Now showing 1 - 10 of 10
- PublicationGeomorphological changes in the coastal area of Farasan Al-Kabir Island (Saudi Arabia) since mid Holocene based on a multi-proxy approachThe geomorphological evolution of the southeastern coastal area of Farasan Al-Kabir Island (Saudi Arabia) is revealed by the mapping of modern landforms and a multi-proxy and high spatial resolution study including grain size, particulate organic carbon, mineralogy, element geochemistry, benthic foraminifera analysis and radiocarbon dating of a 3.3-m long sediment core. The modern geomorphological features comprise a variety of arid landforms, such as plateau, cliffs and pediments of Pleistocene coral limestones, playa depressions located on plateau surfaces, alluvial fans, butte and sandy beaches. The mid Holocene evolution of the borehole area is resulted from the detailed analysis of five sedimentary units detected along the core Matar-1, and includes three distinct stages: (a) from 5253 ± 223 y cal BP to 3138 ± 223 y cal BP, carbonate coarse-grained material consisting of coral fragments, molluscs, calcareous algae and benthic foraminifera are deposited on a shallow marine fringing reefal platform, which becomes progressively a nearshore backreef (around 3675 ± 215 y cal BP), and later (around 3138 ± 223 y cal BP) a reef ramp; (b) since 3040 ± 220 y cal BP the borehole area obtains the characteristics of a high-energy beach that receives increasing inputs of terrigenous material; (c) subsequently, a supratidal backshore setting is established influenced mostly by terrestrial processes and occasionally by marine processes, as it is indicated by the decreasing and sometimes sporadic presence of benthic foraminifera, and recently, a sedimentary veneer consisting of terrigenous, carbonate and evaporite material is formed by terrestrial, mainly wadi and aeolian, processes. © 2018 Elsevier Ltd and INQUA
Scopus© Citations 6 209
- PublicationGeomorphological evolution and paleoenveronment reconstruction in the northeastern part of lemnos Island (North Aegean Sea)The area where the study was made is located in the northeastern coast of Lemnos Island (Greece- North Aegean Sea). This area covers the archaeological settlement of Hephestia which is located in the north part of Purnia Gulf and the coastal area of Alyki Lagoon, which is located in the southeast part of Lemnos coast. The archaeological importance of this area is pointed out not only by its archaeological remains but also by its significant location. The most important site which has been discovered close Hephestia is Poliochni. This is an ancient city considered to have the same date with Troy. The excavations of archaeological site of Hephestia indicate continuous human presence from Late Bronze Age till Byzantine time. The study of the eustatic sea level oscillation in correlation with the neotectonic regimes and die geomorphological observadons, and also the analyses of the deposed sediments, helps us to make a palaeogeographycal reconstruction of the landscape and its impotence to human societies. Therefore, detailed geomorphological mapping, micromorphological, sedimentological and micropaleontological studies of the Holocene coastal deposits have been accomplished. Six boreholes at Alyki lagoon were drilled at selected locations, the deepest one reaches a depth of 11m, and two other boreholes were drilled in Hephestia. The stratigraphy of the late Holocene sediments was studied in detail and samples collected from selected sedimentary layers, were analysed by using micropaleontological techniques. The calculated age from the boreholes gives dates between 5100 B.C. till 820 A.D. Twenty samples of shells and roots were dated using the AMS radiocarbon method in Lyon C14 Laboratory. Geomorphological mapping was carried out using topographic maps at scale of 1:50.000, geological map at a scale of 1:50.000 and observations on the field. Landforms of the coastal alluvial plain, in die shoreline and in die inland were marked and recorded at a scale of 1:50.000. Sea level rise along the interaction of landscape evolution and the impact of human civilization were concluded.
- PublicationHolocene lithostratigraphy and its implementation in the geoarchaeological research of the Athenian Basin, GreeceThe Athenian Basin is a very interesting area from an archaeological point of view, since it is inhabited from Neolithic time. The human impact on the landscape is shown by the ancient constructions such as the Long Walls and the canalization of the rivers in the area of the Athenian Basin and Piraeus. The aim of the study is to detect the paleogeographical evolution of this area. In order to manipulate all the available information obtained from literature review (topographic maps, geological maps, ancient maps and references) and the stratigraphic data from 227 boreholes from the Athenian Basin, a GIS database was established. After the interpretation of the stratigraphy from the boreholes, six lithostratigraphic units were defined. Maps and 3D models were designed to represent the succession of the lithostratigraphy of each period. Paleogeographic maps were created in order to represent the landscape for each lithostratigraphic unit of the Athenian basin, and extract results for the temporal and spatial changes of the paleo-landscape and the involvement of the human impact on the depositional process in the Athenian Basin during Holocene. © 2014, Springer-Verlag Berlin Heidelberg.
Scopus© Citations 1 161
- PublicationHolocene relative sea-level variations and archeological implications, Abu Dhabi western region, United Arab EmiratesNew results from fieldwork in the western region of the Emirate of Abu Dhabi showed meaningful differences in relative sea-level variations during Holocene and recorded unknown late marine highstands. These dynamics may have induced important environmental changes and affected human settlement. Surveys have been carried out in the Emirate of Abu Dhabi in order to construct local sea-level variations. These results rely on identifying, characterizing, and dating sea-level indicators and particularly beachrocks. Two main areas were studied: Ghagha island and Ras Khumays peninsula. Data obtained from our surveys highlight significant differences and suggest local processes that need to be understood. From an archeological perspective, this work helps to better understand human settlement dynamic through the Holocene.
Scopus© Citations 7 241 41
- PublicationMultiproxy paleoenvironmental reconstruction: the Piraeus Coastal Plain case studyThe joint application of benthic foraminifera, pollen and NPPs and magnetic sus-ceptibility analyses in Piraeus coastal plain deposits resulted in the detailed study of palaeoenvironmental evolution of the area during almost the last 9000 years and the distinction of five lithostratigraphical-paleoenvironmental units and subunits. Com-bined results of our analyses features the occurrence of an inner lagoon (unit Aa) followed by an open lagoon (Unit Ab) depositional environment that was trans-formed to a shallow marine paleoenvironment with lagoonal features (Unit B) after 7800 BP. Since about 4800 BP a closed oligohaline lagoon (Unit C) used for graz-ing, occurred in the area, while after 2800 BP a marshy oligohaline depositional environment (Unit D) and signs of intensive agricultural activities are evidenced. The very good correlation of benthic foraminiferal, palynological and magnetic sus-ceptibility data and resulted indices is indicative of the potential of the applied methodologies as a paleoenvironmental tool box. Περίληψη Η μελέτη της λεπτομερούς παλαιοπεριβαλλοντικής εξέλιξης για τα τελευταία περίπου 9000 χρόνια βασίστηκε σε ανάλυση των βενθονικών τρηματοφόρων, των γυρεόκοκκων και «άλλων» παλυνόμορφων και της μαγνητικής επιδεκτικότητας των αποθέσεων της παράκτιας πεδιάδας του Πειραιά. Διακρίθηκαν πέντε λιθοστρωματογραφικές-παλαιοπεριβαλλοντικές ενότητες και υποενότητες, στις οποίες καταγράφετε η εξέλιξη της περιοχής από μία αρχικά κλειστή ολιγόαλη λιμνοθάλασσα (Unit Aa) αρχικά σε μια ανοικτή (Unit Ab) και στη συνέχεια, περίπου 7800 έτη πριν από σήμερα σε ένα ρηχό θαλάσσιο περιβάλλον (Unit B). Περίπου πριν από 4800 έτη πριν από σήμερα στην περιοχή υπήρχε μία ολιγόαλη λιμνοθάλασσα (Unit C), την οποία οι κάτοικοι της περιοχής χρησιμοποιούσαν ως βοσκότοπο, ενώ μετά το 2800 έτη πριν από σήμερα τα στοιχεία μας δηλώνουν την ύπαρξη ενός ολιγόαλου έλους (Unit D), αλλά και σημαντικές αγροτικές δραστηριότητες στην περιοχή. Η εξαιρετική συσχέτιση των αποτελεσμάτων των επιμέρους μεθόδων ανασύστασης του παλαιοπεριβάλλοντος που χρησιμοποιήθηκαν είναι ενδεικτική των δυνατοτήτων εφαρμογής τους ως μια συντονισμένη παλαιοπεριβαλλοντική εργαλειοθήκη. Λέξεις κλειδιά: βενθονικά τρηματοφόρα, γυρεόκοκκοι, άλλα παλυνόμορφα μαγνητική επιδεκτικότητα, Ολόκαινο.
- PublicationPalaeoenvironmental evolution and sea-level changes in the coastal area of NE Lemnos Island (Greece) during the HoloceneThe study area is located on the northeastern coast of Lemnos Island (North Aegean Sea, 40°2'30N, 25°00'00E). It covers the archaeological settlement of Hephestia located in the Purnia Gulf and the coastal area of Alyki Lagoon. Reconstruction of the palaeogeography used palaeoenvironment data delivered from foraminifera and sea-level changes, providing archeological data about the presence of a potential harbour in the area.Geomorphological mapping as well as sedimentological and micropalaeontological studies of the Holocene coastal deposits were conducted. Four boreholes were drilled from the Alyki Lagoon, reaching 2.5m to 11m at the deepest and two from Hephestia area, reaching a depth of 6m. Twenty-four samples were dated using the AMS radiocarbon method, providing a chronology of the sedimentary units.The calculated age from the boreholes provides dates from 7050calBP to 990calBP There was a constant sea-level rise during the last 7000calBP in the study area. Results from the model of Lambeck sea level curve and sea level index point from Hephestia and Alyki show a vertical difference of 0.5-1.5m below sea level. The foraminiferal fauna analysis shows the development of shallow marine conditions with fresh water influx during 7000-4000calBP and a temporary lagoon environment with fluctuations to shallow bay environment from 4000 to 990calBP. © 2012 Elsevier Ltd and INQUA.
Scopus© Citations 19 52
- PublicationPleistocene uplift evidences and geomorphological processes, along the Daghmar-Dibbab coastal area, (NE Oman)The study coastal area between Daghmar and Dibab (NE Oman) was uplifted up to 200 m due to different tectonic processes which can be detected on different elevations of the coastal teracces cascading. The teracces formed due to Neogene to Quaternary tectonic movements which continued into the Upper Pleistocene and may be active during the Holocene. The combination of methods such as geodatabase creation, multi-criteria analysis of the landforms through the processing of the study's area DEM, field work-samplings and laboratory analysis (XRF, thin sections, dating's, OSL-14C), combined with semi-automated geomorphological mapping and the differential GPS profiles and measurements, and SAR interferometry (InSAR), contributed in the data processing. The results of the multi proxy and interdisciplinary methodological approach are used as tools for understanding the geomorphological evolution of the Neogene to Quaternary landscape, where landforms are presented as indicators of the area's evolution and define the processes that formed the current situation of the relief. At least three tectonic terraces were detected. A karstified planation surface of Eocene rocks is well developed. This planation surface is attached to the marineterraces and marks an elevation of 160-135m. The mapped terraces (depending on the locations) are at altitudes of about 120-90m. (T3), 75-45 m. (T2) and 35-20 m. (T1) with their foreheads (cliffs) vary in elevations from 15 to 30m. The preliminary results of this study area indicate an along strike the terraces, divided into different at least two tectonic blocks, with estimated uplift rate from 2.3mm/year (northern part) to 2.9 mm/year (southern part) respectively. The blocks are separated by perpendicular to the terraces striking faults. However, the kinematic of faults ,i.e. normal, reverse or strike-slip, could not be estimates Uplift and the sedimentary cover of the terraces (e.g. conglomerates, screes) confirm a swift transformation of the coastline area form at least the MIS 3 (24-59 ka) until the mid-late Holocene, accepting the global sea level chnanges.
- PublicationReview on Late Pleistocene-Holocene relative sea-level changes in Kuwait : New evidence from Failaka islandNew results from fieldwork carried out on Failaka island testify to relative sea-level fluctuations during Late Pleistocene and Holocene. This study is based on analysing, sampling and dating geomorphological sea-level indicators, including beach ridges or beachrocks. The results have been compared and harmonised with recalibrated data from pre-existing literature to reconstruct the relative sea-level local chronology. The vertical displacement identified may have induced coastline mobility and significant environmental changes and impacted the human occupation in Failaka and along the coastal areas of Kuwait. Eventually, the results highlight the impact of large-scale crustal deformations on regional relative sea-level variations.
Scopus© Citations 2 179 33
- PublicationThe Holocene evolution of the Kalamas delta (northwestern Greece) derived from geophysical and sedimentological surveyThis article aims to present the Holocene dynamics that are responsible for the creation and the evolution of the delta of the Kalamas River (65 km 2, the smallest delta of Epirus, northwestern Greece). Archaeological remains prove a continuous occupation since the Upper Paleolithic times (site of Pyrgos Raghiou). In connection with the two archaeological sites of Mastilitsa (Bronze Age) and Pirgos Raghiou (continuous occupation since the Upper Paleolithic) and the published archaeological data, this paper presents the first results concerning the Holocene evolution of the delta. The methodology adopted crosses both geophysical data (seven profiles of electrical resistivity along three transects) and sedimentological studies, obtained through fourteen cores. The results are presented in two complementary parts: the first one emphasises the existence of several Holocene buried palaeochannels near the archaeological sites. The second presents the first description of the successive environments since 7440 BP. These results, associated with a series of three 14C datings, can open up interesting prospects for research on the environmental changes that occurred at the beginning of the Holocene.
Scopus© Citations 1 201 62
- PublicationWas the Piraeus peninsula (Greece) a rocky island? Detection of pre-Holocene rocky relief with borehole data and resistivity tomography analysisAccording to historical documents, Piraeus was a rocky island consisting of the steep hill of Munichia, known as modern-day Kastella. It was connected to the mainland by a low-lying stretch of land ("Halipedon") that would flood with sea water most of the year and was used as a salt field whenever it dried up. Apart from being an area of archaeological interest, the extended area of "Halipedon" is densely populated, thus being of geotechnical interest and is currently being investigated through borehole and geophysical data analysis. 52 boreholes were lithologically-geomorphologically analyzed and results from 11 resistivity tomography profiles were considered. Lithostratigraphy of the borehole data was classified into three lithostratigraphic units: Cultural deposits, Pleistocene-Holocene deposits, pre-Holocene bedrock ("Marls of Piraeus"). The deeper unit shows a big depression in the southeastern part of the survey area and a circular sinking (channel) in its north part. These depressions were probably covered by the sea at a time when the southern part of the Piraeus peninsula was an island. This is confirmed by stratigraphical and geophysical investigation in the area where resistivity tomography profiles could be performed. The big southeastern depression is covered by the river sediments implying a high sedimentation rate. © 2013 Elsevier Ltd.
Scopus© Citations 7 51