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Mud volcanism on the Mediterranean Ridge: Initial results of Ocean Drilling Program Leg 160

1996; Geological Society of America; Volume: 24; Issue: 3 Linguagem: Inglês

10.1130/0091-7613(1996)024 2.3.co;2

1943-2682

Alastair H.F. Robertson, Ocean Drilling Program Leg Scientific Party,

Geology and Paleoclimatology Research

Research Article| March 01, 1996 Mud volcanism on the Mediterranean Ridge: Initial results of Ocean Drilling Program Leg 160 Alastair Robertson; Alastair Robertson 1Department of Geology and Geophysics, University of Edinburgh, Edinburgh EH9 3JW, United Kingdom Search for other works by this author on: GSW Google Scholar Ocean Drilling Program Leg 160 Scientific Party Ocean Drilling Program Leg 160 Scientific Party Search for other works by this author on: GSW Google Scholar Author and Article Information Alastair Robertson 1Department of Geology and Geophysics, University of Edinburgh, Edinburgh EH9 3JW, United Kingdom Ocean Drilling Program Leg 160 Scientific Party Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1996) 24 (3): 239–242. https://doi.org/10.1130/0091-7613(1996)024 2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Alastair Robertson; Ocean Drilling Program Leg 160 Scientific Party, Mud volcanism on the Mediterranean Ridge: Initial results of Ocean Drilling Program Leg 160. Geology 1996;; 24 (3): 239–242. doi: https://doi.org/10.1130/0091-7613(1996)024 2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Drilling during Ocean Drilling Program Leg 160 (April–May, 1995) revealed important new evidence concerning the internal composition, depositional processes, and age of two mud volcanoes within the Mediterranean Ridge accretionary complex. Holes were drilled at ca. 2000 m water depth on the crest areas, across the flanks of the mud volcanoes, and onto adjacent deep-sea sediments. The main depositional units forming the flanks of both mud volcanoes are debris flows ("mud breccias") composed of a volumetrically dominant mud matrix, containing clasts of mainly clay, mudstone, siltstone, sandstone, and limestone. More variable muddy, silty, and sandy sediments were recovered from the crestal areas of both volcanoes. The lowest mud-volcano units drilled include well-sorted medium- to coarse-grained sediments, mainly composed of clay, that were deposited partly by turbidity currents. The mud-volcano sediments are associated with background deep-sea sediments that allow dating by using microfossils. The Milano mud volcano is at least 1.75 Ma, and is apparently now dormant, and the Napoli mud volcano started prior to, or during, 1.5–1.2 Ma and is currently active. Pore fluids at Napoli, and to a lesser extent at Milano, indicate the presence of halite of presumed latest Miocene age beneath the volcanoes. Hydrocarbon gas is venting from the crest of the Napoli mud volcano, and gas was also detected on the crest of the Milano mud volcano. Methane hydrates (clathrates) are also inferred to exist beneath the crest of the Milano mud volcano. The mud volcanoes are located above a shallowly dipping subduction zone in an area where the accretionary complex is apparently being thrust northward over a backstop of continental crust, related to initial collision of the African and Eurasian plates. Mud volcanism may have begun when backthrusting punctured a seal of latest Miocene evaporites, allowing the escape of overpressured materials. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.