Gas migration pathways and slope failures in the Danube Fan, Black Sea
| Autor: | O. Atgin, Ingo Klaucke, David N. Awwiller, Günay Çifçi, Shray Badhani, Joerg Bialas, Tina M. Drexler, Jess I. T. Hillman, Howard R. Feldman |
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| Rok vydání: | 2018 |
| Předmět: |
010504 meteorology & atmospheric sciences
Lithology Stratigraphy Chimneys 010502 geochemistry & geophysics Oceanography 01 natural sciences Slope failure Gas hydrate Bathymetry Black sea 14. Life underwater Petrology 0105 earth and related environmental sciences Canyon geography geography.geographical_feature_category Sediment Submarine Geology Seafloor spreading Geophysics Black Sea 13. Climate action Economic Geology Gas migration Danube Fan |
| Zdroj: | Marine and Petroleum Geology, 92 . pp. 1069-1084. Marine And Petroleum Geology (0264-8172) (Elsevier Sci Ltd), 2018-04, Vol. 92, P. 1069-1084 |
| ISSN: | 0264-8172 |
| DOI: | 10.1016/j.marpetgeo.2018.03.025 |
| Popis: | Highlights: • Identify 3 groups of gas migration structures in seismic data from the Danube Fan. • Migration structures related to shallow gas migration and flares at the seafloor. • Gas migration is controlled by lithological heterogeneity and sediment deformation. • Mass transport deposits play a role in controlling vertical migration occurrence. Abstract: A large geophysical dataset, including bathymetry, and 2D and 3D P-cable seismic data, revealed evidence of numerous gas flares near the S2 Canyon in the Danube Fan, northwestern Black Sea. This dataset allows us to investigate potential relationships between gas migration pathways, gas vents observed at the seafloor and submarine slope failures. Vertical gas migration structures as revealed in the seismics appear to be concentrated near submarine slope failure structures. Where these seismically defined features extend upwards to the seafloor, they correlate with the location of gas flares. However, not all these structures reach the seafloor, in some cases because they are capped by overlying sediments. A strong correlation is inferred between gas migration pathways, heterogeneous mass transport deposits and contacts between adjacent units of contrasting lithology. Although missing age constrains prevent a final judgement, we discuss the potential relationship between submarine slope failures and gas migration in order to determine if gas migration is a precursor to failure, or if the presence of slope failures and associated mass transport deposits facilitates the migration of gas. Our observations indicate that lithological heterogeneity, mass transport deposits and minor sediment deformation control gas migration pathways and the formation of gas chimney-like features. Gas migration is focused and gradual, resulting in gas flares where the chimney-like features extend to the seafloor, with no evidence of erosive features such as pockmarks. |
| Databáze: | OpenAIRE |
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