Landscape evolution of the southeastern Tibetan Plateau – Temporal and spatial relationships between glacial and fluvial landforms

2020 ◽  
Author(s):  
Ramona A.A. Schneider ◽  
Arjen P. Stroeven ◽  
Robin Blomdin ◽  
Natacha Gribenski ◽  
Marc W. Caffee ◽  
...  
Keyword(s):  
Landscape Evolution ◽  
Active Regions ◽  
Luminescence Dating ◽  
Spatial Correlations ◽  
Geomorphological Mapping ◽  
Exposure Dating ◽  
Fluvial Terraces ◽  
Infrared Stimulated Luminescence ◽  
Tectonically Active ◽  
Temporal And Spatial

<p>Landscape system components interact in ways which are not yet fully understood, and in tectonically active regions it is of particular interest whether endogenic or exogenic factors are the main drivers of landscape evolution. For example, fluvial terraces may form in response to exogenic disturbances like climatic changes or to endogenic forces like tectonic uplift. This study explores how temporal and spatial correlations between end moraines (denoting the advance of glaciers due to climate change) and fluvial terraces can yield insights about exogenic-endogenic processes determining landscape evolution during the Quaternary on the southern margin of the Shaluli Shan plateau, SE Tibet, a formerly glaciated and tectonically active region. A high-resolution TanDEM-X Digital Elevation Model (12 m) was used to produce detailed geomorphological maps of glacial valleys, marginal moraines, glacial lineations, and fluvial terraces. The geomorphological mapping was complemented with geomorphological and sedimentological field observations. Samples for Optically Stimulated Luminescence dating were taken from extensive and distinct terraces located in pull-apart basins bordering the plateau and samples for cosmogenic nuclide exposure dating were collected from selected boulders on end moraines formed by valley glaciers draining the Mt Genie massif on the Shaluli Shan plateau. Infrared stimulated luminescence (IRSL) signals from feldspar multi grains aliquots, and <sup>10</sup>Be and <sup>26</sup>Al concentrations from quartz, were used to determine depositional ages of terraces and moraines, respectively. In combining both dating techniques, we compare the timing of glacial expansions with the depositonal ages of the terraces to tease out the effects of exogenic and endogenic drivers on terrace formation and to formulate a conceptual model of landscape evolution.</p>

Landscape evolution and landform inheritance in tectonically active regions: The case of the Southwestern Peloponnese, Greece

2016 ◽  
Vol 60 (2) ◽  
pp. 171-193 ◽  
Author(s):  
Johan Kleman ◽  
Ingmar Borgström ◽  
Alasdair Skelton ◽  
Adrian Hall
Keyword(s):  
Landscape Evolution ◽  
Active Regions ◽  
Tectonically Active

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 The need for protecting, promoting, and managing a Quaternary geoheritage site: Bahluiet Valley at Costești village (Moldavian Plateau, North-Eastern Romania

2021 ◽  
Author(s):  
Mihai Niculita
Keyword(s):  
National Level ◽  
Archaeological Site ◽  
Luminescence Dating ◽  
Fluvial Deposits ◽  
Geomorphological Mapping ◽  
Fluvial Terraces ◽  
River Incision ◽  
Plateau Area ◽  
Complex Landslide ◽  
Active Processes

Abstract The Bahluieț Valley at Costești village geosite has been recently studied and proposed as a geoheritage site. Previously this area was investigated due to the presence of the Costești-Cier archaeological site, which is currently integrated into the National Archaeological Repertoire. In this archaeological site, different levels of populations have been studied (Eneolithic Cucuteni A, Cucuteni AB, and Horodiștea-Erbiceni Culture populations) as well as an earth wall from La Tene (8th‒10th/11th century BC), and a 15th‒17th century AD necropolis. In the area of the present-day Costești village, Bahluieț River leaves the Suceava Plateau area (with altitudes of 350‒550 m a.s.l.) and enters the Jijia Hills (with altitudes of 50 to 200 m a.s.l.), flowing between Ulmiș Hill (306 m a.s.l., at north) and Ruginii Hill (326 m a.s.l., at the south). The valley, which is incised more than 100 m below the plateau level, suddenly becomes broader because of massive Late Pleistocene landslides that covered the former Bahluieț river floodplain and are now fossilized by fluvial deposits. During the Holocene, the river incision detached paleochannels and fluvial terraces while the landslides reactivated through retrogressive mechanisms, creating a complex landslide. A cut-off meander island hosts the Costești-Cier archaeological site, being currently actively eroded by the river. In the riverbank of this island, a multi-layered stratigraphy can be seen, consisting of landslide and fluvial deposits, paleosoils, and archaeological remains. The layered deposits, the complex landslide, and the fluvial processes have the potential to become one of the most representative Quaternary sites of the Moldavian Plateau and Romania. By using geomorphosite assessment, geomorphological mapping optically stimulated luminescence dating, and geoconservation ideas, I show (i) the importance of the geosite due to the presence of the oldest dated fossil landslide from Romania and the landslide-fluvial-archaeological relations, (ii) the needs for protection at local, regional and national level considering the active processes that affect the site, and propose (iii) management and (iv) promotion of the geoheritage site using a geoconservation strategy.

Post-LGM evolution of the Dora Baltea glacial system and paleoclimatic implications in the Western Italian Alps 

2021 ◽  
Author(s):  
Elena Serra ◽  
Pierre G. Valla ◽  
Natacha Gribenski ◽  
Fabio Magrani ◽  
Julien Carcaillet ◽  
...  
Keyword(s):  
Luminescence Dating ◽  
Areal Interpolation ◽  
Geomorphological Mapping ◽  
Exposure Dating ◽  
Ice Surface ◽  
Surface Reconstructions ◽  
The Alps ◽  
Climatic Cooling ◽  
Glacial Landforms ◽  
Exposure Ages

<p>Alpine glaciers repeatedly advanced and retreated from the high Alps to the forelands during the Quaternary and most recently reached their maximum extent and thickness during the Last Glacial Maximum (LGM, 26.5-19.0 ka ago)<sup> [1]</sup>. After the LGM, glaciers abandoned the Alpine foreland and retreated within the internal valleys. However, post-LGM withdrawal was not continuous but interrupted by stages of ice stasis or re-advance (stadials<sup> [2]</sup>), related to episodes of temporary climatic cooling. Glacial landforms and deposits associated to post-LGM ice stadials have been recognised across the Alps <sup>[2]</sup>. Our study contributes to this line of research by quantitatively reconstructing the age and configuration of several ice stages from the LGM to the Holocene, within the Dora Baltea (DB) catchment (SW Alps, Italy).</p><p>Following a detailed geomorphological mapping of glacial landforms and deposits, sixteen erratic boulders and two glacially-polished bedrocks were sampled along the DB valley for <em>in-situ</em><sup><em> </em>10</sup>Be surface-exposure dating, and five samples for luminescence dating were collected from fluvio-lacustrine and fluvio-glacial deposits. The obtained chronologies, combined with recalculated <sup>10</sup>Be surface-exposure ages from previous works in the study area <sup>[1, 3, 4, 5]</sup>, constrain seven post-LGM ice stages in the DB valley. The first three retreat stages occurred between the end of the LGM and the early Lateglacial, probably with rapid ice decay. The following three stages correspond to the well-known Gschnitz, Daun and Egesen Alpine Lateglacial stadials <sup>[2]</sup>, while we also identified a late-Holocene ice re-advance in the upstream DB catchment.</p><p>Paleo-ice configurations of each stage (including the LGM) were obtained with a semi-automatic ArcGIS routine (similar approach to GlaRe ArcGIS toolbox <sup>[6]</sup>), based on the areal interpolation of 2D ice surface profiles generated through Profiler v.2 <sup>[7]</sup>. Glacier equilibrium-line altitudes (ELAs) were computed for the eight 3D ice surface reconstructions <sup>[8]</sup>, with the aim of deriving potential paleoclimatic implications of the different reconstructed ice stages in comparison to other paleoclimatic proxies.</p><p> </p><p><strong>References</strong></p><p><sup>[1] </sup>Wirsig, C. et al., 2016, Quaternary Science Reviews.</p><p><sup>[2] </sup>Ivy-ochs, S., 2015, Cuadernos de Investigación Geográfica.</p><p><sup>[3] </sup>Gianotti, F. et al., 2015, Alpine and Mediterranean Quaternary.</p><p><sup>[4] </sup>Deline, P. et al., 2015, Quaternary Science Reviews.</p><p><sup>[5] </sup>Le Roy, M., 2012. Université Grenoble Alpes.</p><p><sup>[6] </sup>Pellitero, R. et al., 2016, Computers and Geosciences.</p><p><sup>[7] </sup>Benn, D., Hulton, N., 2010, Quaternary Science Reviews.</p><p><sup>[8] </sup>Pellitero, R. et al., 2015, Computers and Geosciences.</p>

Holocene rockfalls in the southern Negev Desert, Israel and their relation to Dead Sea fault earthquakes

2014 ◽  
Vol 81 (2) ◽  
pp. 260-273 ◽  
Author(s):  
Yair Rinat ◽  
Ari Matmon ◽  
Maurice Arnold ◽  
Georges Aumaître ◽  
Didier Bourlès ◽  
...  
Keyword(s):  
Active Regions ◽  
Numerical Approach ◽  
Arid Environment ◽  
Dead Sea ◽  
Cosmogenic Nuclides ◽  
Earthquake Activity ◽  
Production Rates ◽  
Exposure Dating ◽  
Tectonically Active ◽  
Simple Exposure

AbstractRockfall ages in tectonically active regions provide information regarding frequency and magnitude of earthquakes. In the hyper-arid environment of the Dead Sea fault (DSF), southern Israel, rockfalls are most probably triggered by earthquakes. We dated rockfalls along the western margin of the DSF using terrestrial cosmogenic nuclides (TCN). At each rockfall site, samples were collected from simultaneously exposed conjugate boulders and cliff surfaces. Such conjugate samples initially had identical pre-fall (“inherited”) TCN concentrations. After boulder detachment, these surfaces were dosed by different production rates due to differences in post-fall shielding and geometry. However, in our study area, pre-rockfall inheritance and post-rockfall production rates of TCN cannot be evaluated. Therefore, we developed a numerical approach and demonstrated a way to overcome the above-mentioned problems. This approach can be applied in other settings where rockfalls cannot be dated by simple exposure dating. Results suggest rockfall ages between 3.6 ± 0.8 and 4.7 ± 0.7 ka. OSL ages of sediment accumulated behind the boulders range between 0.6 ± 0.1 and 3.4 ± 1.4 ka and support the TCN results. Our ages agree with dated earthquakes determined in paleoseismic studies along the entire length of the DSF and support the observation of intensive earthquake activity around 4–5 ka.

scholarly journals Geomorphological and Geochronological Analysis Applied to the Quaternary Landscape Evolution of the Yeltes River (Salamanca, Spain)

2020 ◽  
Vol 12 (19) ◽  
pp. 7869 ◽  
Author(s):  
Iván Martín-Martín ◽  
Pablo-Gabriel Silva ◽  
Antonio Martínez-Graña ◽  
Javier Elez
Keyword(s):  
Transfer Functions ◽  
Sedimentary Basins ◽  
Central Spain ◽  
Geomorphological Mapping ◽  
Fluvial Terraces ◽  
Digital Elevation ◽  
Late Neogene ◽  
Climate Evolution ◽  
Reported Data ◽  
Geomorphological Evolution

This paper aims to study the Quaternary geomorphological evolution of the Yeltes river-valley (Duero Basin, Central Spain) primarily based on the study of the Late Neogene piedmont dissected by the river and its Quaternary terrace sequence, since fluvial terraces are excellent archives to study the landscape and climate evolution during this period. Detailed geomorphological mapping implemented in GIS-based digital elevation models was used to the further applications of existing fluvial chronofunctions (relative terrace height-age transfer functions) to establish a numerical geochronology to the sequence of fluvial terraces in the zone. The obtained theoretical ages points to an onset of fluvial incision in the zone after 2.0–2.5 Myr ago, with the dissection of the “Raña surface” (a Gelasian alluvial piedmont widely developed in Central Spain). The obtained terrace ages coincide, in most cases, with warm isotopic stages (MIS) or mainly with the transit of cold to warm MIS. Additionally, this study suggests that the full connectivity of the Yeltes drainage (Ciudad Rodrigo Basin) with the Atlantic drainage was not completely effective until MIS 9 (c. 0.29 Myr). The new reported data allows for the exploration of the timing and processes involved in the capture of inland sedimentary basins (Ciudad Rodrigo, Duero basins) by the Atlantic drainage during the early Quaternary.

Seasonal and water-depth variations in sediment luminescence and in sedimentation from sediment trap samples at Gerlache Strait, Antarctic Peninsula

2009 ◽  
Vol 21 (5) ◽  
pp. 483-499 ◽  
Author(s):  
Glenn W. Berger ◽  
Sara Ante ◽  
Eugene W. Domack
Keyword(s):  
Sediment Trap ◽  
Trap Depth ◽  
Dry Mass ◽  
Luminescence Dating ◽  
Fine Silt ◽  
Sediment Fluxes ◽  
Depositional Processes ◽  
Infrared Stimulated Luminescence ◽  
Depositional Controls ◽  
Susceptibility Profiles

AbstractSediment trap arrays were deployed in Brialmont Cove and Andvord Bay, eastern Gerlache Strait, from December 2001–March 2003. The recovered sediments (representing instantaneous deposition from the viewpoint of luminescence dating) encompass all the annual and local glaciomarine depositional processes. Magnetic susceptibility profiles were used to infer seasonality in the trap cores, and thus to select subsamples for luminescence measurements. Multi-aliquot infrared stimulated luminescence (IRSL) apparent ages were used to assess the effectiveness of ‘clock zeroing’ (by daylight) of light sensitive luminescence within fine silt polymineral samples from each trap depth. IRSL apparent ages for 24 samples indicate that the largest age-depth differences occur with the autumn season samples at both trap sites, suggesting a previously unrecognized and regional (within the Gerlache Strait) change in depositional controls in the autumn compared to other seasons. The apparent ages also indicate some differences between the fjords, and a more complex oceanographic regime at Andvord Bay than at Brialmont Cove. Dry-mass sediment fluxes varied from 0.4 to 0.7 g cm-2 yr-1, with the largest flux at Brialmont Cove (∼0.7 g cm-2 yr-1) occurring in the bottom trap, whereas at Andvord Bay, the largest flux (∼0.6 g cm-2 yr-1) occurred in the middle trap (∼45 m above seafloor).

scholarly journals Geomorphic evidence of recent activity along the Vodice thrust fault in the Ljubljana Basin (Slovenia) – a preliminary study

2014 ◽  
Vol 56 (6) ◽  
Author(s):  
Petra Jamšek Rupnik ◽  
Lucilla Benedetti ◽  
Frank Preusser ◽  
Miloš Bavec ◽  
Marko Vrabec
Keyword(s):  
Slip Rate ◽  
Surface Expression ◽  
Thrust Fault ◽  
Luminescence Dating ◽  
Quaternary Sediments ◽  
Infrared Stimulated Luminescence ◽  
Recent Activity ◽  
The Town ◽  
Geomorphological Analysis ◽  
Central Slovenia

<p>We investigated two prominent, <strong><sup>~</sup></strong>E-W trending scarps in Quaternary sediments, located close to the town of Vodice in the Ljubljana Basin (central Slovenia). By using detailed geomorphological analysis of the scarps, field surveying, and structural observations of deformed Quaternary sediments, we conclude that the scarps are the surface expression of a N-dipping thrust fault that has been active during the Quaternary. From Optically Stimulated Luminescence and Infrared Stimulated Luminescence dating of deformed Quaternary sediments we estimate a slip rate of 0.1 to 0.3 mm a<sup>-1 </sup>in the last 133 ka. Using the published empirical fault-scaling relationships, we estimate that an earthquake of magnitude 5.9 to 6.5 may be expected on the Vodice thrust fault. The fault may, therefore, present a major seismic hazard for the densely populated and urbanised region of central Slovenia.</p>

scholarly journals Estimation of absolute stress in the hypocentral region of the 2019 Ridgecrest, California, earthquakes

2020 ◽  
Author(s):  
Yuri Fialko
Keyword(s):  
Seismic Data ◽  
Plate Tectonics ◽  
Active Faults ◽  
Active Regions ◽  
Seismogenic Zone ◽  
Shear Stresses ◽  
Strong Earthquakes ◽  
Frictional Strength ◽  
Tectonically Active ◽  
Weak Fault

Abstract Strength of the upper brittle part of the Earth's lithosphere controls deformation styles in tectonically active regions, surface topography, seismicity, and the occurrence of plate tectonics, yet it remains one of the least constrained and most debated quantities in geophysics. Seismic data (in particular, earthquake focal mechanisms) have been used to infer orientation of the principal stress axes. Here I show that the focal mechanism data can be combined with information from precise earthquake locations to place robust constraints not only on the orientation, but also on the magnitude of absolute stress at depth. The proposed method uses machine learning to identify quasi-linear clusters of seismicity associated with active faults. A distribution of the relative attitudes of conjugate faults carries information about the amplitude and spatial heterogeneity of the deviatoric stress and frictional strength in the seismogenic zone. The observed diversity of dihedral angles between conjugate faults in the Ridgecrest (California, USA) area that hosted a recent sequence of strong earthquakes suggests the effective coefficient of friction of 0.4-0.6, and depth-averaged shear stresses on the order of 25-40 MPa, intermediate between predictions of the "strong" and "weak" fault theories.

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