Palaeogene alluvial–volcaniclastic deposits in the Mesta Basin (SW Bulgaria): depositional setting and basin evolution

2009 ◽  
Vol 147 (3) ◽  
pp. 321-338 ◽  
Author(s):  
ANDREAS SIEMES ◽  
TOM McCANN ◽  
ANNE FISCHER
Keyword(s):  
Volcanic Activity ◽  
Drainage System ◽  
Explosive Volcanism ◽  
Late Eocene ◽  
Sediment Supply ◽  
Tectonic Activity ◽  
Density Currents ◽  
Volcanic Material ◽  
Sedimentary Evolution ◽  
Sedimentary Architecture

AbstractThe Mesta half-graben is one in a series of extensional basins in SW Bulgaria that record the onset of extension within the Rhodope Zone in the Late Eocene. Tectonic activity on a continuous detachment along the eastern margin was a major control on subsidence, accommodation space creation, sediment supply and facies distribution in the basin. The sedimentary architecture was complicated by synsedimentary rotation, the presence of intrabasinal faults and the resulting compartmentalization, as well as synsedimentary volcanic activity. Facies and structural analysis of a key transverse section in the central part of the basin, together with supporting observations from other parts of the basin, indicate a pulsed tectono-sedimentary evolution of the basin with three distinct stages. The first stage (Late Eocene) is a phase of rapid extension with an initial alluvial setting. Basin margin fans and an axial fluvial through-drainage system were the major depositional systems in this stage. The second stage (Early Oligocene) marks the onset of volcanic activity within the Mesta Basin and is characterized by the formation of volcanic centres, an intense phase of explosive volcanism and rapid infilling of the previous basin topography with volcanic material deposited from pyroclastic density currents. The third stage (Late Oligocene) represents waning volcanic activity in a mixed alluvial–volcaniclastic environment. This stage is characterized by alternating alluvial and volcaniclastic depositional cycles, as well as partial reworking of volcanic material.

scholarly journals Lifecycle of an Intermontane Plio-Pleistocene Fluvial Valley of the Northern Apennines: From Marine-Driven Incision to Tectonic Segmentation and Infill

Geosciences ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 141
Author(s):  
Massimiliano Ghinassi ◽  
Mauro Aldinucci ◽  
Valeria Bianchi ◽  
Andrea Brogi ◽  
Enrico Capezzuoli ◽  
...  
Keyword(s):  
Sea Level ◽  
Drainage System ◽  
Northern Apennines ◽  
Sediment Supply ◽  
Tectonic Activity ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Sedimentary Evolution ◽  
Fluvial Sedimentation ◽  
Forced Regression

Downcutting and infill of incised valley systems is mostly controlled by relative sea-level changes, and studies on valley-fill successions accumulated independently from relative sea-level or lake-level oscillations are limited. This study focuses on the Plio-Pleistocene evolution of a fluvial drainage system developed in Southern Tuscany (Italy) following a regional marine forced regression at the end of Piacentian. Subsequent in-valley aggradation was not influenced by any relative sea-level rise, and valley morphological and depositional history mainly resulted from interaction between sediment supply and tectonic activity, which caused segmentation of the major valley trunk into localized subsiding depocenters separated by upwarping blocks. Fluvial sedimentation occurred until late Calabrian time, when the major river abandoned that valley, where minor fluvio-lacustrine depocenters allowed accumulation of siliciclastic and carbonate deposits. The present study demonstrates that the infill of the valley was not controlled by the forcing that caused its incision. Accumulation of the fluvial succession is discussed here in relation with localized, tectonic-controlled base levels, which commonly prevent from establishing of a clear downdip stratigraphic correlations. Chronological reconstruction of the study depositional dynamics provides solid constrains to frame them in the tectono-sedimentary evolution of the Northern Apennines.

scholarly journals Radiocarbon Ages of Lacustrine Deposits in Volcanic Sequences of the Lomas Coloradas Area, Socorro Island, Mexico

Radiocarbon ◽  
1993 ◽  
Vol 35 (2) ◽  
pp. 253-262 ◽  
Author(s):  
Jack D. Farmer ◽  
Maria C. Farmer ◽  
Rainer Berger
Keyword(s):  
Volcanic Activity ◽  
Drainage System ◽  
Explosive Volcanism ◽  
Volcanic Hazards ◽  
Lacustrine Deposits ◽  
Socorro Island ◽  
Recent Phase ◽  
Sloping Terrain ◽  
Basaltic Flow ◽  
Historical Accounts

Extensive eruptions of alkalic basalt from low-elevation fissures and vents on the southern flank of the dormant volcano, Cerro Evermann, accompanied the most recent phase of volcanic activity on Socorro Island, and created the Lomas Coloradas, a broad, gently sloping terrain comprising the southern part of the island. We obtained 14C ages of 4690 ± 270 BP (5000–5700 cal BP) and 5040 ± 460 BP (5300–6300 cal BP) from lacustrine deposits that occur within volcanic sequences of the lower Lomas Coloradas. Apparently, the sediments accumulated within a topographic depression between two scoria cones shortly after they formed. The lacustrine environment was destroyed when the cones were breached by headward erosion of adjacent stream drainages. This was followed by the eruption of a thin basaltic flow from fissures near the base of the northernmost cone. The flow moved downslope for a short distance and into the drainages that presently bound the study area on the east and west. The flow postdates development of the present drainage system and may be very recent. Our 14C data, along with historical accounts of volcanic activity over the last century, including submarine eruptions that occurred a few km west of Socorro in early 1993, underscore the high risk for explosive volcanism in this region and the need for a detailed volcanic hazards plan and seismic monitoring.

Geological Techniques

2000 ◽  
Author(s):  
Herman R. Kudrass ◽  
Dennis A. Ardus
Keyword(s):  
Continental Shelf ◽  
Slope Failure ◽  
Three Dimensional ◽  
Ocean Basin ◽  
Sediment Supply ◽  
Geological Survey ◽  
Tectonic Activity ◽  
Sea Level Fluctuations ◽  
Sedimentary Evolution

In the previous chapters, the use of geophysical data for delineating the continental shelf has been discussed in some detail. But the determination of the case for any extension of the legal continental shelf beyond 200 nautical miles (M) from the territorial sea baseline may in some circumstances require a geological survey to confirm that a topographic or geophysical feature comprising what appears to be a natural prolongation of land territory is of continental or oceanic origin. A geological survey may also be necessary to determine the occurrence, thickness, and extent of sediments beyond the foot of the slope. Continental margins represent regions of transition from the landmass to the ocean basin and may be present-day areas of sediment erosion or deposition. Sediment supply to the continental shelf and slope, or the extent of erosion on the continental shelf and upper slope, is influenced by tectonic activity, sea-level fluctuations, climate change, variation in the wave or current regime, and various other processes. Bottom currents or gravity transport (turbidity) processes combine to varying degrees with pelagic sedimentation (the accumulation of the remains of marine organisms) to extend the supply of sediment well beyond the shelf and slope to the continental rise, ocean trench, or abyssal plain (Evans et al., 1998). In order to understand the geology of such areas, it is necessary to determine the structural setting, the tectonic and sedimentary evolution, the chrono-and lithostratigraphy, and the volcanic history. Understanding the ocean floor is a prerequisite for the determination of the extent of the continental shelf under UNCLOS. It is also highly relevant to the identification and delineation of mineral and energy resources, for determining the waste disposal potential of parts of the seafloor, and for undertaking an assessment of the risk of slope failure. None of these are directly relevant to establishing the new limits of the continental shelf, but they are highly relevant to its long-term exploitation. In order to achieve the necessary level of knowledge, the seafloor morphology and seabed character derived from bathymetric and sonar surveys (described in chapters 9 and 10) and the three-dimensional geology determined by geophysical surveys using seismic profiling, magnetometer, and gravity meter (discussed in chapters 12 and 13) need to be calibrated or "ground truthed" by sampling and coring (figure 14.1; Stoker et al., 1994).

Geodynamic evolution of the East Carpathian Foreland Basin since the Middle Miocene: Implications for sediment supply to the Black Sea and Dacian Basin

2020 ◽  
Author(s):  
Arjan de Leeuw ◽  
Stephen Vincent ◽  
Anton Matoshko ◽  
Andrei Matoshko ◽  
Marius Stoica ◽  
...  
Keyword(s):  
Black Sea ◽  
Large Scale ◽  
Drainage System ◽  
Foreland Basin ◽  
Continental Collision ◽  
Sediment Supply ◽  
The Black Sea ◽  
Accretionary Wedge ◽  
Sedimentary Architecture ◽  
The Impact

<p>The Carpathian orogen is part of the Alpine-Himalayan collision zone and formed as the result of the collision of the Tisza-Dacia and ALCAPA mega-units with the European southern margin, following a protracted phase of subduction, slab roll-back and accretionary wedge formation. The foreland basin of the East Carpathians is 800 km long and stretches out across Poland, Ukraine, Moldova and Romania. We use the results of our intensive field research to unravel the sedimentary architecture of this basin and reveal how it responded to the final phases of foreland vergent thrusting, continental collision and subsequent slab detachment. We discuss the asymmetry in the basins evolution and eventual inversion and relate this to the diachronous evolution of the Carpathian orogen. We also address the impact of changing subsidence patterns and base-level changes on connectivity with the Central and Eastern Paratethys, important for faunal exchange and patterns of endemism. We finally show that continental collision led to the establishment of a Late Miocene NW-SE prograding axial drainage system in the foreland supplying abundant sediment to the NW Black Sea, thus triggering large-scale shelf edge progradation.</p>

scholarly journals Impact of volcanic and post volcanic activity on fluvial relief

2019 ◽  
pp. 49-66
Author(s):  
E. V. Lebedeva
Keyword(s):  
Explosive Volcanism ◽  
Hydrothermal Activity ◽  
River Network ◽  
Tectonic Activity ◽  
Lava Tubes ◽  
Near Surface ◽  
Volcanic Material ◽  
Mud Volcanism ◽  
High Erosion Rate ◽  
Characteristic Features

The characteristic features of the river network, the structure and functioning of the valleys affected by effusive and explosive volcanism, volcano-tectonic phenomena, gas hydrothermal activity and mud volcanism are revealed. It has been established that within flows and covers of effusives, the formation of new streams channels can occur not only due to backward erosion, but also as a result of the collapse of the roof of the near-surface lava tubes, which are actively used by underground runoff. A high erosion rate, a large volume of solid runoff, and a significant role of deflation in the transformation of the fluvial relief are characteristic for regions of domination of explosive activity. There valleys become zones of accumulation of volcanic material, which is gradually processed by mudflow, alluvial, aeolian and other processes. Volcanic-tectonic activity changes the rivers position, direction of streams and morphology of the valleys, leading to numerous reorganizations of the river network, as a result of which the valleys of modern watercourses often consist of uneven-age fragments. Valleys of hydrothermal zones are characterized by the active development of slope processes, which leads to the formation in them not only of sinter terraces, but also numerous landslide ones. Mud volcanic processes periodically lead to the filling and blocking of the valleys with mud breccia flows, which affects both the composition of the alluvium of watercourses and the morphology of the valleys.

Late Pliocene volcaniclastic products from Southern Apennines: distal witness of early explosive volcanism in the central Tyrrhenian Sea

2008 ◽  
Vol 145 (4) ◽  
pp. 521-536 ◽  
Author(s):  
GIACOMO PROSSER ◽  
MARIO BENTIVENGA ◽  
MARINELLA A. LAURENZI ◽  
ALFREDO CAGGIANELLI ◽  
PIERFRANCESCO DELLINO ◽  
...  
Keyword(s):  
Explosive Volcanism ◽  
Western Mediterranean ◽  
Tyrrhenian Sea ◽  
Density Currents ◽  
Southern Apennines ◽  
Late Pliocene ◽  
Volcanic Material ◽  
High K ◽  
History Of ◽  
Volcaniclastic Rocks

AbstractTwo volcaniclastic successions intercalated in Pliocene basinal clays from the Southern Apennines have been analysed to determine their provenance and their relationship with the geodynamic evolution of the Western Mediterranean. The studied deposits are exclusively made up of ashy pyroclasts, dominated by fresh acidic to intermediate glass, mostly in the form of shards, pumice fragments and groundmass fragments with vitrophyric texture. Crystals include Pl, Opx, Cpx, Hbl and rare Bt. Sedimentological features suggest that the volcanic material accumulated near the basin margin by primary fallout processes and was later remobilized by density currents. 40Ar–39Ar geochronology allowed dating of one succession at 2.24±0.06 Ma, corresponding to the Late Pliocene. Composition of the volcaniclastic material is typical of a transitional high-K calc-alkaline series. The age and chemical composition constrain the provenance of the volcaniclastic rocks from the Southern Tyrrhenian domain. Here, volcanic centres were active during Pliocene time, approximately at the northern end of a volcanic arc formed before the opening of the southernmost part of the sea. This paper shows that a detailed study of volcaniclastic products from the southern Apennines and Calabria can be very useful in collecting new pieces of information on the eruption history of the southern Tyrrhenian domain, since they record additional data not available from the study of exposed volcanic edifices.

scholarly journals Tectono-Sedimentary Evolution of the Cenozoic Basins in the Eastern External Betic Zone (SE Spain)

Geosciences ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 394
Author(s):  
Manuel Martín-Martín ◽  
Francesco Guerrera ◽  
Mario Tramontana
Keyword(s):  
Strike Slip ◽  
Alluvial Fan ◽  
Tectonic Activity ◽  
Time Interval ◽  
Se Spain ◽  
The Third ◽  
Sedimentary Evolution ◽  
Marine Sedimentation ◽  
Geodynamic Processes ◽  
Early Paleocene

Four main unconformities (1–4) were recognized in the sedimentary record of the Cenozoic basins of the eastern External Betic Zone (SE, Spain). They are located at different stratigraphic levels, as follows: (1) Cretaceous-Paleogene boundary, even if this unconformity was also recorded at the early Paleocene (Murcia sector) and early Eocene (Alicante sector), (2) Eocene-Oligocene boundary, quite synchronous, in the whole considered area, (3) early Burdigalian, quite synchronous (recognized in the Murcia sector) and (4) Middle Tortonian (recognized in Murcia and Alicante sectors). These unconformities correspond to stratigraphic gaps of different temporal extensions and with different controls (tectonic or eustatic), which allowed recognizing minor sedimentary cycles in the Paleocene–Miocene time span. The Cenozoic marine sedimentation started over the oldest unconformity (i.e., the principal one), above the Mesozoic marine deposits. Paleocene-Eocene sedimentation shows numerous tectofacies (such as: turbidites, slumps, olistostromes, mega-olistostromes and pillow-beds) interpreted as related to an early, blind and deep-seated tectonic activity, acting in the more internal subdomains of the External Betic Zone as a result of the geodynamic processes related to the evolution of the westernmost branch of the Tethys. The second unconformity resulted from an Oligocene to Aquitanian sedimentary evolution in the Murcia Sector from marine realms to continental environments. This last time interval is characterized as the previous one by a gentle tectonic activity. On the other hand, the Miocene sedimentation was totally controlled by the development of superficial thrusts and/or strike-slip faults zones, both related to the regional geodynamic evolutionary framework linked to the Mediterranean opening. These strike-slip faults zones created subsidence areas (pull-apart basin-type) and affected the sedimentation lying above the third unconformity. By contrast, the subsidence areas were bounded by structural highs affected by thrusts and folds. After the third unconformity, the Burdigalian-Serravallian sedimentation occurred mainly in shallow- to deep-water marine environments (Tap Fm). During the Late Miocene, after the fourth unconformity, the activation of the strike-slip faults zones caused a shallow marine environment sedimentation in the Murcia sector and a continental (lacustrine and fluvial) deposition in the Alicante sector represented the latter, resulting in alluvial fan deposits. Furthermore, the location of these fans changed over time according to the activation of faults responsible for the tectonic rising of Triassic salt deposits, which fed the fan themselves.

scholarly journals U–Pb dating of middle Eocene–Pliocene multiple tectonic pulses in the Alpine foreland

Solid Earth ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 2539-2551
Author(s):  
Luca Smeraglia ◽  
Nathan Looser ◽  
Olivier Fabbri ◽  
Flavien Choulet ◽  
Marcel Guillong ◽  
...  
Keyword(s):  
Middle Eocene ◽  
Regional Scale ◽  
Earthquake Hazard ◽  
Late Eocene ◽  
Passive Margin ◽  
Tectonic Activity ◽  
Thrust Belt ◽  
Fold And Thrust Belt ◽  
Earthquake Hazard Assessment ◽  
Alpine Foreland

Abstract. Foreland fold-and-thrust belts (FTBs) record long-lived tectono-sedimentary activity, from passive margin sedimentation, flexuring, and further evolution into wedge accretion ahead of an advancing orogen. Therefore, dating fault activity is fundamental for plate movement reconstruction, resource exploration, and earthquake hazard assessment. Here, we report U–Pb ages of syn-tectonic calcite mineralizations from four thrusts and three tear faults sampled at the regional scale across the Jura fold-and-thrust belt in the northwestern Alpine foreland (eastern France). Three regional tectonic phases are recognized in the middle Eocene–Pliocene interval: (1) pre-orogenic faulting at 48.4±1.5 and 44.7±2.6 Ma associated with the far-field effect of the Alpine or Pyrenean compression, (2) syn-orogenic thrusting at 11.4±1.1, 10.6±0.5, 9.7±1.4, 9.6±0.3, and 7.5±1.1 Ma associated with the formation of the Jura fold-and-thrust belt with possible in-sequence thrust propagation, and (3) syn-orogenic tear faulting at 10.5±0.4, 9.1±6.5, 5.7±4.7, and at 4.8±1.7 Ma including the reactivation of a pre-orogenic fault at 3.9±2.9 Ma. Previously unknown faulting events at 48.4±1.5 and 44.7±2.6 Ma predate the reported late Eocene age for tectonic activity onset in the Alpine foreland by ∼10 Myr. In addition, we date the previously inferred reactivation of pre-orogenic strike-slip faults as tear faults during Jura imbrication. The U–Pb ages document a minimal time frame for the evolution of the Jura FTB wedge by possible in-sequence thrust imbrication above the low-friction basal decollement consisting of evaporites.

scholarly journals Morphometry and geomorphic development of the Bagmati River Basin, Nepal Himalaya

2013 ◽  
Vol 46 ◽  
Author(s):  
Pramila Shrestha ◽  
Naresh Kazi Tamrakar
Keyword(s):  
River Basin ◽  
Quantitative Description ◽  
Drainage System ◽  
Higher Order ◽  
Tectonic Activity ◽  
Mature Stage ◽  
Channel Network ◽  
Order Stream ◽  
Tectonic Zone ◽  
Bagmati River

Morphometric analysis of a watershed provides a quantitative description of the drainage system which is an important aspect of characterization of watershed. The analysis requires measurement of linear features, aerial aspects, gradient of channel network and contributing ground slopes of the drainage basin. The morphometric characteristics at the watershed-scale may contain important information regarding its formation and development because all hydrologic and geomorphic processes occur within the watershed. In this study morphometric property of the Bagmati River Basin (BRB) was investigated using different morphometric attributes and hypsometric analysis in order to investigate geomorphic development of the river basin, in an active tectonic zone. DEM has been prepared from the contour and spot height data using digital topographic maps of 1:25000-scale acquired from the Department of Survey, Nepal. The main stem Bagmati River is the eighth order perennial river that stretches for 206 km with an elongated catchment of area 3761 sq. km. It consists of 39 sub-basins of fourth order and higher. The study shows that the drainage system of the BRB is attaining a mature stage from a youth stage from lower order streams to the higher order streams in geomorphic development process. Some exceptions occurred at higher order stream segments, where drainage development seems to control by structure and lithology. According to the analytical results, erosional stage and level of tectonic activity of sub-basins differ from each other. Generally, the lithology and geological structure seems to control the drainage texture and relief of the BRB. The river system within the Kathmandu Valley is attaining maturity having meandering channels with wide flood plains, whereas rivers of the Lesser Himalaya and the Siwaliks are at youth stage with erosional potential. The downstream part of higher order stream segments are in mature stage having potential for lateral erosion and meander migration. Therefore, the Bagmati River stretch, especially the eight order one poses vulnerability to bank erosion.

scholarly journals A multidisciplinary study of ecosystem evolution through early Pleistocene climate change from the marine Arda River section, Italy

2018 ◽  
Vol 89 (2) ◽  
pp. 533-562 ◽  
Author(s):  
Gaia Crippa ◽  
Andrea Baucon ◽  
Fabrizio Felletti ◽  
Gianluca Raineri ◽  
Daniele Scarponi
Keyword(s):  
Climate Change ◽  
Integrated Approach ◽  
Early Pleistocene ◽  
Tectonic Activity ◽  
Delta Front ◽  
Multidisciplinary Study ◽  
Sedimentary Evolution ◽  
Pleistocene Climate ◽  
Pleistocene Climate Change ◽  
Uplift And Erosion

AbstractThe Arda River marine succession (Italy) is an excellent site to apply an integrated approach to paleoenvironmental reconstructions, combining the results of sedimentology, body fossil paleontology, and ichnology to unravel the sedimentary evolution of a complex marine setting in the frame of early Pleistocene climate change and tectonic activity. The succession represents a subaqueous extension of a fluvial system, originated during phases of advance of fan deltas affected by high-density flows triggered by river floods, and overlain by continental conglomerates, indicating a relative sea level fall and the establishment of a continental environment. An overall regressive trend is observed through the section, from prodelta to delta front and intertidal settings. The hydrodynamic energy and the sedimentation rate are not constant through the section, but they are influenced by hyperpycnal flows, whose sediments were mainly supplied by an increase in Apennine uplift and erosion, especially after 1.80 Ma. The Arda section documents the same evolutionary history of coeval successions in the Paleo-Adriatic region, as well as the climatic changes of the early Pleistocene. The different approaches used complement quite well one another, giving strength and robustness to the obtained results.

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