Now showing 1 - 10 of 15
- 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 6 205
- 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 1 157
- 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 7 234 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 51
- 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.
- PublicationRelative Sea-Level Changes on the Southwestern Arabian Gulf since the Last Glacial MaximumSeveral works have been carried out regarding Late Pleistocene–Holocene sea-level changes in the Arabian Gulf. Nevertheless, a global and regional approach is still lacking, and some critical issues remain unsolved. In this paper, a review and a reinterpretation of all published data regarding sea-level changes in the area have been completed and compared with new results obtained from fieldworks carried out in Failaka Island, Kuwait, and in Abu Dhabi Emirate, United Arab Emirates. This work relies mostly on studying geomorphological sea-level indicators, such as beach rocks and beach ridges besides combining archaeological data. Results show different trends in vertical movement within the studied area since the Last Glacial Maximum, which cannot be explained alone by the existing sea-level model, implying different, specific and local factors, such as tectonic deformations and diapirism.