scholarly journals Snail assemblages in Holocene floodplain research – an example from the southern Caucasus

2020 ◽  
Vol 69 (2) ◽  
pp. 247-260
Author(s):  
Hans von Suchodoletz ◽  
Christiane Richter ◽  
Frank Walther ◽  
Marcel Bliedtner ◽  
Mariam Eloshvili ◽  
...  
Keyword(s):  
Late Holocene ◽  
Large Scale ◽  
Late Quaternary ◽  
River Sediments ◽  
Tectonic Activity ◽  
Natural Forests ◽  
Late Neolithic ◽  
Caucasus Region ◽  
Southern Caucasus ◽  
Local Shift

Abstract. During the last decades, rivers and their deposits in different regions were intensively studied to better understand the late-Quaternary landscape evolution and former human activities. One proxy for paleoecological and paleoclimatic reconstructions is the analysis of gastropods (snails) from carbonatic river sediments. In the scope of this study, we investigated gastropod assemblages from a Holocene fluvial sediment–paleosol sequence at the upper Alazani River in the southeastern Caucasus. On the one hand, we aimed to derive reliable independent information about possible long-lasting human activity since the late Neolithic–Chalcolithic in the upper Alazani floodplain. This was formerly suggested by n-alkane biomarker vegetation reconstructions from the fluvial sediments. However, the reliability of that method is still debated. On the other hand, we aimed to obtain reliable information about a formerly suggested, possibly tectonic-driven, large-scale shift of the river course during the Late Holocene. In agreement with the n-alkane biomarkers, our results demonstrate that the studied site was free of the natural forests during the Early and Middle Holocene until ca. 4.5 cal kyr BP. Since this contrasts with a pollen-based vegetation reconstruction from a neighboring floodplain that was covered with forests during that time, the open vegetation in the upper Alazani valley was probably caused by continuous settlement activity as is also indicated by archeological finds in the sequence. Therefore, using our paleoecological proxies it is possible that we identified a settlement center in the upper Alazani floodplain that was populated from the late Neolithic–Chalcolithic. This center was not known thus far, since the settlement remains are covered by thick floodloam today that hindered their detection during archeological surface surveys. Therefore, our findings suggest that the area in the southern Caucasus region that was settled during the late-Neolithic–Chalcolithic period should have been larger than was known thus far. Furthermore, increasing contributions of wetland gastropods since ca. 4 cal kyr BP confirm a local shift of the river course towards the investigated site during the Late Holocene, possibly linked with ongoing tectonic activity. However, in contrast to former suggestions our gastropod assemblages indicate a slow rather than abrupt process. Our study demonstrates the high value of gastropod assemblages for geoarcheological and geomorphological research in floodplains with carbonatic river sediments at both a regional and local spatial scale.

Late Quaternary fluvial dynamics and landscape evolution at the lower Shulaveris Ghele River (southern Caucasus)

2017 ◽  
Vol 89 (1) ◽  
pp. 254-269 ◽  
Author(s):  
Hans von Suchodoletz ◽  
Dominik Faust
Keyword(s):  
Late Quaternary ◽  
Eastern Mediterranean ◽  
Eastern Mediterranean Region ◽  
Anthropogenic Factors ◽  
Neolithic Period ◽  
Late Neolithic ◽  
Fluvial Dynamics ◽  
History Of ◽  
Southern Caucasus ◽  
Fluvial Sedimentation

AbstractThe southern Caucasus was intensively settled through the Neolithic period to present. Studies of late Quaternary fluvial dynamics and landscape development at the lower Shulaveris Ghele River in southeastern Georgia aid understanding of the Quaternary history of this region. Our studies show that following river aggradation to form a fan-shaped alluvial surface during the late Pleistocene, fluvial sedimentation shifted west, leaving a fan surface subject only to local fluvial and colluvial processes as well as late Neolithic settlement. At about 6 ka, the river avulsed to the east and eroded some late Neolithic settlements occupying the eastern portion of the fan. The avulsion was followed by 3 distinct episodes of aggradation at about 6 ka, 3–2 ka, and since 1.0 ka. No such aggradation is evident in the early Holocene. Regional Holocene fluvial activity in this area was apparently influenced by vegetation dynamics, possibly controlled by regional climatic and/or anthropogenic factors, and significantly differs from the eastern Mediterranean region. All late Neolithic settlements were originally built far from an active river, possibly indicating late Neolithic water management systems.

scholarly journals Beyond Newgrange: Brú na Bóinne in the later Neolithic

2021 ◽  
pp. 1-30
Author(s):  
Stephen Davis ◽  
Knut Rassmann
Keyword(s):  
Large Scale ◽  
Morphological Characteristics ◽  
World Heritage ◽  
Geophysical Survey ◽  
World Heritage Site ◽  
Late Neolithic ◽  
Non Invasive ◽  
Heritage Site ◽  
New Evidence

The Brú na Bóinne World Heritage Site, Ireland is best known for its megalithic monuments, in particular the great developed passage tombs of Knowth, Dowth, and Newgrange, and its abundance of megalithic art. However, our understanding of the wider Brú na Bóinne landscape has changed beyond all recognition in the last decade owing to the application of modern, non-invasive survey technologies – in particular LiDAR and large-scale geophysical survey – and most recently as a result of the hot, dry summer of 2018 which revealed a series of remarkable cropmarks between Newgrange and the River Boyne. Despite a lack of excavation it can be argued, based on their morphological characteristics, that many of the structures revealed belong within the corpus of late Neolithic ritual/ceremonial structures, including earthen henges, square-in-circle monuments, palisaded enclosures, and pit/post-alignments. These display both extraordinary diversity, yet also commonality of design and architecture, both as a group and with the passage tombs that preceded them. This paper provides an up-to-date survey of the late Neolithic and presumed late Neolithic landscape of Brú na Bóinne. It provides new evidence and new insights from ongoing survey campaigns, suggesting parallels within the British Neolithic but also insular development within some monument classes.

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 Large Evaporite Provinces: Geothermal rather than Solar Origin?

2020 ◽  
Author(s):  
Zhanjie Qin ◽  
Chunan Tang ◽  
Xiying Zhang ◽  
Tiantian Chen ◽  
Xiangjun Liu ◽  
...  
Keyword(s):  
Large Scale ◽  
Climatic Factors ◽  
Temporal Distribution ◽  
Tectonic Activity ◽  
Driving Mechanism ◽  
Solar Origin ◽  
Tectonically Active ◽  
Spatio Temporal ◽  
Thermal Influence ◽  
The Masses

Abstract Large evaporite provinces (LEPs) represent prodigious volumes of evaporites widely developed from the Sinian to Neogene. The reasons why they often quickly develop on a large scale with large areas and thicknesses remain enigmatic. Possible causes range from warming from above to heating from below. The fact that the salt deposits in most salt-bearing basins occur mainly in the Sinian-Cambrian, Permian-Triassic, Jurassic-Cretaceous, and Miocene intervals favours a dominantly tectonic origin rather than a solar driving mechanism. Here, we analysed the spatio-temporal distribution of evaporites based on 138 evaporitic basins and found that throughout the Phanerozoiceon, LEPs occurred across the Earth’s surface in most salt-bearing basins, especially in areas with an evolutionary history of strong tectonic activity. The masses of evaporites, rates of evaporite formation, tectonic movements, and large igneous provinces (LIPs) synergistically developed in the Sinian-Cambrian, Permian, Jurassic-Cretaceous, and Miocene intervals, which are considered to be four of the warmest times since the Sinian. We realize that salt accumulation can proceed without solar energy and can generally be linked to geothermal changes in tectonically active zones. When climatic factors are involved, they may be manifestations of the thermal influence of the crust on the surface.

scholarly journals Understanding the Stability of Early Iron Age folks of South India with Special Reference to Krishna-Tungabhadra- Kaveri, Karnataka; Their Past-Present-Future

2014 ◽  
Vol 13 (4) ◽  
pp. 47
Author(s):  
Arjun R
Keyword(s):  
Iron Age ◽  
Large Scale ◽  
South India ◽  
Early Iron Age ◽  
Late Neolithic ◽  
Early Historic Period ◽  
Indigenous Development ◽  
Iron Smelting ◽  
The Stability ◽  
The Hill

There are about 1933 Early Iron Age Megalithic sites spread across South India. The Early Iron Age of South India is implicit either in the form of burial sites, habitation sites, habitation cum burial sites, Iron Age rock art sites, and isolated iron smelting localities near a habitation or burials. This paper is an attempt to take a rough computation of the potentiality of the labour, technology and quantity of artifact output that this cultural phase might have once had, in micro or in macro level. Considering the emergence of technology and its enormous output in Ceramics, Agriculture, Metallurgy and Building up Burials as industries by themselves, that has economic, ethnographic and socio-technique archaeological imprints. This helps in understanding two aspects: one, whether they were nomadic, semi settled or settled at one location; two, the Diffusion versus Indigenous development. A continuity of late Neolithic phase is seen into Early Iron Age and amalgamation of Early Iron Age with the Early Historic Period as evident in the sites like Maski, Brahmagiri, Sanganakallu, Tekkalakota, T-Narasipur. In few cases, Iron Age folks migrated from one location to the other and settled on the river banks in large scale like that in Hallur and Koppa. In rare cases, they preferred to climb up the hill and stay on the rocky flat surface for example Aihole and Hiere Bekal– sites which are located close to or on the banks of the river or its tributaries of Krishna-Tungabhadra- Kaveri.Keywords: Labour, Industry, Production, Megaliths, Nomadic, Semi Settled, Early Iron Age.

­Utilization and Medicinal Uses of Eucalyptus in Uttar Pradesh, India

2015 ◽  
Vol 22 (1) ◽  
pp. 43-46
Author(s):  
Amit Tomar
Keyword(s):  
Large Scale ◽  
Folk Medicine ◽  
Uttar Pradesh ◽  
Natural Forests ◽  
Wooden Floor ◽  
Medicinal Uses ◽  
Eucalyptus Wood ◽  
Major Species ◽  
The World ◽  
Private Farm

In this paper highlights a brief description of Eucalyptus is provided along with its utilization and importance. It is one of the fastest growing trees in the world and many species attain great heights. It is popularly known as Safeda and Gum tree, several species are cultivated in this region of Uttar Pradesh. Wood is buying back with rate of kg. 12-14 Rs. /kg. One plant becomes sale out minimum Rs. 2500-3000. Large scale plantations have been raised in government owned and private farm lands, the planting is continuing. Eucalyptus supplies for people and industries and has helped to reduce pressure on natural forests. The economics of its plantations varies depending upon the use to which it is put. Firewood is the main source of energy in Uttar Pradesh. The Eucalyptus wood which is marketed is used either as firewood or as pulpwood by the paper and rayon industries. Its wood has been tried as timber for constructional purpose, furniture making. Wooden floor, Charcoal and pulp and paper. It is also used to preparation of folk medicine in this area. These species are grown and identified as major species, Eucalyptus globulus Labill, E. umbellata Domin, E. paniculata Sm., E. citriodora Hook., E. rudis and E. camaldulensis Dehnh. in Uttar Pradesh.

Hydrofractures and crustal-scale fluid flow

2021 ◽  
Author(s):  
Paul D. Bons ◽  
Tamara de Riese ◽  
Enrique Gomez-Rivas ◽  
Isaac Naaman ◽  
Till Sachau
Keyword(s):  
Fluid Flow ◽  
Large Scale ◽  
Low Flow ◽  
Fault System ◽  
Tectonic Activity ◽  
Field Evidence ◽  
Dehydration Reactions ◽  
Matrix Flow ◽  
Matrix Porosity ◽  
Fluid Sources

<p>Fluids can circulate in all levels of the crust, as veins, ore deposits and chemical alterations and isotopic shifts indicate. It is furthermore generally accepted that faults and fractures play a central role as preferred fluid conduits. Fluid flow is, however, not only passively reacting to the presence of faults and fractures, but actively play a role in their creation, (re-) activation and sealing by mineral precipitates. This means that the interaction between fluid flow and fracturing is a two-way process, which is further controlled by tectonic activity (stress field), fluid sources and fluxes, as well as the availability of alternative fluid conduits, such as matrix porosity. Here we explore the interaction between matrix permeability and dynamic fracturing on the spatial and temporal distribution of fluid flow for upward fluid fluxes. Envisaged fluid sources can be dehydration reactions, release of igneous fluids, or release of fluids due to decompression or heating.</p><p> </p><p>Our 2D numerical cellular automaton-type simulations span the whole range from steady matrix-flow to highly dynamical flow through hydrofractures. Hydrofractures are initiated when matrix flow is insufficient to maintain fluid pressures below the failure threshold. When required fluid fluxes are high and/or matrix porosity low, flow is dominated by hydrofractures and the system exhibits self-organised critical phenomena. The size of fractures achieves a power-law distribution, as failure events may sometimes trigger avalanche-like amalgamation of hydrofractures. By far most hydrofracture events only lead to local fluid flow pulses within the source area. Conductive fracture networks do not develop if hydrofractures seal relatively quickly, which can be expected in deeper crustal levels. Only the larger events span the whole system and actually drain fluid from the system. We present the 10 square km hydrothermal Hidden Valley Mega-Breccia on the Paralana Fault System in South Australia as a possible example of large-scale fluid expulsion events. Although field evidence suggests that the breccia formed over a period of at least 150 Myrs, actual cumulative fluid duration may rather have been in the order of days only. This example illustrates the extreme dynamics that crustal-scale fluid flow in hydrofractures can achieve.</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 Ancient DNA shows domestic horses were introduced in the southern Caucasus and Anatolia during the Bronze Age

2020 ◽  
Vol 6 (38) ◽  
pp. eabb0030
Author(s):  
Silvia Guimaraes ◽  
Benjamin S. Arbuckle ◽  
Joris Peters ◽  
Sarah E. Adcock ◽  
Hijlke Buitenhuis ◽  
...  
Keyword(s):  
Bronze Age ◽  
Iron Age ◽  
Large Scale ◽  
Early Neolithic ◽  
The Caucasus ◽  
Domestic Horses ◽  
Third Millennium Bce ◽  
History Of ◽  
Southern Caucasus ◽  
The Bronze Age

Despite the important roles that horses have played in human history, particularly in the spread of languages and cultures, and correspondingly intensive research on this topic, the origin of domestic horses remains elusive. Several domestication centers have been hypothesized, but most of these have been invalidated through recent paleogenetic studies. Anatolia is a region with an extended history of horse exploitation that has been considered a candidate for the origins of domestic horses but has never been subject to detailed investigation. Our paleogenetic study of pre- and protohistoric horses in Anatolia and the Caucasus, based on a diachronic sample from the early Neolithic to the Iron Age (~8000 to ~1000 BCE) that encompasses the presumed transition from wild to domestic horses (4000 to 3000 BCE), shows the rapid and large-scale introduction of domestic horses at the end of the third millennium BCE. Thus, our results argue strongly against autochthonous independent domestication of horses in Anatolia.

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