RT journal article
T1 Biogeochemistry of surface sediments in mud volcanoes of the Gulf of Cádiz
A1 Jiménez López, María Dolores
A1 Sierra Padilla, Ana
A1 Ortega Díaz, Teodora
A1 Manzano Medina, Sandra
A1 Fernández Puga, María del Carmen
A1 López González, Nieves
A1 Vázquez, Juan-Tomás
A1 Forja Pajares, Jesús
A2 Biología
A2 Ciencias de la Tierra
A2 Química Física
K1 Mud volcanoes
K1 Sediment
K1 Biogeochemical processe
K1 Authigenic carbonates
K1 Fluid migration
K1 Gulf of Cádiz
AB The shallowest sediment of three mud volcanoes (MVs) located in the middle slope of the Gulf of Cádiz, Anastasya, Pipoca and St. Petersburg, have been seasonally studied during June and December 2016. These structures are locally important contributors of many biogeochemical active substances to the water column, with a special attention in the emission of methane (CH4). Along this study, the role of organic matter diagenesis and its contribution to the difusive fuxes estimated in the sediment–water interface from the three MVs have been investigated mainly. For this, the frst combined analyses of sediment properties (granulometry, porosity, density, organic carbon) and pore water chemistry (major elements, dissolvedinorganic carbon (DIC), nutrients, CH4 and nitrous oxide) have been carried out. Anastasya and St. Petersburg MVs presented similar behaviours, with a slight concentration variation for the chemical variables in the top layers of the sedimentary record followed by a more intense vertical variation in deeper layers. Anastasya MV showed some typical processes of these structures, such as the clay dehydration, the dissolution of halite and the precipitation of authigenic carbonates, which was also observed in St. Petersburg MV. Organic matter diagenesis clearly altered the biogeochemical profles, except for Pipoca MV. Moreover, mud breccia with a mousse-like texture has been identifed in the deepest levels of Anastasya andSt. Petersburg MVs. Here, anaerobic oxidation of methane is linked to the decrease of SO2−4 and the increases of CH4 and DIC with the core depth. Changes across the sediment–water interface presented low difusive fuxes in the three MVs due to the presence of other processes as the irrigation by benthic macrofauna, the action of bottom currents and/or the upward fuid migration. From the obtained results, we can conclude that Anastasya MV presents a certain venting activity at present.
PB Springer
SN 1432-1157
YR 2021
FD 2021-06-16
LK http://hdl.handle.net/10498/30581
UL http://hdl.handle.net/10498/30581
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 07-nov-2026