The Yellow River, well-known for its tremendous sediment load, originates from the northeast of the Tibetan Plateau, and flows eastwards to the Bohai Sea. As one of the longest rivers in the world, the evolution of the Yellow River is a very interesting topic for Chinese geomorphologists. River terraces provide compelling evidence to understand the evolution history of rivers Bridgland and Westaway, ; Vandenberghe, The Yellow River terraces in the Jinshaan Canyon have been widely investigated, and dated mainly using luminescence techniques and palaeomagnetic dating method Cheng, et al. However, the dates of the terraces obtained are not enough to construct the precise chronology of a series of terraces in the region. This is further complicated by the fact that some terraces with the same elevations above the modern river have different formation ages because their formations are controlled by knickpoint migration Guo et al. Therefore, it is necessary to determine more Yellow River terraces in different localities of the region. The pictures of Exposures A and D are also shown in Fig.
Fluvial terraces are elongated terraces that flank the sides of floodplains and fluvial valleys all over the world. Because of the manner in which they form, fluvial terraces are underlain by fluvial sediments of highly variable thickness. Fluvial terraces are the remnants of earlier floodplains that existed at a time when either a stream or river was flowing at a higher elevation before its channel downcut to create a new floodplain at a lower elevation.
Changes in elevation can be due to changes in the base level elevation of the lowest point in the fluvial system, usually the drainage basin of the fluvial system, which leads to headward erosion along the length of either a stream or river, gradually lowering its elevation. For example, downcutting by a river can lead to increased velocity of a tributary, causing that tributary to erode toward its headwaters.
Optically stimulated luminescence (OSL) dating shows that fine-grained and homogeneous sediment in the studied fluvial terrace was deposited at ± ka.
Skip to search form Skip to main content You are currently offline. Some features of the site may not work correctly. DOI: Repka and R. Anderson and R. Repka , R.
Landscape dynamics revealed by luminescence signals of feldspars from fluvial terraces
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However, the geological history of its fluvial plain is poorly understood due the lack of geochronological data. Most of the studies are focused in the low and middle reaches, whereas the region upstream of the Porto Primavera dam is an almost unknown area in terms of geomorphic evolution. In order to achieve this goal, we used an integrated approach including remote sensing data, geomorphology, sedimentology, geochronology and bathymetric profiles. The geomorphological units were correlated with previous studies downstream of the studied area and their sedimentary characteristics and depositional ages suggest that their genesis is linked to changes in climatic and hydrological conditions during the Late Quaternary.
Unit 2 is a compartment with unique morphological characteristics, therefore not correlated with units presented in previous works. Further, two main knickpoints were identified, suggesting an important control in the sedimentation and development of the terrace levels. The Quaternary period is characterized by large amplitude cyclic climatic variations glacial-interglacial that produced significant environmental changes in vegetation, sediment production and fluvial regime Vandenberghe,
COSMOGENIC DATING OF FLUVIAL TERRACES, FREMONT RIVER, UTAH
All publications more feeds DOI: BibTeX file. Fluvial terraces are widespread geomorphic features, which formed dominantly during the Quaternary. Besides tectonics, the formation of Quaternary fluvial terraces is related to paleoclimatic changes and corresponding changes in fluvial discharge and sediment load.
These river terraces records tectonic uplift in the Mut basin. (OSL) dating of the fluvial sediments of the youngest terrace (T16) provides a.
Climate and tectonics effect the fluvial evolution of the Mediterranean Mut basin. These river terraces records tectonic uplift in the Mut basin. Optically stimulated luminescence OSL dating of the fluvial sediments of the youngest terrace T16 provides a chronology for the assessment of the important impacts of climatic changes. The ages from the youngest river terrace deposits in T16 may be subdivided into two intervals: 1 The differences in climate-driven fluvial evolution between this Mediterranean fluvial system and the classical, well-studied temperate-periglacial river systems in Europe may be the result of different vegetation cover and greater thaw of more intense snowfalls.
N2 – Climate and tectonics effect the fluvial evolution of the Mediterranean Mut basin. AB – Climate and tectonics effect the fluvial evolution of the Mediterranean Mut basin. Overview Fingerprint. Abstract Climate and tectonics effect the fluvial evolution of the Mediterranean Mut basin. Access to Document Quaternary Research United States , 91 2 , In: Quaternary Research United States.
Quaternary Research United States.
In: Quaternaire , vol. Fluvial Archives Group. Clermond-Ferrant
Single-grain optically stimulated luminescence (OSL) dating of quartz was applied in this study to investigate the timing of the formation of three fluvial terraces in.
Fluvial sequences, particularly terrace staircases, represent archives of Quaternary palaeoclimatic fluctuation and can serve as stratigraphical frameworks for geochronology and for correlation with other depositional environments, in particular, the global marine oxygen isotope record. Fluvial lithostratigraphical frameworks also provide contexts for records, from fossils and artefacts, of faunal evolution and human occupation; conversely, both records can be means of relative dating of riverine sequences.
Three fluvial sequences are examined as case studies. First is the Severn-Avon system in the English Midlands, which has biostratgraphical evidence and an amino acid geochronology, together with marker inputs from three different glaciations. The fluvial terraces of the River Arun, the final case study, lack dating evidence but are interspersed within the Sussex raised beach staircase. Although various lines of evidence suggest that the rivers discussed have formed terraces in response to climatic fluctuation, an intriguing difference is that interglacial sediments occur at the bases of terrace formations in the Severn-Avon, whereas in the Somme they occur at the tops of sequences, beneath loessic overburden.
Pleistocene evolution of the Solent River of southern England. Allen T. Interglacial sea-level change: evidence for brackish water sedimentation at Purfleet, Essex. Antoine P.
Dating fluvial terraces with and profiles: application to the Wind River, Wyoming
The Osip-cheon River flows along a linear valley that runs approximately parallel to the Osip-cheon Fault. The present study was undertaken to elucidate the tectono-geomorphic evolution of the Osip-cheon Basin during the late Quaternary by employing cosmogenic 10 Be surface exposure dating and optically stimulated luminescence OSL dating on a flight of fluvial strath terraces.
Several morphometric indices e.
We attempt to date terraces through optically stimulated luminescence (OSL) dating of terrace sands and silts. We use our new displacement and age data.
Jonathan L. Garber , College of William and Mary. I determined ages and on fluvial terraces of the South Fork of the Shenandoah River, Virginia, obtained from depth profiles of in situ 10Be. These dates represent the first numerically constrained ages on fluvial terraces in the Shenandoah system, and allow us to assess the timing of perturbations to the river system and to estimate longterm river incision rates. I sampled three terrace treads near Lynnwood, Virginia, originally identified in mapping completed by King and Bell King suggested a Pleistocene age for the higher terraces, but the terraces are otherwise undated.
To estimate terrace age corrected for inherited 10Be, A MATLAB script iteratively solved for age and inheritance through a least squares fit of modeled 10Be concentration profiles to measured profiles on each terrace. T3 showed an exponential profile, which yielded minimum age of kyr and inheritance of 4. The maximum age and terrace erosion rate was kyr and 4.
The T4 deposit showed mixing in the top three data points which 5 corresponded to a paler layer in the profile. To date these terraces a new Inventory method that took into account both radioactive decay of the isotope as well as allow for the input of terrace erosion rates to the model. The age was then checked by iteratively solving for the exponential curve using the inheritance derived from the Inventory calculations.
The incision rates were also comparable to other Appalachian rivers, which suggest disequilibrium across the Central Appalachian landscape. Possible cause of this landscape disequilibrium include 1 the differential response of the landscape to increases in the amplitude and frequency of climate fluctuations at the onset of the Pleistocene, and 2 isostatic flexural uplift caused by loading on the Atlantic Continental shelf and lightening of the Appalachian Plateau from increased erosion of Atlantic draining streams.