Reconstruction of Late Quaternary Neotectonic Movements and Fluvial Activity in Sikkimese-Bhutanese Himalayan Piedmont

2015 ◽  
Vol 49 (1) ◽  
Author(s):  
Leszek Starkel ◽  
Dominik Płoskonka ◽  
Grzegorz Adamiec
Keyword(s):  
Late Quaternary ◽  
Tectonic Activity ◽  
Soil Profiles ◽  
Alluvial Fans ◽  
Piedmont Zone

AbstractIn the part of Sikkimese-Bhutanese Himalaya the youngest Siwalik overthrust had not developed, and the piedmont zone with extensive fans forms a semicircular gulf dismembered by several faults and minor overthrusts. Some uplifted parts of older deformed alluvial fans contain the lenses of organic clays which were earlier dated at 22–34 ka BP byTo distinguish various alluvial formations and phases of tectonic activity the authors dated older levels in several localities by OSL method as well as investigated soil profiles. Most mature soils over elevated blocks built of coarse alluvia were dated between 50 and 60 ka BP. Probably the previous

scholarly journals Late Quaternary tectonic activity and lake level change in the Rukwa Rift Basin

1998 ◽  
Vol 26 (3) ◽  
pp. 397-421 ◽  
Author(s):  
D. Delvaux ◽  
F. Kervyn ◽  
E. Vittori ◽  
R.S.A. Kajara ◽  
E. Kilembe
Keyword(s):  
Lake Level ◽  
Late Quaternary ◽  
Tectonic Activity ◽  
Rift Basin ◽  
Lake Level Change ◽  
Level Change

scholarly journals Methods for soil enhancement in geoheritage research: a case study from Veglia-Devero Natural Park (Lepontine Alps)

2021 ◽  
Author(s):  
Anna Masseroli ◽  
Irene M. Bollati ◽  
Luca Trombino ◽  
Manuela Pelfini
Keyword(s):  
Late Quaternary ◽  
Chemical Properties ◽  
Soil Characteristics ◽  
Parent Material ◽  
Soil Types ◽  
Conservation Strategies ◽  
Soil Profiles ◽  
Mountain Environments ◽  
Natural Park ◽  
Lepontine Alps

<p>In mountain environments, the high variability of soil forming factors (i.e., parent material, climate, relief, organism, time) is responsible for the presence of different soil types, which not only contribute to the pedodiversity but are also a component of the local cultural heritage.</p><p>Up to now, scarce attention has been paid to the soil in the geoheritage/geoconservation scientific analyses.</p><p>To promote soil as element concurring to mountain geoheritage definition, we propose a strategy to include pedological topics within a multidisciplinary trail planned in the Veglia-Devero Natural Park (Lepontine Alps). The geomorphological dynamicity and environmental change affecting during times the small mountain catchment of Buscagna hydrographic basin are illustrated with a specific address to soil characteristics. The physical and chemical properties, and pedological features of soils reflect the interaction among the other ecosystem components (i.e. geology, geomorphology and vegetation), underlining the role of soil as natural archive for reconstructing landscape evolution and for achieving a more complete assessment of Late Quaternary geomorphic events, especially surface processes.</p><p>Geopedological researches carried out in the study area, allowed to detect 7 soil profiles as potential sites of pedological interest, located in safe and accessible places, along already existing hiking paths. The selected soil profiles not only mirror the main soil types that characterize the area but also represent evidence of past environmental conditions and geomorphic dynamics.</p><p>The opportunities for hikers and mountaineers, to observe the exposed soils along the Buscagna valley, thanks to the presence of erosional scarps and subsidence areas, allow also to get more awareness of the need of geoheritage conservation strategies addressed to soil, especially in the mountain landscape where soil characteristics reflect the striking influence of its forming factors.</p>

Eruptive frequency of the Bora-Baricha-Tullu Moye (BBTM) volcanic system in the Central Main Ethiopian Rift

2021 ◽  
Author(s):  
Amdemichael Zafu Tadesse ◽  
Karen Fontijn ◽  
Abate Assen Melaku ◽  
Ermias Filfilu Gebru ◽  
Victoria Smith ◽  
...  
Keyword(s):  
Late Quaternary ◽  
Volcanic Eruptions ◽  
Volcanic Field ◽  
Tectonic Activity ◽  
Explosive Eruptions ◽  
Ethiopian Rift ◽  
Rift System ◽  
Diagnostic Features ◽  
Volcanic System ◽  
Main Ethiopian Rift

<p>The Main Ethiopian Rift (MER) is the northern portion of the East African Rift System and separates the Eastern and Western plateaus of Ethiopia. The recent volcanic and tectonic activity is largely focused within the rift basin along a 20 km wide zone on the rift floor. Large silicic volcanic complexes are aligned along this central rift axis but their eruptive histories are not well constrained.</p><p>The Bora-Baricha-Tullu Moye (BBTM) volcanic field is situated in the central Main Ethiopian Rift and has a different appearance than the other MER volcanic systems. The BBTM constitutes several late Quaternary edifices, the major ones are: Tullu Moye, Bora and Baricha. In addition, there are multiple smaller eruptive vents (e.g. Oda and Dima), cones, and domes across the ca. 20 X 20 km wide area. Currently, there is very little information on the frequency and magnitude of past volcanic eruptions. We present a new dataset of field observations, componentry, petrography, geochronology (<sup>40</sup>Ar/<sup>39</sup>Ar), and glass major and trace element chemistry. The data are assessed as potential fingerprints to assign diagnostic features and correlate units across the area, and establish a tephrostratigraphic framework for the BBTM volcanic field.</p><p>Two large-volume and presumably caldera-forming eruptions are identified, the younger of which took place at 100 ka. The volcanic products exposed in the BBTM area show that the volcanic field has undergone at least 20 explosive eruptions since then. The post-caldera eruptions have comenditic (Tullu Moye) and pantelleretic (Bora and Baricha) magma compositions. Other smaller edifices such as Oda and Dima also erupted pantelleritic magmas, and only differ slightly in composition than tephra of Bora and Baricha. Tullu Moye had two distinct explosive eruptions that dispersed tephra up to 14 km away and on to the eastern plateau. Bora and Baricha together had at least 8 explosive eruptions. Their deposits can be distinguished by their light grey color and unique lithic components. Oda had 7 eruptions, the most recent of which generated a pyroclastic density current that travelled up to 10 km away from the vent. Dima experienced at least 3 eruptions, generating tephra with a bluish-grey colour.</p><p>This mapping and compositional analysis of the deposits from the BBTM in the MER indicates that the region has been more active in the last 100 ka than previously thought, which has implications for hazards assessments for the region.</p>

Late Quaternary aggradation and incision in the headwaters of the Yangtze River, eastern Tibetan Plateau, China

2021 ◽  
Author(s):  
Yang Yu ◽  
Xianyan Wang ◽  
Shuangwen Yi ◽  
Xiaodong Miao ◽  
Jef Vandenberghe ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Yangtze River ◽  
Late Quaternary ◽  
Cold Climate ◽  
Luminescence Dating ◽  
Tectonic Activity ◽  
The Yangtze River ◽  
Eastern Tibetan Plateau ◽  
Sedimentary Process ◽  
Fluvial Terraces

River aggradation or incision at different spatial-temporal scales are governed by tectonics, climate change, and surface processes which all adjust the ratio of sediment load to transport capacity of a channel. But how the river responds to differential tectonic and extreme climate events in a catchment is still poorly understood. Here, we address this issue by reconstructing the distribution, ages, and sedimentary process of fluvial terraces in a tectonically active area and monsoonal environment in the headwaters of the Yangtze River in the eastern Tibetan Plateau, China. Field observations, topographic analyses, and optically stimulated luminescence dating reveal a remarkable fluvial aggradation, followed by terrace formations at elevations of 55−62 m (T7), 42−46 m (T6), 38 m (T5), 22−36 m (T4), 18 m (T3), 12−16 m (T2), and 2−6 m (T1) above the present floodplain. Gravelly fluvial accumulation more than 62 m thick has been dated prior to 24−19 ka. It is regarded as a response to cold climate during the last glacial maximum. Subsequently, the strong monsoon precipitation contributed to cycles of rapid incision and lateral erosion, expressed as cut-in-fill terraces. The correlation of terraces suggests that specific tectonic activity controls the spatial scale and geomorphic characteristics of the terraces, while climate fluctuations determine the valley filling, river incision and terrace formation. Debris and colluvial sediments are frequently interbedded in fluvial sediment sequences, illustrating the episodic, short-timescale blocking of the channel ca. 20 ka. This indicates the potential impact of extreme events on geomorphic evolution in rugged terrain.

scholarly journals VÝZKUM POZDNĚ KVARTÉRNÍ AKTIVITY ZLOMU KOSÍŘE V HORNOMORAVSKÉM ÚVALU ANEB PROČ JE DOBRÉ STUDOVAT SVAHOVINY A SEISMOGRAMY

2016 ◽  
Vol 22 (1-2) ◽  
Author(s):  
Petr Špaček ◽  
Vít Ambrož
Keyword(s):  
Late Pleistocene ◽  
Late Quaternary ◽  
Slip Rate ◽  
Fault Scarp ◽  
Strike Slip ◽  
Tectonic Activity ◽  
Temporary Increase ◽  
Normal Faulting ◽  
Major Fault ◽  
Complex Sequences

Preliminary results of a research into the late Quaternary slip of a major fault in the seismically active Upper Morava Basin are given. Three trenches, up to 6 m deep, were excavated at the foot of the Kosíř Fault scarp near Stařechovice and Čelechovice. The exposed complex sequences of colluvium and loess, now only partly dated by OSL and 14C, is heavily faulted. The faulting is explained by a tectonic slip at the Kosíř Fault and, in the Stařechovice trench, also by simultaneous slope deformations. None of the faults do off set the Holocene topsoil but the youngest of them were clearly active aft er the deposition of the youngest loess and indicate the slip of up to 1.4 m in Late Pleistocene. In Čelechovice trenches the minimum vertical throw of 4 m is indicated for the lower part of the sequence with assumed Late Pleistocene age. The geometry of the deformed zone suggests an oblique normal faulting with significant strike-slip component. The sense of shearing in the horizontal plane was not resolved. Minimum tectonic slip rate of 0.1‒0.3 mm/year in Late Pleistocene is suggested but this must be confi rmed by new dating. Our observations reveal surprisingly young and large deformation which may suggest a temporary increase of tectonic activity during Late Pleistocene.

scholarly journals The Carboneras Fault Zone (southeastern Spain) revisited with Ground Penetrating Radar – Quaternary structural styles from high-resolution images

2001 ◽  
Vol 80 (3-4) ◽  
pp. 129-138 ◽  
Author(s):  
K.R. Reicherter ◽  
S. Reiss
Keyword(s):  
High Resolution ◽  
Fault Zone ◽  
Ground Penetrating Radar ◽  
Late Quaternary ◽  
Strike Slip ◽  
Tectonic Activity ◽  
Active Set ◽  
Southeastern Spain ◽  
Betic Cordilleras ◽  
Ground Penetrating

AbstractThe Carboneras Fault Zone (CFZ) represents an active set of sinistral strike-slip faults in the Betic Cordilleras of southeastern Spain. It constitutes a major segment of the ‘Trans-Alboran shear zone’ during the Cenozoic, striking NE-SW. The CFZ separates the Cabo de Gata Block (Neogene volcanics) against Neogene basinal sediments and the metamorphic basement of the Alpujarride Complex.Three sites along the CFZ were examined with Ground Penetrating Radar techniques. Radar surveying was complemented by structural studies. Shallow-depth high-resolution imaging of Tyrrhenian beach terraces exhibited both vertical and minor horizontal offsets in the Rambla Morales site in the south. A sinistral strike-slip fault associated with minor thrust faults in a positive flower structure was detected in the middle segment along the La Serrata ridge, sealed by a caliche of late Pleistocene age (> 10 ka). The Playa de Bolmayor section yielded sub-surface evidence for several faults probably related to recent activity of individual fault strands. Our results suggest a distributed tectonic activity of the CFZ during the Late Quaternary.

scholarly journals Late Quaternary Tectonic Activity of the Udine-Buttrio Thrust, Friulian Plain, NE Italy

Geosciences ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 84
Author(s):  
Andrea Viscolani ◽  
Christoph Grützner ◽  
Manuel Diercks ◽  
Klaus Reicherter ◽  
Kamil Ustaszewski
Keyword(s):  
Late Quaternary ◽  
Tectonic Setting ◽  
Surface Expression ◽  
Vertical Surface ◽  
Fault System ◽  
Tectonic Activity ◽  
Morphological Evidence ◽  
Seismic Reflection Data ◽  
Reflection Data ◽  
Ne Italy

The NW-SE trending Udine-Buttrio Thrust is a partly blind fault that affects the Friulian plain southeast of Udine in NE Italy. It is part of a wider fault system that accommodates the northward motion of the Adriatic plate. Although seismic reflection data and morphological evidence show that the fault was active during the Quaternary, comparably little is known about its tectonic activity. We used high-resolution digital elevation models to investigate the surface expression of the fault. Measured vertical surface offsets show significant changes along strike with uplift rates varying between 0 and 0.5 mm/yr. We then analyze a topographic scarp near the village of Manzano in more detail. Field mapping and geophysical prospections (Georadar and Electrical Resistivity Tomography) were used to image the subsurface geometry of the fault. We found vertical offsets of 1–3 m in Natisone River terraces younger than 20 ka. The geophysical data allowed the identification of deformation of the fluvial sediments, supporting the idea that the topographic scarp is a tectonic feature and that the terraces have been uplifted systematically over time. Our findings fit the long-term behaviour of the Udine-Buttrio Thrust. We estimate a post-glacial vertical uplift rate of 0.08–0.17 mm/yr recorded by the offset terraces. Our results shed light on the Late Quaternary behaviour of this thrust fault in the complicated regional tectonic setting and inform about its hitherto overlooked possible seismic hazard.

scholarly journals The Subsurface Geology and Landscape Evolution of the Volturno Coastal Plain, Italy: Interplay between Tectonics and Sea-Level Changes during the Quaternary

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3386
Author(s):  
Giuseppe Corrado ◽  
Sabrina Amodio ◽  
Pietro P. C. Aucelli ◽  
Gerardo Pappone ◽  
Marcello Schiattarella
Keyword(s):  
Cross Sections ◽  
Coastal Plain ◽  
Late Quaternary ◽  
Slip Rate ◽  
Tectonic Activity ◽  
Paleoenvironmental Reconstruction ◽  
Sea Level Changes ◽  
Plan View ◽  
North West ◽  
The North

The Volturno alluvial-coastal plain is a relevant feature of the Tyrrhenian side of southern Italy. Its plan-view squared shape is due to Pliocene-Quaternary block-faulting of the western flank of the south-Apennines chain. On the basis of the stratigraphic analysis of almost 700 borehole logs and new geomorphological survey, an accurate paleoenvironmental reconstruction before and after the Campania Ignimbrite (CI; about 40 ky) eruption is here presented. Tectonics and eustatic forcing have been both taken into account to completely picture the evolution of the coastal plain during Late Quaternary times. The upper Pleistocene-Holocene infill of the Volturno plain has been here re-organized in a new stratigraphic framework, which includes seven depositional units. Structural analysis showed that two sets of faults displaced the CI, so accounting for recent tectonic activity. Yet Late Quaternary tectonics is rather mild, as evidenced by the decametric vertical separations operated by those faults. The average slip rate, which would represent the tectonic subsidence rate of the plain, is about 0.5 mm/year. A grid of cross sections shows the stratigraphic architecture which resulted from interactions among eustatic changes, tectonics and sedimentary input variations. On the basis of boreholes analysis, the trend of the CI roof was reconstructed. An asymmetrical shape of its ancient morphology—with a steeper slope toward the north-west border—and the lack of coincidence between the present course of the Volturno River and the main buried bedrock incision, are significant achievements of this study. Finally, the morpho-evolutionary path of the Volturno plain has been discussed.

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