New discoveries of mud volcanoes on the eastern Mediterranean Ridge

Data from two mud volcanoes discovered on the eastern Mediterranean Ridge are presented, showing thar these features have erupted episodically within historical time. Both volcanoes mark the site of active gas and fluid venting from deep within the sedimentary pile. Large volumes of mud breccia have been extruded onto the volcano slopes. For the first time, clasts up to c. Im in size have been recovered from sea-floor mud volcanoes. The submarine clasts show lithologies ranging from shallow water bioclastic sandstones to marls and limestones, dated using microfauna as Oligocene, Miocene and perhaps Cretaceous in age. Deep-towed video footage of one of the volcanoes shows clasts up to several metres across within the crater area. Deep-towed, high resolution side-scan sonar data and core data are presented to compare the two examples. The paper documents the discovery of the two volcanoes: the Dublin mud volcano and the Stoke-on-Trent mud volcano, the clasts that have been recovered from them, the intermittence of the eruptions as interpreted from gravity-core data, and how the volcanoes contrast with other mud volcanoes further to the west.