed in the 150 km<sup>2</sup> wideAugustaBasin, located in the eastern Sicily Ionian coast, a region repeatedly hit by strong earthquakes in historical time, with the end of identifying possible evidence of active tectonics. Seismostratigraphy shows two main reflectors: R1, formed between 60 ka and 19 ka BP, and R2 that is the top of the Holocene deposits. Morphobathymetry reveals two marine abrasion surfaces, Ms1 and Ms2 that are related to the 35 ka and 25 ka BP marine high stills, respectively. This study highlights that R1 and the onlapping Holocene sediments are affected by normal and probably strike-slip faulting. A set of NE-SW striking normal faults represents the oldest system, because they dislocate R1 but not the Holocene deposit. NNW-SSE striking extensional faults show more recent activity since they displace Ms2, the Holocene sequence and cause seafloor up-warping. NE-SW normal faults produce asymmetric basins where the Holocene deposits form wedged bodies. ENE-WSW left-lateral faults dissect a paleo-island, Ms2 and the NNW-SSE fault system. Moreover, seismically induced  slumps involving the Holocene sediments, are found at the foot of some fault scarps. The presence of slumped bodies and active faults indicates ongoing deformation in the basin. Identified active faults are consistent with the main regional Malta Escarpment fault system, of which they can be considered as the incipient westernmost extension. This study supports the hypothesis that the Malta Escarpment is active and can be responsible for the regional seismicity.</p>

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