Browsing by Autor "Liviu Giosan"

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A 10 m vertical displacement on the Romanian Black Sea coast during modern history
(2024) Virgil Drăgușin; Nicolaie Alexandru; Mihai Caminschi; F. Chitea; Vasile Ersek; Alina Floroiu; Liviu Giosan; Georgiana Alexandra Grigore; Diana Hanganu; Maria Ilie
Abstract. Sea level reconstructions in the Black Sea basin and elsewhere rely on the identification of sea level markers and on the understanding of their post-genetic vertical movements. We present here evidence of a fast, bi-directional vertical displacement on the western Black Sea shore at Mangalia, Romania. We argue that an area situated near the shoreline was submerged 4 meters, subsequently filled with marine silts and sands, then uplifted by 10 m, where it currently stands. Radiocarbon dating of several types of materials from the infill, as well as archaeological evidence, indicate that this displacement occurred during the 18th–19th century. While performing radiocarbon dating, we found that near shore clam shells can show a 14C reservoir age offset of ~900 years probably due to the hard water effect, adding more complications to the already problematic dating of Black Sea coastal sediments. Our findings offer strong evidence of short-term, local tectonic movements that should be considered when past sea levels are calculated, while at the same time serve a warning for urban and marine development planners.
A 10-m vertical displacement on the Romanian Black Sea coast during modern history
(Springer Nature, 2025) Virgil Drăgușin; Nicolaie Alexandru; Mihai Caminschi; F. Chitea; Vasile Ersek; Alina Floroiu; Liviu Giosan; Georgiana Alexandra Grigore; Diana Hanganu; Maria Ilie
Abstract Sea level reconstructions in the Black Sea basin and elsewhere rely on the identification of sea level markers and on the understanding of their post-genetic vertical movements. We present here evidence of a fast, bi-directional vertical displacement on the western Black Sea shore at Mangalia, Romania. We argue that an area situated near the shoreline was submerged 4 m, subsequently filled with marine silts and sands, then uplifted by 10 m, where it currently stands. Radiocarbon dating of several types of materials from the infill, as well as archaeological evidence, indicate that this displacement occurred during the eighteenth to nineteenth centuries. Mollusc shells found in anatomical connection close to the top of the sediment sequence have a 14 C reservoir age offset of ~ 900 years, probably due to the hard water effect. This is much larger than the ~ 400 year offset that is generally considered for the Black Sea and highlights the problematic dating of Black Sea coastal sediments. The findings of this study offer strong evidence of short-term, local tectonic movements that should be considered when past sea levels are calculated, while at the same time serve a warning for urban and marine development planners.
Morphodynamic Foundations of Sumer
(Public Library of Science, 2025) Liviu Giosan; Reed Goodman
Economic mechanisms behind the emergence of ancient Sumer remain unavoidably speculative and should benefit from a better understanding of their environmental context. Abundance sustaining increased social complexity during the Uruk period (c. 6,000-5,200 y BP) has been traditionally ascribed to pastoralism, trade, and/or resource diversity. However, contemporary agricultural surpluses are hard to explain before adoption of large-scale irrigation systems. Here we use high-resolution satellite-based topography and paleoenvironmental proxies from a new drill core at Lagash/Tell Al Hiba, together with previous geological and archaeological data, to reconstruct the morphodynamic evolution of coastal Sumer. We propose that tidal irrigation offers a plausible jumpstarting mechanism for high-yield, diversified agriculture providing an impetus for urbanization. As access to sea was restricted by delta build-up and tides shifted with the advancing deltaic coast, intensified reliance on mercurial river regimes eventually led to the expansive fluvial irrigation network of Early Dynastic city-states. By positioning coastal morphodynamics as a pivotal factor in urbanization and political ecology, we underscore the intricate interconnections between naturally evolving systems and collective human agency.
Reply to: No evidence for a 10-m historical tectonic uplift at Mangalia, (Romanian Black Sea coast): Comment on Drăgușin et al. (2025) by Vespremeanu-Stroe et al.
(Springer Nature, 2026) Bogdan Ispas; Nicolaie Alexandru; Mihai Caminschi; F. Chitea; Vasile Ersek; Alina Floroiu; Liviu Giosan; Georgiana Alexandra Grigore; Diana Hanganu; Maria Ilie