Extreme wave events recorded in sedimentary archives of the Geropotamos River (north-central Crete, Greece)

2019 ◽  
Vol 62 (2) ◽  
pp. 63-100
Author(s):  
Vera Werner ◽  
Kalliopi Baika ◽  
Anastasia Tzigounaki ◽  
Klaus Reicherter ◽  
Ioannis Papanikolaou ◽  
...  
Keyword(s):  
Bronze Age ◽  
Sedimentary Environment ◽  
River Mouth ◽  
High Energy ◽  
River Valley ◽  
Coarse Grained ◽  
Northern Coast ◽  
Natural Setting ◽  
Extreme Wave ◽  
Cretan Sea

Recent tsunami events have shown that tsunamis may propagate far inland by entering rivers mouths and may cause massive damage along the river banks. However, so far, only a few studies have been conducted such a search for studying tsunami signals in incised valley systems along the Mediterranean coasts although the tsunami hazard is high. The island of Crete is known to have been affected several times by strong tsunamis, e. g., by the AD 365 and the Late Bronze Age (LBA) Santorini tsunamis. The narrow Geropotamos River valley, distinctly incised into local bedrock and located at the northern coast of Crete and fully exposed to the Cretan Sea, was selected as a promising natural setting to search for palaeotsunami signatures in fluvial sedimentary archives. Based on a multi-electrode geoelectrical survey and a set of sediment cores, we investigated the event-geochronostratigraphic record of both the Geropotamos River mouth area and the river valley ca. 1 km upstream by means of sedimentological, geo-chemical, geochronological, geomorphological, and micropalaeontological methods. The sedimentary environment towards the present-day river mouth is dominated by (fluvio-)lagoonal muds since the mid- Holocene. These lagoonal sediments are intersected by six coarse-grained sand layers each representing an extreme wave event (EWE). EWE layers are up to several decimetres thick and are characterized by an allochthonous foraminiferal assemblage comprising shallow marine to open marine species. Also ca. 1 km further upstream, the sedimentary record revealed grain size and microfossil evidence of two high-energy events showing a clear marine imprint. Based on this, we suggest inundation from the seaside that reached minimum 1 km inland and left EWE signatures in a presently inactive external bank position of the Geropotamos River. Considering the sedimentary characteristics, the local wind and wave climate of the Cretan Sea, and the overall geomorphological setting, we interpret these EWE layers as tsunami- related. A major hiatus identified in the Geropotamos River mouth sediments seems to be related to the LBA Santorini tsunami as can be inferred based on local age-depth relations. The LBA tsunami is known to have severely hit the northern coast of Crete. However, the hiatus may also reflect changes in the subsidence rate and the local accommodation space architecture. The youngest EWE signal in the Geropotamos River archive appears to have been caused by the AD 365 tsunami event. Candidate deposits for both tsunami deposits were identified ca. 1 km further inland. Evidence of EWE impact documents channelling and acceleration effects of intruding water masses caused by the narrow and steeply incised Geropotamos River valley in an upstream direction. Further geochronological studies based on OSL dating are necessary for a reliable age control of these EWE candidate layers.

Evolution and stratigraphy of the Nakdong River valley deposits in response to late Quaternary sea-level change

2020 ◽  
Author(s):  
Dong-Geun Yoo ◽  
Seok-Hwi Hong ◽  
Gwang-Soo Lee ◽  
Jin-Cheul Kim ◽  
Gil-Young Kim ◽  
...  
Keyword(s):  
Sea Level ◽  
River Mouth ◽  
River Valley ◽  
Coarse Grained ◽  
Nakdong River ◽  
Delta Front ◽  
Delta Plain ◽  
Depositional System ◽  
Depositional Systems ◽  
The Nakdong River

<p>Sequence analysis using borehole samples and high-resolution seismic data in the Nakdong River valley reveals that the Nakdong River valley deposits, approximately 60 - 70 m thick, consist of a set of lowstand, transgressive, and highstand systems tracts that corresponds to a fifth-order (20 ka) sea-level cycle. Four main depositional systems, including ten sedimentary facies, constitute these systems tracts: fluvial, estuary, coastal/shoreface, and delta. The lowstand systems tract (LST), consisting of gravelly sand, forms a fluvial depositional system (Unit I) which fills the thalweg of river valley mainly developed approximately before 12 ka. The transgressive systems tract (TST) can be divided into two depositional systems (Unit II and III). The river-derived sediments were trapped within the paleo-estuary, forming an estuarine depositional system (Unit II) developed between 12 and 6 ka. As the transgression continued, the coarse sediments were deposited and redistributed by coastal processes, resulting in coastal/shoreface depositional system (Unit III). It is characterized by an isolated sand body and thin sand veneer. The HST is composed of deltaic depositional system including delta plain, delta front, and prodelta (Unit IV). During the delta progradation, most coarse-grained sands derived from the river were deposited in the lower delta plain and delta front, forming sand bars and shoals less than 15 m deep. The remaining fine-grained sediments were transported further offshore in a suspension mode and deposited in the inner shelf off the present river mouth, forming a subaqueous prodelta. Radiocarbon and optica<strong>lly stimulated luminescence (OSL</strong>) dating suggest that the recent deltaic system was initiated by aggradational and progradational stacking patterns at approximately 8 ka during the last stage of decelerated sea-level rise, and was then followed by a prograding clinoform after the highest sea level at approximately 6 ka.</p>

scholarly journals Characterization of a glacial paleo-outburst flood using high-resolution 3-D seismic data: Bjørnelva River Valley, SW Barents Sea

2021 ◽  
pp. 1-17
Author(s):  
B. Bellwald ◽  
S. Planke ◽  
S. Polteau ◽  
N. Lebedeva-Ivanova ◽  
J.I. Faleide ◽  
...  
Keyword(s):  
Seismic Data ◽  
Barents Sea ◽  
Ice Sheets ◽  
River System ◽  
High Energy ◽  
River Valley ◽  
Coarse Grained ◽  
Early Pleistocene ◽  
Braided River ◽  
River Systems

Abstract Proglacial braided river systems discharge large volumes of meltwater from ice sheets and transport coarse-grained sediments from the glaciated areas to the oceans. Here, we test the hypothesis if high-energy hydrological events can leave distinctive signatures in the sedimentary record of braided river systems. We characterize the morphology and infer a mode of formation of a 25 km long and 1–3 km wide Early Pleistocene incised valley recently imaged in 3-D seismic data in the Hoop area, SW Barents Sea. The fluvial system, named Bjørnelva River Valley, carved 20 m deep channels into Lower Cretaceous bedrock at a glacial paleo-surface and deposited 28 channel bars along a paleo-slope gradient of ~0.64 m km−1. The landform morphologies and position relative to the paleo-surface support that Bjørnelva River Valley was formed in the proglacial domain of the Barents Sea Ice Sheet. Based on valley width and valley depth, we suggest that Bjørnelva River Valley represents a braided river system fed by violent outburst floods from a glacial lake, with estimated outburst discharges of ~160 000 m3 s−1. The morphological configuration of Bjørnelva River Valley can inform geohazard assessments in areas at risk of outburst flooding today and is an analogue for landscapes evolving in areas currently covered by the Greenland and Antarctic ice sheets.

scholarly journals ARCHAEOLOGY AT RAS MUARI: SONARI, A BRONZE AGE FISHER-GATHERERS SETTLEMENT AT THE HAB RIVER MOUTH (KARACHI, PAKISTAN)

2020 ◽  
pp. 1-51
Author(s):  
Paolo Biagi ◽  
Renato Nisbet ◽  
Michela Spataro ◽  
Elisabetta Starnini
Keyword(s):  
Material Culture ◽  
Bronze Age ◽  
Arabian Sea ◽  
Environmental Changes ◽  
River Mouth ◽  
Archaeological Sites ◽  
Northern Coast ◽  
Indus Civilisation ◽  
Different Parts ◽  
Ams Dates

This paper describes the results of the surveys carried out along Ras Muari (Cape Monze, Karachi, Sindh) by the Italian Archaeological Mission in Lower Sindh and Las Bela in 2013 and 2014. The surveyed area coincides with part of the mythical land of the Ichthyophagoi, mentioned by the classical chroniclers. Many archaeological sites, mainly scatters and spots of fragmented marine and mangrove shells, were discovered and AMS dated along the northern part of the cape facing the Hab River mouth. The surveys have shown that fisher and shell gatherer communities temporarily settled in different parts of the headland. They began to exploit the sea resources during the Neolithic. However, the most important discovery consists of a unique fishers’ settlement with rectangular stone-walled structures located on a limestone terrace near Sonari (SNR-1), the first ever found along the northern coast of the Arabian Sea. The AMS dates show that it was settled mainly during the first half of the third millennium cal bc when the Indus Civilisation flourished in the area. Considering the importance of the discovery, all the material culture remains from the Sonari sites have been described and analysed in detail and, whenever possible, framed into the different phases of environmental changes and human adaptation to the coastal environment that have been interpreted thanks to a good series of AMS dates from marine and mangrove shells.

Stratigraphy and palaeoenvironments of the Red Crag and Norwich Crag formations between Aldeburgh and Sizewell, Suffolk, England

1988 ◽  
Vol 322 (1210) ◽  
pp. 221-272 ◽  
Keyword(s):  
Amino Acid ◽  
High Energy ◽  
Coarse Grained ◽  
Core Material ◽  
Stage System ◽  
Pollen And Spores ◽  
Shallow Marine Sediments ◽  
Amino Acid Chronology ◽  
Tectonic Origin ◽  
Borehole Core

This study uses a variety of criteria to examine short-range correlation within the Crag deposits in order to assess the validity of longer-range correlations within the British Pleistocene stage system. To this end, six rotary cored boreholes spaced at 0.5-1.0 km intervals were drilled along a north-south-aligned traverse between Aldeburgh and Sizewell, Suffolk. These show that the thick Red/Norwich Crag sequence is confined to a deep, sharply bounded basin, which is of probable erosional rather than tectonic origin. The undisturbed borehole core material enabled an assessment of the limits of stratigraphic resolution within these dominantly high-energy, shallow marine sediments to be made. Subdivision of the sequence was done on the basis of lithostratigraphical and biostratigraphical (foraminifera, pollen and spores, dinoflagellate cysts, and molluscs) criteria; chronostratigraphical methods (palaeomagnetism and amino acid chronology) were also applied. The various subdivisions indicated by each of these disciplines were in large part consistent, demonstrating that valid stratigraphic units had been identified. Only amino acid chronology did not indicate any obvious subdivision of the sequence. Three lithostratigraphical units were recognized within the thick Crag sequence. The lowest unit (AS-Lith 1) consists of coarse shelly sands interbedded with thinly laminated muds and fine sands. The middle unit (AS-Lith 2) consists of fine- to coarse-grained shelly sands arranged in two coarsening-upwards cycles. Units AS-Lith 1 and AS-Lith 2 are correlated on a lithostratigraphical basis with the Red Crag Formation of the adjacent Aldeburgh-Orford area to the south and are named the Sizewell Member and the Thorpeness Member respectively. The uppermost unit (AS-Lith 3) comprises fine- to medium-grained, well-sorted sands; it correlates with the Chillesford Sand Member of the Norwich Crag Formation of the adjacent Aldeburgh-Orford area. The Sizewell Member of the Red Crag Formation is normally magnetized and palaeontologically distinctive. The pollen, foraminifera and dinoflagellate assemblages firmly establish it as Pre-Ludhamian in age, and probably equivalent to an interval within the Reuverian C to Praetiglian Stages of the Netherlands. The Thorpeness Member of the Red Crag Formation is less easy to place within the British Pleistocene stage system. It is reverse magnetized, at least in part, and foraminifera assemblages suggest possible correlation with the Ludhamian Stage. No identifiable pollen or dinoflagellate assemblages were obtained. The Chillesford Sand Member of the Norwich Crag Formation is largely unfossiliferous but the borehole material has yielded a single pollen spectrum that suggests correlation with the Bramertonian Stage.

scholarly journals Description of extreme-wave deposits on the northern coast of Bonaire, Netherlands Antilles

2010 ◽  
Author(s):  
Steven G. Watt ◽  
Bruce E. Jaffe ◽  
Robert A. Morton ◽  
Bruce M. Richmond ◽  
Guy Gelfencaum
Keyword(s):  
Northern Coast ◽  
Extreme Wave ◽  
Netherlands Antilles

scholarly journals In the Sorraia River Valley (Coruche, Portugal): Settlement Dynamics of Ancient Peasant Societies on the Left Bank of the Lower Tagus River (5500 to 1800 B.C.E.)

2021 ◽  
Vol 31 ◽  
pp. 95-158
Author(s):  
Ana Catarina Sousa ◽  
Victor S. Gonçalves ◽  
André Texugo ◽  
Ana Ramos-Pereira
Keyword(s):  
Bronze Age ◽  
River Valley ◽  
Early Bronze Age ◽  
Left Bank ◽  
Late Neolithic ◽  
Economic Changes ◽  
Tagus River ◽  
Settlement Dynamics

This article is the result of archaeological and paleoenvironmental investigations carried out within the scope of the ANSOR project in the Sorraia valley (Coruche), on the left bank of the Lower Tagus. In the analysis of settlement dynamics between 5500 and 1800 a.n.e. we considered four moments: 1) The first peasant societies of the ancient Neolithic; 2) The Middle and Late Neolithic; 3) Chalcolithic; 4) The Early Bronze Age. The Sorraia valley was also framed in the framework of the Center and South of Portugal during the period under analysis. Interpretative models are presented for changes in the implantation patterns in the four stages under study, oscillating between paleoenvironmental factors and the socio-economic changes registered in the old peasant societies. 

scholarly journals Microstructural Transitions during Powder Metallurgical Processing of Solute Stabilized Nanostructured Tungsten Alloys

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 159
Author(s):  
Nicholas Olynik ◽  
Bin Cheng ◽  
David J. Sprouster ◽  
Chad M. Parish ◽  
Jason R. Trelewicz
Keyword(s):  
Extreme Environments ◽  
High Energy ◽  
Grain Structure ◽  
Coarse Grained ◽  
Ultrafine Grain ◽  
Grain Boundary Engineering ◽  
Carbon Impurities ◽  
Grain Structures ◽  
Metallurgical Processing ◽  
Size Population

Exploiting grain boundary engineering in the design of alloys for extreme environments provides a promising pathway for enhancing performance relative to coarse-grained counterparts. Due to its attractive properties as a plasma facing material for fusion devices, tungsten presents an opportunity to exploit this approach in addressing the significant materials challenges imposed by the fusion environment. Here, we employ a ternary alloy design approach for stabilizing W against recrystallization and grain growth while simultaneously enhancing its manufacturability through powder metallurgical processing. Mechanical alloying and grain refinement in W-10 at.% Ti-(10,20) at.% Cr alloys are accomplished through high-energy ball milling with transitions in the microstructure mapped as a function of milling time. We demonstrate the multi-modal nature of the resulting nanocrystalline grain structure and its stability up to 1300 °C with the coarser grain size population correlated to transitions in crystallographic texture that result from the preferred slip systems in BCC W. Field-assisted sintering is employed to consolidate the alloy powders into bulk samples, which, due to the deliberately designed compositional features, are shown to retain ultrafine grain structures despite the presence of minor carbides formed during sintering due to carbon impurities in the ball-milled powders.

scholarly journals Stone Industry of Layer 2 at Ust’-Kutarey Site (North Angara Region)

2019 ◽  
Vol 18 (3) ◽  
pp. 62-73
Author(s):  
A. N. Chekha
Keyword(s):  
Bronze Age ◽  
18Th Century ◽  
Northeast Asia ◽  
River Mouth ◽  
Hydroelectric Power Station ◽  
Left Bank ◽  
Hydroelectric Power ◽  
The North ◽  
Layer 2 ◽  
Stone Industry

Purpose. There are many archaeological sites located in the North Angara region. Although this territory has been investigated since 18th century, most intensive work was done during rescue archaeological works on Boguchany hydroelectric power station in 2008–2011. One of the valuable sources of artifacts is the Kutarey site. Our work contains a brief analysis of stone industries of the Kutarey River Mouth site. The main goal of this work is to apply technical and typological analysis to mark the specificity of the stone industries of layer 2 of the Kutarey River Mouth site in comparison with the results that had been previously published on layer 3 in the context of new data of this region in terms of ceramics complexes. We introduce a previously unpublished collection of stone artifacts of layer 2 of the Kutarey River Mouth site, which significantly extends the source base of the Neolithic and Bronze Age in this region. Results. The Kutarey River Mouth site is located on the left bank of the Angara River, 15 km down from the Kezhma village, on the right bank of the Kutarey River. The location was found in 1974 by N. I. Drozdov and his squad. The site was further investigated in 2008 and in 2010 by an IAE SB RAS squad (guided by A. N. Savin). Firstly, the site was determined as a Neolithic location, but as result of 2010 excavations three Neolithic-Middle Age cultural horizons were discovered. In the context of the difficulties connected with conducting investigations in this region, namely an open location, a low stratigraphy situation, a high extend of technogenic interruption, the materials of layer 3 are most perspective due to a high grade of saturation of the artifacts and minimal technogenic interruptions. These materials belong to the Neolithic and Paleometal Era. In order to clarify cultural and chronological specificity of this complex, it is necessary to analyze materials from layer 2. The stone industry of layer 2 is represented by retouching microblades, bladelets, tools for blades, flakes, scrapers including one microscraper, bifaces, several adzes, axes, and one piercing tool. Of special interest are blade points and trihedral and tetrahedral points. Conclusion. Our technical and typological analyses show that in comparison to layer 3, layer 2 is characterized by a small number of massive axes and adzes, no flints, few double scrapers, and only volume splitting tools aimed mainly at obtaining a small blade. Also, despite the fact that the core of the collection is the product of the hornstones of local origin, we observe a significant increase in the percentage of artifacts made of flint (13 %), which may indicate some new commodity strategies. The most interesting analogy can be traced with the dedicated Upper Kolyma Early Holocene complex, which contained blade points widely distributed in Northeast Asia and was present directly or indirectly in the materials from Chukotka (Verkhnetirsky IV and Nizhnechutinsky IV), Yakutia (Olbinski burial ground, Jubilee), Kamchatka (the Ushki I–IV layer, Avacha 1,9). This complex is believed to belong to specific Volbinsky traditions, which formed in the first half of the Holocene, about 8800–6000 years ago. It is also worth comparing these materials with other Kutarey sites – Sen’kin (Siniy) Kamen’, Ruchei Povarny, Gora Kutarey and adjacent territories.

scholarly journals Alalakh: an account of the excavations at Tell Atchana in the Hatay, 1937–1949

2004 ◽  
Author(s):  
Leonard Woolley
Keyword(s):  
Bronze Age ◽  
Large Scale ◽  
River Valley ◽  
Early Bronze Age ◽  
Late Bronze Age ◽  
13Th Century ◽  
Gold Silver

This monograph describes large-scale excavations undertaken by Sir Leonard Woolley from 1937 to 1939, and again from 1946 to 1949, at the site of Alalakh (modern Tell Atchana) – a late Bronze Age city in the Amuq River valley of Turkey's Hatay Province. Described is the evidence of a series of superimposed palaces and temples, town defences, private houses and graves, in 17 archaeological levels reaching from late Early Bronze Age (Level XVII, c. 2200–2000 BC to Late Bronze Age (Level 0, 13th century BC). Supplementary reports describe the architecture and frescoes, sculptures, and portable objects in fired clay, gold, silver, ivory, stone, and glass.

scholarly journals THE LAND BEHIND THE LAND BEHIND BAGHDAD: ARCHAEOLOGICAL LANDSCAPES OF THE UPPER DIYALA (SIRWAN) RIVER VALLEY

Iraq ◽  
2017 ◽  
Vol 79 ◽  
pp. 47-69 ◽  
Author(s):  
Jesse Casana ◽  
Claudia Glatz
Keyword(s):  
Bronze Age ◽  
Physical Geography ◽  
River Valley ◽  
Archaeological Sites ◽  
Archaeological Survey ◽  
Near Eastern ◽  
The North ◽  
Wide Range ◽  
Regional Project ◽  
The Rich

While the Diyala (Kurdish Sirwan) River Valley is storied in Near Eastern archaeology as home to the Oriental Institute's excavations in the 1930s as well as to Robert McC. Adams’ pioneering archaeological survey, The Land Behind Baghdad, the upper reaches of the river valley remain almost unknown to modern scholarship. Yet this region, at the interface between irrigated lowland Mesopotamia and the Zagros highlands to the north and east, has long been hypothesized as central to the origins and development of complex societies. It was hotly contested by Bronze Age imperial powers, and offered one of the principle access routes connecting Mespotamia to the Iranian Plateau and beyond. This paper presents an interim report of the Sirwan Regional Project, a regional archaeological survey undertaken from 2013–2015 in a 4000 square kilometre area between the modern city of Darbandikhan and the plains south of Kalar. Encompassing a wide range of environments, from the rugged uplands of the Zagros front ranges to the rich irrigated basins of the Middle Diyala, the project has already discovered a wealth of previously unknown archaeological sites ranging in date from the Pre-Pottery Neolithic through the modern period. Following an overview of the physical geography of the Upper Diyala/Sirwan, this paper highlights key findings that are beginning to transform our understanding of this historically important but poorly known region.

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